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WO2016187585A1 - Lieur désimmunisé et méthodes d'utilisation - Google Patents

Lieur désimmunisé et méthodes d'utilisation Download PDF

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Publication number
WO2016187585A1
WO2016187585A1 PCT/US2016/033629 US2016033629W WO2016187585A1 WO 2016187585 A1 WO2016187585 A1 WO 2016187585A1 US 2016033629 W US2016033629 W US 2016033629W WO 2016187585 A1 WO2016187585 A1 WO 2016187585A1
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Prior art keywords
seq
amino acid
acid sequence
immunotoxin
variable region
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English (en)
Inventor
Shilpa CHOONIEDASS
Rachelle L. DILLON
Jeannick Cizeau
Arjune Premsukh
Glen Macdonald
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Viventia Bio Inc
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Viventia Bio Inc
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Publication of WO2016187585A1 publication Critical patent/WO2016187585A1/fr
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K7/00—Peptides having 5 to 20 amino acids in a fully defined sequence; Derivatives thereof
    • C07K7/04—Linear peptides containing only normal peptide links
    • C07K7/08—Linear peptides containing only normal peptide links having 12 to 20 amino acids
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/18—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans
    • C07K16/28—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants
    • C07K16/30—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against receptors, cell surface antigens or cell surface determinants from tumour cells
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K16/00—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies
    • C07K16/18—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans
    • C07K16/32—Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies against material from animals or humans against translation products of oncogenes
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N9/00—Enzymes; Proenzymes; Compositions thereof; Processes for preparing, activating, inhibiting, separating or purifying enzymes
    • C12N9/14—Hydrolases (3)
    • C12N9/48—Hydrolases (3) acting on peptide bonds (3.4)
    • C12N9/50—Proteinases, e.g. Endopeptidases (3.4.21-3.4.25)
    • C12N9/64—Proteinases, e.g. Endopeptidases (3.4.21-3.4.25) derived from animal tissue
    • C12N9/6421—Proteinases, e.g. Endopeptidases (3.4.21-3.4.25) derived from animal tissue from mammals
    • C12N9/6424—Serine endopeptidases (3.4.21)
    • C12N9/6454—Dibasic site splicing serine proteases, e.g. kexin (3.4.21.61); furin (3.4.21.75) and other proprotein convertases
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12Y—ENZYMES
    • C12Y304/00—Hydrolases acting on peptide bonds, i.e. peptidases (3.4)
    • C12Y304/21—Serine endopeptidases (3.4.21)
    • C12Y304/21075—Furin (3.4.21.75)
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/50—Immunoglobulins specific features characterized by immunoglobulin fragments
    • C07K2317/55—Fab or Fab'
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2317/00—Immunoglobulins specific features
    • C07K2317/60—Immunoglobulins specific features characterized by non-natural combinations of immunoglobulin fragments
    • C07K2317/62—Immunoglobulins specific features characterized by non-natural combinations of immunoglobulin fragments comprising only variable region components
    • C07K2317/626—Diabody or triabody
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K2319/00—Fusion polypeptide
    • C07K2319/55—Fusion polypeptide containing a fusion with a toxin, e.g. diphteria toxin

Definitions

  • the present invention is directed to novel deimmunized furin protease- sensitive peptide linkers that have been specifically engineered to lack T-cell epitopes and therefore elicit reduced immune response.
  • the present disclosure also relates to immunotoxins comprising such linkers and methods of use of said immunotoxins comprising such linkers.
  • linker for an immunotoxin has been typically dictated by the type of enzymes that are either present in most cells, known to be upregulated in target cells, or selected from different regions of the cell (Fuchs et al, 2006) (Heisler et al, 2003) (Keller et al, 2001). Some proteases are ubiquitously expressed. Others are linked to particular cell types or areas within or around the cells. A furin-sensitive linker is commonly used because furin is a ubiquitous enzyme known to be present in both the endosome and the Golgi apparatus of most cells and is thus expected to cleave a conjugate in any cell it enters.
  • T-cell epitopes There are many instances whereby the efficacy of a therapeutic protein is limited by an unwanted immune reaction to the therapeutic protein.
  • the key to the induction of an immune response is the presence within the protein of peptides that can stimulate the activity of T-cells via presentation on MHC, so-called "T-cell epitopes.”
  • T-cell epitope identification is the first step to epitope elimination.
  • T-cell epitopes may be removed by the use of judicious amino acid substitution within the protein of interest.
  • such techniques are not adapted for the screening of multiple potential epitopes to a wide diversity of MHC allotypes, nor can they confirm the ability of a binding peptide to function as a T-cell epitope.
  • a therapeutic protein such as an immunotoxin has a number of regions that are potential sources of unwanted immune reaction, for example, the antibody or antibody fragment, the toxin and the linker connecting the two.
  • the present invention relates to novel immunotoxins, which are both effective in tumor targeting and killing and has reduced propensity to elicit an immune reaction, and methods for treating or preventing cancer by administering, to a patient in need thereof, an effective amount of said recombinant immunotoxin that specifically binds to (and therefore is "targeted to") a protein on the surface of cancer cells.
  • the immunotoxin may be co-administered, concurrently administered, and/or sequentially administered with one or more other anti-cancer agents, and/or in conjunction with radiation or surgery.
  • the invention contemplates a modified furin protease sensitive peptide linker, wherein said modified peptide linker has a reduced propensity to activate an immune response.
  • said peptide linker has a reduced propensity to activate T-cells and is modified at one or more amino acid residues in a T-cell epitope.
  • the peptide linker is modified at one or more amino acid residues in a T-cell epitope represented by SEQ ID NO: 17.
  • the peptide linker is modified at amino acid position 12 of SEQ ID NO: 17.
  • the amino acid sequence of the modified peptide linker shares at least 90% sequence identity to the amino acid sequence shown in SEQ ID NO: 17.
  • the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 32. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 33. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 34. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 35. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 36. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 119. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 124.
  • the invention contemplates an immunotoxin comprising: (a) a binding protein and; (b) a toxin, wherein the binding protein and toxin are linked by a modified furin protease sensitive peptide linker.
  • the modified peptide linker has a reduced propensity to activate an immune response.
  • the peptide linker has a reduced propensity to activate T-cells and is modified at one or more amino acid residues in a T-cell epitope.
  • the peptide linker is modified at one or more amino acid residues in a T-cell epitope represented by SEQ ID NO: 17.
  • the peptide linker is modified at amino acid position 12 of SEQ ID NO: 17.
  • the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 32.
  • the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 33.
  • the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 34.
  • the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 35.
  • the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 36.
  • the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 119.
  • the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 124.
  • the binding protein of the immunotoxin comprises an antibody or antibody fragment.
  • the antibody or antibody fragment comprises an anti-epithelial cell adhesion molecule (EpCAM) antibody or an anti-EpCAM antibody fragment.
  • the anti-EpCAM antibody or antibody fragment comprises a heavy chain having an amino acid sequence selected from SEQ ID NO: 49, SEQ ID NO: 53, SEQ ID NO: 56, and SEQ ID NO: 57, and a light chain having an amino acid sequence selected from SEQ ID NO: 51 and SEQ ID NO: 55.
  • the heavy chain has an amino acid sequence as shown in SEQ ID NO: 49
  • the light chain has an amino acid sequence as shown in SEQ ID NO: 51.
  • the heavy chain has an amino acid sequence as shown in SEQ ID NO: 53, and the light chain has an amino acid sequence as shown in SEQ ID NO: 55.
  • the heavy chain has an amino acid sequence as shown in SEQ ID NO: 56, and the light chain has an amino acid sequence as shown in SEQ ID NO: 55.
  • the heavy chain has an amino acid sequence as shown in SEQ ID NO: 57, and the light chain has an amino acid sequence as shown in SEQ ID NO: 55.
  • the anti-EpCAM antibody or antibody fragment is selected from the group consisting of Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, immunoglobulin scaffolds, multimers, and any combination thereof.
  • the anti-EpCAM antibody fragment is an Fab.
  • the antibody or antibody fragment comprises an anti- HER2/neu antibody or an anti-HER2/neu antibody fragment.
  • the anti-HER2/neu antibody or the anti-HER2/neu antibody fragment comprises the complementarity determining region (CDR) sequences of SEQ ID NOs: 5-10.
  • the anti-HER2/neu antibody or the anti-HER2/neu antibody fragment comprises a heavy chain variable region.
  • the heavy chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 2.
  • the heavy chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 2.
  • the anti-HER2/neu antibody or the anti-HER2/neu antibody fragment comprises a light chain variable region.
  • the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 4.
  • the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 4.
  • the anti-HER2/neu antibody fragment is selected from the group consisting of Fab, Fab', F(ab')2, scFv, dsFv, ds- scFv, dimers, minibodies, diabodies, bispecific antibody fragments, immunoglobulin scaffolds, multimers, and any combination thereof.
  • the anti- HER2/neu antibody fragment is a diabody.
  • the diabody is comprised of a heavy chain variable region and a light chain variable region.
  • the heavy chain variable region and the light chain variable region are linked by a linker.
  • the linker is encoded by an amino acid sequence shown in SEQ ID NO: 15.
  • the HER2/neu heavy chain variable region and light chain variable region are encoded by amino acid sequences set forth in SEQ ID NOs: 125, 127, 129, 131, 133 and 135.
  • the HER2/neu heavy chain variable region and light chain variable region are encoded by the amino acid sequence of SEQ ID NO: 131.
  • the anti-HER2/neu antibody fragment is a scFv.
  • the anti-HER2/neu antibody fragment is an Fab.
  • the antibody or antibody fragment comprises an Hl l antibody or Hl l antibody fragment.
  • the Hl l antibody or antibody fragment comprises the complementarity determining region (CDR) sequences of SEQ ID NOs: 105-110.
  • the Hl l antibody or antibody fragment comprises a heavy chain variable region and a heavy chain constant region.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 101. In a further embodiment, the heavy chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 101.
  • the Hl l antibody or antibody fragment comprises a light chain variable region and a light chain constant region. In another embodiment, the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 100. In a further embodiment, the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 100.
  • the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 103. In a further embodiment, the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 103. In some embodiments, the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 120. In a further embodiment, the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 120. In another embodiment, the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 123.
  • the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 123.
  • the Hl l antibody or Hl l antibody fragment comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 99 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the HI 1 antibody or antibody fragment is selected from the group consisting of Fab, Fab', F(ab') 2 , scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, immunoglobulin scaffolds, multimers, and any combination thereof.
  • the Hl l antibody fragment is an Fab.
  • the toxin portion of the immunotoxin is deimmunized bouganin.
  • the deimmunized bouganin toxin is encoded by an amino acid sequence selected from SEQ ID NO: 12, SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60 and SEQ ID NO: 61.
  • the deimmunized bouganin toxin is linked to the binding protein by a modified furin protease sensitive linker encoded by an amino acid sequence chosen from SEQ ID NOs: 32-36, 119 and 124.
  • the toxin portion of the immunotoxin is deimmunized diptheria toxin.
  • the invention also relates to a method of treating or preventing cancer comprising administering an effective amount of an immunotoxin to a subject in need thereof, wherein said immunotoxin comprises: (a) a binding protein and; (b) a toxin, wherein the binding protein and toxin are linked by a modified furin protease sensitive peptide linker of the present invention.
  • the binding protein comprises an anti-EpCAM antibody or antibody fragment of the present invention.
  • the binding protein comprises an anti-HER2/neu antibody or antibody fragment of the present invention.
  • the binding protein comprises an Hl l antibody or antibody fragment of the present invention.
  • the toxin portion of the immunotoxin is deimmunized bouganin.
  • the toxin portion of the immunotoxin is deimmunized diphtheria toxin.
  • the cancer is selected from the group consisting of lung cancer, gastric cancer, renal cancer, thyroid cancer, breast cancer, bladder cancer, ovarian cancer, colorectal cancer, head and neck cancer, hepatocellular carcinoma, esophageal, pancreas, and prostate cancer.
  • the cancer is of neuro-ectodermal origin.
  • the cancer is neuroblastoma, glioblastoma, melanoma or sarcoma.
  • the immunotoxin is administered directly to the cancer site.
  • the direct administration is intratumoral, intravesicular or peritumoral.
  • the direct administration is systemic.
  • the direct administration is intravenous.
  • the direct administration is intracranial infusion.
  • the invention also relates to additionally comprising the administration of one or more further cancer therapeutics for simultaneous, separate or sequential treatment or prevention of cancer.
  • the invention also relates to a method for enhancing the activity of an anticancer agent comprising administering to a subject in need thereof an anti-cancer agent and an effective amount of an immunotoxin, wherein said immunotoxin comprises: (a) a binding protein and; (b) a toxin, wherein the binding protein and toxin are linked by a modified furin protease sensitive peptide linker of the present invention.
  • the binding protein comprises an anti-EpCAM antibody or antibody fragment of the present invention.
  • the binding protein comprises an anti-HER2/neu antibody or antibody fragment of the present invention.
  • the binding protein comprises an HI 1 antibody or antibody fragment of the present invention.
  • the toxin portion of the immunotoxin is deimmunized bouganin. In another embodiment, the toxin portion of the immunotoxin is deimmunized diphtheria toxin.
  • the invention also relates to a kit for treating or preventing cancer comprising an effective amount of an immunotoxin comprising: (a) a binding protein; (b) a toxin, wherein the binding protein and toxin are linked by a modified furin protease sensitive peptide linker of the present invention, and; (c) directions for the use thereof to treat the cancer.
  • the binding protein comprises an anti-EpCAM antibody or antibody fragment of the present invention.
  • the binding protein comprises an anti-HER2/neu antibody or antibody fragment of the present invention. In another embodiment, the binding protein comprises an Hl l antibody or antibody fragment of the present invention. In one embodiment, the toxin portion of the immunotoxin is deimmunized bouganin. In another embodiment, the toxin portion of the immunotoxin is deimmunized diphtheria toxin.
  • the invention also related to an expression vector comprising an immunotoxin comprising: (a) a binding protein and; (b) a toxin, wherein the binding protein and toxin are linked by a modified furin protease sensitive peptide linker of the present invention.
  • the binding protein comprises an anti-EpCAM antibody or antibody fragment of the present invention.
  • the binding protein comprises an anti- HER2/neu antibody or antibody fragment of the present invention.
  • the binding protein comprises an HI 1 antibody or antibody fragment of the present invention.
  • the toxin portion of the immunotoxin is deimmunized bouganin.
  • the toxin portion of the immunotoxin is deimmunized diphtheria toxin.
  • FIG. 1 shows an analysis of the junction comprised of the C-terminal end of the light chain Fab fragment, furin linker and N-terminus end of deBouganin (highlighted red in the "Sequence" row using iTopeTM). Peptides spanning the entire sequence were tested as 9mer peptides in one amino acid increments. The position of pi anchor residues comprises the first residue of a MHC class II ligand (core 9mer) and is highlighted as a yellow box if the binding score was 0.55-0.6 and as a red box if the binding score was >0.6.
  • Regions containing potentially immunogenic peptides are indicated in the "Promiscuous High” and “Promiscuous Moderate” rows; red indicates promiscuous high affinity MHC class II binding peptides, yellow indicates promiscuous moderate affinity MHC class II binding peptides.
  • regions representing closely homologous peptides from the T cell epitope database are shown in green.
  • FIG. 2 shows Western blot analysis of VB6-901-DI linker variants.
  • Lane 2 corresponds to the ladder.
  • the arrow indicates the full-length proteins.
  • FIG. 3A-3D shows MTS curves and serum stability.
  • OVCAR3 and FIG. 3B CAL27 cytotoxicity curves obtained after 5 days treatment with VB6-901-DI linker H (black circle), linker K (white circle), linker N (black triangle), linker S (white triangle) and VB6-901-WT (black square).
  • FIG. 3C-3D Time course analysis (0, 24, 48 and 72 hours) of VB6-901-DI linker K (lanes 1 to 4), VB6-901-DI linker N (lane 5 to 8) and VB6-901-WT (lane 9 to 12) incubated in FIG. 3C) mouse and FIG. 3D) human serum by Western blot.
  • Lane C corresponds to serum only, lane L to ladder and lane 13 to 200ng loaded of purified VB6-901-WT.
  • FIG. 4 shows an analysis of the linker sequence (highlighted red in the "Sequence” row using iTopeTM). Peptides spanning the entire sequence were tested as 9mer peptides in one amino acid increments.
  • the position of pi anchor residues comprises the first residue of a MHC class II ligand (core 9mer) and is highlighted as a yellow box if the binding score was 0.55-0.6 and as a red box if the binding score was >0.6.
  • Regions containing potentially immunogenic peptides are indicated in the "Promiscuous High” and "Promiscuous Moderate” rows; red indicates promiscuous high affinity MHC class II binding peptides, yellow indicates promiscuous moderate affinity MHC class II binding peptides.
  • regions representing closely homologous peptides from the T cell epitope database are shown in green.
  • FIG. 5A-5B shows Western blot analysis of deBouganin-F-AvP07-17 linker variants.
  • FIG. 5 A Two independent induced deBouganin-F(E)-AvP07-17-His (lanes 2 and 3, SEQ ID NO: 125), deBouganin-F(P)-AvP07-17-His (lanes 4 and 5, SEQ ID NO: 129), deBouganin-F(T)-AvP07-17-His (lanes 6 and 7, SEQ ID NO: 127) supernatants were loaded under non-reducing conditions on a SDS-PAGE gel and immunoblotted with a rabbit anti- deBouganin antibody followed by an anti-rabbit-HRP antibody and compared to deBouganin- F-AvP07-17-His induced supernatant (lane 1).
  • FIG. 5B Two independent induced deBouganin-F(E)-AvP07-17 (lanes 2 and 3, SEQ ID NO: 131) and deBouganin-F(P)-AvP07- 17 (lanes 4 and 5, SEQ ID NO: 135) supernatants were analyzed as described previously and the expression level compared to deBouganin-F-AvP07-17 (lane 5, amino acids 23-529 of SEQ ID NO: 25). Lane L corresponds to the ladder. The full arrows indicate the full-length protein.
  • FIG. 6A-6B shows MTS curves.
  • FIG. 7A-7B shows serum stability.
  • FIG. 8 shows immunogenicity risk scores for the first 100 amino acids of furin-deBouganin (top panel) and furin(K)-deBouganin (bottom panel).
  • aC represents any antibody, or antigen binding fragment thereof, either monoclonal, polyclonal or derivative thereof that recognizes specifically the chondroitin sulfate A (CSA) antigen and distinguishes between cancer and noncancer cells.
  • CSA chondroitin sulfate A
  • animal includes, but is not limited to, humans and non-human vertebrates such as wild, domestic and farm animals.
  • Antibody fragments that may be used include Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, multimers, and any combination thereof, and fragments from recombinant sources and/or produced in transgenic animals.
  • the antibody or fragment may be from any species including mice, rats, rabbits, hamsters and humans.
  • Chimeric antibody derivatives i.e., antibody molecules that combine a non-human animal variable region and a human constant region are also contemplated within the scope of the invention.
  • Chimeric antibody molecules can include, for example, humanized antibodies which comprise the antigen binding domain from an antibody of a mouse, rat, or other species, with human constant regions. Conventional methods may be used to make chimeric antibodies. It is expected that chimeric antibodies would be less immunogenic in a human subject than the corresponding non-chimeric antibody.
  • the humanized antibodies can be further stabilized for example as described in WO 00/61635 and is incorporated by reference in its entirety.
  • Anticancer agents or “cancer therapeutics” refers to compounds or treatments that are effective in treating or preventing cancer including, without limitation, chemical agents, other immunotherapeutics, cancer vaccines, anti-angiogenic compounds, certain cytokines, certain hormones, gene therapy, radiotherapy, surgery, and dietary therapy.
  • binding protein refers to proteins that specifically bind to another substance such as an antigen.
  • binding proteins are antibodies or antibody fragments.
  • binding proteins are engineered non-immunoglobulin proteins.
  • binding proteins can be scaffolds.
  • CSA refers to the glycosaminoglycan or antigen recognized by an Hl l antibody, an Hl l antibody fragment or an Hl l scaffold on a cancer cell.
  • CSA positive cancer cells refer to cancer cells that express CSA on their cell surface.
  • a "cell line” or “cell culture” denotes bacterial, plant, insect or higher eukaryotic cells grown or maintained in vitro. The descendants of a cell may not be completely identical (either morphologically, genotypically, or phenotypically) to the parent cell.
  • a monoclonal antibody may be produced by a hybridoma or other cell. Methods of making hybridomas, both murine and human, are known in the art.
  • De-immunized refers to a molecule that lacks or elicits reduced immune response when compared to the wild type counterpart.
  • De-immunized antibodies or “de-immunized antibody fragments” refers to antibodies and antibody fragments that lack one or more T-cell epitopes and elicit reduced immune response when compared to the wild type counterpart.
  • deimmunized bouganin toxin refers to a bouganin toxin that has been modified by nucleotide or amino acid substitution, deletions, additions, or truncations of the protein in order to have a reduced propensity to elicit an immune response, preferably a T-cell response, as compared to a non-deimmunized or non- modified bouganin toxin.
  • the deimmunized or modified bouganin toxin can be a modified full length sequence or a modified fragment of the non-deimmunized or non-modified bouganin toxin.
  • the deimmunized or modified bouganin toxin may also contain other changes as compared to the wild-type bouganin sequence which do not alter immunogenicity of the peptide.
  • the deimmunized or modified bouganin toxin will preferably have the same biological activity as the non-deimmunized or non-modified bouganin toxin.
  • deimmunized diphtheria toxin refers to a diphtheria toxin that has been modified by nucleotide or amino acid substitution, deletions, additions, or truncations of the protein in order to have a reduced propensity to elicit an immune response, preferably a T-cell response, as compared to a non- deimmunized or non-modified diphtheria toxin.
  • the deimmunized or modified diphtheria toxin can be a modified full length sequence or a modified fragment of the non-deimmunized or non-modified diphtheria toxin.
  • the deimmunized or modified diphtheria toxin may also contain other changes as compared to the wild-type diphtheria sequence which do not alter immunogenicity of the peptide.
  • the deimmunized or modified diphtheria toxin will preferably have the same biological activity as the non-deimmunized or non-modified diphtheria toxin.
  • deimmunized furin linker refers to a furin protease sensitive linker that has been modified by nucleotide or amino acid substitution, deletions, additions, or truncations of the linker in order to have a reduced propensity to elicit an immune response, preferably a T-cell response, as compared to a non-deimmunized or non-modified furin protease sensitive linker.
  • the deimmunized or modified furin protease sensitive linker can be a modified full length sequence or a modified fragment of the non-deimmunized or non-modified furin protease sensitive linker.
  • the deimmunized or modified furin protease sensitive linker may also contain other changes as compared to the wild-type furin protease sensitive linker which do not alter immunogenicity of the linker.
  • the deimmunized or modified furin protease sensitive linker will preferably have the same biological activity as the non-deimmunized or non-modified furin protease sensitive linker.
  • the deimmunized furin protease sensitive linker comprises a sequence selected from SEQ ID NOs: 32-36, 119 and 124.
  • De-immunized VB5-845 refers to Fab fragment of anti-EpCAM antibody wherein the putative T-cell epitopes on the VH domain and the VL domain are mutated and might result in eliciting a reduced immune response when compared to the non-deimmunized Fab fragment VB5-845 (VB5-845-WT).
  • De-immunized VB5-845 Fab fragment (VB5-845- DI) comprises a de-immunized VH-CH domain (SEQ ID NO: 49) and a de-immunized VL-CL domain (SEQ ID NO: 51).
  • the non-deimmunized VB5-845 Fab fragment (VB5-845-WT) comprises a wild type VH-CH domain (SEQ ID NO: 63) and a wild type VL-CL domain (SEQ ID NO: 65).
  • VB5-845-WT comprises a wild type VH-CH domain (SEQ ID NO: 63) and a wild type VL-CL domain (SEQ ID NO: 65).
  • De-immunized anti-EpCAM antibodies and antibody fragments are described in PCT/CA2014/050950, which is incorporated herein in its entirety.
  • Effective amount or “therapeutically effective amount” means an amount effective, at dosages and for periods of time necessary to achieve the desired result. Effective amounts of an immunotoxin may vary according to factors such as the disease state, age, sex, weight of the animal. Dosage regimen may be adjusted to provide the optimum therapeutic response. For example, several divided doses may be administered daily or the dose may be proportionally reduced as indicated by the exigencies of the therapeutic situation.
  • fusion polypeptide is a polypeptide comprising regions in a different position in the sequence than occurs in nature.
  • the regions may normally exist in separate proteins and are brought together in the fusion polypeptide; they may normally exist in the same protein but are placed in a new arrangement in the fusion polypeptide; or they may be synthetically arranged.
  • the invention encompasses recombinant proteins that are comprised of a functional portion of a HER2/neu binding protein and a toxin.
  • the invention encompasses recombinant proteins that are comprised of a functional portion of an EpCAM binding protein and a toxin. Methods of making these fusion proteins are known in the art and are described for instance in WO93/07286.
  • a functionally equivalent fragment of, for instance, a polypeptide or polynucleotide varies from the native sequence by any combination of additions, deletions, or substitutions while preserving at least one functional property of the fragment relevant to the context in which it is being used.
  • a functionally equivalent fragment of a polynucleotide encoding a binding protein for HER2/neu either encodes a polypeptide that is functionally equivalent to a HER2/neu binding protein when produced by an expression system, or has similar hybridization specificity as a polynucleotide encoding a HER2/neu binding protein when used in a hybridization assay.
  • a functionally equivalent fragment of a HER2/neu binding protein typically has one or more of the following properties: ability to bind a human epidermal growth factor receptor 2; ability to bind at least one type of cancer cell in a specific manner; and an ability to elicit an immune response with a similar antigen specificity as that elicited by a HER2/neu binding protein.
