HK1251589B

HK1251589B - Targeted/immunomodulatory fusion proteins and methods for making same

Info

Publication number: HK1251589B
Application number: HK18110998.1A
Authority: HK
Inventors: Nagaraj Govindappa; Kedarnath Sastry; Maria Melina Soares
Original assignee: Biocon Limited
Priority date: 2012-04-30
Filing date: 2018-08-27
Publication date: 2023-04-14

Description

CROSS REFERENCE TO RELATED APPLICATIONS

The application claims priority to Indian Patent Application No. 1689/CHE/2012 filed on April 30, 2012 and Indian Patent Application No. 1690/CHE/2012 filed on April 30, 2012 .

BACKGROUND OF THE INVENTION Technical Field

The present invention relates generally to the field of generating fusion proteins to be used in cancer therapy, wherein the fusion or chimeric polypeptides comprises at least one targeting moiety and at least one immunomodulatory moiety that counteracts the immune tolerance of cancer cells.

Related Art

The immune system provides the human body with a means to recognize and defend itself against microorganisms and substances recognized as foreign or potentially harmful. While passive immunotherapy of cancer with monoclonal antibodies and passive transfer of T cells to attack tumor cells have demonstrated clinical efficacy, the goal of active therapeutic vaccination to induce these immune effectors and establish immunological memory against tumor cells has remained challenging. Several tumor-specific and tumor-associated antigens have been identified, yet these antigens are generally weakly immunogenic and tumors employ diverse mechanisms to create a tolerogenic environment that allows them to evade immunologic attack. Strategies to overcome such immune tolerance and activating robust levels of antibody and/or T cell responses hold the key to effective cancer immunotherapy. More important, the individual proteins and how to create an active chimeric polypeptide with an active tertiary structure needs to be explored. WO2011/109789 discloses chimeric molecules comprising a targeting moiety fused with an immunomodulatory moiety. WO 2009/027471 discloses optimized fusion proteins and methods for the preparation thereof.

SUMMARY OF THE INVENTION

The present invention provides polypeptides that are expressed in cancer cells. These expressed polypeptides are useful in a variety of therapeutic methods for the treatment of cancer. Also disclosed are methods of reducing growth of cancer cells by counteracting immune tolerance of cancer cells, wherein T cell remain active and inhibit the recruitment of T-regulatory that are known to suppress the immune system's response to the tumor. Thus the chimeric polypeptides of the present invention are useful for treating cancer because of the expressed fusion or chimeric polypeptides.

The present invention provides for a bi-specific chimeric fusion protein consisting of a targeting moiety that binds to CTLA4 and an immunomodulating moiety that binds to PD-L1, wherein the targeting moiety and the immunomodulating moiety are linked by an amino acid spacer selected from SEQ ID NO: 3 or SEQ ID NO: 11, wherein the immunomodulating moiety is PD1 consisting of the amino acid sequence of SEQ ID NO: 10, wherein the targeting moiety is anti-CTLA4 antibody consisting of heavy chain SEQ ID NO: 7 and light chain SEQ ID NO: 8, wherein SEQ ID NO: 10 is attached via the amino acid spacer to the C-terminus of SEQ ID NO: 7 or SEQ ID NO: 8

The present invention is based on expression of fusion proteins that counteract or reverse immune tolerance of cancer cells. Cancer cells are able to escape elimination by chemotherapeutic agents or tumor-targeted antibodies via specific immunosuppressive mechanisms in the tumor microenvironment and such ability of cancer cells is recognized as immune tolerance. Such immunosuppressive mechanisms include immunosuppressive cytokines (for example, Transforming growth factor beta (TGF-β)) and regulatory T cells and/or immunosuppressive myeloid dendritic cells

(DCs). By counteracting tumor-induced immune tolerance, the present invention provides effective compositions and methods for cancer treatment, optional in combination with another existing cancer treatment. The present invention provides strategies to counteract tumor-induced immune tolerance and enhance the antitumor efficacy of chemotherapy by activating and leveraging T cell-mediated adaptive antitumor against resistant or disseminated cancer cells.

The immunomodulatory moiety specifically binds Programmed death-1 ligand 1 (PD-Ll) .

The targeting moiety includes an antibody that specifically binds to cytotoxic T-lymphocyte antigen-4 (CTLA-4).

The targeting moiety includes an antibody that specifically binds to cytotoxic T-lymphocyte antigen-4 (CTLA-4) and the immunomodulatory moiety includes an extracellular ligand-binding domain or ectodomain of Programmed Death-1 (PD-1).

The therapeutically active antibody-peptide fusion protein is a targeting antibody fused to one immunomodulating moiety that counteracts immune tolerance of a cancer cell. The immunomodulating moiety is linked by an amino acid spacer of sufficient length to allow bi-specific binding of the molecule. The immunomodulating moiety is bound to either the C-terminus of the heavy or light chain of the antibody.

The immunomodulating moiety is Programmed death-1 (PD-1) and the targeting antibody binds CTLA-4.

The present invention provides therapeutically active antibody-peptide fusion proteins and such expression may be conducted in a transient cell line or a stable cell line. The transient expression is accomplished by transfecting or transforming the host with vectors carrying the fusion proteins into mammalian host cells.

Once the fusion peptides are expressed, they are preferably subjected to purification and in-vitro tests to check its bi-specificity, that being, having the ability to bind to both the target moiety and immunomodulating moiety. Such tests may include in-vitro test such as ELISA or NK/T-cell binding assays to validate bi-functional target binding or immune cell stimulation.

Notably once the specific fusion peptides demonstrate the desired bi-specificity, such fusion peptides are selected for sub-cloning into a stable cell line for larger scale expression and purification. Such stable cell lines are previously disclosed, such as a mammalian cell line, including but not limited to HEK293, CHO or NSO.

Other features and advantages of the invention will be apparent from the following detailed description, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures 1-8 and 10-65 are not according to the invention and are present for illustration purposes only.

Figure 1 shows the amino acid sequences of Anti-HER2/neu-TGFβRII fusion protein at LC constant region with the amino acid sequence of anti-HER2/neu heavy chain (SEQ ID NO: 1) and anti-HER2/neu light chain (SEQ ID NO: 2) attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters and wherein a linker (SEQ ID NO: 3) is positioned between the anti-HER2/neu light chain and TGF-βRII and shown in italics.
Figure 2 shows the amino acid sequences of Anti-EGFR1-TGFβRII fusion protein at LC constant region with amino acid sequence of Anti-EGFR1 heavy chain (SEQ ID NO: 5) and the amino acid sequence of Anti-EGFR1 light chain (SEQ ID NO: 6) attached to amino acid residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters and wherein a linker (SEQ ID NO: 3) is positioned between the Anti-EGFR1 light chain and TGF-βRII and shown in italics.
Figure 3 shows the amino acid sequences of Anti-CTLA4-TGFβRII fusion protein at LC constant region with amino acid sequence of anti-CTLA4 heavy chain (SEQ ID NO: 7) and amino acid sequence of anti-CTLA4 light chain (SEQ ID NO: 8) attached to amino acid residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters and wherein a linker (SEQ ID NO: 3) is positioned between the anti-CTLA4 light chain and TGF-βRII and shown in italics.
Figure 4 shows the amino acid sequences of Anti-HER2/neu HC-4-1BB and LC-TGFβRII fusion protein with amino acid sequence of Anti-HER2/neu/HC-4-1BB fusion protein wherein the amino acid sequence for Anti-HER2/neu heavy chain (SEQ ID NO: 1) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font and amino acid sequence of anti-HER2/neu light chain (SEQ ID NO: 2) attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters and wherein a linker (SEQ ID NO: 3) is positioned between the anti-HER2/neu light chain and TGF-βRII and shown in italics.
Figure 5 shows the amino acid sequence of Anti-EGFR1 HC-4-1BB and LC-TGFβRII fusion protein with amino acid sequence of Anti-EGFR1 heavy chain-4-1BB fusion protein wherein the amino acid sequence for Anti-EGFR1 heavy chain (SEQ ID NO: 5) is attached to a linker (SEQ ID NO: 3) is shown in italics and the sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font and amino acid sequence of light chain Anti-EGFR1 (SEQ ID NO: 6) attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 6 shows the amino acid sequence of Anti-CTLA4 HC-4-1BB and LC-TGFβRII fusion protein with amino acid sequence of Anti-CTLA4 heavy chain-4-1BB fusion protein wherein the amino acid sequence for Anti-CTLA4 heavy chain (SEQ ID NO: 7) is attached to a linker (SEQ ID NO: 3) is shown in italics and the sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font and amino acid sequence of Anti-CTLA4 light chain (SEQ ID NO: 8) is attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 7 shows the amino acid sequence of Anti-HER2/neu HC-PD1 and LC-TGFβRII fusion protein with amino acid sequence of Anti-HER2/neu heavy chain-PD1 fusion protein wherein the amino acid sequence for the Anti-HER2/neu heavy chain (SEQ ID NO: 1) is attached to a linker (SEQ ID NO: 3) is shown in italics and the sequence for PD1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font and amino acid sequence of Anti-HER2/neu light chain (SEQ ID NO: 2) is attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 8 shows the amino acid sequence of Anti-EGFR1 HC-PD1 and LC-TGFβRII fusion protein with amino acid sequence of Anti-EGFR1 heavy chain-PD1 fusion protein wherein the amino acid sequence Anti-EGFR1 heavy chain (SEQ ID NO: 5) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for PD1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font and amino acid sequence of Anti-EGFR1 light chain (SEQ ID NO: 6) attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 9 shows the amino acid sequence of Anti-CTLA4 HC-PD1 and LC-TGFβRII fusion protein with amino acid sequence of Anti-CTLA4 heavy chain-PD1 fusion protein wherein the amino acid sequence Anti-CTLA4 heavy chain (SEQ ID NO: 7) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for PD1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font and amino acid sequence of Anti-CTLA4 light chain (SEQ ID NO: 8) attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 10 shows the amino acid sequence of Anti-HER2/neu HC-TGFβRII-4-1BB fusion protein with amino acid sequence of Anti-HER2/neu heavy chain-TGFβRII-4-1BB fusion protein wherein the amino acid sequence for Anti-HER2/neu heavy chain (SEQ ID NO: 1 with an additional Lys on the C-terminal) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font with linker between (SEQ ID No: 11) and including the amino acid sequence of Anti-HER2/neu light chain (SEQ ID NO: 2).
Figure 11 shows the amino acid sequence of Anti-EGFR1 HC-TGFβRII-4-1BB fusion protein with amino acid sequence of Anti-EGFR1 heavy chain-TGFβRII-4-1BB fusion protein wherein the amino acid sequence for Anti-EGFR1 heavy chain (SEQ ID NO: 5 with an additional Lys on the C-terminal) sequence is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font with linker between (SEQ ID NO: 11) and including the amino acid sequence of Anti-EGFR1 light chain (SEQ ID NO: 6).
Figure 12 shows the amino acid sequence of Anti-CTLA4 HC-TGFβRII-4-1BB fusion protein with amino acid sequence of Anti-CTLA4 heavy chain-TGFβRII-4-1BB fusion protein wherein the amino acid sequence Anti-CTLA4 heavy chain (SEQ ID NO: 7 with an additional Lys on the C-terminal) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font with linker between (SEQ ID NO: 11) and including the amino acid sequence of Anti-CTLA4 light chain (SEQ ID NO: 8).
Figure 13 shows the amino acid sequence of Anti-HER2/neu HC-TGFβRII-PD1 fusion protein with amino acid sequence of Anti-HER2/neu heavy chain-TGFβRII-PD1 fusion protein wherein the amino acid sequence Anti-HER2/neu heavy chain (SEQ ID NO: 1 with an additional Lys on the C-terminal) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for PD-1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font with linker between (SEQ ID No: 11) and including the amino acid sequence of Anti-HER2/neu light chain (SEQ ID NO: 2).
Figure 14 shows the amino acid sequence of Anti-EGFR1 HC-TGFβRII-PD1 fusion protein with amino acid sequence of Anti-EGFR1 heavy chain-TGFβRII-PD1 fusion protein wherein the amino acid sequence Anti-EGFR1 heavy chain (SEQ ID NO: 5 with an additional Lys on the C-terminal) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for PD-1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font with linker between (SEQ ID No: 11) and including the amino acid sequence of Anti-EGFR1 light chain (SEQ ID NO: 6).
Figure 15 shows the of Anti-CTLA4 HC-TGFβRII-PD1 fusion protein with amino acid sequence of Anti-CTLA4 heavy chain-TGFβRII-PD1 fusion protein wherein the amino acid sequence Anti-CTLA4 heavy chain (SEQ ID NO: 7 with an additional Lys on the C-terminus) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for PD-1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font with linker between (SEQ ID NO: 11) and including the amino acid sequence of Anti-CTLA4 light chain (SEQ ID NO: 8).
Figure 16 shows the nucleotide sequence of Anti-HER2/neu heavy chain constant region with linker (SEQ ID NO: 12) and TGFβRII ECD (SEQ ID NO: 13) that have been codon optimized for expression in CHO cell.
Figure 17 shows the nucleotide sequence of Anti-HER2/neu heavy chain variable region (SEQ ID NO: 14), Anti-HER2/neu light chain variable region (SEQ ID NO: 15) and Anti-EGFR1 heavy chain constant region with linker (SEQ ID NO: 16) that have been codon optimized for expression in CHO cell.
Figure 18 shows the nucleotide sequence of Anti-EGFR1 heavy chain variable region (SEQ ID NO: 17), Anti-EGFR1 light chain variable region (SEQ ID NO: 18), Anti-CTLA4 heavy chain variable region (SEQ ID NO: 19) and Anti-CTLA4 light chain variable region (SEQ ID NO: 20) that have been codon optimized for expression in CHO cell.
Figure 19 shows the nucleotide sequence of Anti CD20 IgG1 molecule (SEQ ID NO: 21), Anti-CD20 heavy chain variable region (SEQ ID NO: 22) and Anti-CD20 light chain variable region (SEQ ID NO: 23) that have been codon optimized for expression in CHO cell.
Figure 20 shows the nucleotide sequence of 4-1BB (SEQ ID NO: 24) and Anti-IL6R heavy chain (SEQ ID NO: 25) that have been codon optimized for expression in CHO cell.
Figure 21 shows the nucleotide sequence of Anti-IL6R light chain variable region (SEQ ID NO: 26), Anti-4-1BB heavy chain (SEQ ID NO: 27) and Anti-4-1BB light chain variable region (SEQ ID NO: 28) that have been codon optimized for expression in CHO cell.
Figure 22 shows the analysis of Protein A purified Anit-HER2/neu-TGFβRII and Anti-EGFR1- TGFβRII at 12 % PAGE
Figure 23 A shows Anti-HER2/neu-TGFβRII samples analyzed by Protein A/SEC Chromtography and B Anti-EGFR1-TGFβRII samples analyzed by Protein A/SEC Chromtography.
Figure 24 A shows that Anti-HER2/neu-TGFβRII and Anti-EGFR1-TGFβRII molecules bind to the TGFβ indicating that the fusion protein is functional and B shows that Anti-HER2-TGFβRII inhibits the proliferation of BT474 cell line similar to the Bmab200 (Herceptin).
Figure 25 shows that Anti-EGFR1-TGFβRII-inhibits the proliferation of A431 cell line similar to the Cetuximab.
Figure 26 shows the ADCC activity of Anti-HER2-TGFβRII on BT474 cells is similar to that of Bmab200 (Herceptin).
Figure 27 shows the ADCC activity of Anti-EGFR1-TGFβRII on A431 cells wherein the ADCC activities are similar to that of Cetuximab.
Figure 28 shows the ADCC activity of ADCC activity of Anti-EGFR1-4-1BB in comparison with Anti-EGFR1-TGFβRIIand cetuximab.
Figure 29 A shows that the binding activity of Anti-CTLA4-TGFβRII to TGFβ1 is comparable to Anti-EGFR1-TGFβRII and B shows that the binding activity of Anti-CTLA4-TGFβRII to CTLA4.
Figure 30 A shows the binding activity of Anti-CTLA4-TGFβRII to determine the level of PD1-Fc binding and B shows the binding activity of Anti-EGRF1-4-1BB to determine the binding of 4-1BBL.
Figure 31 shows the binding activity of Anti-EGFR1-4-1BB to EGFR and B shows the binding activity of PD1-Fc-4-1BB to find out PDL1-Fc.