  • a functionally equivalent fragment of a polynucleotide encoding a binding protein for EpCAM either encodes a polypeptide that is functionally equivalent to an EpCAM binding protein when produced by an expression system, or has similar hybridization specificity as a polynucleotide encoding an EpCAM binding protein when used in a hybridization assay.
  • a functionally equivalent fragment of an EpCAM binding protein typically has one or more of the following properties: ability to bind epithelial cell adhesion molecule; ability to bind at least one type of cancer cell in a specific manner; and an ability to elicit an immune response with a similar antigen specificity as that elicited by an EpCAM binding protein.
  • Hl l antibody means an antibody or antibody fragment that recognizes cancer cells from a wide variety of cancers but does not recognize normal, noncancerous cells. By “does not recognize” is meant that noncancer cells are either not specifically bound to by Hl l or are only poorly recognized by the antibody. "Hl l " is an antibody obtained from the fusion of peripheral blood lymphocytes of a 64 year old male with a low grade glioma and fused to a human myeloma cell line to produce a hybridoma designated NBGM1/H1 1.
  • the antibodies are designated aC and include Hl l and any antibody with the "immunologic specificity" of Hl l , that is, recognizing the antigen recognized by Hl l, and that is specific for at least one type of cancer cell but does not recognize normal cells.
  • These antigen binding fragments include, but are not limited to, whole native antibodies, exemplified by Hl l; bispecific antibodies; chimeric antibodies; Fab, Fab', single chain V region fragments (scFv), diabodies, fusion polypeptides and Hl l scaffolds.
  • An Hl l antibody is described in US Patent Nos. 6,207,153 and 7,166,286, each of which is incorporated herein by reference in its entirety.
  • Oi l VH-CH-F(K)- deBouganin refers to an antibody fragment comprised of, starting at the N-terminus: an anti- chondroitin sulfate antigen Oi l heavy chain (VH-CH) (SEQ ID NO: 99), a de-immunized furin protease sensitive peptide linker (SEQ ID NO: 33), and a deBouganin toxin (SEQ ID NO: 12).
  • VH-CH anti- chondroitin sulfate antigen Oi l heavy chain
  • SEQ ID NO: 33 de-immunized furin protease sensitive peptide linker
  • deBouganin toxin SEQ ID NO: 12
  • VB6-011-C H -deBouganin refers to an Fab comprised of Oi l VH-CH- F(K)-deBouganin and an 011 light chain (V L -C L ) (SEQ ID NO: 120).
  • deBouganin- F(E)-VH-CH Oi l refers to an antibody fragment comprised of, starting at the N-terminus: a deBouganin toxin (SEQ ID NO: 12), a de-immunized furin protease sensitive peptide linker (SEQ ID NO: 119), and an anti-chondroitin sulfate antigen Oi l heavy chain (VH-CH) (SEQ ID NO: 99).
  • VB6-011-NV H -deBouganin refers to an Fab comprised of deBouganin-F(E)-VH-CH Oi l and an Oi l light chain (V L -C L ) (SEQ ID NO: 120).
  • VB6-011 refers to an Fab of an anti-chondroitin sulfate antigen 011 antibody.
  • HER2/neu refers to a human epidermal growth factor receptor 2.
  • HER2/neu can also be known as erbB2.
  • anti-HER2/neu binding protein means a binding protein, an antibody or antibody fragment, respectively, that recognizes a human epidermal growth factor receptor 2 expressed on cancer cells.
  • the antibodies or antibody fragments include, but are not limited to, whole native antibodies, bispecific antibodies, chimeric antibodies, Fab, Fab', single chain
  • the anti-HER2/neu antibody fragment is a diabody engineered with the C6.5 anti-HER2 scFv (in V H -V L orientation) with a short G 4 S linker (SEQ ID NO: 15) between the
  • HER2/neu antibody is an antibody or antibody fragment obtained from the humanization of the murine monoclonal antibody 4D5 (mumAb4D5).
  • the antibodies are designated humAb4D5 and include any antibody with the "immunologic specificity" of a humAb4D5, that is, recognizing the antigen recognized by humAb4D5, and that is specific for at least one type of cancer cell.
  • HER2/neu antibodies are described in US Patent Nos.
  • PelB-DeBouganin-F-AvP07-17-(V H -V L -C6.5)-His refers to an antibody fragment comprised of, starting at the N-terminus: a PelB leader sequence, deBouganin toxin, wild-type furin linker (SEQ ID NO: 17), an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), and a His tag at the C-terminus, and which is represented by SEQ ID NO: 22 (nucleotide sequence) and SEQ ID NO: 23 (amino acid sequence).
  • deBouganin-AvP07-17- His and “deBouganin-AvP07-17-(V H -VL)-His” refer to an antibody fragment comprised of amino acids 23-535 of the amino acid sequence shown in SEQ ID NO: 23.
  • PelB- DeBouganin-F-AvP07-17-(VH-VL-C6.5) refers to an antibody fragment comprised of, starting at the N-terminus: a PelB leader sequence, deBouganin toxin, wild-type furin linker (SEQ ID NO: 17), an anti-HER2/neu heavy chain variable region (VH) linked to an anti- HER2/neu light chain variable region (VL), and which is represented by SEQ ID NO: 24 (nucleotide sequence) and SEQ ID NO: 25 (amino acid sequence).
  • deBouganin- AVP07-17-(VH-V l ) refers to an antibody fragment comprised of amino acids 23-529 of the amino acid sequence shown in SEQ ID NO: 25.
  • PelB-AvP07-17-(VH-VL-C6.5)-F-deBouganin-His refers to an antibody fragment comprised of, starting at the N-terminus: a PelB leader sequence, an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), wild- type furin linker (SEQ ID NO: 17), deBouganin toxin, and a His tag at the C-terminus, and which is represented by SEQ ID NO: 26 (nucleotide sequence) and SEQ ID NO: 27 (amino acid sequence).
  • AvP07-17-deBouganin-His and "AVP07-17(VH-VL)- deBouganin-His” refer to an antibody fragment comprised of amino acids 23-535 of the amino acid sequence shown in SEQ ID NO: 27.
  • PelB-AvP07-17-(V H -V L -C6.5)-F- deBouganin refers to an antibody fragment comprised of, starting at the N-terminus: a PelB leader sequence, an anti-HER2/neu heavy chain variable region (VH) linked to an anti- HER2/neu light chain variable region (VL), wild-type furin linker (SEQ ID NO: 17) and deBouganin toxin, and which is represented by SEQ ID NO: 28 (nucleotide sequence) and SEQ ID NO: 29 (amino acid sequence).
  • AvP07-17-deBouganin and “AvP07- 17(VH-VL)-deBouganin” refer to an antibody fragment comprised of amino acids 23-529 of the amino acid sequence shown in SEQ ID NO: 29.
  • PelB-deBouganin-F-AvP07- 17-(VL-VH-C6.5) refers to an antibody fragment comprised of, starting at the N-terminus: a PelB leader sequence, deBouganin toxin, wild-type furin linker (SEQ ID NO: 17), an anti- HER2/neu light chain variable region (VL) linked to an anti-HER2/neu heavy chain variable region (VH), and which is represented by SEQ ID NO: 30 (nucleotide sequence) and SEQ ID NO: 31 (amino acid sequence).
  • deBouganin-AvP07-17(VL-VH) and “ deBouganin- VL-VH AVP07-17” refer to an antibody fragment comprised of amino acids 23- 529 of the amino acid sequence shown in SEQ ID NO: 31.
  • His-AvP07-17- deBouganin refers to an antibody fragment comprised of, starting at the N-terminus: a His tag, an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), wild-type furin linker (SEQ ID NO: 17) and deBouganin toxin.
  • deBouganin-F(E)-AvP07-17-His refers to an antibody fragment comprised of, starting at the N-terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 119), an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), and a His tag at the C-terminus, and which is represented by nucleotides 132-1670 of SEQ ID NO: 126 (nucleotide sequence) and by SEQ ID NO: 125 (amino acid sequence).
  • deBouganin-F(T)-AvP07-17-His refers to an antibody fragment comprised of, starting at the N-terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 124), an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), and a His tag at the C-terminus, and which is represented by nucleotides 132-1670 of SEQ ID NO: 128 (nucleotide sequence) and by SEQ ID NO: 127 (amino acid sequence).
  • deBouganin-F(P)-AvP07-17-His refers to an antibody fragment comprised of, starting at the N-terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 35), an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), and a His tag at the C-terminus, and which is represented by nucleotides 132-1670 of SEQ ID NO: 130 (nucleotide sequence) and by SEQ ID NO: 129 (amino acid sequence).
  • deBouganin-F(E)-AvP07-17 refers to an antibody fragment comprised of, starting at the N-terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 119), an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), and which is represented by nucleotides 132-1652 of SEQ ID NO: 132 (nucleotide sequence) and by SEQ ID NO: 131 (amino acid sequence).
  • deBouganin-F(T)-AvP07-17 refers to an antibody fragment comprised of, starting at the N-terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 124), an anti-HER2/neu heavy chain variable region (V H ) linked to an anti-HER2/neu light chain variable region (VL), and which is represented by nucleotides 132-1652 of SEQ ID NO: 134 (nucleotide sequence) and by SEQ ID NO: 133 (amino acid sequence).
  • deBouganin-F(P)-AvP07-17 refers to an antibody fragment comprised of, starting at the N- terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 35), an anti-HER2/neu heavy chain variable region (V H ) linked to an anti-HER2/neu light chain variable region (VL), and which is represented by nucleotides 132-1652 of SEQ ID NO: 136 (nucleotide sequence) and by SEQ ID NO: 135 (amino acid sequence).
  • the PelB leader sequence which directs an immunotoxin to the periplasm, is cleaved off after localization of the immunotoxin to the periplasm.
  • the terms "trastuzumab-deBouganin”, “Herceptin- deBouganin”, “T-deB”, and “Herc-deB” refer to the humanized anti-Her2/neu antibody (described in US Patent Nos. 5677171 ; 5821337; 6054297; 6165464; 6339142; 6407213; 6639055; 6719971 ; 6800738; 7074404, which are incorporated herein by reference in their entirety, and in Coussens et al. (1985) Science 230: 1132-1139; Slamon et al. (1989) Science 244:707-712; Carter et al. (1992) Proc. Natl.
  • T- DM1 refers to trastuzumab conjugated to maytansinoid, a microtubule-disrupting agent.
  • the term "heavy chain variable region” refers to the variable region of a heavy chain of an antibody molecule.
  • the heavy chain variable region has three complementarity determining regions (CDRs) termed heavy chain complementarity determining region 1 (CDR-H1), heavy chain complementarity determining region 2 (CDR- H2) and heavy chain complementarity determining region 3 (CDR-H3) from the amino terminus to carboxy terminus.
  • CDRs complementarity determining regions
  • CDR-H1 heavy chain complementarity determining region 1
  • CDR- H2 heavy chain complementarity determining region 2
  • CDR-H3 heavy chain complementarity determining region 3
  • the heavy chain CDRs comprise SEQ ID NOs: 5-7.
  • the heavy chain CDRs comprise SEQ ID NOs: 105-107.
  • heterologous means derived from a genotypically distinct entity from the rest of the entity to which it is being compared.
  • a polynucleotide may be placed by genetic engineering techniques into a plasmid or vector derived from a different source, and is a heterologous polynucleotide.
  • a promoter removed from its native coding sequence and operatively linked to a coding sequence other than the native sequence is a heterologous promoter.
  • homologous sequences or “homologs” are thought, believed, or known to be functionally related.
  • a functional relationship may be indicated in any one of a number of ways, including, but not limited to: (a) degree of sequence identity and/or (b) the same or similar biological function. Preferably, both (a) and (b) are indicated.
  • the degree of sequence identity may vary, but in one embodiment, is at least 50% (when using standard sequence alignment programs known in the art), at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least 98.5%, or at least about 99%, or at least 99.5%, or at least 99.8%, or at least 99.9%.
  • Homology can be determined using software programs readily available in the art, such as those discussed in Current Protocols in Molecular Biology (F.M.
  • the term "host cell” denotes a prokaryotic or eukaryotic cell that has been genetically altered, or is capable of being genetically altered by administration of an exogenous polynucleotide, such as a recombinant plasmid or vector.
  • an exogenous polynucleotide such as a recombinant plasmid or vector.
  • genetically altered cells refers both to the originally altered cell, and to the progeny thereof.
  • Humanized antibody or antibody fragment means that the antibody or fragment comprises human framework regions.
  • the term "immunologic activity" of HER2/neu binding protein or EpCAM binding protein refers to the ability to specifically bind a human epidermal growth factor receptor 2 or an epithelial cell adhesion molecule, respectively. Such binding may or may not elicit an immune response.
  • a specific immune response may comprise antibody, B cells, T cells, and any combination thereof, and effector functions resulting therefrom. Included are the antibody-mediated functions ADCC and complement-mediated cytolysis (CDC).
  • the T cell response includes T helper cell function, cytotoxic T cell function, inflammation/inducer T cell function, and T cell mediated suppression.
  • a compound able to elicit a specific immune response according to any of these criteria is referred to as "immunogenic.”
  • immunoconjugate refers to a binding protein conjugated to an effector molecule.
  • the binding protein is an antibody.
  • the antibody may be full length antibody or antibody fragments, such as Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, multimers, and any combination thereof, and fragments from recombinant sources and/or produced in transgenic animals.
  • the antibody may be a synthetic protein, a binding protein or a polypeptide.
  • the effector molecule may be a toxin, a radionucleotide, a radiopharmaceutical, a labeling agent, a drug, a cytotoxic agent, a peptide, a protein and the like. These effector molecules may be capable of killing, lysing or labeling or inducing other effects when the antibody binds to an antigen.
  • the term “immunotoxin” comprises (1) a binding protein attached to (2) a toxin.
  • the terms “immunotoxin” and “immunoconjugate” are used interchangeably herein.
  • the immunotoxin is administered directly to the cancer site refers to direct or substantially direct introduction including, without limitation, single or multiple injections of the immunotoxin directly into the tumor or peritumorally, continuous or discontinuous perfusion into the tumor or peritumorally, introduction of a reservoir into the tumor or peritumorally, introduction of a slow-release apparatus into the tumor or peritumorally, introduction of a slow-release formulation into the tumor or peritumorally, direct application onto the tumor, direct injection into an artery that substantially directly feeds the area of the tumor, direct injection into a lymphatic vessel that substantially drains into the area of the tumor, direct or substantially direct introduction in a substantially enclosed cavity (e.g., pleural cavity) or lumen (e.g., intravesicular).
  • a substantially enclosed cavity e.g., pleural cavity
  • lumen e.g., intravesicular
  • Peritumoral is a term that describes a region, within about 10 cm, preferably within 5 cm, more preferably within 1 cm, of what is regarded as the tumor boundary, such as, but not limited to, a palpable tumor border.
  • Direct administration in the context of prevention of occurrence or prevention of recurrence is defined as administration directly into a site at risk for development or recurrence of a cancer. In one embodiment, direct administration is by systemic delivery.
  • leader sequence is a short amino acid sequence that directs a newly synthesized protein through a cellular membrane, usually the endoplasmic reticulum in eukaryotic cells, and either the inner membrane or both inner and outer membranes of bacteria. Leader sequences are typically at the N-terminal portion of a polypeptide and are typically removed enzymatically between biosynthesis and secretion of the polypeptide from the cell. The leader sequence is not present in the secreted protein, only during protein production. In one embodiment, the leader sequence comprises PelB (pectate lyase B) shown in SEQ ID NO: 21.
  • ligand that binds to a protein on the cancer cell includes any molecule that can selectively target the immunotoxin to the cancer cell by binding to a protein on the cancer cells.
  • the targeted protein on the cancer cell is preferably a tumor associated antigen that is expressed at higher levels on the cancer cell as compared to normal cells.
  • light chain variable region refers to the variable region of a light chain of an antibody molecule.
  • Light chain variable regions have three complementarity determining regions (CDRs) termed light chain complementarity determining region 1 (CDR- Ll), light chain complementarity determining region 2 (CDR-L2) and light chain complementarity determining region 3 (CDR-L3) from the amino terminus to the carboxy terminus.
  • CDR- Ll complementarity determining region 1
  • CDR-L2 light chain complementarity determining region 2
  • CDR-L3 light chain complementarity determining region 3
  • the light chain CDRs comprise SEQ ID NOs: 8-10.
  • the light chain CDRs comprise SEQ ID NOs: 108-110.
  • linker refers to a short peptide sequence that occurs between protein domains.
  • linkers are composed of flexible residues like glycine and serine so that the adjacent protein domains are free to move relative to one another. Longer linkers are used when it is necessary to ensure that two adjacent domains do not sterically interfere with one another. In another embodiment, linkers are rigid and function to prohibit unwanted interactions between discrete protein domains. Fusion proteins or polypeptides can use linkers to connect the regions that do not naturally occur together in nature.
  • a furin protease sensitive peptide linker connects, links, joins or fuses a toxin to a binding protein that recognizes one or more tumor associated antigens on the surface of cancer cells.
  • a "furin protease sensitive peptide linker”, “furin protease sensitive linker” or “furin linker” comprises a furin cleavage site that is recognized and cleaved by furin, an enzyme which belongs to the subtilisin-like proprotein convertase family. The members of this family are proprotein convertases that process latent precursor proteins into their biologically active products.
  • This encoded protein is a calcium-dependent serine endoprotease that can efficiently cleave precursor proteins at their paired basic amino acid processing sites.
  • a furin protease sensitive peptide linker fuses a binding protein portion to a toxin portion in an immunotoxin.
  • the toxin is cleaved from the binding protein of the immunotoxin by a furin enzyme once the immunotoxin is internalized in a cancer cell, allowing the free toxin to exert its cytotoxic effect.
  • polypeptide polypeptide
  • peptide and “protein” are used interchangeably herein to refer to polymers of amino acid residues of any length.
  • the polymer may be linear or branched, it may comprise modified amino acids or amino acid analogs, and it may be interrupted by chemical moieties other than amino acids.
  • the terms also encompass an amino acid polymer that has been modified naturally or by intervention; for example, disulfide bond formation, glycosylation, lipidation, acetylation, phosphorylation, or any other manipulation or modification, such as conjugation with a labeling or bioactive component.
  • polynucleotide is a polymeric form of nucleotides of any length, which contain deoxyribonucleotides, ribonucleotides, and analogs in any combination analogs. Polynucleotides may have any three-dimensional structure, and may perform any function, known or unknown.
  • polynucleotide includes double-, single-stranded, and triple-helical molecules. Unless otherwise specified or required, any embodiment of the invention described herein that is a polynucleotide encompasses both the double-stranded form and each of two complementary single-stranded forms known or predicted to make up the double stranded form of either the DNA, RNA or hybrid molecules.
  • polynucleotides a gene or gene fragment, exons, introns, mRNA, tRNA, rRNA, ribozymes, cDNA, recombinant polynucleotides, branched polynucleotides, plasmids, vectors, isolated DNA of any sequence, isolated RNA of any sequence, nucleic acid probes, and primers.
  • a polynucleotide may comprise modified nucleotides, such as methylated nucleotides and nucleotide analogs, uracyl, other sugars and linking groups such as fluororibose and thioate, and nucleotide branches.
  • sequence of nucleotides may be interrupted by non-nucleotide components.
  • a polynucleotide may be further modified after polymerization, such as by conjugation with a labeling component.
  • Other types of modifications included in this definition are caps, substitution of one or more of the naturally occurring nucleotides with an analog, and introduction of means for attaching the polynucleotide to proteins, metal ions, labeling components, other polynucleotides, or a solid support.
  • polynucleotide means a polynucleotide of genomic, cDNA, semisynthetic, or synthetic origin which either does not occur in nature or is linked to another polynucleotide in a nonnatural arrangement.
  • “Pharmaceutically acceptable” refers to general clinical use and/or approval by a regulatory agency of the Federal or state government, listing in the United States Pharmacopoeia, or general acceptance by those skilled in the relevant art.
  • "Physiologic conditions" for antibody binding reflect but do not necessarily exactly duplicate the conditions in which, for instance, an EpCAM-binding polypeptide would encounter an EpCAM molecule in vivo. Binding under physiologic conditions should be reasonably predictive that binding in vivo will occur.
  • Preventing cancer refers to prevention of cancer occurrence.
  • the preventative treatment reduces the recurrence of the cancer.
  • preventative treatment decreases the risk of a patient from developing a cancer, or inhibits progression of a pre-cancerous state (e.g. a colon polyp) to actual malignancy.
  • a pre-cancerous state e.g. a colon polyp
  • Reduced dose refers to a dose that is below the normally administered and/or recommended dose.
  • the normally administered dose of an anticancer agent can be found in reference materials well known in the art such as, for example, the latest edition of the Physician's Desk Reference.
  • Reduced propensity to elicit an immune response means that the modified anti-EpCAM antibody or the antibody fragment is less immunogenic than non- modified anti-EpCAM antibody.
  • a modified furin protease sensitive linker is less immunogenic than a non-modified furin protease sensitive linker.
  • the term "reduced propensity to activate human T-cells" as used herein means the modified furin protease sensitive peptide linker has a reduced propensity to activate human T-cells as compared to the non-modified furin protease sensitive peptide linker.
  • One of skill in the art can test whether or not a modified furin protease sensitive peptide linker has a reduced propensity to activate T-cells using assays known in the art including assessing the stimulation index of the peptide.
  • the term "scaffold” refers to at least one engineered protein, polypeptide or protein domain that yields specificity and affinity for a particular antigen or antigens.
  • the scaffolds can include a diverse group of compact and stably folded proteins differing in size, structure and origin that serve as novel binding reagents.
  • the scaffolds can be generated by rational design and molecular evolution procedures, often involving creating a random library by mutagenesis.
  • the random library consists of a collection of amino acid sequences focused at a loop region or at an otherwise permissible surface area, and selection of variant amino acid sequences against a given target biomolecule or antigen can be by known molecular display methods such as phage display, yeast display, ribosome/mRNA display or other techniques.
  • scaffolds can also possess other desirable molecular properties, such as stability, better tissue penetration, solubility, and pharmacokinetic behavior.
  • a HER2/neu scaffold has specificity and affinity for a human epidermal growth factor receptor 2.
  • an EpCAM scaffold has specificity and affinity for an epithelial cell adhesion molecule.
  • Examples of a protein and/or protein domain that is engineered as a scaffold include an Affibody ® , a Kunitz protease inhibitor domain, a fibronectin domain, a lipocalin domain, a designed ankyrin repeat domain, a thioredoxin, a cell surface receptor A domain, and/or a cysteine-rich knottin peptide.
  • the present invention also contemplates scaffolds that incorporate only non- immunoglobulin components or both non-immunoglobulin and immunoglobulin components.
  • stimulation index refers to the measure of the ability of the modified or non-modified furin protease sensitive peptide linker to activate human T cells.
  • the modified or non-modified furin protease sensitive peptide linkers thereof can be tested for their ability to evoke a proliferative response in human T-cells cultured in vitro.
  • a stimulation index equal to or greater than 2.0 is a useful measure of induced proliferation.
  • the stimulation index is conventionally derived by division of the proliferation score (e.g. counts per minute of radioactivity if using H-thymidine incorporation) measured to the test peptide by the score measured in cells not contacted with a test peptide.
  • T-cell epitope means an amino acid sequence which is able to bind a major histocompatibility complex (MHC), able to stimulate T-cells and/or also able to bind (without necessarily measurably activating) T-cells in complex with MHC.
  • MHC major histocompatibility complex
  • Therapeutic means an agent utilized to discourage, combat, ameliorate, prevent or improve an unwanted condition, disease or symptom of a patient.
  • toxin refers to any anticellular agent, and includes, but is not limited to, cytotoxins and/or any combination of anticellular agents.
  • the toxin is, for example, a plant toxin, a fungal toxin, a bacterial toxin, a ribosome inactivating protein (RIP) or a combination thereof.
  • Toxins include, but are not limited to, Abrin A chain, Diphtheria Toxin (DT) A-Chain, Pseudomonas exotoxin, RTA, Shiga Toxin A chain, Shiga- like toxin, Gelonin, Momordin, Pokeweed Antiviral Protein, Saporin, Trichosanthin, Barley toxin, Bouganin and various other toxins known in the art.
  • DT Diphtheria Toxin
  • RTA Shiga Toxin A chain
  • Shiga- like toxin Shiga- like toxin
  • Gelonin Gelonin
  • Momordin Momordin
  • Pokeweed Antiviral Protein Saporin
  • Trichosanthin Barley toxin
  • Bouganin and various other toxins known in the art.
  • Modified bouganin proteins are described in WO 2005/090579, which is incorporated herein by reference in its entirety.
  • V region or "V domain” of an antibody or antibody fragment refers to the variable region or domain of a light chain or the variable region or domain of a heavy chain, either alone or in combination. These V regions are contained in, for example, SEQ ID NOs: 2, 4, 49, 51, 53, 55, 56, 57, 99-101, 103, 120-123, 125, 127, 129, 131, 133, 135.
  • Variant refers to any pharmaceutically acceptable derivative, analogue, or fragment of an immunotoxin, an antibody or antibody fragment, a toxin (e.g., Pseudomonas toxin), or an effector molecule described herein.
  • a variant also encompasses one or more components of a multimer, multimers comprising an individual component, multimers comprising multiples of an individual component (e.g., multimers of a reference molecule), a chemical breakdown product, and a biological breakdown product.
  • an immunotoxin may be a "variant" relative to a reference immunotoxin by virtue of alteration(s) in the EpCAM-binding portion and/or the toxin portion of the reference immunotoxin.
  • a variant immunotoxin may contain multimers of the antibody portion and/or the toxin portion.
  • a variant of the toxin portion of the molecule retains toxicity of at least 10%, at least 30%, at least 50%, at least 80%, at least 90%, in a standard assay used to measure toxicity of a preparation of the reference toxin.
  • a variant may also refer to polypeptides having at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or 95% sequence identity to the immunotoxin of the present invention.
  • a variant antibody may refer to polypeptides or proteins having at least 30%, at least 60%, at least 70%, at least 80%, at least 90%, or 95% sequence identity of the antibody of the present invention.
  • a variant antibody or the immnunoconjugate may refer to polypeptides or proteins having at least 30%, at least 60%, at least 70%, at least 80%, at least 90%, or 95% binding affinity of the antibody of the present invention when measured by a competitive binding assay.
  • a variant immunotoxin having a variation of the EpCAM-binding portion of the reference immunotoxin competes with the binding of an anti-EpCAM reference antibody, under physiologic conditions, by at least 10 percent and preferably at least 30 percent (and see infra). Competition by 10 percent means that, in an assay where a saturating concentration of anti-EpCAM reference antibody is bound to EpCAM, 10 percent of these bound reference antibodies is displaced when equilibrium is reached with an equivalent concentration of the variant anti-EpCAM immunotoxin.
  • competition between antibodies, or between an antibody and an immunotoxin is measured by binding labeled anti-EpCAM reference antibody to EpCAM on the surface of cells or to an EpCAM-coated solid substrate, such that virtually all EpCAM sites are bound by the antibody, contacting these antibody-antigen complexes with unlabeled test anti-EpCAM antibody or unlabeled test immunotoxin, and measuring the amount of labeled antibody displaced from EpCAM binding sites, wherein the amount of freed, labeled antibody indicates the amount of competition that has occurred.
  • the term "vector” refers to a recombinant DNA or RNA plasmid or virus that comprises a heterologous polynucleotide to be delivered into a target cell, either in vitro or in vivo.
  • the heterologous polynucleotide may comprise a sequence of interest for purposes of therapy, and may optionally be in the form of an expression cassette.
  • a vector need not be capable of replication in the ultimate target cell or subject.
  • the term includes cloning vectors for the replication of a polynucleotide, and expression vectors for translation of a polynucleotide encoding sequence.
  • viral vectors which comprise a polynucleotide encapsidated or enveloped in a viral particle.
  • VB5-845 refers to a Fab fragment of EpCAM antibody without toxin conjugate.
  • VB6-845" or "VB6-901" are used interchangeably herein and refer to a Fab fragment of anti-EpCAM antibody genetically linked to a modified bouganin protein (deBouganin) toxin.
  • VB6-845 has been described in U.S. Patent No. 7,339,031 and is incorporated herein by reference in its entirety.
  • 4D5MOC-B or "4D5" means the humanized scFv MOC31 antibody grafted onto the artificial human consensus framework of scFv 4D5 as described in WO 00/61635 which is incorporated herein by reference in its entirety.
  • 4D5MOC-B is represented by SEQ ID NO: 66.
  • MOC-31 antibody means the murine anti-EpCAM or anti-EGP-2 antibody and is available from commercial sources such as BioGenex, Cat No. MU316-UC, Zymed Laboratories Inc., Cat No. 18-0270 or United States Biological, Cat No. M4165.
  • TAAs tumor-associated antigens
  • EpCAM Epithelial Cell Adhesion Molecule
  • HER2/neu human epidermal growth factor receptor 2
  • erbB2 a transmembrane glycoprotein with tyrosine kinase activity
  • HER2/neu is highly expressed in breast cancer cells. The amplification of the HER2/neu gene occurs in 20-30% of human breast cancers and is associated with aggressive tumor growth and poor clinical outcome.
  • the resulting humanized anti-HER2 antibody of the IgGl isotype, trastuzumab (Herceptin ® ) has been approved for treatment of HER2 overexpressing metastatic breast cancer.
  • CSA chondroitin sulfate A
  • Hl l antibody or antibody fragment recognizes CSA.
  • T-cell epitopes are commonly defined as any amino acid residue sequence with the ability to bind to MHC molecules.
  • T-cell epitope means an epitope, which when bound to MHC molecules, can be recognized by a T- cell receptor (TCR), and which can, at least in principle, cause the activation of these T-cells by engaging a TCR to promote a T-cell response.
  • TCR T- cell receptor
  • Each part of an immunotoxin such as the binding protein portion, the toxin, and the linker that joins the two can potentially harbor peptides that can trigger an immune response.
  • an immunotoxin such as the binding protein portion, the toxin, and the linker that joins the two can potentially harbor peptides that can trigger an immune response.
  • de-immunized peptide linkers that can be used to link the binding protein portion and the toxin portion of an immunotoxin.
  • the deimmunized peptide linker is a modified furin protease sensitive peptide linker.
  • a furin protease sensitive peptide linker comprises a furin cleavage site that is recognized and cleaved by furin, an enzyme which belongs to the subtilisin-like proprotein convertase family. The members of this family are proprotein convertases that process latent precursor proteins into their biologically active products.
  • This encoded protein is a calcium-dependent serine endoprotease that can efficiently cleave precursor proteins at their paired basic amino acid processing sites.
  • the linker When the furin protease sensitive peptide linker is used to link a toxin and a binding protein in an immunotoxin, the linker is cleaved when the immunotoxin is taken up by a cancer cell.
  • the toxin released from the immunotoxin by cleavage can then kill the cancer cell by, for example, interfering with translation by ribosomes as in the case of the bouganin toxin.
  • the modified furin protease sensitive peptide linker has a reduced propensity to activate an immune response.
  • the peptide linker has a reduced propensity to activate T-cells compared to a non-modified furin protease sensitive peptide linker and has a biological function that is comparable to non- modified furin protease sensitive peptide linker.
  • the modified furin protease sensitive peptide linker is modified at one or more T-cell epitopes in the peptide linker sequence.
  • a method that can be used to generate the modified furin protease sensitive peptide linkers with modified T-cell epitopes comprises the following steps: (i) determining the amino acid sequence of the peptide linker; (ii) identifying one or more potential T-cell epitopes within the amino acid sequence of the peptide linker by methods such as determination of the binding of the peptides to MHC molecules using in vitro or in silico techniques or biological assays; (iii) designing new sequence variants with one or more amino acids within the identified potential T-cell epitopes modified in such a way to substantially reduce or eliminate the activity of the T-cell epitope as determined by the binding of the peptide linkers to MHC molecules using in vitro or in silico techniques or biological assays.
  • sequence variants are created in such a way to avoid creation of new potential T-cell epitopes by the sequence variations unless such new potential T-cell epitopes are, in rum, modified in such a way to substantially reduce or eliminate the activity of the T- cell epitope; (iv) constructing such sequence variants by recombinant DNA techniques and testing said variants in order to identify one or more variants with desirable properties according to well-known recombinant techniques; and (v) optionally repeating steps (ii) to (iv).
  • step (iii) is carried out by substitution, addition or deletion of amino acid residues in any of the T-cell epitopes in the non-modified furin protease sensitive peptide linker.
  • the method to make the modified furin protease sensitive peptide linker is made with reference to the homologous peptide sequence and/or in silico modeling.
  • the modified furin protease sensitive peptide linker has at least one T-cell epitope removed.
  • the modified furin protease sensitive peptide linker has biological function, such as the linking of the binding protein portion and the toxin portion of an immunotoxin.
  • amino acid substitutions are made at appropriate points within the peptide sequence predicted to achieve substantial reduction or elimination of the activity of the T-cell epitope.
  • an appropriate point will in one embodiment equate to an amino acid residue binding within one of the pockets provided within the MHC class II binding groove.
  • the epitopes are compromised by mutation to result in sequences no longer able to function as T-cell epitopes. It is possible to use recombinant DNA methods to achieve directed mutagenesis of the target sequences and many such techniques are available and well known in the art. In practice a number of modified furin protease sensitive peptide linkers will be produced and tested for the desired immune and functional characteristic. Mutations to the peptide linker to eliminate T-cell epitopes are also dependent upon the sequence context of the peptide linker in an immunotoxin construct, for example, what sequence residues exist at the amino-terminal and carboxy-terminal junctions of the peptide linker.
  • the peptide linker is modified at one or more amino acid residues in a T-cell epitope represented by SEQ ID NO: 17. In another embodiment, the peptide linker is modified at amino acid position 12 of SEQ ID NO: 17.
  • the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 32. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 33. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 34. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 35. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 36. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 119. In another embodiment, the amino acid sequence of the modified peptide linker comprises SEQ ID NO: 124. In certain embodiments, the amino acid sequence of the modified peptide linker shares at least 90% sequence identity to the amino acid sequence shown in SEQ ID NO: 17.
  • immunotoxins comprising: (a) a binding protein and; (b) a toxin, wherein the binding protein and toxin are linked by a deimmunized peptide linker.
  • the binding protein comprises an antibody or antibody fragment.
  • the antibody or antibody fragment comprises an anti-epithelial cell adhesion molecule (EpCAM) antibody or an anti-EpCAM antibody fragment.
  • the antibody may have a heavy chain with an amino acid sequence of SEQ ID NO: 49, SEQ ID NO: 53, SEQ ID NO: 56, or SEQ ID NO: 57; and a light chain with an amino acid sequence of SEQ ID NO: 51 or SEQ ID NO: 55.
  • the antibody may be full length antibody or antibody fragments, such as Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, multimers, and any combination thereof.
  • the anti-EpCAM antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 49, and a light chain with an amino acid sequence of SEQ ID NO: 51. In some embodiments, the antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 53, and a light chain with an amino acid sequence of SEQ ID NO: 55. In some embodiments, the antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 49, and a light chain with an amino acid sequence of SEQ ID NO: 55.
  • the antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 53, and a light chain with an amino acid sequence of SEQ ID NO: 51. In some embodiments, the antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 56, and a light chain with an amino acid sequence of SEQ ID NO: 51. In some embodiments, the antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 56, and a light chain with an amino acid sequence of SEQ ID NO: 55. In some embodiments, the antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 57, and a light chain with an amino acid sequence of SEQ ID NO: 51. In some embodiments, the antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 57, and a light chain with an amino acid sequence of SEQ ID NO: 55.
  • the antibody or antibody fragment comprises an anti- HER2/neu antibody or an anti-HER2/neu antibody fragment.
  • the anti- HER2/neu antibody or the anti-HER2/neu antibody fragment comprises the complementarity determining region (CDR) sequences of SEQ ID NOs: 5-10.
  • the antibody may be full length antibody or antibody fragments, such as Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, multimers, and any combination thereof.
  • the anti-HER2/neu antibody fragment is a diabody.
  • the diabody is comprised of a heavy chain variable region and a light chain variable region.
  • the heavy chain variable region and the light chain variable region are linked by a linker.
  • the linker is encoded by an amino acid sequence shown in SEQ ID NO: 15.
  • the HER2/neu heavy chain variable region and light chain variable region are encoded by amino acid sequences set forth in SEQ ID NOs: 125, 127, 129, 131, 133 and 135.
  • the HER2/neu heavy chain variable region and light chain variable region are encoded by an amino acid sequence set forth in SEQ ID NO: 131.
  • the anti-HER2/neu antibody or the anti-HER2/neu antibody fragment comprises a heavy chain variable region encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 2.
  • the heavy chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 2.
  • the anti-HER2/neu antibody or the anti-HER2/neu antibody fragment comprises a light chain variable region encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 4.
  • the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 4.
  • the antibody or antibody fragment comprises an Hl l antibody or Hl l antibody fragment.
  • the Hl l antibody or Hl l antibody fragment comprises the complementarity determining region (CDR) sequences of SEQ ID NOs: 105-110.
  • the antibody may be full length antibody or antibody fragments, such as Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, multimers, and any combination thereof.
  • the HI 1 antibody or antibody fragment comprises a heavy chain variable region and a heavy chain constant region.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 101.
  • the heavy chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 101.
  • the Hl l antibody or antibody fragment comprises a light chain variable region and a light chain constant region.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 100.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 100.
  • the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 103.
  • the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 103.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 120. In a further embodiment, the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 120. In another embodiment, the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 123. In a further embodiment, the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 123. In certain embodiments, the Hl l antibody or Hl l antibody fragment comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 99 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the antibody or fragment may be from any species including mice, rats, rabbits, hamsters and humans.
  • Chimeric antibody derivatives i.e., antibody molecules that combine a non-human animal variable region and a human constant region are also contemplated within the scope of the invention.
  • Chimeric antibody molecules can include, for example, humanized antibodies which comprise the antigen binding domain from an antibody of a mouse, rat, or other species, with human constant regions.
  • Conventional methods may be used to make chimeric antibodies (See, for example, Morrison et al., Proc. Natl Acad. Sci. U.S.A. 81 : 6851 (1985); Takeda et al, Nature 314: 452 (1985), Cabilly et al, U.S.
  • the sequences of the light chain and the heavy chain fragments may be modified or replaced with other amino acids such that the antibody elicits reduced immune response in humans.
  • humanized antibody or antibody fragments any method known in the art may be used.
  • human antibody fragments can be obtained by screening human antibody libraries.
  • Another solution is to transplant the specificity of a non-human monoclonal antibody by grafting the CDR regions onto a human framework.
  • humanized antibodies or antibody fragments with improved binding behavior can be produced by incorporating additional residues derived from said non-human antibody.
  • Fab fragments, VH regions and Fv regions can be expressed in bacteria using phage expression libraries (See for example Ward et al, Nature 341 : 544-546: (1989); Huse et al, Science 246: 1275-1281 (1989); and McCafferty et al. Nature 348: 552-554 (1990)).
  • phage expression libraries See for example Ward et al, Nature 341 : 544-546: (1989); Huse et al, Science 246: 1275-1281 (1989); and McCafferty et al. Nature 348: 552-554 (1990)).
  • SCID-hu mouse for example the model developed by Genpharm, can be used to produce antibodies or fragments thereof.
  • the antibody fragment may be Fab, and the light chain and the heavy chain are linked by a covalent bond.
  • the covalent linkage may be disulfide bond.
  • the covalent linkage may be through chemical crosslinkers, such as dimethyl adipimidate, dimethyl suberimidate, and the like.
  • amino acid crosslinkers such as (Gly 4 -Ser) n may be used.
  • the sequences of the light chain and the heavy chain described herein may be used to derive scFv, diabodies, tribodies, tetrabodies, and the like.
  • Various protein linking strategies may be used to produce bivalent or bispecific Fab and scFvs, as well as bifunctional Fab and scFv fusions.
  • the immunotoxin comprises an anti-EpCAM antibody fragment.
  • the anti-EpCAM antibody fragment is an Fab.
  • the Fab is comprised of a heavy chain with an amino acid sequence of SEQ ID NO: 49, SEQ ID NO: 53, SEQ ID NO: 56, or SEQ ID NO: 57; and a light chain with an amino acid sequence of SEQ ID NO: 51 or SEQ ID NO: 55.
  • the anti- EpCAM Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 49, and a light chain with an amino acid sequence of SEQ ID NO: 51.
  • the anti- EpCAM Fab described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 53, and a light chain with an amino acid sequence of SEQ ID NO: 55. In some embodiments, the anti-EpCAM Fab described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 49, and a light chain with an amino acid sequence of SEQ ID NO: 55. In some embodiments, the anti-EpCAM Fab described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 53, and a light chain with an amino acid sequence of SEQ ID NO: 51.
  • the anti-EpCAM Fab described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 56, and a light chain with an amino acid sequence of SEQ ID NO: 51. In some embodiments, the anti-EpCAM Fab described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 57, and a light chain with an amino acid sequence of SEQ ID NO: 55. In some embodiments, the anti-EpCAM Fab described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 56, and a light chain with an amino acid sequence of SEQ ID NO: 55. In some embodiments, the anti-EpCAM Fab described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 57, and a light chain with an amino acid sequence of SEQ ID NO: 51.
  • the immunotoxin comprises an anti-HER2/neu antibody fragment.
  • the anti-HER2/neu antibody fragment is a diabody.
  • the anti-HER2/neu diabody comprises a heavy chain variable region and a light chain variable region.
  • the HER2/neu heavy chain variable region and light chain variable region are encoded by amino acid sequences set forth in SEQ ID NOs: 125, 127, 129, 131, 133 and 135.
  • the HER2/neu heavy chain variable region and light chain variable region are encoded by an amino acid sequence set forth in SEQ ID NO: 131.
  • the heavy chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 2. In another embodiment, the heavy chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 2. In one embodiment, the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 4. In another embodiment, the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 4. In another embodiment, the heavy chain variable region and the light chain variable region are linked by a linker. In another embodiment, the linker is encoded by an amino acid sequence shown in SEQ ID NO: 15.
  • the immunotoxin comprises an HI 1 antibody fragment.
  • the Hl l antibody fragment is an Fab.
  • the Fab is comprised of a heavy chain variable region and a heavy chain constant region.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 101.
  • the heavy chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 101.
  • the Hl l antibody or antibody fragment comprises a light chain variable region and a light chain constant region.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 100.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 100.
  • the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 103.
  • the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 103.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 120.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 120.
  • the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 123.
  • the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 123.
  • the Hl l antibody or Hl l antibody fragment comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 99 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the antibody fragments described herein may be cloned and expressed in E. coli in a biologically functional form.
  • Antibodies and antibody fragments may also be produced by recombinant DNA technology using either bacterial or mammalian cells.
  • affinity maturation process may be used whereby the binding specificity, affinity or avidity of the antibody described herein can be modified.
  • a number of laboratory techniques have been devised whereby amino acid sequence diversity is created by the application of various mutation strategies, either on the entire antibody fragment or on selected regions such as the CDRs.
  • the variant amino acid sequences of the heavy chain and the light chain have at least 50%, preferably at least 60%, more preferably at least 70%, most preferably at least 80%, even more preferably at least 90%, and even most preferably 95% sequence identity to SEQ ID NOS: 49 and 51, respectively.
  • the variant amino acid sequences of the heavy chain and the light chain have at least 50%, preferably at least 60%, more preferably at least 70%, most preferably at least 80%, even more preferably at least 90%, and even most preferably 95% sequence identity to SEQ ID NOS: 53 and 55, respectively.
  • the variant amino acid sequences of the heavy chain variable region have at least 50%, preferably at least 60%, more preferably at least 70%, most preferably at least 80%, even more preferably at least 90%, and even most preferably 95% sequence identity to SEQ ID NO: 2.
  • the variant amino acid sequences of the light chain variable region have at least 50%, preferably at least 60%, more preferably at least 70%, most preferably at least 80%, even more preferably at least 90%, and even most preferably 95% sequence identity to SEQ ID NO: 4.
  • the variant amino acid sequences of the heavy chain variable region and the light chain variable region have at least 50%, preferably at least 60%, more preferably at least 70%, most preferably at least 80%, even more preferably at least 90%, and even most preferably 95% sequence identity to SEQ ID NOS: 125, 127, 129, 131, 133 and 135. In other embodiments, the variant amino acid sequences of the heavy chain variable region and the light chain variable region have at least 50%, preferably at least 60%, more preferably at least 70%, most preferably at least 80%, even more preferably at least 90%, and even most preferably 95% sequence identity to SEQ ID NO: 131.
  • the variant amino acid sequences of the heavy chain have at least 50%, preferably at least 60%, more preferably at least 70%, most preferably at least 80%, even more preferably at least 90%, and even most preferably 95% sequence identity to SEQ ID NOs: 99 and 101.
  • the variant amino acid sequences of the light chain have at least 50%, preferably at least 60%, more preferably at least 70%, most preferably at least 80%, even more preferably at least 90%, and even most preferably 95% sequence identity to SEQ ID NOS: 100 and 103.
  • the variant amino acid sequences of the light chain have at least 50%, preferably at least 60%, more preferably at least 70%, most preferably at least 80%, even more preferably at least 90%, and even most preferably 95% sequence identity to SEQ ID NOS: 120 and 123.
  • the variant amino acid sequences of the heavy chain and the light chain have at least 50%, preferably at least 60%, more preferably at least 70%, most preferably at least 80%, even more preferably at least 90%, and even most preferably 95% sequence identity to SEQ ID NOS: 99 and 120, respectively.
  • the binding protein portion of the immunotoxin may be immunoglobulin derived, i.e., can be traced to a starting molecule that is an immunoglobulin (or antibody).
  • the ligand may be produced by modification of an immunoglobulin scaffold using standard techniques known in the art.
  • immunoglobulin domains e.g., variable heavy and/or light chains
  • Non-immunoglobulin scaffolds can include an Affibody ® , a Kunitz protease inhibitor domain, a fibronectin domain, a lipocalin domain, a designed ankyrin repeat domain, a thioredoxin, a cell surface receptor A domain, and/or a cysteine-rich knottin peptide.
  • the ligand may be developed by, without limitation, chemical reaction or genetic design.
  • an immunotoxin may comprise (1) an immunoglobulin-derived polypeptide (e.g., an antibody selected from an antibody library), or variant thereof, that specifically binds to cancer cells, and (2) a deimmunized bouganin toxin or variant thereof.
  • Such immunoglobulin polypeptide ligands can be re-designed to affect their binding characteristics to a target tumor associated molecule, or to improve their physical characteristics, for example.
  • the immunotoxin disclosed herein may be an antibody or antibody fragment attached to an effector molecule by a deimmunized furin linker.
  • the antibody or antibody fragment comprises a human kappa light chain.
  • the effector molecule is deimmunized bouganin encoded by an amino acid sequence selected from SEQ ID NOs: 12, 58, 59, 60 and 61.
  • the antibody fragment may be an Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, multimers, and any combination thereof.
  • the immunotoxins can comprise SEQ ID NOs: 67, 69, 71, 73, 75-89, 92, 94-98, 99-104, 120-123, 125, 127, 129, 131, 133 and 135.
  • the immunotoxin disclosed herein may be an antibody attached to an effector molecule, wherein the antibody comprises a heavy chain having an amino acid sequence of SEQ ID NO: 49, SEQ ID NO: 53, SEQ ID NO: 56, or SEQ ID NO: 57; and a light chain having an amino acid sequence of SEQ ID NO: 51 or SEQ ID NO: 55.
  • the antibody may be an antibody fragment, such as Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, multimers, and any combination thereof.
  • the antibody or the antibody fragment may be any of the de-immunized antibodies or de-immunized antibody fragments disclosed herein.
  • the antibody in the immunotoxin may have a heavy chain with an amino acid sequence of SEQ ID NO: 49, and a light chain with an amino acid sequence of SEQ ID NO: 51. In some embodiments, the antibody in the immunotoxin may have a heavy chain with an amino acid sequence of SEQ ID NO: 53, and a light chain with an amino acid sequence of SEQ ID NO: 55. In some embodiments, the antibody in the immunotoxin may have a heavy chain with an amino acid sequence of SEQ ID NO: 49, and a light chain with an amino acid sequence of SEQ ID NO: 55.
  • the antibody in the immunotoxin may have a heavy chain with an amino acid sequence of SEQ ID NO: 53, and a light chain with an amino acid sequence of SEQ ID NO: 51.
  • the antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 56, and a light chain with an amino acid sequence of SEQ ID NO: 51.
  • the antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 56, and a light chain with an amino acid sequence of SEQ ID NO: 55.
  • the antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 57, and a light chain with an amino acid sequence of SEQ ID NO: 51.
  • the antibodies described herein may have a heavy chain with an amino acid sequence of SEQ ID NO: 57, and a light chain with an amino acid sequence of SEQ ID NO: 55.
  • the immunotoxin disclosed herein may be an antibody attached to an effector molecule, wherein the antibody comprises a heavy chain variable region encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 2.
  • the heavy chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 2.
  • the antibody comprises a light chain variable region encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 4.
  • the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 4.
  • the antibody comprises the complementarity determining region (CDR) sequences of SEQ ID NOs: 5-10.
  • the antibody may be an antibody fragment, such as Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, multimers, and any combination thereof.
  • the antibody fragment is a diabody.
  • the diabody is comprised of a heavy chain variable region and a light chain variable region.
  • the heavy chain variable region and the light chain variable region are linked by a linker.
  • the linker is encoded by an amino acid sequence shown in SEQ ID NO: 15.
  • the heavy chain variable region and light chain variable region are encoded by amino acid sequences set forth in SEQ ID NOs: 125, 127, 129, 131, 133 and 135. In some embodiments the heavy chain variable region and light chain variable region are encoded by an amino acid sequence set forth in SEQ ID NO: 131.
  • the immunotoxin disclosed herein may be an antibody attached to an effector molecule, wherein the antibody comprises a heavy chain variable region and a heavy chain constant region.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 101.
  • the heavy chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 101.
  • the Hl l antibody or antibody fragment comprises a light chain variable region and a light chain constant region.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 100.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 100.
  • the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 103.
  • the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 103.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 120. In a further embodiment, the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 120. In another embodiment, the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 123. In a further embodiment, the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 123.
  • the Hl l antibody or Hl l antibody fragment comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 99 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the antibody comprises the complementarity determining region (CDR) sequences of SEQ ID NOs: 105- 110.
  • the antibody may be an antibody fragment, such as Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, multimers, and any combination thereof.
  • the effector molecule may be radioisotopes, antineoplastic agents, immunomodulators, biological response modifiers, lectins, toxins, a chromophore, a fluorophore, a chemiluminescent compound, an enzyme, a metal ion, and any combination thereof.
  • the effector molecule may be a toxin, such as abrin, modeccin, viscumin, gelonin, bouganin, modified or de-immunized bouganin protein (deBouganin), saporin, ricin, ricin A chain, bryodin, luffin, momordin, restrictocin, Pseudomonas exotoxin A, pertussis toxin, tetanus toxin, botulinum toxin, Shigella toxin, cholera toxin, diphtheria toxin and any combination thereof.
  • a toxin such as abrin, modeccin, viscumin, gelonin, bouganin, modified or de-immunized bouganin protein (deBouganin), saporin, ricin, ricin A chain, bryodin, luffin, momordin, restrictocin, Pseudomonas exotoxin A, pertussis
  • the toxin may be deBouganin as shown in SEQ ID NO: 12, SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60, or SEQ ID NO: 61.