Figure 32 shows the binding activity of Anti-EGFR1-PD1 to EGFR and PD1.
Figure 33 shows photographs of expressed proteins and reduction alkylation thereof.
Figure 34 A shows the mass spectrum Mass Spectrum of light chain (LC) (Reduced) of Anti-HER2/neu-TGFβRII ECD fusion and B shows Deconvoluted Mass Spectrum of LC (Reduced) of Anti-HER2/neu-TGFβRII ECD fusion.
Figure 35 shows the Mass Spectrum of heavy chain (HC) (Reduced) of Anti-HER2/neu-TGFβRII ECD fusion.
Figure 36A shows the Mass Spectrum of LC (Reduced) of Anti-EGFR1-TGFβRII ECD and B shows the Deconvoluted Mass Spectrum of LC (Reduced) of Anti-EGFR1-TGFβRII ECD.
Figure 37 shows the Mass Spectrum of HC (Reduced) of Anti-EGFR1-TGFβRII ECD.
Figure 38 A shows the UV Chromatogram of Tryptic Peptides of Anti-HER2/neu-TGFβRII ECD fusion protein and B shows the Total Ion Chromatogram (TIC) of Tryptic Peptides of Anti-HER2/neu-TGFβRII ECD fusion protein.
Figures 39, 40 and 41 provide lists of expected/observed tryptic peptide of the light chain, heavy chain and linked motif of the Anti-HER2/neu-TGFβRII ECD fusion protein, respectively.
Figure 42 A shows the UV Chromatogram of Tryptic Peptides of Anti-EGFR1-TGFβRII ECD fusion protein and B shows the Total Ion Chromatogram (TIC) of Tryptic Peptides of Anti-EGFR1-TGFβRII ECD fusion protein.
Figure 43 provides a list of expected/observed tryptic peptide of the light chain of the Anti-EGFR1-TGFβRII ECD fusion protein.
Figure 44 shows the list of expected/observed tryptic peptide of the heavy chain of the Anti-EGFR1-TGFβRII ECD fusion protein.
Figure 45 shows the list of expected/observed tryptic peptide of the heavy chain of the Anti-EGFR1-TGFβRII ECD fusion protein.
Figure 46 shows the amino acid sequences of Cantuzumab -TGFβRII fusion protein at LC constant region with amino acid sequence of Cantuzumab heavy chain (SEQ ID NO: 29) and amino acid sequence of Cantuzumab light chain (SEQ ID NO: 30) attached to amino acid residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters and wherein a linker (SEQ ID NO: 3) is positioned between the Cantuzumab light chain and TGF-βRII and shown in italics.
Figure 47 shows the amino acid sequences of Cixutumumab-TGFβRII fusion protein at LC constant region with amino acid sequence of Cixutumumab heavy chain (SEQ ID NO: 31) and amino acid sequence of Cixutumumab light chain (SEQ ID NO: 32 with an additional Ser on the C-terminus) attached to amino acid residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters and wherein a linker (SEQ ID NO: 3) is positioned between the Cixutumumab light chain and TGF-βRII and shown in italics.
Figure 48 shows the amino acid sequences of Clivatuzumab-TGFβRII fusion protein at LC constant region with amino acid sequence of Clivatuzumab heavy chain (SEQ ID NO: 33) and amino acid sequence of Clivatuzumab light chain (SEQ ID NO: 34) attached to amino acid residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters and wherein a linker (SEQ ID NO: 3) is positioned between the Clivatuzumab light chain and TGF-βRII and shown in italics.
Figure 49 shows the amino acid sequences of Pritumumab-TGFβRII fusion protein at LC constant region with amino acid sequence of Pritumumab heavy chain (SEQ ID NO: 35) and amino acid sequence of Pritumumab light chain (SEQ ID NO: 36) attached to amino acid residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters and wherein a linker (SEQ ID NO: 3) is positioned between the Pritumumab light chain and TGF-βRII and shown in italics.
Figure 50 shows the amino acid sequence of Cantuzumab HC-4-1BB and LC-TGFβRII fusion protein wherein the amino acid sequence for the Cantuzumab heavy chain (SEQ ID NO: 29) is attached to a linker (SEQ ID NO: 3) which is shown in italics and the sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font and amino acid sequence of Cantuzumab light chain (SEQ ID NO: 30) is attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 51 shows the amino acid sequence of Cixutumumab HC-4-1BB and LC-TGFβRII fusion protein wherein the amino acid sequence for the Cixutumumab heavy chain (SEQ ID NO: 31) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font and amino acid sequence of Cixutumumab light chain (SEQ ID NO: 32 with an additional Ser on the C-terminus) is attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 52 shows the amino acid sequence of Clivatuzumab HC-4-1BB and LC-TGFβRII fusion protein wherein the amino acid sequence for the Clivatuzumab heavy chain (SEQ ID NO: 33) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font and amino acid sequence of Clivatuzumab light chain (SEQ ID NO: 34) is attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 53 shows the amino acid sequence of Pritumumab HC-4-1BB and LC-TGFβRII fusion protein wherein the amino acid sequence for the Pritumumab heavy chain (SEQ ID NO: 35) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font and amino acid sequence of Pritumumab light chain (SEQ ID NO: 36) is attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 54 shows the amino acid sequence of Cantuzumab - HC-PD1 and LC-TGFβRII fusion protein wherein the amino acid sequence for the Cantuzumab heavy chain (SEQ ID NO: 29) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for PD1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font and amino acid sequence of Cantuzumab light chain (SEQ ID NO: 30) is attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 55 shows the amino acid sequence of Cixutumumab - HC-PD1 and LC-TGFβRII fusion protein wherein the amino acid sequence for the Cixutumumab heavy chain (SEQ ID NO: 31) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for PD1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font and amino acid sequence of Cixutumumab light chain (SEQ ID NO: 32 with an additional Ser on the C-terminus) is attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 56 shows the amino acid sequence of Clivatuzumab - HC-PD1 and LC-TGFβRII fusion protein wherein the amino acid sequence for the Clivatuzumab heavy chain (SEQ ID NO: 33) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for PD1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font and amino acid sequence of Clivatuzumab light chain (SEQ ID NO: 34) is attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 57 shows the amino acid sequence of Pritumumab - HC-PD1 and LC-TGFβRII fusion protein wherein the amino acid sequence for the Pritumumab heavy chain (SEQ ID NO: 35) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for PD1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font and amino acid sequence of Pritumumab light chain (SEQ ID NO: 36) is attached to amino residues for TGF-βRII (immunomodulatory moiety) (SEQ ID NO: 4) identified in bold letters with a linker (SEQ ID NO: 3) therebetween.
Figure 58 shows the amino acid sequence of Cantuzumab HC-TGFβRII-4-1BB fusion protein wherein the amino acid sequence for Cantuzumab heavy chain (SEQ ID NO: 29) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font with linker between (SEQ ID No: 11) and including the amino acid sequence of Cantuzumab light chain (SEQ ID NO: 30).
Figure 59 shows the amino acid sequence of Cixutumumab HC-TGFβRII-4-1BB fusion protein wherein the amino acid sequence for Cixutumumab heavy chain (SEQ ID NO: 31) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font with linker between (SEQ ID No: 11) and including the amino acid sequence of Cixutumumab light chain (SEQ ID NO: 32 with an additional Ser on the C-terminus).
Figure 60 shows the amino acid sequence of Clivatuzumab HC-TGFβRII-4-1BB fusion protein wherein the amino acid sequence for Clivatuzumab heavy chain (SEQ ID NO: 33) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font with linker between (SEQ ID No: 11) and including the amino acid sequence of Clivatuzumab light chain (SEQ ID NO: 34).
Figure 61 shows the amino acid sequence of Pritumumab HC-TGFβRII-4-1BB fusion protein wherein the amino acid sequence for Pritumumab heavy chain (SEQ ID NO: 35) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for 4-1BB (immunomodulatory moiety) (SEQ ID NO: 9) is in written text font with linker between (SEQ ID No: 11) and including the amino acid sequence of Pritumumab light chain (SEQ ID NO: 36).
Figure 62 shows the amino acid sequence of Cantuzumab HC-TGFβRII-PD1 fusion protein wherein the amino acid sequence for Cantuzumab heavy chain (SEQ ID NO: 29) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for PD1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font with linker between (SEQ ID No: 11) and including the amino acid sequence of Cantuzumab light chain (SEQ ID NO: 30).
Figure 63 shows the amino acid sequence of Cixutumumab HC-TGFβRII-PD1 fusion protein wherein the amino acid sequence for Cixutumumab heavy chain (SEQ ID NO: 31) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for PD1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font with linker between (SEQ ID No: 11) and including the amino acid sequence of Cixutumumab light chain (SEQ ID NO: 32 with an additional Ser on the C-terminus).
Figure 64 shows the amino acid sequence of Clivatuzumab HC-TGFβRII-PD1 fusion protein wherein the amino acid sequence for Clivatuzumab heavy chain (SEQ ID NO: 33) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for PD1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font with linker between (SEQ ID No: 11) and including the amino acid sequence of Clivatuzumab light chain (SEQ ID NO: 34).
Figure 65 shows the amino acid sequence of Pritumumab HC-TGFβRII-PD1 fusion protein wherein the amino acid sequence for Pritumumab heavy chain (SEQ ID NO: 35) is attached to a linker (SEQ ID NO: 3) shown in italics and the sequence for TGFβRII (immunomodulatory moiety) (SEQ ID NO: 4) is identified in bold letters and the amino acid sequence for PD1 (immunomodulatory moiety) (SEQ ID NO: 10) is in written text font with linker between (SEQ ID No: 11) and including the amino acid sequence of Pritumumab light chain (SEQ ID NO: 36).