  • the toxin may be deimmunized diphtheria toxin.
  • the toxin comprises an agent that acts to disrupt DNA.
  • toxins may be, without limitation, enediynes (e.g., calicheamicin and esperamicin) and non-enediyne small molecule agents (e.g., bleomycin, methidiumpropyl- EDTA-Fe(II)).
  • Other toxins useful in accordance with the invention include, without limitation, daunorubicin, doxorubicin, distamycin A, cisplatin, mitomycin C, ecteinascidins, duocarmycin/CC-1065, and bleomycin/pepleomycin.
  • the toxin comprises an agent that acts to disrupt tubulin.
  • toxins may comprise, without limitation, rhizoxin/maytansine, paclitaxel, vincristine and vinblastine, colchicine, auristatin, dolastatin 10, peloruside A, alkylating agents, antimitotic agents, topoisomerase I inhibitors, and camptothecin derivatives.
  • the toxin comprises an agent that acts to disrupt tubulin.
  • toxins may comprise, without limitation, rhizoxin/maytansine, paclitaxel, vincristine and vinblastine, colchicine, auristatin, dolastatin 10, peloruside A, alkylating agents, antimitotic agents, topoisomerase I inhibitors, and camptothecin derivatives.
  • the toxin portion of the immunotoxin may be an alkylating agent including, without limitation, busulfan, carboxyphthalatoplatinum, chlorambucil, chlorozotocin, cisplatinum, clomesone, cyanomorpholinodoxorubicin, cyclodisone, dianhydrogalactitol, fluorodopan, hepsulfam, hycanthone, melphalan, mitomycin C, mitozolamide, nitrogen mustard, piperazine, piperazinedione, pipobroman, porfiromycin, spirohydantoin mustard, teroxirone, tetraplatin, triethylenemelamine, and the like.
  • alkylating agent including, without limitation, busulfan, carboxyphthalatoplatinum, chlorambucil, chlorozotocin, cisplatinum, clomesone, cyanomorpholinodoxorubicin, cyclodisone, dianhydrogal
  • the toxin portion of the immunotoxin of the invention may be an antimitotic agent including, without limitation, allocolchicine, halichondrin B, colchicine, colchicine derivative, maytansine, rhizoxin, taxol, taxol derivative, thiocolchicine, trityl cysteine, vinblastine sulfate, and vincristine sulfate.
  • the toxin portion of an immunotoxin of the invention may comprise an topoisomerase I inhibitor including, without limitation, camptothecin NSC 94600, camptothecin, Na salt NSC 100880, aminocamptothecin NSC 603071, camptothecin derivative NSC 95382, camptothecin derivative NSC 107124, camptothecin derivative NSC 643833, camptothecin derivative NSC 629971, camptothecin derivative NSC 295500, camptothecin derivative NSC 249910, camptothecin derivative NSC 606985, camptothecin derivative NSC 374028, camptothecin derivative NSC 176323, camptothecin derivative NSC 295501, camptothecin derivative NSC 606172, camptothecin derivative NSC 606173, camptothecin derivative NSC 610458, camptothecin derivative NSC 618939, camptothecin derivative NSC 610457
  • the toxin portion of an immunotoxin of the invention may comprise a topoisomerase II inhibitor including, without limitation, doxorubicin, amonafide, anthrapyrazole derivative, pyrazoloacridine, bisantrene HC1, daunorubicin, deoxydoxorubicin, mitoxantrone, menogaril, ⁇ , ⁇ -dibenzyl daunomycin, oxanthrazole, and rubidazone.
  • doxorubicin amonafide
  • anthrapyrazole derivative pyrazoloacridine
  • bisantrene HC1 bisantrene HC1, daunorubicin, deoxydoxorubicin, mitoxantrone, menogaril, ⁇ , ⁇ -dibenzyl daunomycin, oxanthrazole, and rubidazone.
  • the toxin portion of the immunotoxin may be an RNA or DNA antimetabolite including, without limitation 5-azacytidine, 5- fluorouracil, acivicin, aminopterin, aminopterin derivative, 5,6-dihydro-5-azacytidine, methotrexate, methotrexate derivative, N-(phosphonoacetyl)-L-aspartate, pyrazofurin, trimetrexate, 2'-deoxy-5-fluorouridine, aphidicolin glycinate, 5-aza-2'-deoxycytidine, cyclocytidine, guanazole, hydroxyurea, inosine glycodialdehyde, macbecin II, pyrazoloimidazole, thioguanine, and thiopurine.
  • 5-azacytidine 5- fluorouracil, acivicin, aminopterin, aminopterin derivative, 5,6-dihydro-5-azacytidine
  • a cytotoxin may be altered to decrease or inhibit binding outside of the context of the immunotoxin, or to reduce specific types of toxicity.
  • the cytotoxin may be altered to adjust the isoelectric point to approximately 7.0 such that liver toxicity is reduced.
  • the immunotoxin is a humanized antibody fragment that binds to the extracellular domain of human EpCAM linked to a modified bouganin.
  • the immunotoxin may be a recombinant stabilized and humanized Fab fragment of EpCAM antibody that has been fused to a modified bouganin by a deimmunized furin protease sensitive peptide linker. This immunotoxin may bind to EpCAM expressed on cancer cells.
  • the immunotoxin is a humanized antibody fragment that binds to human epidermal growth factor receptor 2 (HER2/neu) and is fused to a modified bouganin by a deimmunized furin protease sensitive peptide linker.
  • HER2/neu human epidermal growth factor receptor 2
  • the immunotoxin is an Hl l antibody fragment that binds to CSA. Once bound, the immunotoxin is internalized and the toxin kills cells or blocks the protein synthesis, thereby leading to cell death. Importantly, since most normal normal cells do not widely express tumor-associated antigens, and therefore cannot internalize the immunotoxin, they are protected from the potential side-effects of the toxin.
  • the immunotoxin may be a Fab attached to a modified bouganin by a deimmunized furin protease sensitive peptide linker.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 49 and a light chain with an amino acid sequence of SEQ ID NO: 51, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 49.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 49 and a light chain with an amino acid sequence of SEQ ID NO: 51, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 51.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 53 and a light chain with an amino acid sequence of SEQ ID NO: 55, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 53.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 53 and a light chain with an amino acid sequence of SEQ ID NO: 55, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 55.
  • the Fab may have a heavy chain with an amino acid sequence selected from SEQ ID NOs: 63, 92, 95 and 96 and a light chain with an amino acid sequence selected from SEQ ID NOs: 65, 94, 97 and 98.
  • the immunotoxin may be a diabody attached to modified bouganin by a deimmunized furin protease sensitive peptide linker.
  • the diabody may have a heavy chain variable region with an amino acid sequence of SEQ ID NO: 2 and a light chain variable region with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin is fused to the N-terminus of SEQ ID NO: 2.
  • the diabody may have a heavy chain with an amino acid sequence of SEQ ID NO: 2 and a light chain with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 4.
  • the diabody may have a heavy chain with an amino acid sequence of SEQ ID NO: 2 and a light chain with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin is fused to the N-terminus of SEQ ID NO: 4.
  • the diabody may have a heavy chain with an amino acid sequence of SEQ ID NO: 2 and a light chain with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 2.
  • the immunotoxin may be an anti-HER2/neu diabody attached to modified bouganin encoded by amino acid sequences depicted by SEQ ID NOs: 23, 25, 27, 29, 31 (amino acid sequences) and SEQ ID NOs: 22, 24, 26, 28, 30 (nucleotide sequences).
  • the immunotoxin comprises amino acids 23-535 of the amino acid sequence shown in SEQ ID NO: 23.
  • the immunotoxin comprises amino acids 23-529 of the amino acid sequence shown in SEQ ID NO: 25.
  • the immunotoxin comprises amino acids 23-535 of the amino acid sequence shown in SEQ ID NO: 27.
  • the immunotoxin comprises amino acids 23-529 of the amino acid sequence shown in SEQ ID NO: 29. In another embodiment, the immunotoxin comprises amino acids 23-529 of the amino acid sequence shown in SEQ ID NO: 31. In some embodiments, the immunotoxin may be an anti- HER2/neu diabody attached to modified bouganin encoded by amino acid sequences depicted by SEQ ID NOs: 125, 127, 129, 131, 133 and 135 (amino acid sequences) and SEQ ID NOs: 126, 128, 130, 132, 134 and 136 (nucleotide sequences).
  • the immunotoxin may be a Fab attached to a modified bouganin by a deimmunized furin protease sensitive peptide linker.
  • the Fab may have a heavy chain variable region and a heavy chain constant region.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 101.
  • the heavy chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 101.
  • the HI 1 antibody or antibody fragment comprises a light chain variable region and a light chain constant region.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 100.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 100.
  • the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 103.
  • the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 103. In some embodiments, the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 120. In a further embodiment, the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 120. In another embodiment, the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 123. In a further embodiment, the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 123.
  • the Hl l antibody or Hl l antibody fragment comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 99 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the Fab may have a heavy chain with an amino acid sequence selected from SEQ ID NOs: 121 and 122 and a light chain with an amino acid sequence selected from SEQ ID NOs: 100 and 120.
  • the Fab may have a heavy chain with an amino acid sequence shown in SEQ ID NO: 121 and a light chain with an amino acid sequence shown in SEQ ID NO: 120.
  • the Fab may have a heavy chain with an amino acid sequence shown in SEQ ID NO: 122 and a light chain with an amino acid sequence shown in SEQ ID NO: 120.
  • the immunotoxin may be an Fab attached to modified diphtheria toxin by a peptide linker.
  • the modified diphtheria toxin has a reduced propensity to elicit an immune response.
  • the modified diphtheria toxin has a reduced propensity to activate T-cells and the modified diphtheria toxin is modified at one or more amino acid residues in a T-cell epitope.
  • the modified bouganin has a reduced propensity to elicit an immune response.
  • the modified bouganin has a reduced propensity to activate T-cells and the modified bouganin is modified at one or more amino acid residues in a T-cell epitope.
  • the modified bouganin protein (deBouganin) has amino acids as shown in SEQ ID NO: 12.
  • the modified bouganin protein may have amino acids as shown in SEQ ID NO: 58.
  • the modified bouganin protein may have amino acids as shown in SEQ ID NO: 59.
  • the modified bouganin protein may have amino acids as shown in SEQ ID NO: 60.
  • the modified bouganin protein may have amino acids as shown in SEQ ID NO: 61.
  • the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 69 and a second polypeptide as shown in SEQ ID NO: 51. The first and the second polypeptide may be joined by one or more di-sulfide linkages.
  • the immunotoxin may be VB6-901 Fab having a first polypeptide selected from SEQ ID NOS: 49, 53, 56, or 57, and a second polypeptide as shown in SEQ ID NO: 71.
  • the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 49 and a second polypeptide as shown in SEQ ID NO: 71. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 73 and a second polypeptide as shown in SEQ ID NO: 55. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide selected from SEQ ID NOS: 49, 53, 56, or 57, and a second polypeptide as shown in SEQ ID NO: 75.
  • the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 56 and a second polypeptide as shown in SEQ ID NO: 75. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 76 and a second polypeptide as shown in SEQ ID NO: 51. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide selected from SEQ ID NOS: 49, 53, 56, or 57, and a second polypeptide as shown in SEQ ID NO: 77.
  • the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 78 and a second polypeptide as shown in SEQ ID NO: 55.
  • the immunotoxin may be VB6-901 Fab having a first polypeptide selected from SEQ ID NOS: 49, 53, 56, or 57, and a second polypeptide as shown in SEQ ID NO: 79.
  • the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 80 and a second polypeptide as shown in SEQ ID NO: 55.
  • the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 81 and a second polypeptide as shown in SEQ ID NO: 55. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 82 and a second polypeptide as shown in SEQ ID NO: 55. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 83 and a second polypeptide as shown in SEQ ID NO: 55.
  • the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 84 and a second polypeptide as shown in SEQ ID NO: 51. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 84 and a second polypeptide as shown in SEQ ID NO: 55. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide selected from SEQ ID NOS: 49, 53, 56, or 57, and a second polypeptide as shown in SEQ ID NO: 85.
  • the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 86 and a second polypeptide as shown in SEQ ID NO: 51. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 86 and a second polypeptide as shown in SEQ ID NO: 55. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide selected from SEQ ID NOS: 49, 53, 56, or 57, and a second polypeptide as shown in SEQ ID NO: 87.
  • the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 88 and a second polypeptide as shown in SEQ ID NO: 51. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 88 and a second polypeptide as shown in SEQ ID NO: 55. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 89 and a second polypeptide as shown in SEQ ID NO: 51. In some embodiments, the immunotoxin may be VB6-901 Fab having a first polypeptide as shown in SEQ ID NO: 89 and a second polypeptide as shown in SEQ ID NO: 55.
  • the immunotoxin may be VB6-011 Fab having a first polypeptide as shown in SEQ ID NO: 121 and a second polypeptide as shown in SEQ ID NO: 120.
  • the immunotoxin may be VB6-011 Fab having a first polypeptide as shown in SEQ ID NO: 122 and a second polypeptide as shown in SEQ ID NO: 120.
  • first and the second polypeptide disclosed herein in the above immunotoxins may be joined by one or more di-sulfide linkages.
  • the antibodies or the antibody fragments described herein may be conjugated to the effector molecule by any means.
  • the antibody or the antibody fragment may be attached to the toxin by chemical or recombinant means.
  • Chemical means for preparing fusions or conjugates are known in the art and can be used to prepare the immunotoxin.
  • the method used to conjugate the antibody or the antibody fragment and toxin must be capable of joining the antibody with the toxin without interfering with the ability of the antibody or the antibody fragment to bind to the target molecule.
  • the antibody and toxin are both proteins and can be conjugated using techniques well known in the art.
  • the crosslinker is generally chosen based on the reactive functional groups available or inserted on the antibody or toxin.
  • a photoactivatible crosslinker can be used.
  • Crosslinking agents known to the art include the homobifunctional agents: glutaraldehyde, dimethyladipimidate and bis(diazobenzidine) and the heterobifunctional agents: m- maleimidobenzoyl-N-hydrox-ysuccinimide and sulfo-m maleimidobenzoyl-N- hydroxysuccinimide.
  • TPCH and TPMPH react at the carbohydrate moieties of glycoproteins that have been previously oxidized by mild periodate treatment, thus forming a hydrazone bond between the hydrazide portion of the crosslinker and the periodate generated aldehydes.
  • hetero-bifunctional crosslinkers GMBS N-gama- malimidobutyryloxy)-succinimide
  • SMCC succinimidyl 4-(N-maleimido- methyl)cyclohexane
  • crosslinkers can be used which introduce long spacer arms between components and include derivatives, such as n-succinimidyl-3-(2- pyridyldithio)propionate (SPDP).
  • SPDP n-succinimidyl-3-(2- pyridyldithio)propionate
  • An antibody-effector molecule fusion protein may also be prepared using recombinant DNA techniques.
  • a DNA sequence encoding the antibody is fused to a DNA sequence encoding an effector molecule, such as a toxin, resulting in a chimeric DNA molecule.
  • a cleavable linker can be inserted between the antibody and the effector molecule.
  • the chimeric DNA sequence is transfected into a host cell that expresses the antibody-effector molecule fusion protein.
  • the fusion protein can be recovered from the cell culture and purified using techniques known in the art.
  • the cleavable linker fuses an anti-HER2/neu antibody or antibody fragment to a deBouganin toxin. In one embodiment, the cleavable linker fuses an anti-EpCAM antibody or antibody fragment to a deBouganin toxin. In another embodiment, the cleavable linker comprises a furin protease sensitive linker. In another embodiment, the furin linker has been mutated. In yet another embodiment, the mutated furin linker is deimmunized. In another embodiment, the amino acid sequence encoding the mutated furin linker is truncated compared to the wild type furin linker.
  • the amino acid sequence encoding the mutated furin linker has one or more amino acids substituted, deleted or added compared to the wild type furin linker.
  • the wild type furin linker is encoded by SEQ ID NO: 17 (amino acid sequence) and by SEQ ID NO: 16 (nucleotide sequence).
  • the mutated furin linker is encoded by SEQ ID NOs: 32-36, 119 and 124 (amino acid sequences) and by SEQ ID NOs: 38-47 (nucleotide sequences).
  • an immunotoxin that comprises an anti-EpCAM antibody or antibody fragment that binds EpCAM positive cancer cells is fused to a deimmunized Bouganin toxin by a furin linker of SEQ ID NO: 17.
  • the anti-EpCAM fragment comprises an Fab.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 49 and a light chain with an amino acid sequence of SEQ ID NO: 51, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 49 by a furin linker of SEQ ID NO: 17.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 49 and a light chain with an amino acid sequence of SEQ ID NO: 51, and the modified bouganin is fused to the C- terminus of SEQ ID NO: 51 by a furin linker of SEQ ID NO: 17.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 53 and a light chain with an amino acid sequence of SEQ ID NO: 55, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 53 by a furin linker of SEQ ID NO: 17.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 53 and a light chain with an amino acid sequence of SEQ ID NO: 55, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 55 by a furin linker of SEQ ID NO: 17.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 49 and a light chain with an amino acid sequence of SEQ ID NO: 51, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 49 by a furin linker selected from SEQ ID NOs: 32-36, 119 and 124.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 49 and a light chain with an amino acid sequence of SEQ ID NO: 51, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 51 by a furin linker selected from SEQ ID NOs: 32-36, 119 and 124.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 53 and a light chain with an amino acid sequence of SEQ ID NO: 55, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 53 by a furin linker selected from SEQ ID NOs: 32-36, 119 and 124.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 53 and a light chain with an amino acid sequence of SEQ ID NO: 55, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 55 by a furin linker selected from SEQ ID NOs: 32-36, 119 and 124.
  • an immunotoxin that comprises an anti-HER2/neu antibody or antibody fragment that binds HER2/neu positive cancer cells is fused to a deimmunized Bouganin toxin by a furin linker of SEQ ID NO: 17.
  • the anti-HER2/neu antibody fragment comprises a diabody.
  • the diabody may have a heavy chain variable region with an amino acid sequence of SEQ ID NO: 2 and a light chain variable region with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin protein is fused to the N-terminus of SEQ ID NO: 2 by a furin linker of SEQ ID NO: 17.
  • the diabody may have a heavy chain with an amino acid sequence of SEQ ID NO: 2 and a light chain with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin protein is fused to the C-terminus of SEQ ID NO: 4 by a furin linker of SEQ ID NO: 17.
  • the diabody may have a heavy chain with an amino acid sequence of SEQ ID NO: 2 and a light chain with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin protein is fused to the N-terminus of SEQ ID NO: 4 by a furin linker of SEQ ID NO: 17.
  • the diabody may have a heavy chain with an amino acid sequence of SEQ ID NO: 2 and a light chain with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin protein is fused to the C- terminus of SEQ ID NO: 2 by a furin linker of SEQ ID NO: 17.
  • the diabody may have a heavy chain variable region with an amino acid sequence of SEQ ID NO: 2 and a light chain variable region with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin protein is fused to the N-terminus of SEQ ID NO: 2 by a furin linker selected from SEQ ID NOs: 32-36, 119 and 124.
  • the diabody may have a heavy chain variable region with an amino acid sequence of SEQ ID NO: 2 and a light chain variable region with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin protein is fused to the N-terminus of SEQ ID NO: 2 by a furin linker of SEQ ID NO: 119.
  • the diabody may have a heavy chain with an amino acid sequence of SEQ ID NO: 2 and a light chain with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin protein is fused to the C-terminus of SEQ ID NO: 4 by a furin linker selected from SEQ ID NOs: 32-36, 119 and 124.
  • the diabody may have a heavy chain with an amino acid sequence of SEQ ID NO: 2 and a light chain with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin protein is fused to the N-terminus of SEQ ID NO: 4 by a furin linker selected from SEQ ID NOs: 32-36, 119 and 124.
  • the diabody may have a heavy chain with an amino acid sequence of SEQ ID NO: 2 and a light chain with an amino acid sequence of SEQ ID NO: 4, and the modified bouganin protein is fused to the C-terminus of SEQ ID NO: 2 by a furin linker selected from SEQ ID NOs: 32-36, 119 and 124.
  • the anti- HER2/neu diabody comprises the complementarity determining region (CDR) sequences of SEQ ID NOs: 5-10.
  • an immunotoxin that comprises an Hl l antibody or antibody fragment that binds CSA positive cancer cells is fused to a deimmunized Bouganin toxin by a furin linker of SEQ ID NO: 17.
  • the Hl l antibody fragment comprises an Fab.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 99 and a light chain with an amino acid sequence of SEQ ID NO: 120, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 99 by a furin linker of SEQ ID NO: 17.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 99 and a light chain with an amino acid sequence of SEQ ID NO: 100, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 99 by a furin linker of SEQ ID NO: 17.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 99 and a light chain with an amino acid sequence of SEQ ID NO: 120, and the modified bouganin is fused to the N- terminus of SEQ ID NO: 99 by a furin linker of SEQ ID NO: 17.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 99 and a light chain with an amino acid sequence of SEQ ID NO: 100, and the modified bouganin is fused to the N-terminus of SEQ ID NO: 99 by a furin linker of SEQ ID NO: 17.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 99 and a light chain with an amino acid sequence of SEQ ID NO: 120, and the modified bouganin is fused to the C-terminus of SEQ ID NO: 99 by a furin linker selected from the group consisting of SEQ ID NOs: 32-36, 119 and 124.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 99 and a light chain with an amino acid sequence of SEQ ID NO: 100, and the modified bouganin is fused to the C- terminus of SEQ ID NO: 99 by a furin linker selected from the group consisting of SEQ ID NOs: 32-36, 119 and 124.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 99 and a light chain with an amino acid sequence of SEQ ID NO: 120, and the modified bouganin is fused to the N-terminus of SEQ ID NO: 99 by a furin linker selected from the group consisting of SEQ ID NOs: 32-36, 119 and 124.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 99 and a light chain with an amino acid sequence of SEQ ID NO: 100, and the modified bouganin is fused to the N-terminus of SEQ ID NO: 99 by a furin linker selected from the group consisting of SEQ ID NOs: 32-36, 119 and 124.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 99 and a light chain with an amino acid sequence of SEQ ID NO: 120, and the modified bouganin is fused to the C- terminus of SEQ ID NO: 99 by a furin linker of SEQ ID NO: 33.
  • the 011 Fab comprises a heavy chain with an amino acid sequence of SEQ ID NO: 121 and a light chain with an amino acid sequence of SEQ ID NO: 120.
  • the 011 Fab is VB6-011-C H -deBouganin.
  • the Fab may have a heavy chain with an amino acid sequence of SEQ ID NO: 99 and a light chain with an amino acid sequence of SEQ ID NO: 120, and the modified bouganin is fused to the N-terminus of SEQ ID NO: 99 by a furin linker of SEQ ID NO: 119.
  • the 011 Fab comprises a heavy chain with an amino acid sequence of SEQ ID NO: 122 and a light chain with an amino acid sequence of SEQ ID NO: 120.
  • the 011 Fab is VB6-011-NV H - deBouganin.
  • the 011 Fab comprises the complementarity determining region (CDR) sequences of SEQ ID NOs: 105-110.
  • the invention encompasses expression vectors comprising immunotoxins comprised of polypeptides of SEQ ID NOs: 49, 51, 53, 55-57, 69, 71, 73, 75- 89, 92, 94-98.
  • the immunotoxin comprises a variant of an immunotoxin comprised of polypeptides of SEQ ID NOs: 49, 51, 53, 55-57, 69, 71, 73, 75- 89, 92, 94-98.
  • a variant binds to the same EpCAM epitope or to a substantially similar EpCAM epitope that is bound by an immunotoxin comprised of polypeptides of SEQ ID NOs: 49, 51, 53, 55-57, 69, 71, 73, 75-89, 92, 94-98, and the variant may competitively inhibit binding to EpCAM by an immunotoxin comprised of polypeptides of SEQ ID NOs: 49, 51, 53, 55-57, 69, 71, 73, 75-89, 92, 94-98, under physiologic conditions, by at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%.
  • a variant may comprise the same deBouganin toxin as SEQ ID NOs: 69, 71, 73, 75- 89, 92, 94-98, or may comprise a different portion of the same toxin or a different toxin.
  • the immunotoxin comprises an EpCAM- binding portion comprising the variable region of an anti-EpCAM antibody or an anti- EpCAM antibody fragment, or a variant thereof. Binding of any of these immunotoxins to EPCAM may be reduced by at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% by competition with the reference anti- EpCAM antibody or anti-EpCAM antibody fragment under physiologic conditions.
  • the invention encompasses an expression vector comprising an immunotoxin comprised of amino acids 23-535 of the amino acid sequence shown in SEQ ID NO: 23 or SEQ ID NO: 27, or an immunotoxin comprised of amino acids 23-529 of the amino acid sequence shown in SEQ ID NO: 25, SEQ ID NO: 29 or SEQ ID NO: 31.
  • the disclosure encompasses an expression vector comprising an immunotoxin comprised of an amino acid sequence selected from SEQ ID NOs: 125, 127, 129, 131, 133 and 135.
  • the disclosure encompasses an expression vector comprising an immunotoxin comprised of an amino acid sequence set forth in SEQ ID NO: 131.
  • the immunotoxin comprises a variant of an immunotoxin comprised of amino acids 23-535 of the amino acid sequence shown in SEQ ID NO: 23 or SEQ ID NO: 27, or a variant of an immunotoxin comprised of amino acids 23-529 of the amino acid sequence shown in SEQ ID NO: 25, SEQ ID NO: 29 or SEQ ID NO: 31.
  • the immunotoxin comprises a variant of an immunotoxin comprised of an amino acid sequence selected from SEQ ID NOs: 125, 127, 129, 131, 133 and 135.