DETAILED DESCRIPTION OF THE INVENTION

The practice of the present invention will employ, unless otherwise indicated, conventional techniques of immunology, molecular biology, microbiology, cell biology and recombinant DNA, which are within the skill of the art. See, e.g., Sambrook, et al. MOLECULAR CLONING: A LABORATORY MANUAL, 2nd edition (1989); CURRENT PROTOCOLS IN MOLECULAR BIOLOGY (F. M. Ausubel, et al. eds., (1987)); the series METHODS IN ENZYMOLOGY (Academic Press, Inc.): PCR 2: A PRACTICAL APPROACH (M. J. MacPherson, B. D. Hames and G. R. Taylor eds. (1995)), Harlow and Lane, eds. (1988) ANTIBODIES, A LABORATORY MANUAL, and ANIMAL CELL CULTURE (R. I. Freshney, ed. (1987)).

Definitions

Unless otherwise defined, all technical and scientific terms used herein have the meaning commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The following terms have the meanings given:

The term "polynucleotide" as used herein means a sequence of nucleotides connected by phosphodiester linkages. Polynucleotides are presented herein in the direction from the 5' to the 3' direction. A polynucleotide can be a deoxyribonucleic acid (DNA) molecule or ribonucleic acid (RNA) molecule. Where a polynucleotide is a DNA molecule, that molecule can be a gene or a cDNA molecule. Nucleotide bases are indicated herein by a single letter code: adenine (A), guanine (G), thymine (T), cytosine (C), inosine (I) and uracil (U). A polynucleotide can be prepared using standard techniques well known to one of skill in the art.

The term, "optimized" as used herein means that a nucleotide sequence has been altered to encode an amino acid sequence using codons that are preferred in the production cell or organism, generally a eukaryotic cell, for example, a cell of Pichia, a cell of Trichoderma, a Chinese Hamster Ovary cell (CHO) or a human cell. The optimized nucleotide sequence is engineered to retain completely or as much as possible the amino acid sequence originally encoded by the starting nucleotide sequence, which is also known as the "parental" sequence. The optimized sequences herein have been engineered to have codons that are preferred in CHO mammalian cells; however optimized expression of these sequences in other eukaryotic cells is also envisioned herein. The amino acid sequences encoded by optimized nucleotide sequences are also referred to as optimized. The term "expression" as used herein is defined as the transcription and/or translation of a particular nucleotide sequence driven by its promoter.

The term "transfection" of a cell as used herein means that genetic material is introduced into a cell for the purpose of genetically modifying the cell. Transfection can be accomplished by a variety of means known in the art, such as transduction or electroporation.

The term "cancer" as used herein is defined as disease characterized by the rapid and uncontrolled growth of aberrant cells. Cancer cells can spread locally or through the bloodstream and lymphatic system to other parts of the body. Examples of various cancers include but are not limited to, breast cancer, prostate cancer, ovarian cancer, cervical cancer, skin cancer, ocular cancer, pancreatic cancer, colorectal cancer, renal cancer, liver cancer, brain cancer, lymphoma, leukemia, lung cancer and the like.

The term "transgene" is used in a broad sense to mean any heterologous nucleotide sequence incorporated in a vector for expression in a target cell and associated expression control sequences, such as promoters. It is appreciated by those of skill in the art that expression control sequences will be selected based on ability to promote expression of the transgene in the target cell. An example of a transgene is a nucleic acid encoding a chimeric fusion protein of the present invention.

The term "expression vector" as used herein means a vector containing a nucleic acid sequence coding for at least part of a gene product capable of being transcribed. Expression vectors can contain a variety of control sequences, which refer to nucleic acid sequences necessary for the transcription and possibly translation of an operatively linked coding sequence in a particular host organism. In addition to control sequences that govern transcription and translation, vectors and expression vectors may contain nucleic acid sequences that serve other functions as well. The term also includes a recombinant plasmid or virus that comprises a polynucleotide to be delivered into a host cell, either in vitro or in vivo. Preferably the host cell is a transient cell line or a stable cell line and more preferably a mammalian host cell and selected from the group consisting of HEK293, CHO and NSO.

The tern "subject," as used herein means a human or vertebrate animal including a dog, cat, horse, cow, pig, sheep, goat, chicken, monkey, rat, and mouse.

The term "therapeutically effective amount" as used herein means the amount of the subject compound that will elicit the biological or medical response of a tissue, system, animal or human that is being sought by the researcher, veterinarian, medical doctor or other clinician.

The term "pharmaceutically acceptable" as used herein means the carrier, diluent or excipient must be compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.

The term "recombinant" as used herein means a genetic entity distinct from that generally found in nature. As applied to a polynucleotide or gene, this means that the polynucleotide is the product of various combinations of cloning, restriction and/or ligation steps, and other procedures that result in the production of a construct that is distinct from a polynucleotide found in nature.