  • the immunotoxin comprises a variant of an immunotoxin comprised of an amino acid sequence set forth in SEQ ID NO: 131.
  • a variant binds to the same HER2/neu epitope or to a substantially similar HER2/neu epitope that is bound by an immunotoxin comprised of amino acids 23-535 of the amino acid sequence shown in SEQ ID NO: 23 or SEQ ID NO: 27, an immunotoxin comprised of amino acids 23-529 of the amino acid sequence shown in SEQ ID NO: 25, SEQ ID NO: 29 or SEQ ID NO: 31, or an immunotoxin comprised of an amino acid sequence selected from SEQ ID NOs: 125, 127, 129, 131, 133 and 135, and the variant may competitively inhibit binding to HER2/neu by an immunotoxin comprised of amino acids 23-535 of the amino acid sequence shown in SEQ ID NO: 23 or SEQ ID NO: 27, an immunotoxin comprised of amino acids 23-529 of the amino acid sequence shown in SEQ ID NO: 25, SEQ ID NO: 29 or SEQ ID NO: 31, or an immunotoxin comprised of an amino acid sequence selected from SEQ ID NOs: 125, 127
  • a variant may comprise the same deBouganin toxin as SEQ ID NOs: 23, 25, 27, 29, 31, 125, 127, 129, 131, 133 and 135, or may comprise a different portion of the same toxin or a different toxin.
  • the immunotoxin comprises a HER2/neu-binding portion comprising the variable region of an anti-HER2/neu antibody or an anti-HER2/neu antibody fragment, or a variant thereof. Binding of any of these immunotoxins to HER2/neu may be reduced by at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% by competition with the reference anti-HER2/neu antibody or anti-HER2/neu antibody fragment under physiologic conditions.
  • the invention encompasses expression vectors comprising immunotoxins comprised of polypeptides of SEQ ID NOs: 99-101, 103, 120-123.
  • the immunotoxin comprises a variant of an immunotoxin comprised of polypeptides of SEQ ID NOs: 99-101, 103, 120-123.
  • a variant binds to the same CSA epitope or to a substantially similar CSA epitope that is bound by an immunotoxin comprised of polypeptides of SEQ ID NOs: 99-101, 103, 120-123 and the variant may competitively inhibit binding to CSA by an immunotoxin comprised of polypeptides of SEQ ID NOs: 99-101, 103, 120-123 under physiologic conditions, by at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%.
  • a variant may comprise the same deimmunized diptheria toxin, or may comprise a different portion of the same toxin or a different toxin.
  • the immunotoxin comprises a CSA- binding portion comprising the variable region of an HI 1 antibody or an HI 1 antibody fragment, or a variant thereof. Binding of any of these immunotoxins to CSA may be reduced by at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% by competition with the reference Hl l antibody or Hl l antibody fragment under physiologic conditions.
  • specificity determining residues can be identified.
  • SDR specificity determining residue
  • CDR residues CDR residues, the individual substitution of which by alanine, independently of any other mutations, diminishes the affinity of the antibody for the epitope by at least 10 fold, preferably by at least 100 fold, more preferably by at least 1000 fold. This loss in affinity underscores that residue's importance in the ability of the antibody to bind the epitope.
  • the effect of single or multiple mutations on binding activity, particularly on binding affinity, may be evaluated contemporaneously to assess the importance of a particular series of amino acids on the binding interaction (e.g., the contribution of the light or heavy chain CDR2 to binding). Effects of an amino acid mutation may also be evaluated sequentially to assess the contribution of a single amino acid when assessed individually. Such evaluations can be performed, for example, by in vitro saturation scanning (see, e.g., U.S. Pat. No. 6,180,341 ; Hilton et al, 1996, "Saturation mutagenesis of the WSXWS motif of the erythropoietin receptor," J Biol Chem.
  • Sites of ligand-receptor or other biological interaction can also be identified by physical analysis of structure as determined by, for example, nuclear magnetic resonance, crystallography, electron diffraction, or photoaffinity labeling, in conjunction with mutation of putative contact site amino acids (see, e.g., de Vos et al, 1992, "Human growth hormone and extracellular domain of its receptor: crystal structure of the complex," Science 255: 306- 312; Smith et al, 1992, “Human interleukin 4. The solution structure of a four-helix bundle protein," J Mol Biol.
  • the avidity of an immunotoxin for a cancer cell antigen is a measure of the strength of the immunotoxin's binding of the cancer cell antigen, which can have multiple binding sites.
  • the functional binding strength between the cancer cell antigen and the immunotoxin represents the sum strength of all the affinity bonds, and thus an individual component may bind with relatively low affinity, but a multimer of such components may demonstrate potent biological effect.
  • the multiple interactions between immunotoxin and cancer cell antigen epitopes may demonstrate much greater than additive biological effect, i.e., the advantage of multivalence can be many orders of magnitude with respect to the equilibrium constant.
  • the portion of the HER2/neu-binding protein that binds a HER2/neu epitope has a structure substantially similar to that of an anti- HER2/neu antibody.
  • the substantially similar structure can be characterized by reference to epitope maps that reflect the binding points of the immunotoxin's HER2/neu-binding portion to a HER2/neu molecule.
  • an immunotoxin comprises an anti-HER2/neu diabody.
  • the anti-HER2/neu diabody comprises the complementarity determining region (CDR) sequences of SEQ ID NOs: 5-10.
  • the portion of the EpCAM-binding protein that binds an EpCAM epitope has a structure substantially similar to that of an anti- EpCAM antibody.
  • the substantially similar structure can be characterized by reference to epitope maps that reflect the binding points of the immunotoxin's EpCAM-binding portion to an EpCAM molecule.
  • an immunotoxin comprises an anti- EpCAM Fab.
  • the portion of the CSA-binding protein that binds a CSA epitope has a structure substantially similar to that of an HI 1 antibody.
  • the substantially similar structure can be characterized by reference to epitope maps that reflect the binding points of the immunotoxin's CSA-binding portion to a CSA molecule.
  • an immunotoxin comprises an HI 1 Fab.
  • the Hl l Fab comprises the complementarity determining region (CDR) sequences of SEQ ID NOs: 105-110.
  • the antibody portion of an immunotoxin may be immunoglobulin derived, i.e., can be traced to a starting molecule that is an immunoglobulin (or antibody).
  • the antibody may be produced by modification of an immunoglobulin scaffold using standard techniques known in the art.
  • immunoglobulin domains e.g., variable heavy and/or light chains
  • the antibody may be developed by, without limitation, chemical reaction or genetic design.
  • an immunotoxin may comprise an immunoglobulin-derived polypeptide (e.g., an antibody selected from an antibody library), or variant thereof, that specifically binds to liver cancer cells; and a toxin or variant thereof.
  • an immunoglobulin-derived polypeptide e.g., an antibody selected from an antibody library
  • Such immunoglobulin polypeptides can be re-designed to affect their binding characteristics to a target a tumor associated molecule, or to improve their physical characteristics, for example.
  • an immunotoxin may comprise a non-immunoglobulin polypeptide (e.g., Affibody®), or variant thereof, that specifically binds to liver cancer cells; and a toxin or variant thereof.
  • a non-immunoglobulin polypeptide e.g., Affibody®
  • Such non-immunoglobulin polypeptide can be designed to bind to a target tumor associated molecule.
  • non-immunoglobulin polypeptide can be engineered to a desired affinity or avidity and can be designed to tolerate a variety of physical conditions, including extreme pH ranges and relatively high temperature.
  • non- immunoglobulin polypeptide for use in a pharmaceutical composition, the design of a non- immunoglobulin polypeptide with a relatively long half-life at physiological conditions (e.g., 37° C. in the presence of peptidases) can be advantageous. Furthermore, such molecules, or variants thereof, may demonstrate good solubility, small size, proper folding and can be expressed in readily available, low-cost bacterial systems, and thus manufactured in commercially reasonable quantities. The ability to design a non-immunoglobulin polypeptide is within the skill of the ordinary artisan.
  • epitope-binding polypeptides include, without limitation, ligands comprising a fibronectin type III domain, binding molecules based on assembly of repeat protein domains comprising Pleckstrin-Homology (PH) domains, ankyrin repeats, and the like.
  • Other epitope-binding polypeptides or domains include a Kunitz protease inhibitor domain, a lipocalin domain, a thioredoxin, a cell surface receptor A domain, and/or a cysteine-rich knottin peptide.
  • the immunotoxin comprises a variant that has amino acid sequences, by at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% identical to deimmunized bouganin as shown in SEQ ID NOs: 12, 58, 59, 60 or 61.
  • the immunotoxin comprises a variant that has amino acid sequences, by at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% identical to deimmunized diphtheria toxin.
  • Deimmunized Bouganin toxin Deimmunized Bouganin toxin
  • the toxin comprises a polypeptide having ribosome- inactivating activity including, without limitation, gelonin, bouganin, saporin, ricin A chain, bryodin, diphtheria toxin, restrictocin, and variants thereof.
  • the protein is a ribosome- inactivating protein, the immunotoxin must be internalized upon binding to the cancer cell in order for the toxin to be cytotoxic to the cells.
  • the toxin portion comprises at least a toxic portion of bouganin toxin, or a variant thereof.
  • the toxin comprises a deimmunized Bouganin toxin ("deBouganin").
  • DeBouganin is a type 1 Ribosome Inactivating Protein (RIP) isolated from Bougainvillea spectabilis willd that has been de- immunized for systemic delivery.
  • the deimmunized Bouganin toxin comprises SEQ ID NO: 12 (amino acid sequence) and SEQ ID NO: 11 (nucleotide sequence).
  • the deimmunized Bouganin toxin comprises SEQ ID NOs: 58, 59, 60 or 61. It is understood that one of skill in the art can codon optimize the deimmunized Bouganin toxin to optimize expression in a cell.
  • a codon optimized deBouganin sequence is exemplified by SEQ ID NO: 13. Modified bouganin proteins are described in WO 2005/090579, which is incorporated herein by reference.
  • the modified bouganin protein has reduced propensity to activate human T cells compared to a non-modified bouganin protein and has a biological activity that is comparable to non-modified bouganin protein. In some embodiments, the modified bouganin protein has reduced propensity to activate human T cells compared to a non-modified bouganin protein and has biological activity that is lower than the non-modified bouganin protein. In yet another embodiment, the disclosure provides a modified bouganin protein wherein the modified bouganin protein has reduced propensity to activate human T cells and no biological activity.
  • the modified bouganin peptide is modified at one or more T-cell epitopes in the bouganin protein sequence.
  • T-cell epitope means an amino acid sequence which is able to bind major histocompatibility complex (MHC) class II, able to stimulate T-cells and/or also able to bind (without necessarily measurably activating) T-cells in complex with MHC class II.
  • MHC major histocompatibility complex
  • a method that can be used to generate the modified bouganin proteins with modified T-cell epitopes comprises the following steps: (i) determining the amino acid sequence of the protein or part thereof; (ii) identifying one or more potential T-cell epitopes within the amino acid sequence of the protein by methods such as determination of the binding of the peptides to MHC molecules using in vitro or in silico techniques or biological assays; (iii) designing new sequence variants with one or more amino acids within the identified potential T-cell epitopes modified in such a way to substantially reduce or eliminate the activity of the T-cell epitope as determined by the binding of the peptides to MHC molecules using in vitro or in silico techniques or biological assays.
  • Such sequence variants are created in such a way to avoid creation of new potential T-cell epitopes by the sequence variations unless such new potential T-cell epitopes are, in turn, modified in such a way to substantially reduce or eliminate the activity of the T-cell epitope; (iv) constructing such sequence variants by recombinant DNA techniques and testing said variants in order to identify one or more variants with desirable properties according to well-known recombinant techniques; and (v) optionally repeating steps (ii) to (iv).
  • step (iii) is carried out by substitution, addition or deletion of amino acid residues in any of the T-cell epitopes in the non-modified bouganin protein.
  • the method to make the modified bouganin protein is made with reference to the homologous protein sequence and/or in silico modeling.
  • the modified bouganin protein has at least one T-cell epitope removed. In another embodiment, the modified bouganin protein of the invention has one, two or three T-cell epitopes removed.
  • the invention also contemplates a modified bouganin protein wherein 1 to 9 amino acid residues are modified, preferably in the T-cell epitope. In another embodiment, 1 to 5 amino acid residues are modified. In another embodiment the modified bouganin protein has a biological activity, such as cell cytotoxicity.
  • amino acid substitutions are made at appropriate points within the peptide sequence predicted to achieve substantial reduction or elimination of the activity of the T-cell epitope.
  • an appropriate point will in one embodiment equate to an amino acid residue binding within one of the pockets provided within the MHC class II binding groove.
  • the epitopes are compromised by mutation to result in sequences no longer able to function as T-cell epitopes. It is possible to use recombinant DNA methods to achieve directed mutagenesis of the target sequences and many such techniques are available and well known in the art. In practice a number of modified bouganin proteins will be produced and tested for the desired immune and functional characteristic. It is particularly important when conducting modifications to the protein sequence that the contemplated changes do not introduce new immunogenic epitopes. This event is avoided in practice by re-testing the contemplated sequence for the presence of epitopes and/or of MHC class II ligands by any suitable means.
  • the modified bouganin proteins of the invention may also contain or be used to obtain or design "peptide mimetics.”
  • “Peptide mimetics” are structures which serve as substitutes for peptides in interactions between molecules. Peptide mimetics include synthetic structures which may or may not contain amino acids and/or peptide bonds but retain the structural and functional features of the modified bouganin protein, including biological activity and a reduced propensity to activate human T cells. Peptide mimetics also include peptoids and oligopeptoids.
  • Peptide mimetics may be designed based on information obtained by systematic replacement of L-amino acids by D-amino acids, replacement of side chains with groups having different electronic properties, and by systematic replacement of peptide bonds with amide bond replacements. Local conformational constraints can also be introduced to determine conformational requirements for activity of a candidate peptide mimetic.
  • the mimetics may include isosteric amide bonds, or D-amino acids to stabilize or promote reverse turn conformations and to help stabilize the molecule. Cyclic amino acid analogues may be used to constrain amino acid residues to particular conformational states.
  • the mimetics can also include mimics of the secondary structures of the proteins of the invention. These structures can model the 3-dimensional orientation of amino acid residues into the known secondary conformations of proteins.
  • Peptoids which are oligomers of N-substituted amino acids, can be used as motifs for the generation of chemically diverse libraries of novel molecules.
  • the toxin comprises a polypeptide having ribosome- inactivating activity including, without limitation, gelonin, bouganin, saporin, ricin A chain, bryodin, diphtheria toxin, restrictocin, and variants thereof.
  • the protein is a ribosome- inactivating protein, the immunotoxin must be internalized upon binding to the cancer cell in order for the toxin to be cytotoxic to the cells.
  • the toxin portion comprises at least a toxic portion of diphtheria toxin ("DT"), or a variant thereof.
  • Diphtheria toxin is a member of the mono-ADP-ribosylating toxin family which further includes such toxins as cholera toxin, pseudomonas exotoxin A, pertussis toxin, and Clostridium C3-like toxin. Members of this family contain many similar protein domains and motifs, in particular the catalytic site of the toxins.
  • DT is composed of three domains: a catalytic domain; a transmembrane domain; and a receptor binding domain.
  • Native DT is targeted to cells that express heparin binding epidermal growth factor-like receptors (Naglish et at., Cell, 69: 1051 -1061 (1992)). Once the toxin, toxin conjugate or fusion toxin has bound to the cell surface receptor the cell internalizes the toxin bound receptor via endocytic vesicles.
  • the vesicles As the vesicles are processed they become acidified and the translocation domain of the DT toxophore undergoes a structural reorganization which inserts the nine transmembrane segments of the toxin into the membrane of the endocytic vesicle. This event triggers the formation of a productive pore through which the catalytic domain of the toxin is threaded.
  • the cytotoxic portion comprises a DT variant that, when administered alone, is substantially unable to bind to cells.
  • the cytotoxic portion comprises DT.
  • the cytotoxic portion may comprises one or more diphtheria toxins known in the art (see U. S. Patent No. 8,470,314, which is incorporated herein by reference in its entirety), or variants thereof.
  • Modifications to toxin can include modifications to produce polypeptides that exhibit reduced immunogenicity (T-cell, B-cell, or both) and reduced capacity to cause vascular leak syndrome (VLS) (i.e., reduced binding to endothelial cells and vascular endothelial cells and reduced disruption of endothelial cell junctions and other indications of vascular leak syndrome).
  • VLS vascular leak syndrome
  • toxin e.g., diphtheria toxin
  • VLS motifs domain deletions and combinations thereof
  • modification of both T-cell epitopes and VLS motifs is desired.
  • modification of at least one amino acid within at least one T-cell epitope within the toxin should not create a VLS motif.
  • modification of at least one amino acid within at least one VLS motif within the toxin should not create a T-cell epitope.
  • modification of a T-cell epitope or a VLS motif should not re-introduce a previously modified T-cell or VLS motif.
  • modification of such polypeptides can also take into consideration the modification of B-cell epitopes, which when desired, should also not create or re-introduce Tcell epitopes or VLS motifs.
  • Modifications that affect the cytotoxicity of the toxins can also be made. For instance, if one or more modifications to one or more of a T cell epitope, a VLS motif and/or a B cell epitope are made and the cytotoxicity of the modified toxin is less than the unmodified toxin, it is contemplated herein that one or more modifications could be made to restore the cytotoxicity to a level comparable to that of the unmodified toxin or to an effective level.
  • the membrane-inserting domain (translocation domain) of diphtheria toxin (T) contains an amphipathic region that is involved in the delivery of the catalytic (C) domain to the cytosol of a cell.
  • replacement of one or more amino acid residues of the amphipathic region with one or more different amino acid residues that retain the helical structure of the region can maintain cytotoxicity.
  • charged amino residues include Glu, Asp, Asn, Gin, Lys, Arg and His; hydrophobic amino acids include, but are not limited to, alanine and phenylalanine.
  • Modification of the binding cleft of the catalytic domains of the ADPribosylating protein family can also affect cytotoxicity.
  • modification of one or more amino acid residues of the F/Y -X-S-T-X motif of the diphtheria toxin C domain can affect the cytotoxicity of the polypeptide.
  • Replacement of one or more amino acid residues in this region with one or more different amino acid residues that retain the catalytic domain can maintain cytotoxicity.
  • Comparison with related members of the ADP-ribosylating protein family can provide further guidance on amino acid residue modification and composition of domains such as the diphtheria toxin C domain. Modifications such as these are also contemplated herein.
  • Methods of Use Disclosed are methods of using immunotoxins described herein, wherein the immunotoxins comprise a binding protein linked to a toxin by a deimmunized furin protease sensitive linker.
  • the present invention contemplates methods of treating or preventing cancer comprising administering an effective amount of said immunotoxins to a subject in need thereof.
  • the antibodies, the antibody fragments, and/or the immunotoxins used may include any of the de-immunized antibodies/antibody fragments disclosed herein, wherein the antibody/antibody fragment comprises a heavy chain having an amino acid sequence of SEQ ID NO: 49, SEQ ID NO: 53, SEQ ID NO: 56, or SEQ ID NO: 57; and a light chain having an amino acid sequence of SEQ ID NO: 51 or SEQ ID NO: 55.
  • a method of treating a subject with cancer may involve administering a therapeutically effective amount of an immunotoxin, wherein the immunotoxin comprises a heavy chain having an amino acid sequence of SEQ ID NO: 49, SEQ ID NO: 53, SEQ ID NO: 56, or SEQ ID NO: 57; and a light chain having an amino acid sequence of SEQ ID NO: 51 or SEQ ID NO: 55.
  • the method may involve administering an immunotoxin comprising a heavy chain having an amino acid sequence of SEQ ID NO: 49, and a light chain having an amino acid sequence of SEQ ID NO: 51.
  • the method may involve administering an immunotoxin comprising a heavy chain having an amino acid sequence of SEQ ID NO: 53, and a light chain having an amino acid sequence of SEQ ID NO: 55. In another embodiment, the method may involve administering an immunotoxin comprising a heavy chain having an amino acid sequence of SEQ ID NO: 56, and a light chain having an amino acid sequence of SEQ ID NO: 55. In another embodiment, the method may involve administering an immunotoxin comprising a heavy chain having an amino acid sequence of SEQ ID NO: 57, and a light chain having an amino acid sequence of SEQ ID NO: 55.
  • a method of treating or preventing cancer in a subject in need thereof may involve administering a therapeutically effective amount of an immunotoxin, wherein the immunotoxin comprises a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 2, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 4.
  • a method of treating or preventing cancer in a subject in need thereof may involve administering a therapeutically effective amount of an immunotoxin, wherein the immunotoxin comprises a heavy chain variable region having an amino acid sequence of SEQ ID NO: 2, and a light chain variable region having an amino acid sequence of SEQ ID NO: 4.
  • a method of treating or preventing cancer in a subject in need thereof may involve administering a therapeutically effective amount of an immunotoxin, wherein the immunotoxin comprises a heavy chain variable region and a light chain variable region encoded by amino acid sequences set forth in SEQ ID NOs: 125, 127, 129, 131, 133 and 135.
  • a method of treating or preventing cancer in a subject in need thereof may involve administering a therapeutically effective amount of an immunotoxin, wherein the immunotoxin comprises a heavy chain variable region and a light chain variable region encoded by an amino acid sequence set forth in SEQ ID NO: 131.
  • a method of treating or preventing cancer in a subject in need thereof may involve administering a therapeutically effective amount of an immunotoxin, wherein the immunotoxin comprises a heavy chain variable region and a heavy chain constant region.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region and the heavy chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 99.
  • the heavy chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 101.
  • the heavy chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 101.
  • the HI 1 antibody or antibody fragment comprises a light chain variable region and a light chain constant region.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 100.
  • the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 100.
  • the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 103.
  • the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 103. In some embodiments, the light chain variable region and the light chain constant region are encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 120. In a further embodiment, the light chain variable region and the light chain constant region are encoded by an amino acid sequence shown in SEQ ID NO: 120. In another embodiment, the light chain variable region is encoded by an amino acid sequence sharing at least 90% sequence homology to the amino acid sequence shown in SEQ ID NO: 123. In a further embodiment, the light chain variable region is encoded by an amino acid sequence shown in SEQ ID NO: 123.
  • the Hl l antibody or Hl l antibody fragment comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 99 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the immunotoxin comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 121 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the immunotoxin comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 122 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the immunotoxin may comprise an antibody fragment, such as Fab, Fab', F(ab')2, scFv, dsFv, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments, multimers, and any combination thereof.
  • the effector molecule may be a radioisotope, an antineoplastic agent, an immunomodulator, a biological response modifier, lectin, a toxin, a chromophore, a fluorophore, a chemiluminescent compound, an enzyme, a metal ion, and any combination thereof.
  • the effector molecule comprises a deimmunized Bouganin toxin.
  • the effector molecule comprises a deimmunized diphtheria toxin.
  • the antibodies and immunotoxins may be used to treat cancer, such as lung cancer, gastric cancer, renal cancer, thyroid cancer, breast cancer, bladder cancer, ovarian cancer, colorectal cancer, head and neck cancer, hepatocellular carcinoma, esophageal, pancreas, and prostate cancer. Cancers originating from any epithelial cell may also be targeted by these immunotoxins and antibodies.
  • the cancer is amenable to treatment by direct administration of the antibody or immunotoxin to the cancer site.
  • a target tumor mass may be close to the surface of the skin.
  • a diseased tissue may be encapsulated by a cyst, or is found in a substantially enclosed cavity including, without limitation, a lumen.
  • the cancer is amenable to treatment by intravenous administration of the antibody or immunotoxin.
  • a kit for diagnosing cancer may include an immunotoxin comprising a heavy chain having an amino acid sequence of SEQ ID NO: 49, SEQ ID NO: 53, SEQ ID NO: 56, or SEQ ID NO: 57; and a light chain having an amino acid sequence of SEQ ID NO: 51 or SEQ ID NO: 55, and instructions for the use thereof.
  • a kit for diagnosing cancer may include an immunotoxin comprising a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 2, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 4, attached to an effector molecule and instructions for the use thereof.
  • kits for diagnosing cancer may include an immunotoxin comprising a heavy chain variable region having an amino acid sequence of SEQ ID NO: 2, and a light chain variable region having an amino acid sequence of SEQ ID NO: 4, attached to an effector molecule and instructions for the use thereof.
  • a kit for diagnosing cancer may include an immunotoxin comprising a heavy chain variable region and a light chain variable region encoded by an amino acid sequence selected from SEQ ID NOs: 125, 127, 129, 131, 133 and 135.
  • kits for diagnosing cancer may include an immunotoxin comprising a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 101, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 103, attached to an effector molecule and instructions for the use thereof.
  • a kit for diagnosing cancer may include an immunotoxin comprising a heavy chain variable region having an amino acid sequence of SEQ ID NO: 101, and a light chain variable region having an amino acid sequence of SEQ ID NO: 103, attached to an effector molecule and instructions for the use thereof.
  • kits for diagnosing cancer may include an immunotoxin comprising a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 101, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 123, attached to an effector molecule and instructions for the use thereof.
  • a kit for diagnosing cancer may include an immunotoxin comprising a heavy chain variable region having an amino acid sequence of SEQ ID NO: 101, and a light chain variable region having an amino acid sequence of SEQ ID NO: 123, attached to an effector molecule and instructions for the use thereof.
  • kits for diagnosing cancer may include an immunotoxin comprising a heavy chain having an amino acid sequence as shown in SEQ ID NO: 121 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the immunotoxin comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 122 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the kit for detecting cancer may include an anti- EpCAM antibody fragment, and preferably further include a reagent containing a labeled anti-Ig antibody, for example, an anti-Ig antibody linked with an enzyme such as alkaline phosphatase or a radiolabeled anti-Ig antibody.