The term "substantial identity" or "substantial similarity," as used herein when referring to a nucleic acid or fragment thereof, indicates that when optimally aligned with appropriate nucleotide insertions or deletions with another nucleic acid (or its complementary strand), there is nucleotide sequence identity in at least about 95 to 99% of the sequence.

The term "peptide," "polypeptide" and "protein" are used interchangeably to denote a sequence polymer of at least two amino acids covalently linked by an amide bond.

The term "homologous" as used herein and relating to peptides refers to amino acid sequence similarity between two peptides. When an amino acid position in both of the peptides is occupied by identical amino acids, they are homologous at that position. Thus by "substantially homologous" means an amino acid sequence that is largely, but not entirely, homologous, and which retains most or all of the activity as the sequence to which it is homologous. As used herein, "substantially homologous" as used herein means that a sequence is at least 50% identical, and preferably at least 75% and more preferably 95% homology to the reference peptide. Additional peptide sequence modification are included, such as minor variations, deletions, substitutions or derivitizations of the amino acid sequence of the sequences disclosed herein, so long as the peptide has substantially the same activity or function as the unmodified peptides. Notably, a modified peptide will retain activity or function associated with the unmodified peptide, the modified peptide will generally have an amino acid sequence "substantially homologous" with the amino acid sequence of the unmodified sequence.

The term "administering" as used herein is defined as the actual physical introduction of the composition into or onto (as appropriate) the host subject. The method is not dependent on any particular means of introduction and is not to be so construed. Means of introduction are well-known to those skilled in the art, and preferably, the composition is administered subcutaneously or intratumorally. One skilled in the art will recognize that, although more than one route can be used for administration, a particular route can provide a more immediate and more effective reaction than another route. Local or systemic delivery can be accomplished by administration comprising application or instillation of the immunovaccines into body cavities, inhalation or insufflation of an aerosol, or by parenteral introduction, comprising intramuscular, intravenous, intraportal, intrahepatic, peritoneal, subcutaneous, or intradermal administration. In the event that the tumor is in the central nervous system, the composition must be administered intratumorally because there is no priming of the immune system in the central nervous system.

Although chemotherapeutic agents can induce "immunogenic" tumor cell death and facilitate cross-presentation of antigens by dendritic ceils, tumors create a tolerogenic environment that allows them to suppress the activation of innate and adaptive immune responses and evade immunologic attack by immune effector cells. The present invention provides strategies to counteract tumor-induced immune tolerance in the tumor microenvironment and can enhance the antitumor efficacy of chemotherapy by activating and leveraging T cell-mediated adaptive antitumor immunity against disseminated cancer cells.

The present invention is based on the discovery that targeted immunomodulatory antibodies or fusion proteins of the present invention can counteract or reverse immune tolerance of cancer cells. Cancer cells are able to escape elimination by chemotherapeutic agents or tumor-targeted antibodies via specific immunosuppressive mechanisms in the tumor microenvironment and such ability of cancer cells is recognized as immune tolerance. By counteracting tumor-induced immune tolerance, the present invention provides effective compositions and methods for cancer treatment, optional in combination with another existing cancer treatment.

The present invention provides fusion proteins that counteract immune tolerance in the tumor microenvironment and promote T cell-mediated adaptive antitumor immunity for maintenance of durable long-term protection against recurrent or disseminated cancers. These fusion proteins are designed to facilitate effective long term T cell-mediated immune responses against tumor cells by at least one of the following:

a. promoting death of tumor cells via enhancement of antibody-dependent cellular cytotoxicity (ADCC); and
b. increasing activation and proliferation of antitumor CD8+ T cells by negating immune suppression mediated by regulatory T cells and myeloid suppressor cells. These antitumor immune responses may be activated in tandem with the sensitization of tumor cells to immune effector-mediated cytotoxicity, thereby establishing a positive feedback loop that augments tumor cytoreduction and reinforces adaptive antitumor immunity.

In addition, the fusion proteins of the present invention are distinguished from and superior to existing therapeutic, molecules in at least one of the following aspects: (i) To counteract immune tolerance in the tumor microenvironment and promote T cell-mediated adaptive antitumor immunity for maintenance of long-term protection against recurrent or disseminated cancers (for prevention or treatment of diverse cancers); (ii) To produce immune cell compositions for adoptive cellular therapy of diverse cancers; and (iii) To serve as immune adjuvants or vaccines for prophylaxis of diverse cancers or infectious diseases.

The targeted immunostimulatory antibodies and/or fusion proteins of the invention provide the ability to disrupt immunosuppressive networks in the tumor microenvironment. Tumors employ a wide array of regulatory mechanisms to avoid or suppress the immune response. Cancer cells actively promote immune tolerance in the tumor microenvironment via the expression of cytokines and molecules that inhibit the differentiation and maturation of antigen-presenting dendritic cells (DC). The immunosuppressive cytokines and ligands produced by tumor cells include the following: (i) Transforming growth factor-beta (TGF-β); (ii) Programmed death- 1 ligand 1 (PD-L1 ; B7-H1); (iii) Vascular endothelial growth factor (VEGF); and (iv) Interleukin-10 (IL-10).

In addition to blocking dendritic cell (DC) maturation, these molecules promote the development of specialized subsets of immunosuppressive CD4⁺ T cells (regulatory T cells; Treg cells) and myeloid-derived suppressor cells (MDSC). Tregs are a minority sub-population of CD4⁺ T cells that constitutively express CD25 [the interleukin-2 (IL-2) receptor cc-chain] and the forkhead box P3 (FOXP3) transcription factor. Tregs (CD4+CD25+FoxP3+ cells) maintain immune tolerance by restraining the activation, proliferation, and effector functions of a wide range of immune cells, including CD4 and CDS T cells, natural killer (NK) and NKT cells, B cells and antigen presenting cells (APCs) in vitro and in vivo.

The accumulation of Treg cells in the tumor microenvironment reinforces tumor immune tolerance and facilitates tumor progression and metastases. The increased expression of immunosuppressive cytokines (TGF-β; PD-L1 ) and tumor-infiltrating Tregs is correlated with a reduction of survival of patients with diverse types of cancers. The fusion proteins of the present invention inhibit key immunosuppressive molecules expressed by the targeted tumor cell or tumor-infiltrating Treg cells and myeloid suppressor cells (DCs or MDSC). As such, they provide the targeted ability to inhibit the development or function of Tregs within the tumor microenvironment.

As used herein, the term "antibody" includes natural or artificial mono- or polyvalent antibodies including, but not limited to, polyclonal, monoclonal, multispecific, human, humanized or chimeric antibodies, single chain antibodies, Fab fragments. F(ab') fragments, fragments produced by a Fab expression library, anti-idiotypic (anti-Id) antibodies (including, e.g., anti-Id antibodies to antibodies of the invention), and epitope-binding fragments of any of the above. The antibody may be from any animal origin including birds and mammals. In one aspect, the antibody is, or derived from, a human, murine (e.g., mouse and rat), donkey, sheep, rabbit, goat, guinea pig, camel, horse, or chicken. Further, such antibody may be a humanized version of an antibody. The antibody may be monospecific, bispecific, trispecific, or of greater multi specificity. The antibody herein specifically include a "chimeric" antibody in which a portion of the heavy and/or light chain is identical with or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular antibody class or subclass, while the remainder of the chain(s) is identical with or homologous to corresponding sequences in antibodies derived from another species or belonging to another antibody class or subclass, as well as fragments of such antibodies, so long as they exhibit the desired biological activity.