  • the anti-EpCAM antibody fragment may be attached to a chromophore, a fluorophore or a radiolabelled ligand.
  • the kit for detecting cancer may include an anti- HER2/neu antibody fragment, and preferably further include a reagent containing a labeled anti-Ig antibody, for example, an anti-Ig antibody linked with an enzyme such as alkaline phosphatase or a radiolabeled anti-Ig antibody.
  • the anti-HER2/neu antibody fragment may be attached to a chromophore, a fluorophore or a radiolabelled ligand.
  • the kit for detecting cancer may include an Hl l antibody fragment, and preferably further include a reagent containing a labeled anti- Ig antibody, for example, an anti-Ig antibody linked with an enzyme such as alkaline phosphatase or a radiolabeled anti-Ig antibody.
  • the Hl l antibody fragment may be attached to a chromophore, a fluorophore or a radiolabelled ligand.
  • the immunotoxins disclosed herein may also be used to detect or monitor in a subject.
  • a method of detecting or monitoring cancer in a subject may involve contacting a test sample taken from the subject with an immunotoxin to form an immunotoxin-antigen complex; measuring the amount of the immunotoxin-antigen complex in the test sample; and normalizing the results against a control.
  • the test sample may be serum, lymph, ascitic exudate, intercellular fluid, tissue lysate, saliva, tissue sections, cells, biopsy samples, and the like.
  • the immunotoxin-antigen complex may be detected by any means, such as for example, dot-blot method, Western blot method, ELISA method, or sandwich ELISA method.
  • the immunotoxin-antigen complex can be detected by use according to multistage reactions, such as reaction with a biotin-bound anti-Ig antibody and then with an avidin-bound material.
  • the immunotoxin comprises a heavy chain amino acid sequence of SEQ ID NO: 49, SEQ ID NO: 53, SEQ ID NO: 56, or SEQ ID NO: 57; and a light chain having an amino acid sequence of SEQ ID NO: 51 or SEQ ID NO: 55.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 2, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 4.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence of SEQ ID NO: 2, and a light chain variable region having an amino acid sequence of SEQ ID NO: 4.
  • the immunotoxin comprises a heavy chain variable region and a light chain variable region encoded by amino acid sequences set forth in SEQ ID NOs: 125, 127, 129, 131, 133 and 135.
  • the immunotoxin comprises a heavy chain variable region and a light chain variable region encoded by an amino acid sequence set forth in SEQ ID NO: 131.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 101, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 103. In another embodiment, the immunotoxin comprises a heavy chain variable region having an amino acid sequence of SEQ ID NO: 101, and a light chain variable region having an amino acid sequence of SEQ ID NO: 103. In another embodiment, the immunotoxin comprises a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 101, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 123.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence of SEQ ID NO: 101, and a light chain variable region having an amino acid sequence of SEQ ID NO: 123.
  • the immunotoxin comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 121 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the immunotoxin comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 122 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • a method of detecting or monitoring cancer in a subject may involve administering to the subject an immunotoxin and detecting the immunotoxin.
  • the immunotoxin comprises a heavy chain amino acid sequence of SEQ ID NO: 49, SEQ ID NO: 53, SEQ ID NO: 56, or SEQ ID NO: 57; and a light chain having an amino acid sequence of SEQ ID NO: 51 or SEQ ID NO: 55.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 2, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 4.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence of SEQ ID NO: 2, and a light chain variable region having an amino acid sequence of SEQ ID NO: 4.
  • the immunotoxin comprises a heavy chain variable region and a light chain variable region encoded by amino acid sequences set forth in SEQ ID NOs: 125, 127, 129, 131, 133 and 135.
  • the immunotoxin comprises a heavy chain variable region and a light chain variable region encoded by an amino acid sequence set forth in SEQ ID NO: 131.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 101, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 103. In another embodiment, the immunotoxin comprises a heavy chain variable region having an amino acid sequence of SEQ ID NO: 101, and a light chain variable region having an amino acid sequence of SEQ ID NO: 103. In another embodiment, the immunotoxin comprises a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 101, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 123.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence of SEQ ID NO: 101, and a light chain variable region having an amino acid sequence of SEQ ID NO: 123.
  • the immunotoxin comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 121 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the immunotoxin comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 122 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the immunotoxins disclosed herein may be used for imaging a tumor in a subject.
  • a method of imaging a tumor in a subject may involve administering to the subject an immunotoxin and detecting the immunotoxin by in vivo imaging.
  • the immunotoxin comprises a heavy chain amino acid sequence of SEQ ID NO: 49, SEQ ID NO: 53, SEQ ID NO: 56, or SEQ ID NO: 57; and a light chain having an amino acid sequence of SEQ ID NO: 51 or SEQ ID NO: 55.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 2, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 4.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence of SEQ ID NO: 2, and a light chain variable region having an amino acid sequence of SEQ ID NO: 4.
  • the immunotoxin comprises a heavy chain variable region and a light chain variable region encoded by amino acid sequences set forth in SEQ ID NOs: 125, 127, 129, 131, 133 and 135.
  • the immunotoxin comprises a heavy chain variable region and a light chain variable region encoded by an amino acid sequence set forth in SEQ ID NO: 131.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 101, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 103.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence of SEQ ID NO: 101, and a light chain variable region having an amino acid sequence of SEQ ID NO: 103.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence sharing at least 90% homology with SEQ ID NO: 101, and a light chain variable region sharing at least 90% homology with SEQ ID NO: 123.
  • the immunotoxin comprises a heavy chain variable region having an amino acid sequence of SEQ ID NO: 101, and a light chain variable region having an amino acid sequence of SEQ ID NO: 123.
  • the immunotoxin comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 121 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the immunotoxin comprises a heavy chain having an amino acid sequence as shown in SEQ ID NO: 122 and a light chain having an amino acid sequence as shown in SEQ ID NO: 120.
  • the immunotoxin may further include an effector molecule.
  • the effector molecule utilized for detecting cancer or imaging a tumor may be a radioisotope, a chromophore, a fluorophore, a chemiluminescent compound, an enzyme, a metal ion, and any combination thereof.
  • the in vivo imaging may be performed by any known technique in the art, such as near-infrared fluorescence imaging (NIRF), fluorescence reflectance imaging (FRI), fluorescence-mediated tomography (FMT), positron emission tomography (PET), single photon emission tomography (SPECT), magnetic resonance imaging (MRI), PET with concurrent computed tomography imaging (PET/CT), PET with concurrent magnetic resonance imaging (PET/MRI), and any combination thereof.
  • NIRF near-infrared fluorescence imaging
  • FMT fluorescence-mediated tomography
  • PET positron emission tomography
  • SPECT single photon emission tomography
  • MRI magnetic resonance imaging
  • PET/CT concurrent computed tomography imaging
  • the method may further include resecting cancerous tissue, such as a tumor or a part of an organ, after in vivo imaging of the subject. Surgical resection can be performed by any technique known in the art. In some embodiments, the method may further include administering the antibody or immunotoxin after resection to measure the completeness of tumor resection.
  • the antibodies as described herein are labeled with a radiotracer.
  • a radiotracer is typically a substance containing a radioisotope that allows for easy detection and measurement.
  • a number of different forms of hydrogen, carbon, phosphorous, sulfur and iodine are commonly used in medical diagnostics.
  • the antibodies of the present invention may be labeled with any suitable radiotracer.
  • Preferred radiotracers include radiotracers for medical imaging. Common radiotracers used include 18 F, 67 Ga, 81m Kr, 82 Rb, 99m Tc, m In, 12 I, m I, 1 Xe, 201 T1 and 90 Y.
  • the antibodies as described herein are labeled with 18 F, 12 /1 1 I, m In, 90 Y or 99m Tc.
  • the antibodies of the present invention may also be labeled with any fluorescent probes known in the art. Non-limiting examples include fluorescein, amino coumarin acetic acid, tetramethylchodomine isocyanate, Texas Red, Cy 3.0, Cy 5.0, green fluorescent protein, and the like.
  • the antibodies as described herein are labeled with a contrast agent.
  • a contrast agent is a substance used to increase or modify the contrast of organs, fluids or anatomical structures in the human or animal body.
  • the antibodies of the present invention may be labeled with any suitable contrast agent.
  • Preferred contrast agents include contrast agents for medical imaging.
  • the antibodies of the present invention are labeled with an MRI (magnetic resonance imaging) contrast agent such as a superparamagnetic contrast agent or a paramagnetic contrast agent.
  • MRI contrast agents are typically chelated metals or colloids.
  • contrast agents include gadolinium (Gd) based contrast agents such as gadolinium-DTPA, iron oxide based contrast agents such as superparamagnetic Small Particles of Iron Oxide (SPIO) and superparamagnetic Ultrasmall Small Particles of Iron Oxide (USPIO) and paramagnetic contrast agents based on manganese chelates such as Mn-DPDP.
  • Gd gadolinium
  • SPIO superparamagnetic Small Particles of Iron Oxide
  • USPIO superparamagnetic Ultrasmall Small Particles of Iron Oxide
  • Mn-DPDP paramagnetic contrast agents based on manganese chelates
  • the invention also provides methods for reducing the risk of post-surgical complications comprising administering an effective amount of an immunotoxin before, during, or after surgery, and in specific non-limiting embodiments, surgery to treat cancer.
  • the invention also provides methods for preventing occurrence, preventing or delaying recurrence, or reducing the rate of recurrence of cancer comprising directly administering to a patient in need thereof an effective amount of an immunotoxin.
  • the invention also provides methods for sensitizing a tumor or cancer to one or more other cancer therapeutics comprising administering an immunotoxin of the invention.
  • the other cancer therapeutic comprises another EpCAM- targeted immunotoxin.
  • the other cancer therapeutic comprises another anti-HER2/neu immunotoxin.
  • the other cancer therapeutic comprises another Hl l immunotoxin.
  • the other cancer therapeutic comprises radiation.
  • the other cancer therapeutic may be administered prior to, overlapping with, concurrently, and/or after administration of the immunotoxin.
  • the immunotoxin and the other cancer therapeutic may be administered in a single formulation or in separate formulations, and if separately, then optionally, by different modes of administration. Accordingly, the combination of one or more immunotoxins and one or more other cancer therapeutics may synergistically act to combat the tumor or cancer.
  • these other cancer therapeutics may include, without limitation, 2,2',2"trichlorotriethylamine, 6-azauridine, 6-diazo-5-oxo-L-norleucine, 6- mercaptopurine, aceglarone, aclacinomycinsa actinomycin, altretamine, aminoglutethimide, aminoglutethimide, amsacrine, anastrozole, ancitabine, angiogenin antisense oligonucleotide, anthramycin, azacitidine, azaserine, aziridine, batimastar, bcl-2 antisense oligonucleotide, benzodepa, bicalutamide, bisantrene, bleomycin, buserelin, busulfan, cactinomycin, calusterone, carboplatin, carboquone, carmofur, car
  • compositions comprising one or more cancer therapeutics (e.g., FLAG, CHOP) are also contemplated by the present invention.
  • FLAG comprises fludarabine, cytosine arabinoside (Ara-C) and G-CSF.
  • CHOP comprises cyclophosphamide, vincristine, doxorubicin, and prednisone.
  • the immunotoxin of the invention may be used in conjunction with radiation therapy or other known cancer therapeutic modalities.
  • An immunotoxin of the present invention can be administered with a cancer therapeutic modality such as an antibody drug conjugate (ADC).
  • ADC comprises a monoclonal antibody or antibody fragment, a cytotoxic payload or drug and a stable, chemical linker with labile bonds connecting the payload to the antibody.
  • ADCs approved by the FDA and routinely used in the treatment of various cancers include gemtuzumab ozogamicin (Mylotarg ® ), ibritumomab tiuxetan (Zevalin ® ), tositumomab (Bexxar ® ), ado- trastuzumab emtansine (Kadcyla) and Brentuximab Vedotin (Adcetris ® ).
  • An immunotoxin of the present invention can be administered with a cancer therapeutic modality such as immune checkpoint inhibitors.
  • a cancer therapeutic modality such as immune checkpoint inhibitors.
  • checkpoint inhibitor it is meant that the compound inhibits one or more proteins in a number of inhibitory pathways that usually serve to modulate an immune response. The pathways are co-opted by tumors to evade the immune system and proliferate. Proteins in the checkpoint signaling pathways include for example, PD-1, PD-L1, PD-L2, TIM3, LAG3 and CTLA-4.
  • Checkpoint inhibitors are known in the art.
  • the checkpoint inhibitor can be a small molecule.
  • a "small molecule” as used herein, is meant to refer to a composition that has a molecular weight in the range of less than about 5 kD to 50 kD, for example less than about 4 kD, less than about 3.5 kD, less than about 3 kD, less than about 2.5 kD, less than about 2 kD, less than about 1.5 kD, less than about 1 kD, less than 750 daltons, less than 500 daltons, less than about 450 daltons, less than about 400 daltons, less than about 350 daltons, less than 300 daltons, less than 250 daltons, less than about 200 daltons, less than about 150 daltons, less than about 100 daltons.
  • Small molecules can be, e.g., nucleic acids, peptides, polypeptides, peptidomimetics, carbohydrates, lipids or other organic or inorganic molecules.
  • the checkpoint inhibitor is an antibody or antibody fragment thereof.
  • the antibody or antibody fragment thereof is specific to a protein in a checkpoint signaling pathway, such as PD-1, PD-L1, PD-L2, LAG3, TIM3 or CTLA-4.
  • methods of treating cancer comprising administering an immunotoxin in combination with a regimen of radiation therapy.
  • the therapy may also comprise surgery and/or chemotherapy.
  • the immunotoxin may be administered in combination with radiation therapy and cisplatin (Platinol), fluo- rouracil (5-FU, Adrucil), carboplatin (Paraplatin), and/or paclitaxel (Taxol).
  • Treatment with the immunotoxin may allow use according to lower doses of radiation and/or less frequent radiation treatments, which may for example, reduce the incidence of severe sore throat that impedes swallowing function potentially resulting in undesired weight loss or dehydration.
  • compositions for combination therapy may also include, without limitation, antibiotics (e.g., dactinomycin, bleomycin, mithramycin, anthramycin), asparaginase, BCG protein, diphtheria toxin, procaine, tetracaine, lidocaine, propranolol, antimitotic agents, abrin, ricin A, Pseudomonas exotoxin, nerve growth factor, platelet derived growth factor, tissue plasminogen activator, antihistaminic agents, anti-nausea agents, etc.
  • antibiotics e.g., dactinomycin, bleomycin, mithramycin, anthramycin
  • asparaginase BCG protein
  • diphtheria toxin procaine
  • tetracaine lidocaine
  • propranolol propranolol
  • antimitotic agents e.g., dactinomycin, bleomycin, mith
  • the present invention provides methods for treating a tumor or cancer comprising administering a reduced dose of one or more other anticancer agents.
  • combination therapy comprising an immunotoxin to a patient in need of such treatment may permit relatively short treatment times when compared to the duration or number of cycles of standard treatment regimens. Accordingly, the present invention provides methods for treating a tumor or cancer comprising administering one or more other anticancer agents for relatively short duration and/or in fewer treatment cycles.
  • combination therapies comprising an immunotoxin and another anticancer agent may reduce toxicity (i.e., side effects) of the overall cancer treatment.
  • reduced toxicity when compared to a monotherapy or another combination therapy, may be observed when delivering a reduced dose of immunotoxin and/or other anticancer agent, and/or when reducing the duration of a cycle (i.e., the period of a single administration or the period of a series of such administrations), and/or when reducing the number of cycles.
  • Clinical outcomes of cancer treatments using an immunotoxin of the invention are readily discernible by one of skill in the relevant art, such as a physician.
  • standard medical tests to measure clinical markers of cancer may be strong indicators of the treatment's efficacy. Such tests may include, without limitation, physical examination, performance scales, disease markers, 12-lead ECG, tumor measurements, tissue biopsy, cytoscopy, cytology, longest diameter of tumor calculations, radiography, digital imaging of the tumor, vital signs, weight, recordation of adverse events, assessment of infectious episodes, assessment of concomitant medications, pain assessment, blood or serum chemistry, detecting serum markers, urinalysis, CT scan, and pharmacokinetic analysis.
  • synergistic effects of a combination therapy comprising the immunotoxin and another anticancer agent may be determined by comparative studies with patients undergoing monotherapy.
  • the effective dose of immunotoxin to be administered during a cycle varies according to the mode of administration.
  • Direct administration e.g., intratumoral injection
  • the effective dose by direct administration of antibody or immunotoxin may range from about 10 to 3000, 20 to 900, 30 to 800, 40 to 700, 50 to 600, 60 to 500, 70 to 400, 80 to 300, 90 to 200, or 100 to 150 micrograms/tumor/day.
  • the dose may range from approximately 10 to 20, 21 to 40, 41 to 80, 81 to 100, 101 to 130, 131 to 150, 151 to 200, 201 to 280, 281 to 350, 351 to 500, 501 to 1000, 1001 to 2000, or 2001 to 3000 micrograms/tumor/day.
  • the dose may be at least approximately 20, 40, 80, 130, 200, 280, 400, 500, 750, 1000, 2000, or 3000 micrograms/tumor/ day .
  • the antibody or immunotoxin administration is at a dosage of about 0.01 mg/kg/dose to about 2000 mg/kg/dose.
  • the effective dose of antibody or immunotoxin may range from about 100 to 5000, 200 to 4000, 300 to 3000, 400 to 2000, 500 to 1000, 600 to 900, or 700 to 1500 micrograms/tumor/month.
  • the dose may range from approximately 100 to 199, 200 to 399, 400 to 649, 650 to 999, 1000 to 1799, 1800 to 2499, 2500 to 3499, 3500 to 4999, 5000 to 7499, 7500 to 10000, or 10001 to 20000 micrograms/tumor/month.
  • the dose may be at least approximately 100, 200, 400, 650, 1000, 1400, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 7500, 10000, or 20000 micrograms/tumor/month.
  • the antibody or immunotoxin is administered intratumourally at a total dose per cycle equivalent to, or below the maximum tolerated dose established in a safety trial but the dosage is standardized in relation to the tumor volume.
  • subjects will receive between 1 microgram per cm 3 and 500 microgram per cm 3 tumor or a dose sufficient to reach about between 14 picomole and 7 nanomole per cm 3 tumor tissue.
  • the dose will be administered in a volume not exceeding about 20-50% of the tumor volume.
  • the immunotoxin will be diluted in a suitable salt solution.
  • a target dose of 14 picomoles (1 microgram per cm 3 ), and a maximum injection relative volume of about 1/3 of the tumor 3 microgram of immunotoxin will be diluted into about 1 ml of diluent.
  • the effective dose of another cancer therapeutic to be administered together with an immunotoxin during a cycle also varies according to the mode of administration.
  • the one or more anticancer agent may be delivered intratumorally, or by other modes of administration.
  • chemotherapeutic agents are administered systemically. Standard dosage and treatment regimens are known in the art (see, e.g., the latest editions of the Merck Index and the Physician's Desk Reference).
  • the additional anticancer agent comprises dacarbazine at a dose ranging from approximately 200 to 4000 mg/m 2 /cycle. In a preferred embodiment, the dose ranges from 700 to 1000 mg/m 2 /cycle.
  • the additional anticancer agent comprises fludarabine at a dose ranging from approximately 25 to 50 mg/m 2 /cycle.
  • the additional anticancer agent comprises cytosine arabinoside (Ara-C) at a dose ranging from approximately 200 to 2000 mg/m 2 /cycle.
  • the additional anticancer agent comprises docetaxel at a dose ranging from approximately 1.5 to 7.5 mg/kg/cycle.
  • the additional anticancer agent comprises paclitaxel at a dose ranging from approximately 5 to 15 mg/kg/cycle.
  • the additional anticancer agent comprises cisplatin at a dose ranging from approximately 5 to 20 mg/kg/cycle.
  • the additional anticancer agent comprises 5- fluorouracil at a dose ranging from approximately 5 to 20 mg/kg/cycle.
  • the additional anticancer agent comprises doxorubicin at a dose ranging from approximately 2 to 8 mg/kg/cycle.
  • the additional anticancer agent comprises epipodophyllotoxin at a dose ranging from approximately 40 to 160 mg/kg/cycle.
  • the additional anticancer agent comprises cyclophosphamide at a dose ranging from approximately 50 to 200 mg/kg/cycle.
  • the additional anticancer agent comprises irinotecan at a dose ranging from approximately 50 to 75, 75 to 100, 100 to 125, or 125 to 150 mg/m 2 /cycle.
  • the anticancer agent comprises vinblastine at a dose ranging from approximately 3.7 to 5.4, 5.5 to 7.4, 7.5 to 1 1, or 11 to 18.5 mg/m 2 /cycle.
  • the additional anticancer agent comprises vincristine at a dose ranging from approximately 0.7 to 1.4, or 1.5 to 2 mg/m 2 /cycle.
  • the additional anticancer agent comprises methotrexate at a dose ranging from approximately 3.3 to 5, 5 to 10, 10 to 100, or 100 to 1000 mg/m 2 /cycle.
  • Combination therapy with an immunotoxin may sensitize the cancer or tumor to administration of an additional cancer therapeutic.
  • the present invention contemplates combination therapies for preventing, treating, and/or preventing recurrence of cancer comprising administering an effective amount of an immunotoxin prior to, subsequently, or concurrently with a reduced dose of a cancer therapeutic.
  • initial treatment with an immunotoxin may increase the sensitivity of a cancer or tumor to subsequent challenge with a dose of cancer therapeutic. This dose is near, or below, the low range of standard dosages when the cancer therapeutic is administered alone, or in the absence of an immunotoxin.
  • the immunotoxin may be administered separately from the cancer therapeutic, and optionally, via a different mode of administration.
  • the additional cancer therapeutic comprises cisplatin, e.g., PLATINOL or PLATINOL-AQ (Bristol Myers), at a dose ranging from approximately 5 to 10, 11 to 20, 21 to 40, or 41 to 75 mg/m 2 / cycle.
  • cisplatin e.g., PLATINOL or PLATINOL-AQ (Bristol Myers)
  • the additional cancer therapeutic comprises carboplatin, e.g., PARAPLATIN (Bristol Myers), at a dose ranging from approximately 2 to 3, 4 to 8, 9 to 16, 17 to 35, or 36 to 75 mg/m 2 /cycle.
  • carboplatin e.g., PARAPLATIN (Bristol Myers)
  • the additional cancer therapeutic comprises cyclophosphamide, e.g., CYTOXAN (Bristol Myers Squibb), at a dose ranging from approximately 0.25 to 0.5, 0.6 to 0.9, 1 to 2, 3 to 5, 6 to 10, 11 to 20, or 21 to 40 mg/kg/cycle.
  • cyclophosphamide e.g., CYTOXAN (Bristol Myers Squibb)
  • the additional cancer therapeutic comprises cytarabine, e.g., CYTOSAR-U (Pharmacia & Upjohn), at a dose ranging from approximately 0.5 to 1, 2 to 4, 5 to 10, 11 to 25, 26 to 50, or 51 to 100 mg/m 2 /cycle.
  • the additional anticancer agent comprises cytarabine liposome, e.g., DEPOCYT (Chiron Corp.), at a dose ranging from approximately 5 to 50 mg/m 2 /cycle.
  • the additional cancer therapeutic comprises dacarbazine, e.g., DTIC or DTICDOME (Bayer Corp.), at a dose ranging from approximately 15 to 250 mg/m2/cycle or ranging from approximately 0.2 to 2 mg/kg/cycle.
  • dacarbazine e.g., DTIC or DTICDOME (Bayer Corp.)
  • a dose ranging from approximately 15 to 250 mg/m2/cycle or ranging from approximately 0.2 to 2 mg/kg/cycle.
  • the additional cancer therapeutic comprises topotecan, e.g., HYCAMTIN (SmithKline Beecham), at a dose ranging from approximately 0.1 to 0.2, 0.3 to 0.4, 0.5 to 0.8, or 0.9 to 1.5 mg/m 2 /Cycle.
  • topotecan e.g., HYCAMTIN (SmithKline Beecham)
  • HYCAMTIN SmithKline Beecham
  • the additional cancer therapeutic comprises irinotecan, e.g., CAMPTOSAR (Pharmacia & Upjohn), at a dose ranging from approximately 5 to 9, 10 to 25, or 26 to 50 mg/m 2 /cycle.
  • irinotecan e.g., CAMPTOSAR (Pharmacia & Upjohn)
  • the additional cancer therapeutic comprises fludarabine, e.g., FLUDARA (Berlex Laboratories), at a dose ranging from approximately 2.5 to 5, 6 to 10, 11 to 15, or 16 to 25 mg/m 2 /cycle.
  • fludarabine e.g., FLUDARA (Berlex Laboratories)
  • the additional cancer therapeutic comprises cytosine arabinoside (Ara-C) at a dose ranging from approximately 200 to 2000 mg/m2/cycle, 300 to 1000 mg/m2/cycle, 400 to 800 mg/m2/cycle, or 500 to 700 mg/m 2 /cycle.
  • cytosine arabinoside Ara-C
  • the additional cancer therapeutic comprises docetaxel, e.g., TAXOTERE (Rhone Poulenc Rorer) at a dose ranging from approximately 6 to 10, 11 to 30, or 31 to 60 mg/m 2 /cycle.
  • the additional cancer therapeutic comprises paclitaxel, e.g., TAXOL (Bristol Myers Squibb), at a dose ranging from approximately 10 to 20, 21 to 40, 41 to 70, or 71 to 135 mg/kg/cycle.
  • the additional cancer therapeutic comprises 5- fiuorouracil at a dose ranging from approximately 0.5 to 5 mg/kg/cycle, 1 to 4 mg/kg/cycle, or 2-3 mg/kg/cycle.