Examples of antibodies which can be incorporated into compositions and methods disclosed herein include, but are not limited, to antibodies such as trastuzumab (anti-HER2/neu antibody); Pertuzumab (anti-HER2 mAb); cetuximab (chimeric monoclonal antibody to epidermal growth factor receptor EGFR): panitumumab (anti-EGFR antibody); nimotuzumab (anti-EGFR antibody); Zalutumumab (anti-EGFR mAb); Necitumumab (anti-EGFR mAb); MDX-210 (humanized anti-HER-2 bispecific antibody); MDX-210 (humanized anti-HER-2 bispecific antibody); MDX-447 (humanized anti-EGF receptor bispecific antibody); Rituximab (chimeric murine/human anti-CD20 mAb); Obinutuzumab (anti-CD20 mAb); Ofatumumab (anti-CD20 mAb); Tositumumab-1131 (anti-CD20 mAb); ibritumomab tiuxetan (anti-CD20 mAb); Bevacizumab (anti-VEGF mAb); Ramucirumab (anti-VEGFR2 mAb); Ranibizumab (anti-VEGF mAb); Aflibercept (extracellular domains of YEGFR1 and VEGFR2 fused to IgGl Fc): AMG386 (angiopoietin-1 and -2 binding peptide fused to IgGl Fc); Dalotuzumab (anti-lGF-lR mAb): Gemtuzumab ozogamicin (anti-CD33 mAb); Alemtuzumab (anti-Campath-l/CD52 mAb); Brentuximab vedotin (anti-CD30 mAb); Catumaxomab (bispecific mAb that targets epithelial cell adhesion molecule and CD3); Naptumomab (anti-5T4 mAb); Girentuximab (anti-Carbonic anhydrase ix): or Farletuzumab (anti-folate receptor). Other examples include antibodies such as Panorex^™ (17-1 A) (murine monoclonal antibody); Panorex (@ (17-1 A) (chimeric murine monoclonal antibody); BEC2 (ami-idiotypic mAb, mimics the GD epitope) (with BCG): Oncolym (Lym-1 monoclonal antibody); SMART M l 95 Ab, humanized 13' 1 LYM-1 (Oncolym), Ovarex (B43.13, anti-idiotypic mouse mAb); 3622W94 mAb that binds to EGP40 ( 17- 1 A) pancarcinoma antigen on adenocarcinomas; Zenapax (SMART Anti-Tac (IL-2 receptor); SMART Ml 95 Ab, humanized Ab, humanized); NovoMAb-G2 (pancarcinoma specific Ab): TNT (chimeric mAb to histone antigens); TNT (chimeric mAb to histone antigens); GJiomab-H (Monoclonals- Humanized Abs); GN1-250 Mab; EMD-72000 (chimeric-EGF antagonist); LymphoCide (humanized IL.L.2 antibody); and MDX-260 bispecific, targets GD-2, ANA Ab, SMART lDiO Ab, SMART ABL 364 Ab or ImmuRAIT-CEA.

Various methods have been employed to produce antibodies. Hybridoma technology, which refers to a cloned cell line that produces a single type of antibody, uses the cells of various species, including mice (murine), hamsters, rats, and humans. Another method to prepare an antibody uses genetic engineering including recombinant DNA techniques. For example, antibodies made from these techniques include, among others, chimeric antibodies and humanized antibodies. A chimeric antibody combines DNA encoding regions from more than one type of species. For example, a chimeric antibody may derive the variable region from a mouse and the constant region from a human. A humanized antibody comes predominantly from a human, even though it contains nonhuman portions. Like a chimeric antibody, a humanized antibody may contain a completely human constant region. But unlike a chimeric antibody, the variable region may be partially derived from a human. The nonhuman, synthetic portions of a humanized antibody often come from CDRs in murine antibodies. In any event, these regions are crucial to allow the antibody to recognize and bind to a specific antigen.

A hybridoma can produce a targeted fusion protein comprising a targeting moiety and an immunomodulatory moiety. A targeting moiety comprising an antibody, antibody fragment, or polypeptide is linked or fused to an immunomodulatory moiety consisting of a polypeptide, with a linker. The linker is an amino acid linker. A linker is GGGGSGGGGSGGGGS (SEQ ID NO: 3) or EPKSCDK (SEQ ID NO: 11).. The immunomodulatory moiety is a polypeptide that is fused to the C-terminus of the Fc region of the heavy chain of a targeting antibody or Fc-containing fusion protein. The immunomodulatory moiety is a polypeptide that is fused to the C-terminus of the light chain of a targeting antibody.

An antibody fragment can include a portion of an intact, antibody, e.g. including the antigen-binding or variable region thereof. Examples of antibody fragments include Fab, Fab', F(ab')2, and Fv fragments; Fc fragments or Fc-fusion products; diabodies; linear antibodies; single-chain antibody molecules; and multispecific antibodies formed from antibody fragment(s). An intact antibody is one which includes an antigen-binding variable region as well as a light chain constant domain (CL) and heavy chain constant domains, CHI, CH2 and CH3. The constant domains may be native sequence constant domains (e.g., human native sequence constant domains) or amino acid sequence variant thereof tor any other modified Fc (e.g. glycosylation or other engineered Fc).

The fusion proteins of the present invention may be synthesized by conventional techniques known in the art, for example, by chemical synthesis such as solid phase peptide synthesis. Such methods are known to those skilled in the art. In general, these methods employ either solid or solution phase synthesis methods, well known in the art. Specifically, the methods comprise the sequential addition of one or more amino acids or suitably protected amino acids to a growing peptide chain. Normally, either the amino or carboxyl group of the first amino acid is protected by a suitable protecting group. The protected or derivatized amino acid can then be either attached to an inert solid support or utilized in solution by adding the next amino acid in the sequence having the complementary (amino or carboxyl) group suitably protected, under conditions suitable for forming the amide linkage. The protecting group is then removed from this newly added amino acid residue and the next amino acid (suitably protected) is then added, and so forth. After all the desired amino acids have been linked in the proper sequence, any remaining protecting groups and any solid support are removed either sequentially or concurrently to afford the final polypeptide. By simple modification of this general procedure, it is possible to add more than one amino acid at a time to a growing chain, for example, by coupling (under condition that do not racemize chiral centers) a protected tripeptide with a properly protected dipeptide to form, after deprotection, a pentapeptide.

Typical protecting groups include t-butyloxycarbonyl (Boc), 9-fluorenylmethoxycarbonyl (Fmoc), benxyloxycarbonyl (Cbz), p-toluenesulfonyl (Tos); 2,4-dinitrophenyl, benzyl (Bzl), biphenylisopropyloxy-carboxycarbonyl, cyclohexyl, isopropyl, acetyl, o-nitrophenylsulfonyl, and the like. Of these, Boc and Fmoc are preferred.

Typical solid supports are generally cross-linked polymeric materials. These include divinylbenzene cross-linked styrene-based polymers, for example, divinylbenzene-hydroxymethylstyrene copolymers, divinylbenzene-chloromethylstyrene copolymers, and divinylbenzene-benzhydrylaminopolystyrene copolymers. The divinylbenzene-benzhydrylaminopolystyrene copolymers, as illustrated herein using p-methyl-benzhydrylamine resin, offers the advantage of directly introducing a terminal amide functional group into the peptide chain, which function is retained by the chain when the chain is cleaved from the support.

In one method, the polypeptides are prepared by conventional solid phase chemical synthesis on, for example, an Applied Biosystems, Inc. (ABI) 430A peptide synthesizer using a resin that permits the synthesis of the amide peptide form and using t-Boc amino acid derivatives (Peninsula Laboratories, Inc.) with standard solvents and reagents. Polypeptides containing either L- or D-amino acids may be synthesized in this manner. Polypeptide composition is confirmed by quantitative amino acid analysis and the specific sequence of each peptide may be determined by sequence analysis.

Preferably, the polypeptides can be produced by recombinant DNA techniques by synthesizing DNA encoding the desired polypeptide. Once coding sequences for the desired polypeptides have been synthesized or isolated, they can be cloned into any suitable vector for expression. Numerous cloning vectors are known to those of skill in the art, and the selection of an appropriate cloning vector is a matter of choice. The gene can be placed under the control of a promoter, ribosome binding site (for bacterial expression) and, optionally, an operator (collectively referred to herein as "control" elements), so that the DNA sequence encoding the desired polypeptide is transcribed into RNA in the host cell transformed by a vector containing this expression construction. The coding sequence may or may not contain a signal peptide or leader sequence. Heterologous leader sequences can be added to the coding sequence that causes the secretion of the expressed polypeptide from the host organism. Other regulatory sequences may also be desirable which allow for regulation of expression of the protein sequences relative to the growth of the host cell. Such regulatory sequences are known to those of skill in the art, and examples include those which cause the expression of a gene to be turned on or off in response to a chemical or physical stimulus, including the presence of a regulatory compound. Other types of regulatory elements may also be present in the vector, for example, enhancer sequences.

The control sequences and other regulatory sequences may be ligated to the coding sequence prior to insertion into a vector, such as the cloning vectors described above. Alternatively, the coding sequence can be cloned directly into an expression vector which already contains the control sequences and an appropriate restriction site.

The expression vector may then used to transform an appropriate host cell. A number of mammalian cell lines are known in the art and include immortalized cell lines available from the American Type Culture Collection (ATCC), such as, but not limited to, Chinese hamster ovary (CHO) cells, HeLa cells, HEK293, baby hamster kidney (BHK) cells, monkey kidney cells (COS), human hepatocellular carcinoma cells (e.g., Hep G2), Madin-Darby bovine kidney ("MDBK") cells, NOS cells derived from carcinoma cells, such as sarcoma, as well as others. Similarly, bacterial hosts such as E. coli, Bacillus subtilis, and Streptococcus spp., will find use with the present expression constructs. Yeast hosts useful in the present invention include inter alia, Saccharomyces cerevisiae, Candida albicans, Candida maltosa, Hansenula polymorpha, Kluyveromyces fragilis, Kluyveromyces lactis, Pichia guillerimondii, Pichia pastoris, Schizosaccharomyces pombe and Yarrowia lipolytica. Insect cells for use with baculovirus expression vectors include, inter alia, Aedes aegypti, Autographa californica, Bombyx mori, Drosophila melanogaster, Spodoptera frugiperda, and Trichoplusia ni. The proteins may also be expressed in Trypanosomes.

Depending on the expression system and host selected, the proteins of the present invention are produced by growing host cells transformed by an expression vector described above under conditions whereby the protein of interest is expressed. The protein is then isolated from the host cells and purified. If the expression system secretes the protein into growth media, the protein can be purified directly from the media. If the protein is not secreted, it is isolated from cell lysates. The selection of the appropriate growth conditions and recovery methods are within the skill of the art. Once purified, the amino acid sequences of the proteins can be determined, i.e., by repetitive cycles of Edman degradation, followed by amino acid analysis by HPLC. Other methods of amino acid sequencing are also known in the art.

Once synthesized or otherwise produced, the inhibitory activity of a candidate polypeptide can be tested by assessing the ability of the candidate to inhibit the lipopolysaccharide-induced nuclear translocation of NF-.kappa.B by, for example, using murine endothelial cells.

The fusion proteins of the present invention can be formulated into therapeutic compositions in a variety of dosage forms such as, but not limited to, liquid solutions or suspensions, tablets, pills, powders, suppositories, polymeric microcapsules or microvesicles, liposomes, and injectable or infusible solutions. The preferred form depends upon the mode of administration and the particular cancer type targeted. The compositions also preferably include pharmaceutically acceptable vehicles, carriers or adjuvants, well known in the art, such as human serum albumin, ion exchangers, alumina, lecithin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, and salts or electrolytes such as protamine sulfate. Suitable vehicles are, for example, water, saline, dextrose, glycerol, ethanol, or the like, and combinations thereof. Actual methods of preparing such compositions are known, or will be apparent, to those skilled in the art. See, e.g., Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa., 18th edition, 1990.

The above compositions can be administered using conventional modes of delivery including, but not limited to, intravenous, intraperitoneal, oral, intralymphatic, or subcutaneous administration. Local administration to a tumor in question, or to a site of inflammation, e.g., direct injection into an arthritic joint, will also find use with the present invention.

Therapeutically effective doses will be easily determined by one of skill in the art and will depend on the severity and course of the disease, the patient's health and response to treatment, and the judgment of the treating physician.

Experimental

Below are examples for carrying out the present invention. The examples are offered for illustrative purposes only, and are not intended to limit the scope of the present invention in any way. Efforts have been made to ensure accuracy with respect to numbers used (e.g., amounts, temperatures, etc.), but some experimental error and deviation should, of course, be allowed for.

Example 1

The following example is not according to the invention and is present for illustration purposes only. The Fusion proteins comprising of IgG heavy chain linked to immunomodulator (either suppressor or activator) ligands were expressed by codon optimized genes for the expression of CHO cells. The codon optimized nucleotide sequences defined by SEQ ID NOs: 12 to 28 were expressed in (CHO) cells and the expressed chimeric/fusion proteins are shown in Table 1

Anti-HER2/neu heavy chain + TGFβ-RII ECD and Anti-HER2/neu light chain

Anti-EGFR1 heavy chain + TGFβ-RII ECD and Anti- EGFR1 light chain

Anti-CTLA4 heavy chain + TGFβ-RII ECD and Anti-CTLA4 light chain

Anti-CTLA4 heavy chain + PD1 ectodomain and Anti-CTLA4 light chain

Anti-HER2/neu heavy chain + 4-1BBL and Anti-HER2/neu light chain

Anti-EGFR1 heavy chain + 4-1BBL and Anti- EGFR1 light chain

Anti-CTLA4 heavy chain + 4-1BBL and Anti-CTLA4 light chain

PD1 ectodomain-Fc-4-1BBL

TGFβRII ECD-Fc-4-1BBL

Anti-EGFR1 heavy chain + PD1 ectodomain and Anti- EGFR1 light chain

Anti-CD20 heavy chain + 4-1BBL and Anti- CD20 light chain

Anti-HER2/neu heavy chain + PD1 ectodomain and Anti-HER2/neu light chain

Anti-IL6Rheavy chain + PD1 ectodomain and Anti-IL6R light chain

Anti-IL6Rheavy chain + TGFβ-RII ECD and Anti-IL6R light chain

Anti-4-1BB heavy chain + PD1 ectodomain and Anti-4-1BB light chain

The expressed protein were characterized by using SDS PAGE and the expressed fusion proteins Anit-HER2/neu-TGFβRII and Anti-EGFR1- TGFβRII were purified from culture supernatants using ProteinA column and the results are shown in Figure 22. Notably, Anti-EGFR1-TGFβRII light chain mass is higher and it may be because of the presence of two glycosylation sites on the variable regions light and heavy chain. Both the Anti-HER2/neu-TGFβRII & Anti-EGFR1-TGFβRII heavy chains mass are higher because of the TGFβRII. Also Anti-HER2/neu-TGFβRII heavy chain has four N-glycosylation sites while Anti-EGFR1-TGFβRII has five N-glycosylation sites.