  • the additional cancer therapeutic comprises doxorubicin, e.g., ADRIAMYCIN (Pharmacia & Upjohn), DOXIL (Alza), RUBEX (Bristol Myers Squibb), at a dose ranging from approximately 2 to 4, 5 to 8, 9 to 15, 16 to 30, or 31 to 60 mg/kg/cycle.
  • doxorubicin e.g., ADRIAMYCIN (Pharmacia & Upjohn)
  • DOXIL Alza
  • RUBEX Billristol Myers Squibb
  • the additional cancer therapeutic comprises etoposide, e.g., VEPESID (Pharmacia & Upjohn), at a dose ranging from approximately 3.5 to 7, 8 to 15, 16 to 25, or 26 to 50 mg/m 2 /cycle.
  • etoposide e.g., VEPESID (Pharmacia & Upjohn)
  • VEPESID Pharmaacia & Upjohn
  • the additional cancer therapeutic comprises vinblastine, e.g., VELBAN (Eli Lilly), at a dose ranging from approximately 0.3 to 0.5, 0.6 to 0.9, 1 to 2, or 3 to 3.6 mg/m2/cycle.
  • vinblastine e.g., VELBAN (Eli Lilly)
  • VELBAN Eli Lilly
  • the additional cancer therapeutic comprises vincristine, e.g., ONCOVIN (Eli Lilly), at a dose ranging from approximately 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 or 0.7 mg/m 2 /cycle.
  • vincristine e.g., ONCOVIN (Eli Lilly)
  • ONCOVIN Eli Lilly
  • the additional cancer therapeutic comprises methotrexate at a dose ranging from approximately 0.2 to 0.9, 1 to 5, 6 to 10, or 11 to 20 mg/m 2 / cycle.
  • an immunotoxin is administered in combination with at least one other immunotherapeutic which includes, without limitation, rituxan, rituximab, campath-1, gemtuzumab, and trastuzumab.
  • an immunotoxin is administered in combination with one or more anti-angiogenic agents which include, without limitation, angiostatin, thalidomide, kringle 5, endostatin, Serpin (Serine Protease Inhibitor), anti-thrombin, 29 kDa N-terminal and a 40 kDa C-terminal proteolytic fragments of fibronectin, 16 kDa proteolytic fragment of prolactin, 7.8 kDa proteolytic fragment of platelet factor-4, a 13 amino acid peptide corresponding to a fragment of platelet factor-4, a 14-amino acid peptide corresponding to a fragment of collagen I, a 19 amino acid peptide corresponding to a fragment of thrombospondin I, a 20-amino acid peptide corresponding to a fragment of SPARC, and a variant thereof, including a pharmaceutically acceptable salt thereof.
  • anti-angiogenic agents include, without limitation, angiostatin, thalidomide,
  • an immunotoxin is administered in combination with a regimen of radiation therapy.
  • the therapy may also comprise surgery and/or chemotherapy.
  • the immunotoxin may be administered in combination with radiation therapy and cisplatin (Platinol), fluorouracil (5-FU, Adrucil), carboplatin (Paraplatin), and/or paclitaxel (Taxol).
  • Treatment with the immunotoxin may allow use of lower doses of radiation and/or less frequent radiation treatments, which may for example, reduce the incidence of severe sore throat that impedes swallowing function potentially resulting in undesired weight loss or dehydration.
  • an antibody or immunotoxin is administered in combination with one or more cytokines which include, without limitation, lymphokines, tumor necrosis factors, tumor necrosis factor-like cytokine, lymphotoxin, interferon, macrophage inflammatory protein, granulocyte monocyte colony stimulating factor, interleukin (including, without limitation, interleukin-1 , interleukin-2, interleukin-6, interleukin-12, interleukin- 15, interleukin-18), and a variant thereof, including a pharmaceutically acceptable salt thereof.
  • cytokines include, without limitation, lymphokines, tumor necrosis factors, tumor necrosis factor-like cytokine, lymphotoxin, interferon, macrophage inflammatory protein, granulocyte monocyte colony stimulating factor, interleukin (including, without limitation, interleukin-1 , interleukin-2, interleukin-6, interleukin-12, interleukin- 15, interleukin-18), and a variant thereof, including a
  • an immunotoxin is administered in combination with a cancer vaccine including, without limitation, autologous cells or tissues, non- autologous cells or tissues, carcinoembryonic antigen, alpha-feto-protein, human chorionic gonadotropin, BCG live vaccine, melanocyte lineage proteins, and mutated, tumor-specific antigens.
  • a cancer vaccine including, without limitation, autologous cells or tissues, non- autologous cells or tissues, carcinoembryonic antigen, alpha-feto-protein, human chorionic gonadotropin, BCG live vaccine, melanocyte lineage proteins, and mutated, tumor-specific antigens.
  • an immunotoxin is administered in association with hormonal therapy.
  • Hormonal therapeutics include, without limitation, a hormonal agonist, hormonal antagonist (e.g., flutamide, tamoxifen, leuprolide acetate (LUPRON)), and steroid (e.g., dexamethasone, retinoid, betamethasone, Cortisol, cortisone, prednisone, dehydrotestosterone, glucocorticoid, mineralocorticoid, estrogen, testosterone, progestin).
  • a hormonal agonist e.g., flutamide, tamoxifen, leuprolide acetate (LUPRON)
  • steroid e.g., dexamethasone, retinoid, betamethasone, Cortisol, cortisone, prednisone, dehydrotestosterone, glucocorticoid, mineralocorticoid, estrogen, testosterone, progestin.
  • an immunotoxin is administered in association with a gene therapy program to treat or prevent cancer.
  • an EpCAM-targeted immunotoxin is administered in combination with one or more agents that increase expression of EpCAM in the tumor cells of interest.
  • EpCAM expression preferably is increased so that a greater number of EpCAM molecules are expressed on the tumor cell surface.
  • the agent may inhibit the normal cycles of EpCAM antigen endocytosis.
  • Such combination treatment may improve the clinical efficacy of the EpCAM-targeted immunotoxin alone, or with other anticancer agents or radiation therapy.
  • the agent which increases EpCAM expression in the tumor cells is vinorelbine tartrate (Navelbine) and/or paclitaxel (Taxol).
  • a HER2/neu-targeted immunotoxin is administered in combination with one or more agents that increase expression of HER2/neu in the tumor cells of interest.
  • HER2/neu expression preferably is increased so that a greater number of HER2/neu molecules are expressed on the tumor cell surface.
  • the agent may inhibit the normal cycles of HER2/neu endocytosis.
  • Such combination treatment may improve the clinical efficacy of the Her2/neu-targeted immunotoxin alone, or with other cancer therapeutics or radiation therapy.
  • a CSA-targeted immunotoxin is administered in combination with one or more agents that increase expression of CSA in the tumor cells of interest.
  • CSA expression preferably is increased so that a greater number of CSA molecules are expressed on the tumor cell surface.
  • the agent may inhibit the normal cycles of CSA endocytosis.
  • Such combination treatment may improve the clinical efficacy of the CSA-targeted immunotoxin alone, or with other cancer therapeutics or radiation therapy.
  • Combination therapy may thus increase the sensitivity of the cancer or tumor to the administered immunotoxin and/or additional cancer therapeutic. In this manner, shorter treatment cycles may be possible thereby reducing toxic events.
  • the invention provides a method for treating or preventing cancer comprising administering to a patient in need thereof an effective amount of an immunotoxin and at least one other cancer therapeutic for a short treatment cycle.
  • the cycle duration may range from approximately 1 to 30, 2 to 27, 3 to 15, 4 to 12, 5 to 9, or 6-8 days.
  • the cycle duration may vary according to the specific cancer therapeutic in use.
  • the invention also contemplates continuous or discontinuous administration, or daily doses divided into several partial administrations.
  • the cycle duration may range from approximately 10 to 56, 12 to 48, 14 to 28, 16 to 24, or 18 to 20 days.
  • the cycle duration may vary according to the specific cancer therapeutic in use.
  • the immunotoxins described herein may be administered to the patient via any suitable route.
  • the immunotoxins may be administered by injection into the vascular system or by injection into an organ.
  • Preferred administration routes include parenteral, intravascular and/or intravenous injection.
  • Parenteral administration includes subcutaneous, intramuscular, intraperitoneal, intracavity, intrathecal, intratumoral, transdermal and intravenous injection.
  • the antibodies and/or immunotoxins are administered intravenously as a bolus or by continuous infusion over a period of time.
  • the immunotoxin is administered by intracranial infusion.
  • the antibodies and/or immunotoxins may be administered directly to the cancer site.
  • the immunotoxin and antibodies of the present invention can be administered in the conventional manner by any route where they are active. Administration can be systemic, parenteral, topical, or oral. For example, administration can be, but is not limited to, parenteral, oral, buccal, or ocular routes, or intravaginally, by inhalation, by depot injections, or by implants.
  • modes of administration for the antibodies/immunotoxins of the present invention can be, but are not limited to, sublingual, injectable (including short-acting, depot, implant and pellet forms injected subcutaneously or intramuscularly), or by use according to vaginal creams, suppositories, pessaries, vaginal rings, rectal suppositories, intrauterine devices, and transdermal forms such as patches and creams.
  • the immunotoxin and/or other anticancer agent is delivered to the patient by direct administration.
  • the immunotoxin and/or other anticancer agent may be administered, without limitation, by one or more direct injections into the tumor, by continuous or discontinuous perfusion into the tumor, by introduction of a reservoir of the immunotoxin, by introduction of a slow-release apparatus into the tumor, by introduction of a slow-release formulation into the tumor, and/or by direct application onto the tumor.
  • introduction of the immunotoxin and/or other anticancer agent to the area of the tumor, or into a blood vessel or lymphatic vessel that substantially directly flows into the area of the tumor is also contemplated.
  • the pharmaceutical composition is administered in at least an amount sufficient to achieve the endpoint, and if necessary, comprises a pharmaceutically acceptable carrier.
  • the immunotoxins may be administered intratumorally, whereas any other anticancer agent may be delivered to the patient by other modes of administration (e.g., intravenously).
  • the immunotoxin and one or more of the other anticancer agent may be delivered intratumorally, whereas other anticancer agents may be delivered by other modes of administration (e.g., intravenously and orally).
  • a composition may be an antibody described herein and a pharmaceutically acceptable excipient, carrier, buffer or stabilizer.
  • a composition may be an immunotoxin described herein and a pharmaceutically acceptable excipient, carrier, buffer or stabilizer.
  • An immunotoxin according to the invention may be comprised in a pharmaceutical composition or medicament.
  • Pharmaceutical compositions adapted for direct administration include, without limitation, lyophilized powders or aqueous or non-aqueous sterile injectable solutions or suspensions, which may further contain antioxidants, buffers, bacteriostats and solutes that render the compositions substantially isotonic with the blood of an intended recipient.
  • compositions include water, alcohols, polyols, glycerin and vegetable oils, for example.
  • Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets.
  • Immunotoxin may be supplied, for example but not by way of limitation, as a lyophilized powder which is reconstituted with sterile water or saline prior to administration to the patient.
  • compositions of the invention may comprise a pharmaceutically acceptable carrier.
  • suitable pharmaceutically acceptable carriers include essentially chemically inert and nontoxic compositions that do not interfere with the effectiveness of the biological activity of the pharmaceutical composition.
  • suitable pharmaceutical carriers include, but are not limited to, water, saline solutions, glycerol solutions, ethanol, N-(l(2,3-dioleyloxy) propyl)N,N,N-trimethylammonium chloride (DOTMA), diolesylphosphotidyl-ethanolamine (DOPE), and liposomes.
  • DOTMA N-(l(2,3-dioleyloxy) propyl)N,N,N-trimethylammonium chloride
  • DOPE diolesylphosphotidyl-ethanolamine
  • liposomes Such compositions should contain a therapeutically effective amount of the compound, together with a suitable amount of carrier so as to provide the form for direct administration to the patient.
  • a pharmaceutical composition comprises an antibody or immunotoxin and one or more additional anticancer agent, optionally in a pharmaceutically acceptable carrier.
  • composition may be in the form of a pharmaceutically acceptable salt which includes, without limitation, those formed with free amino groups such as those derived from hydrochloric, phosphoric, acetic, oxalic, tartaric acids, etc., and those formed with free carboxyl groups such as those derived from sodium, potassium, ammonium, calcium, ferric hydroxides, isopropylamine, triethylamine, 2-ethylarnino ethanol, histidine, procaine, etc.
  • a pharmaceutically acceptable salt which includes, without limitation, those formed with free amino groups such as those derived from hydrochloric, phosphoric, acetic, oxalic, tartaric acids, etc.
  • free carboxyl groups such as those derived from sodium, potassium, ammonium, calcium, ferric hydroxides, isopropylamine, triethylamine, 2-ethylarnino ethanol, histidine, procaine, etc.
  • the pharmaceutical composition is directly administered to the area of the tumor(s) by, for example, local infusion during surgery, topical application (e.g., in conjunction with a wound dressing after surgery), injection, means of a catheter, means of a suppository, or means of an implant.
  • An implant can be of a porous, non-porous, or gelatinous material, including membranes, such as sialastic membranes, or fibers. Suppositories generally contain active ingredients in the range of 0.5% to 10% by weight.
  • a controlled release system can be placed in proximity of the target tumor.
  • a micropump may deliver controlled doses directly into the area of the tumor, thereby finely regulating the timing and concentration of the pharmaceutical composition.
  • the pharmaceutical carrier may include, without limitation, binders, coating, disintegrants, fillers, diluents, flavors, colors, lubricants, glidants, preservatives, sorbents, sweeteners, conjugated linoleic acid (CLA), gelatin, beeswax, purified water, glycerol, any type of oil, including, without limitation, fish oil or soybean oil, or the like.
  • Pharmaceutical compositions of the antibodies/immunotoxins also can comprise suitable solid or gel phase carriers or excipients. Examples of such carriers or excipients include but are not limited to calcium carbonate, calcium phosphate, various sugars, starches, cellulose derivatives, gelatin, and polymers such as, e.g., polyethylene glycols.
  • the immunotoxins and antibodies can be formulated readily by combining these immunotoxins/antibodies with pharmaceutically acceptable carriers well known in the art.
  • Such carriers enable the immunotoxins of the invention to be formulated as tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspensions and the like, for oral ingestion by a patient to be treated.
  • Pharmaceutical preparations for oral use can be obtained by adding a solid excipient, optionally grinding the resulting mixture, and processing the mixture of granules, after adding suitable auxiliaries, if desired, to obtain tablets or dragee cores.
  • Suitable excipients include, but are not limited to, fillers such as sugars, including, but not limited to, lactose, sucrose, mannitol, and sorbitol; cellulose preparations such as, but not limited to, maize starch, wheat starch, rice starch, potato starch, gelatin, gum tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, and polyvinylpyrrolidone (PVP).
  • disintegrating agents can be added, such as, but not limited to, the cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate.
  • Dragee cores can be provided with suitable coatings.
  • suitable coatings can be used, which can optionally contain gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, and/or titanium dioxide, lacquer solutions, and suitable organic solvents or solvent mixtures.
  • Dyestuffs or pigments can be added to the tablets or dragee coatings for identification or to characterize different combinations of antibodies/immunotoxins doses.
  • compositions which can be used orally include, but are not limited to, push-fit capsules made of gelatin, as well as soft, sealed capsules made of gelatin and a plasticizer, such as glycerol or sorbitol.
  • the push-fit capsules can contain the active ingredients in admixture with filler such as, e.g., lactose, binders such as, e.g., starches, and/or lubricants such as, e.g., talc or magnesium stearate and, optionally, stabilizers.
  • the immunotoxins/antibodies can be dissolved or suspended in suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene glycols.
  • stabilizers can be added. All formulations for oral administration should be in dosages suitable for such administration.
  • compositions can take the form of, e.g., tablets or lozenges formulated in a conventional manner.
  • compositions for use according to the present invention are conveniently delivered in the form of an aerosol spray presentation from pressurized packs or a nebulizer, with the use according to a suitable propellant, e.g., dichlorodifiuoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas.
  • a suitable propellant e.g., dichlorodifiuoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas.
  • a pressurized aerosol the dosage unit can be determined by providing a valve to deliver a metered amount.
  • Capsules and cartridges of, e.g., gelatin for use in an inhaler or insufflator can be formulated containing a powder mix of the immunotoxins/antibodies and a suitable powder base such as lactose or starch.
  • compositions of the present invention can also be formulated in rectal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides.
  • compositions of the present invention can also be formulated as a depot preparation.
  • Such long acting formulations can be administered by implantation (for example subcutaneously or intramuscularly) or by intramuscular injection.
  • the immunotoxins can be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.
  • compositions of the present invention for example, can be applied to a plaster, or can be applied by transdermal, therapeutic systems that are consequently supplied to the organism.
  • compositions of the present invention can also be administered in combination with other active ingredients, such as, for example, adjuvants, protease inhibitors, or other compatible drugs or compounds where such combination is seen to be desirable or advantageous in achieving the desired effects of the methods described herein.
  • active ingredients such as, for example, adjuvants, protease inhibitors, or other compatible drugs or compounds where such combination is seen to be desirable or advantageous in achieving the desired effects of the methods described herein.
  • the disintegrant component comprises one or more of croscarmellose sodium, carmellose calcium, crospovidone, alginic acid, sodium alginate, potassium alginate, calcium alginate, an ion exchange resin, an effervescent system based on food acids and an alkaline carbonate component, clay, talc, starch, pregelatinized starch, sodium starch glycolate, cellulose floe, carboxymethylcellulose, hydroxypropylcellulose, calcium silicate, a metal carbonate, sodium bicarbonate, calcium citrate, or calcium phosphate.
  • the diluent component comprises one or more of mannitol, lactose, sucrose, maltodextrin, sorbitol, xylitol, powdered cellulose, microcrystalline cellulose, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, methylhydroxyethylcellulose, starch, sodium starch glycolate, pregelatinized starch, a calcium phosphate, a metal carbonate, a metal oxide, or a metal aluminosilicate.
  • the optional lubricant component when present, comprises one or more of stearic acid, metallic stearate, sodium stearyl fumarate, fatty acid, fatty alcohol, fatty acid ester, glyceryl behenate, mineral oil, vegetable oil, paraffin, leucine, silica, silicic acid, talc, propylene glycol fatty acid ester, polyethoxylated castor oil, polyethylene glycol, polypropylene glycol, polyalkylene glycol, polyoxyethylene-glycerol fatty ester, polyoxyethylene fatty alcohol ether, polyethoxylated sterol, polyethoxylated castor oil, polyethoxylated vegetable oil, or sodium chloride.
  • Nucleic Acid Molecules Nucleic Acid Molecules
  • the sequences, vectors, and constructs of the present invention are codon optimized to the organism in which they are used.
  • the codon usage in the coding sequences of the present invention is optimized to express one or more immunotoxins described herein.
  • the codons of a deimmunized Bouganin are optimized for expression in non-native bacterial, archaeal, and eukaryotic systems.
  • An exemplary codon optimized deBouganin is shown in SEQ ID NO: 13. Methods of codon-optimization are well-known to those skilled in the art. More information about codon optimization can be found in US2008/0194511, and US2007/0292918, both of which are incorporated herein for all purposes.
  • the nucleic acid sequences of the present application may be incorporated in a known manner into an appropriate expression vector which ensures good expression of the proteins encoded thereof.
  • Possible expression vectors include, but are not limited to, cosmids, plasmids, or modified viruses (e.g. replication defective retroviruses, adenoviruses and adeno-associated viruses), so long as the vector is compatible with the host cell used.
  • the expression vectors are "suitable for transformation of a host cell", which means that the expression vectors contain a nucleic acid molecule of the present application and regulatory sequences selected on the basis of the host cells to be used for expression, which is operatively linked to the nucleic acid molecule. Operatively linked is intended to mean that the nucleic acid is linked to regulatory sequences in a manner which allows expression of the nucleic acid.
  • the present application therefore contemplates a recombinant expression vector of the present application containing a nucleic acid molecule of the present application, or a fragment thereof, and the necessary regulatory sequences for the transcription and translation of the inserted protein sequence.
  • Suitable regulatory sequences may be derived from a variety of sources, including bacterial, fungal, viral, mammalian, or insect genes (For example, see the regulatory sequences described in (Goeddel, 1990), Gene Expression Technology: Methods in Enzymology 185, Academic Press, San Diego, Calif. (1990)). Selection of appropriate regulatory sequences is dependent on the host cell chosen as discussed below, and may be readily accomplished by one of ordinary skill in the art. Examples of such regulatory sequences include: a transcriptional promoter and enhancer or RNA polymerase binding sequence, a ribosomal binding sequence, including a translation initiation signal. Additionally, depending on the host cell chosen and the vector employed, other sequences, such as an origin of replication, additional DNA restriction sites, enhancers, and sequences conferring inducibility of transcription may be incorporated into the expression vector.
  • the recombinant expression vectors of the present application may also contain a selectable marker gene which facilitates the selection of host cells transformed or transfected with a recombinant molecule of the present application.
  • selectable marker genes are genes encoding a protein such as G418 and hygromycin which confer resistance to certain drugs, (3-galactosidase, chloramphenicol acetyltransferase, firefly luciferase, or an immunoglobulin or portion thereof such as the Fc portion of an immunoglobulin preferably IgG.
  • selectable marker gene Transcription of the selectable marker gene is monitored by changes in the concentration of the selectable marker protein such as ⁇ -galactosidase, chloramphenicol acetyltransferase, or firefly luciferase. If the selectable marker gene encodes a protein conferring antibiotic resistance such as neomycin resistance transformant cells can be selected with G418. Cells that have incorporated the selectable marker gene will survive, while the other cells die. This makes it possible to visualize and assay for expression of recombinant expression vectors of the present application and in particular to determine the effect of a mutation on expression and phenotype. It will be appreciated that selectable markers can be introduced on a separate vector from the nucleic acid of interest.
  • the recombinant expression vectors may also contain genes which encode a fusion moiety which provides increased expression of the recombinant protein; increased solubility of the recombinant protein; and aid in the purification of the target recombinant protein by acting as a ligand in affinity purification.
  • a proteolytic cleavage site may be added to the target recombinant protein to allow separation of the recombinant protein from the fusion moiety subsequent to purification of the fusion protein.
  • Typical fusion expression vectors include pGEX (Amrad Corp., Melbourne, Australia), pMal (New England Biolabs, Beverly, Mass.) and pRIT5 (Pharmacia, Piscataway, N.J.) which fuse glutathione S- transferase (GST), maltose E binding protein, or protein A, respectively, to the recombinant protein.
  • GST glutathione S- transferase
  • maltose E binding protein or protein A, respectively, to the recombinant protein.
  • Recombinant expression vectors can be introduced into host cells to produce a transformed host cell.
  • the terms “transformed with”, “transfected with”, “transformation” and “transfection” are intended to encompass introduction of nucleic acid (e.g. a vector) into a cell by one of many possible techniques known in the art.
  • the term “transformed host cell” as used herein is intended to also include cells capable of glycosylation that have been transformed with a recombinant expression vector of the present application.
  • Prokaryotic cells can be transformed with nucleic acid by, for example, electroporation or calcium- chloride mediated transformation.
  • nucleic acid can be introduced into mammalian cells via conventional techniques such as calcium phosphate or calcium chloride co-precipitation, DEAE-dextran mediated transfection, lipofectin, electroporation or microinjection.
  • conventional techniques such as calcium phosphate or calcium chloride co-precipitation, DEAE-dextran mediated transfection, lipofectin, electroporation or microinjection.
  • Suitable methods for transforming and transfecting host cells can be found in (Sambrook et al, 2001) (Molecular Cloning: A Laboratory Manual, 3rd Edition, Cold Spring Harbor Laboratory Press, 2001), and other laboratory textbooks.
  • Suitable host cells include a wide variety of eukaryotic host cells and prokaryotic cells.
  • the proteins of the present application may be expressed in yeast cells or mammalian cells. Other suitable host cells can be found in (Goeddel, 1990), Gene Expression Technology: Methods in Enzymology 185, Academic Press, San Diego, Calif. (1991).
  • the proteins of the present application may be expressed in prokaryotic cells, such as Escherichia coli (Zhang et al, 2004), Science 303(5656): 371-3).
  • a Pseudomonas based expression system such as Pseudomonas fluorescens can be used (US Patent Application Publication No. US 2005/0186666, (Schneider et al, 2005)).
  • Yeast and fungi host cells suitable for carrying out the present application include, but are not limited to Saccharomyces cerevisiae, the genera Pichia or Kluyveromyces and various species of the genus Aspergillus.
  • yeast S. cerevisiae examples include pYepSecl ((Baldari et al, 1987), Embo J. 6: 229- 234), pMFa ((Kurjan and Herskowitz, 1982), Cell 30: 933-943 (1982)), pJRY88 ((Schultz et al., 1987), Gene 54: 113-123), and pYES2 (Invitrogen Corporation, San Diego, Calif).
  • Mammalian cells suitable for carrying out the present application include, among others: COS (e.g., ATCC No. CRL 1650 or 1651), BHK (e.g. ATCC No. CRL 6281), CHO (ATCC No. CCL 61), HeLa (e.g., ATCC No. CCL 2), 293 (ATCC No. 1573) and NS-1 cells.
  • Suitable expression vectors for directing expression in mammalian cells generally include a promoter (e.g., derived from viral material such as polyoma, Adenovirus 2, cytomegalovirus and Simian Virus 40), as well as other transcriptional and translational control sequences.
  • mammalian expression vectors examples include pCDM8 ((Seed, 1987), Nature 329: 840) and pMT2PC ((Kaufman et al, 1987), EMBO J. 6: 187-195).
  • promoters, terminators, and methods for introducing expression vectors of an appropriate type into plant, avian, and insect cells may also be readily accomplished.
  • the proteins of the present application may be expressed from plant cells (see (Sinkar et al, 1987), J.
  • Biosci (Bangalore) 11 : 47-58), which reviews the use of Agrobacterium rhizogenes vectors; see also ((Zambryski et al, 1984), Genetic Engineering, Principles and Methods, Hollaender and Setlow (eds.), Vol. VI, pp. 253-278, Plenum Press, New York), which describes the use of expression vectors for plant cells, including, among others, PAPS2022, PAPS2023, and PAPS2034).
  • Insect cells suitable for carrying out the present application include cells and cell lines from Bombyx, Trichoplusia or Spodotera species.
  • Baculovirus vectors available for expression of proteins in cultured insect cells include the pAc series ((Smith et al., 1983), Mol. Cell. Biol. 3: 2156-2165) and the pVL series ((Luckow and Summers, 1989), Virology 170: 31-39).
  • Some baculovirus-insect cell expression systems suitable for expression of the recombinant proteins of the present application are described in PCT/US/02442.
  • the proteins of the present application may also be expressed in non-human transgenic animals such as rats, rabbits, sheep and pigs ((Hammer et al, 1985). Nature 315:680-683); (Brinster et al, 1985; Palmiter and Brinster, 1985; Palmiter et al, 1983) Science 222:809-814); and ((Leder and Stewart, 1988) U.S. Pat. No. 4,736,866).
  • non-human transgenic animals such as rats, rabbits, sheep and pigs ((Hammer et al, 1985). Nature 315:680-683); (Brinster et al, 1985; Palmiter and Brinster, 1985; Palmiter et al, 1983) Science 222:809-814); and ((Leder and Stewart, 1988) U.S. Pat. No. 4,736,866).
  • the present application provides a recombinant expression vector comprising one or more of the novel nucleic acid sequences as well as methods and uses of the expression vectors in the preparation of recombinant proteins. Further, the application provides a host cell comprising one or more of the novel nucleic acid sequences or expression vectors comprising one or more of the novel nucleic acid sequences.
  • the present application also includes antibody or an antibody fragment comprising one or more of the amino acid sequences disclosed herein (i.e. SEQ ID NOS: 2, 4, 23, 25, 27, 29, 31, 49, 51, 53, 55-57, 69, 71, 73, 75-89, 92, 94-98, 99-101, 103, 120-123, 125, 127, 129, 131, 133 and 135).
  • the antibody or antibody fragment comprises amino acids 23-535 of the amino acid sequence shown in SEQ ID NO: 23 or SEQ ID NO: 27.
  • the antibody or antibody fragment comprises amino acids 23-529 of the amino acid sequence shown in SEQ ID NO: 25, SEQ ID NO: 29 or SEQ ID NO: 31.
  • the antibody or antibody fragment comprises an amino acid sequence selected from SEQ ID NOs: 125, 127, 129, 131, 133 and 135. In another embodiment, the antibody or antibody fragment comprises an amino acid sequence set forth in SEQ ID NO: 131.
  • the antibody or antibody fragment comprises the VH region shown in SEQ ID NO: 2 and the VL region shown in SEQ ID NO: 4.
  • the antibody or antibody fragment comprises a heavy chain variable region and a light chain variable region encoded by amino acid sequences selected from SEQ ID NOs: 125, 127, 129, 131, 133 and 135.
  • the antibody or antibody fragment comprises a heavy chain variable region and a light chain variable region encoded by an amino acid sequence set forth in SEQ ID NO: 131.
  • the antibody or antibody fragment comprises a heavy chain having an amino acid sequence selected from SEQ ID NO: 49, SEQ ID NO: 53, SEQ ID NO: 56, and SEQ ID NO: 57, and a light chain having an amino acid sequence selected from SEQ ID NO: 51 and SEQ ID NO: 55.
  • the antibody or antibody fragment comprises a heavy chain having an amino acid sequence selected from SEQ ID NO: 99, SEQ ID NO: 121 and SEQ ID NO: 122, and a light chain having an amino acid sequence selected from SEQ ID NO: 100 and SEQ ID NO: 120.
  • the present application also includes the use of the novel nucleic acid sequences for the preparation of antibodies or antibody fragments and methods thereof.
  • the present application includes the use of the antibodies or antibody fragments disclosed herein in any and all applications including diagnostic and therapeutic applications.
  • the antibodies or antibody fragments are used for detecting or monitoring cancer.
  • the antibodies or antibody fragments are used for treating cancer.
  • the present application also includes leader sequences.
  • the leader sequence is encoded by the nucleic acid sequence shown in SEQ ID NO: 20 or comprises the amino acid sequence shown in SEQ ID NO: 21.
  • Such leader sequences can be used to optimize the expression of recombinant proteins including immunotoxins.
  • the present application also includes linker sequences.
  • the present application includes the linker sequences encoded by the amino acid sequences shown in SEQ ID NOs: 15, 17, 32-36.
  • the linker sequences can be used in the preparation of immunotoxins.
  • the present invention will be better understood by the following exemplary teachings. The examples set forth herein are not intended to limit the invention.
  • VB6-901 is a recombinant immunotoxin that comprises an anti-Epithelial Cell Adhesion Molecule (EpCAM) MOCB-Fab fragment genetically fused to a de-immunized Bouganin (deBouganin) via a furin protease sensitive linker (VBRR0405 Increased VB6-901 soluble expression via molecular re-engineering).
  • EpCAM anti-Epithelial Cell Adhesion Molecule
  • deBouganin de-immunized Bouganin
  • VBRR0405 Increased VB6-901 soluble expression via molecular re-engineering
  • variable domains were analyzed in-silico by Antitope and a de-immunized VB5-845-DI and VB6-901-DI were engineered and their biological activity characterized (VBRR0733 Biological characterization of the de- immunized anti-EpCAM 4D5 Fab fragment).
  • furin linker that links the C- terminal end of the light chain to the N-terminus end of deBouganin was also examined. The analysis revealed a weak potential T-cell epitope.
  • the leucine residue of the furin linker was mutated to H (SEQ ID NO: 32), K (SEQ ID NO: 33), N (SEQ ID NO: 34), P (SEQ ID NO: 35) or S (SEQ ID NO: 36) and the level of expression, potency and stability for each clone assessed.
  • the VB6-901-DI with mutation L to K was one of the clones with the highest level of expression and was slightly more potent than the other variants.
  • serum stability analysis and storage at various temperatures showed that the K mutation did not change the stability of the VB6-901 fusion protein.
  • the linker variant fragments were obtained by SOE-PCR, cloned into pCR2.1 plasmid and transformed into 10F E. coli cells for sequencing (SOP 2.1.86, Molecular engineering of a DNA fragment using the splice overlap extension polymerase chain reaction method; SOP 2.1.82, Transformation of a Recombinant Plasmid into Chemically Competent and Electrocompetent E. coli Cells; SOP 2.1.2, Purification of Plasmid DNA using a QIAprep Spin Miniprep Kit; SOP 2.1.131, Sequencing Reaction for the CEQ 8000 Genetic Analysis System).
  • SOP 2.1.86 Molecular engineering of a DNA fragment using the splice overlap extension polymerase chain reaction method
  • SOP 2.1.82 Transformation of a Recombinant Plasmid into Chemically Competent and Electrocompetent E. coli Cells
  • SOP 2.1.2 Purification of Plasmid DNA using a QIAprep Spin Miniprep Kit
  • SOP 2.1.131 Sequ
  • the F-deBouganin linker variant and VB6-901-DI fragments were digested with Bsml-Xhol and EcoRI-Bsml, respectively, and ligated into the pING3302 plasmid digested with EcoRl-Xhol restriction enzymes.
  • the resulting plasmids were then transformed into El 04 E. coli cells for expression (SOP 2.1.86, Molecular engineering of a DNA fragment using the splice overlap extension polymerase chain reaction method).
  • Transformed E104 cells containing the VB6-901-DI/3302 plasmid linker variants were inoculated into 5 mL 2xYT containing 25 ⁇ g/mL tetracycline and incubated at 37°C with constant shaking at 225 rpm. After 16 hours of incubation, 300 overnight seed culture was inoculated into 30 mL TB (1% inoculum), and incubated at 37°C with constant shaking at 225 rpm until an OD 6 oo of 2.0 was attained (SOP 2.1.83, Growth and Expression of E. coli Transformed with a Recombinant pING3302 Plasmid).
  • the culture was induced with 150 L-Arabinose (0.1% final), and incubated at 25°C with constant shaking at 225 rpm. At 16 hours post-induction, the culture supernatant was collected for analysis by Western blot. 3) Western Blot Analysis
  • the level of expression of the VB6-901-DI linker variants was estimated by Western blot analysis. Briefly, 16 of induced culture supernatant and 4 LDS sample buffer were loaded onto a NuPAGE 10% Bis-Tris gel (SOP 2.1.55, Electrophoresis, Transfer and Staining of SDS-Page Gels Using the Novex System). The gel was then transferred to a nitrocellulose membrane at 40V for 1 hour. After blocking and washing the membrane, the VB6-901-DI linker variant proteins were detected using an anti-kappa-horseradish peroxidase antibody (1/1000) for 2 hours at room temperature (SOP 2.1.63, Immunodetection of Electroblotted Proteins). The membrane was developed using DAB, and the level of expression of the VB6-901-DI linker proteins compared to VB6-901-DI.
  • Transformed E.coli cells were grown in Glycerol minimal media (15 L) in a 20 L bioreactor to an OD 6 oo of 50 at which time the cells were induced with the addition of L- arabinose for 30 hrs. Then, the culture supernatant was microfiltered, concentrated 10-fold and buffer exchanged against 20 mM sodium phosphate (5x) for binding onto a 50 mL CM sepharose column. The product in the CM eluate was then flowed through a 25 mL Q- sepharose column and captured on a 5 mL SP-sepharose column. The SP eluate was then applied to a 2 L Sephacryl-S200 size exclusion column and the peaks were fractionated.
  • the product peak fractions were pooled and applied to another 5 mL SP-sepharose column.
  • the bound protein was then eluted in 20 mM sodium phosphate, 300 mM NaCl, pH 7.5, filter sterilized and stored at -20°C.
  • Bound VB6-901-DI linker protein was detected using an anti-kappa-horseradish peroxidase antibody (1/1000) for 1 hour at 22°C.
  • the plate was developed using TMB.
  • the pING3302 plasmid induced culture supernatants were used as a positive and negative control, respectively.
  • Binding reactivity Flow cytometry was used to measure the binding reactivity of the VB6-901-DI linker variants (SOP 2.1.101, Detection of cell-surface bound IgG/IgM by flow cytometry). Briefly, VB6-901-DI variants were incubated at 100 ng/mL with 0.2 x 10 6 CAL-27 cells on ice for 2 hours. After washing with PBS-5% FBS, a biotinylated goat-anti-human IgG antibody (1/200) was added and incubated for 1 hour on ice.
  • the cells were washed with PBS-5% FBS and streptavidin-cy chrome (1/120) was added for 30 minutes on ice to detect cell-bound VB6-901-DI linker variants.
  • the selectivity of the binding was assessed with EpCAM-negative cell line, A-375.
  • Cytotoxicity The cytotoxicity was measured with a MTS assay using EpCAM-positive CAL-27 and OVCAR-3 cells seeded at 5000 cells per well (SOP 2.1.15, MTS Assay). VB6-901 was used as a positive control. The selectivity of the potency was measured with EpCAM-negative cell line, A-375.
  • Serum The mouse and human serum stability of VB6-901-DI linker variants (K and N) was determined by Western blot analysis. Briefly, variants were added at a concentration of 80 ⁇ g/mL in 500 of serum and incubated at 37°C, 5% CO2 for 72 hours. At 0 hour, 24, 48 and 72 hours, samples were vortexed and a 45 aliquot was taken and stored at -20°C in presence of 15 ⁇ . LDS. The Western blot was performed as above, loading 200 ng/well of variant.
  • the VB6-901-DI linker proteins were detected using a rabbit-anti-4D5 antibody (1/1000) for 45 minutes at room temperature, followed by an anti- rabbit-horseradish peroxidase antibody (1/2000) for 45 minutes at room temperature.
  • the membrane was developed with DAB.
  • Storage stability The storage stability of VB6-901-DI linker variants K and N was determined at 37°C, 4°C and -20°C. Briefly, samples were divided into 40 ⁇ .
  • the mutated furin linkers were engineered by SOE-PCR and expressed as VB6-901-DI fusion proteins (NB 1394, p26-44).
  • Selected E104 transformed with VB6-901- DI linker variants cloned into the pING3302 plasmid were induced with L-arabinose.
  • Western blot analysis of two independent clones for each linker variant revealed a band migrating ⁇ 65 kDa present in the supernatant, respectively (FIG. 2).
  • the intensity of the supernatant bands was similar to the positive control VB6-901-DI, suggesting that the mutations in the linker did not affect expression.
  • the VB6-901-DI linker variants were grown in a 15L fermentor using HCD conditions.
  • the ELISA measurement of the CM starting material suggested that the K and N linker had the highest level of expression followed by H and S whereas the P linker was poorly expressed (Table 1).
  • the poor expression of the P linker was due to degradation as indicated by the SEC chromatogram which showed a high level of Fab fragment (data not shown).
  • the higher expression level observed from the supernatant translated into higher purified yield for the K and N linker variants.
  • the biological activity was assessed by flow cytometry and MTS.
  • Table 1 Summary of linker clone selection
  • linker variants were incubated at -20°C, 4°C and 37°C and aliquots were taken after 2, 4, 8 and 13 weeks and the percentage of monomer was assessed by HPLC. Both linker variants were stable at 4°C and -20°C as reported earlier for the WT molecule (VBRR0616 Interim report long term stability testing of VB6-901 VBI C03071 (lOmg/mL) at 12 months).
  • the Examples describe the engineering and biological characterization of VB6-901-DI containing one point mutation within the linker leading to its de-immunization.
  • the in silico analysis of the furin linker and deBouganin junction by Antitope identified one weak potential T-cell epitope. Therefore, based on their recommendation, 4 mutations were tested and the level of expression, biological activity, serum and storage stability were determined and used to select the final clone.
  • the VB6-901-DI linker K was the most potent among the variants. Its expression level was one of the highest and the stability of the molecule was not altered compared to wild-type molecule.
  • VB6-901-DI linker K (SEQ ID NOs: 49 and 71) was therefore selected as the final clone.
  • the mutations introduced for the de-immunization of the Fab fragment resulted in lower binding activity as compared to the wild-type molecule explaining the decreased potency of the linker variants (VBRR00676-R02, Engineering and biological testing of T-cell epitope depleted-Fab moiety of VB6-901).
  • deBouganin-F-AvP07-17 is a recombinant immunotoxin that comprises an anti-Her2 C6.5 diabody fragment (AvP07-17) genetically linked to deBouganin via a furin (F) protease sensitive linker.
  • AvP07-17 anti-Her2 C6.5 diabody fragment
  • F furin
  • debouganin-F-AvP07-17 IC5 0 S were in the subnanomolar range with most of the Her2 3+ tumor cell lines.
  • a new junction between the furin linker and the VH domain was created. To ensure that no potential T-cell epitopes were present, the junction was assessed in-silico by Antitope (Cambridge, UK).
  • the linker variant fragments were obtained by SOE-PCR, cloned into pCR2.1 plasmid and transformed into 10F E. coli cells for sequencing. After confirming the sequence, the deBouganin-F linker variant inserts were digested with Spel-Bglll and ligated into the deBouganin-F-AvP07-17-His/pING3302 plasmid digested with the same restriction enzymes. The resulting plasmids were then transformed into El 04 E. coli cells for expression.
  • deBouganin-F(E)-AvP07-17-His refers to an antibody fragment comprised of, starting at the N-terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 119), an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), and a His tag at the C-terminus, and which is represented by nucleotides 132-1670 of SEQ ID NO: 126 (nucleotide sequence) and by SEQ ID NO: 125 (amino acid sequence).
  • deBouganin-F(T)-AvP07-17-His refers to an antibody fragment comprised of, starting at the N-terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 124), an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), and a His tag at the C-terminus, and which is represented by nucleotides 132-1670 of SEQ ID NO: 128 (nucleotide sequence) and by SEQ ID NO: 127 (amino acid sequence).
  • deBouganin-F(P)-AvP07-17-His refers to an antibody fragment comprised of, starting at the N-terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 35), an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), and a His tag at the C-terminus, and which is represented by nucleotides 132-1670 of SEQ ID NO: 130 (nucleotide sequence) and by SEQ ID NO: 129 (amino acid sequence).
  • a final clone without a His tag was generated by swapping the C-terminal end of AvP07-17-His with AvP07-17 using Bsu36I and Xhol restriction enzymes.
  • deBouganin-F(E)-AvP07-17 refers to an antibody fragment comprised of, starting at the N-terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 119), an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), and which is represented by nucleotides 132-1652 of SEQ ID NO: 132 (nucleotide sequence) and by SEQ ID NO: 131 (amino acid sequence).
  • deBouganin-F(T)- AvP07-17 refers to an antibody fragment comprised of, starting at the N-terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 124), an anti-HER2/neu heavy chain variable region (V H ) linked to an anti-HER2/neu light chain variable region (VL), and which is represented by nucleotides 132-1652 of SEQ ID NO: 134 (nucleotide sequence) and by SEQ ID NO: 133 (amino acid sequence).
  • deBouganin-F(P)-AvP07-17 refers to an antibody fragment comprised of, starting at the N-terminus: deBouganin toxin, deimmunized furin linker (SEQ ID NO: 35), an anti-HER2/neu heavy chain variable region (VH) linked to an anti-HER2/neu light chain variable region (VL), and which is represented by nucleotides 132-1652 of SEQ ID NO: 136 (nucleotide sequence) and by SEQ ID NO: 135 (amino acid sequence).
  • Transformed El 04 cells containing the deBouganin-F-AvP07-l 7/3302 linker variants plasmid were inoculated into 5 mL 2xYT containing 25 ⁇ g/mL tetracycline and incubated at 37°C with constant shaking at 225 rpm. After 16 hours of incubation, 300 overnight seed culture was inoculated into 30 mL TB (1% inoculum), and incubated at 37°C with constant shaking at 225 rpm until an OD600 of 2.0 was attained. The culture was induced with 150 L-Arabinose (0.1% final), and incubated at 25°C with constant shaking at 225 rpm. At 16 hours post-induction, the culture supernatant was collected for analysis by Western blot.
  • the level of expression of the deBouganin-F-AvP07-17/3302 linker variants was estimated by Western blot analysis. Briefly, 16 of induced culture supernatant and 4 ⁇ . LDS sample buffer were loaded onto a NuPAGE 10% Bis-Tris gel. The gel was then transferred to a nitrocellulose membrane at 40V for 1 hour. After blocking and washing the membrane, the deBouganin-F-AvP07-17 linker variant proteins were detected using a rabbit anti-deBouganin antibody followed by an anti-rabbit-HRP antibody. The membrane was developed using DAB, and the level of expression of the deBouganin-F-AvP07-17 linker proteins compared to parental molecule.
  • the cytotoxicity was measured with an MTS assay using Her2-positive BT- 474, SkBR3 and MDA-MB-453 cells seeded at 5000 cells per well. The specificity of the potency was confirmed against a Her2 0/1+ MDA-MB-231 cell line. 5) Serum stability
  • the mouse and human serum stability of deBouganin-F-AvP07-17 linker variants was determined by flow cytometry. Briefly, linker variant and parental fusion proteins were incubated at a concentration of 80 ⁇ g/mL in 500 of serum and placed at 37°C, 5% C02 for 48 hours. At 0, 24 and 48 hours, samples were vortexed and a 45 aliquot was taken and stored at -20°C. Flow cytometry was used to measure the binding reactivity of the deBouganin-F-AvP07-17 linker variants and compared to the parental protein.
  • deBouganin-F-AvP07-17 fusion proteins were incubated at 100 ng/mL with 0.2 x 10 6 BT-474 cells on ice for 2 hours. After washing with PBS-5% FBS, a rabbit-anti- deBouganin antibody (1/100) was added and incubated for 1 hour on ice. The cells were washed with PBS-5% FBS and an anti-rabbit-FITC (1/100) was added for 30 minutes on ice to detect cell-bound deBouganin-F-AvP07-17 fusion proteins.
  • T-cell epitope (TRHROPRGWEOLOVO VOSGAEVKK ⁇ GES KT) was performed by Antitope and revealed one high affinity potential T-cell epitope (FIG. 4). Therefore to eliminate the potential T-cell epitope, recommended mutations of the leucine residue (in bold) in order of preference were either proline (P), glutamic acid (E), threonine (T), glycine (G), aspartic acid (D) or alanine (A).
  • P proline
  • E glutamic acid
  • T threonine
  • G glycine
  • D aspartic acid
  • A alanine
  • the first three mutations of the furin linker (P, E and T) were engineered by SOE-PCR and expressed as deBouganin-F-AvP07-17-His fusion proteins (see Molecular engineering in Example 3). Westem blot analysis of two independent clones for each linker variant revealed a deBouganin-F-AvP07-17-His band migrating ⁇ at 50 kDa present in the supernatant (FIG. 5A). The expression level of the linker variants P (SEQ ID NO: 129) and E (SEQ ID NO: 125) was similar to the parental fusion protein whereas linker variant T was slightly lower.
  • the non-His version was engineered for P (SEQ ID NO: 135) and E (SEQ ID NO: 131) linker variants (see Molecular engineering in Example 3). As seen in FIG. 5B, the soluble expression level of both variants was similar to the parental molecule.
  • Examples 3 and 4 describe the engineering and biological characterization of deBouganin fused to the C6.5 diabody fragment with a furin linker containing different point mutations required for its de-immunization.
  • the in silico analysis of the junction between the furin linker and the VH domain by Antitope identified one strong potential T-cell epitope. Therefore, based on their recommendation, 2 mutations were tested and the level of expression, biological activity and serum stability were determined and used to select the final clone.
  • the deBouganin-F(E)-AvP07-17 (SEQ ID NO: 131) potency was similar to the parental molecule against representative Her2 3+ tumor cell lines.
  • the serum stability of the deBouganin-F(E)-AvP07-17 fusion protein was superior to the parental and P linker variant. Therefore, the deBouganin-F(E)-AvP07-17 (SEQ ID NO: 131) was selected for preclinical study. The de-immunization of the furin linker- VH junction will be confirmed using overlapping 15-mer peptides in a T-cell proliferation assay. It is expected that the E mutation will lead to a lower stimulation index of the T-cells.
  • NetMHCII and NetMHCIIpan were employed for the identification of potential T-helper cell epitopes for the most prevalent HLA-alleles, i.e. Alleles found in more than 1% of the population.
  • the first 100 amino acids of Furin-deBouganin and Furin(K)- deBouganin were analyzed for sub-15mer MHC II binding peptides restricted to each of the HLA alleles by decomposing the protein to overlapping 15-mer peptides.

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Abstract

La présente invention concerne de nouveaux lieurs peptidiques sensibles à la furine protéase désimmunisés qui ont été modifiés génétiquement spécifiquement pour être dépourvus d'épitopes de lymphocytes T et par conséquent provoquer une réponse immunitaire réduite. La présente invention concerne également des immunotoxines comprenant de tels lieurs et des méthodes d'utilisation desdites immunotoxines comprenant ces lieurs.
PCT/US2016/033629 2015-05-20 2016-05-20 Lieur désimmunisé et méthodes d'utilisation Ceased WO2016187585A1 (fr)

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US11154622B2 (en) 2015-11-11 2021-10-26 Precigen, Inc. Compositions and methods for expression of multiple biologically active polypeptides from a single vector for treatment of cardiac conditions and other pathologies
US11208634B2 (en) * 2015-10-02 2021-12-28 Regents Of The University Of Minnesota Deimmunized therapeutic compositions and methods
US20220090113A1 (en) * 2019-02-18 2022-03-24 Atb Therapeutics Method of producing a binder-toxin fusion protein in a plant cell or a whole plant

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US20030021792A1 (en) * 2001-06-08 2003-01-30 Roben Paul W. Tissue-specific endothelial membrane proteins
US20080292618A1 (en) * 2007-05-24 2008-11-27 The Regents Of The University Of California Intranuclear protein transduction through a nucleoside salvage pathway
US20100215670A1 (en) * 2006-10-30 2010-08-26 Jeannick Cizeau Immunotoxin Fusions Comprising An Antibody Fragment and a Plant Toxin Linked by Protease Cleavable Linkers
US20130121983A1 (en) * 2011-09-06 2013-05-16 Intrexon Corporation Modified Forms of Pseudomonas Exotoxin A
US20140155581A1 (en) * 2011-07-06 2014-06-05 Medimmune, Llc Methods For Making Multimeric Polypeptides

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US20030021792A1 (en) * 2001-06-08 2003-01-30 Roben Paul W. Tissue-specific endothelial membrane proteins
US20100215670A1 (en) * 2006-10-30 2010-08-26 Jeannick Cizeau Immunotoxin Fusions Comprising An Antibody Fragment and a Plant Toxin Linked by Protease Cleavable Linkers
US20080292618A1 (en) * 2007-05-24 2008-11-27 The Regents Of The University Of California Intranuclear protein transduction through a nucleoside salvage pathway
US20140155581A1 (en) * 2011-07-06 2014-06-05 Medimmune, Llc Methods For Making Multimeric Polypeptides
US20130121983A1 (en) * 2011-09-06 2013-05-16 Intrexon Corporation Modified Forms of Pseudomonas Exotoxin A

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11208634B2 (en) * 2015-10-02 2021-12-28 Regents Of The University Of Minnesota Deimmunized therapeutic compositions and methods
US11154622B2 (en) 2015-11-11 2021-10-26 Precigen, Inc. Compositions and methods for expression of multiple biologically active polypeptides from a single vector for treatment of cardiac conditions and other pathologies
US20220090113A1 (en) * 2019-02-18 2022-03-24 Atb Therapeutics Method of producing a binder-toxin fusion protein in a plant cell or a whole plant

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