Example 2

The following example is not according to the invention and is present for illustration purposes only. Protein A/SEC chromatography. The Anti-HER2/neu-TGFβRII and Anti-EGFR1-TGFβRII samples were analyzed by ProteinA/SEC chromatography and the results are shown in Figure 23. Figure 23 A shows a sharp peak of elution of Bmab200(Herceptin) vs a broader elution peak is believed to be a measure of heterogeneity due to presence of glycosylation as there are three additional N-glycosylation sites that are present in the TGFβRII region. Notably storage at -80C did not causing aggregation. The shift in the position or appearance of the peak early in SEC column indicates that the increase in the molecular weight is because of the fusion partner. This once again confirms that the full length molecule is being expressed. Figure 23 B shows a sharp peak of elution of Bmab200(Herceptin) vs a broader elution peak which is believed to be a measure of heterogeneity due to presence of glycosylation sites as there are three additional N-glycosylation sites are present in the TGFβRII region. Again, storage at -80C did not causing aggregation. The shift in the position or appearance of the peak early in SEC column indicates that the increase in the molecular weight is because of the fusion partner. This once again confirms that the full length molecule is being expressed.

Example 3

The following example is not according to the invention and is present for illustration purposes only. Functional assays for the Fusion proteins. ELISA experiment was carried out to check the binding ability of Anti-HER2/neu-TGFβRII and Anti-EGFR1-TGFβRII to TGFβ. Figure 24 A shows that Anti-HER2/neu-TGFβRII and Anti-EGFR1-TGFβRII molecules bind to the TGFβ indicating that the fusion protein is functional. Figure 24 B shows that Anti-HER2-TGFβRII inhibits the proliferation of BT474 cell line similar to the Bmab200 (Herceptin). Figure 25 shows that Anti-EGFR1-TGFβRII-inhibits the proliferation of A431 cell line similar to the Cetuximab.

Example 4

The following example is not according to the invention and is present for illustration purposes only. Antibody dependent cellular cytotoxicity ADCC activity for Anti-HER2/neu-TGFβRII fusion protein was conducted to determine that the protein binds to the target receptors on the cells. The results are shown in Figure 26 wherein the activity is determined in BT474 cells and it is evident that ADCC activity (%lysis of cells) of Anti-HER2-TGFβRII on BT474 cells is similar to that of Bmab200(Herceptin). Figure 27 shows ADCC activity of Anti-EGFR1-TGFβRII on A431 cells wherein the ADCC activities are similar to that of Cetuximab. Figure 28 shows the ADCC activity of ADCC activity of Anti-EGFR1-4-1BB in comparison with Anti-EGFR1-TGFβRII and cetuximab.

Example 5

The following example is not according to the invention and is present for illustration purposes only. Binding Activity of the expressed proteins. The aim of this assay is to test the functionality of the fusion proteins to bind to the target receptors on the cells in a dose dependent manner. Figure 29 A shows that the binding activity of Anti-CTLA4-TGFβRII to TGFβ1 is comparable to Anti-EGFR1-TGFβRII and B shows that the binding activity of Anti-CTLA4-TGFβRII to CTLA4. Figure 30 A shows the binding activity of Anti-CTLA4-TGFβRII to determine the level of PD1-Fc binding and B shows the binding activity of Anti-EGRF1-4-1BB to determine the binding of 4-1BBL. Figure 31 A shows the binding activity of Anti-EGFR1-4-1BB to EGFR and B shows the binding activity of PD1-Fc-4-1BB to find out PDL1-Fc. Figure 32 shows the binding activity of Anti-EGFR1-PD1 to EGFR and PD1.

Example 6

The following example is not according to the invention and is present for illustration purposes only. Confirmation of primary structure of molecule. As shown in Figure 33, the expressed proteins are evaluated to determine the molecular weight and the presence of glycosylation. The samples were analyzed by reducing and nonreducing SDS PAGE. The heavy and light chains of the antibody are separated by reduction alkylation so that the reduced structures can be evaluated. Tryptic digestion of the fusion proteins provides for the identification of the primary sequence. MS/MS analysis of the proteins is performed.

Mass Spectrometry Analysis of Anti-HER2/neu-TGFβRII and Anti-EGFR1-TGFβRII. The fusion protein shown in Figure 1 was expressed and tested. Figure 34 A shows the mass spectrum Mass Spectrum of light chain (LC )(Reduced) of Anti-HER2/neu-TGFβRII ECD fusion and B shows Deconvoluted Mass Spectrum of LC (Reduced) of Anti-HER2/neu-TGFβRII ECD fusion. Figure 35 shows the Mass Spectrum of heavy chain (HC) (Reduced) of Anti-HER2/neu-TGFβRII ECD fusion.

The fusion protein shown in Figure 2 was expressed and tested. Figure 36 A shows the Mass Spectrum of LC (Reduced) of Anti-EGFR1-TGFβRII ECD and B shows the Deconvoluted Mass Spectrum of LC (Reduced) of Anti-EGFR1-TGFβRII ECD. Figure 37 shows the Mass Spectrum of HC (Reduced) of Anti-EGFR1-TGFβRII ECD.

Example 7

The following example is not according to the invention and is present for illustration purposes only. The fusion proteins having amino acid sequences as described in Figures 1 and 2 were inspected using UV chromatography and providing chromatograms resulting from the chromatographic separation of the tryptic digest of the fusion proteins and tested with UV 218-222 nm wavelength. Total Ion Current (TIC) corresponding to UV trace was also evaluated. Figure 38 A shows the UV Chromatogram of Tryptic Peptides of Anti-HER2/neu-TGFβRII ECD fusion protein and B shows the Total Ion Chromatogram (TIC) of Tryptic Peptides of Anti-HER2/neu-TGFβRII ECD fusion protein. Figures 39, 40 and 41 provide lists of expected/observed tryptic peptide of the light chain, heavy chain and linked motif of the Anti-HER2/neu-TGFβRII ECD fusion protein, respectively. Notably, all the expected peptides of the molecules were identified including the light and heavy chain peptides and the peptides of the linked motif (TGF βRII).

Figure 42 A shows the UV Chromatogram of Tryptic Peptides of Anti-EGFR1-TGFβRII ECD fusion protein and B shows the Total Ion Chromatogram (TIC) of Tryptic Peptides of Anti-EGFR1-TGFβRII ECD fusion protein. Figures 43, 44, and 45 provide lists of expected/observed tryptic peptide of the light chain, heavy chain and linked motif of the Anti-EGFR1-TGFβRII ECD fusion protein, respectively. Again all the expected peptides of the molecules were identified including the light and heavy chain peptides and the peptides of the linked motif (TGF βRII).

Example 8

The host cell line used for the expression of recombinant fusion protein expression is CHO cells or the derivative of the CHO cells. The CHO cells referred here is either freedom CHO-S cells; CHO-S Cells are CHO-derived cells adapted to high density, serum-free suspension culture in chemically-defined medium that are capable of producing high levels of secreted, recombinant protein or CHO K1 cells; having the same as ATCC No. CCL-61. It is basically an adherent cell line. The vectors used for stable cell line:

The Freedom pCHO 1.0 vector, designed by ProBioGen AG, to express one or two genes of interest downstream of the vector's two different hybrid CMV promoters. This vector contains the dihydrofolate reductase (DHFR) selection marker and a puromycin resistance gene, allowing selection using MTX and Puromycin simultaneously.

The light chain or the light chain fusion protein coding nucleic acid sequences are cloned into the restriction enzyme sites AvrII and BstZl7 under the control of EF2/CMV promoter. The heavy chain or the heavy chain fusion protein coding nucleic acid sequences are cloned, in restriction enzyme sites EcoRV and Pad under the control of CMV/EF1 promoter.

The construct(s) are transfected into Freedom CHO-S cells/CHOK1 cells. The high producer single, clonal cell strain is selected for producing the recombinant fusion protein. Prepare the MCB and characterize for cell viability, productivity, stability and other parameters. The cells are used for culturing followed by purification.

Example 9

The cell culture is performed in feed-batch mode. In the cell culture, the mammalian host cells used is Chinese Hamster Ovary (CHO) cells and culture medium are supplied initially. The CHO cells are genetically engineered to produce the Antibody-peptide fusion protein. The zinc sulphate hepta hydrate salt is added in the medium at a concentration of 0.4 mM. In contrast, there is no addition of any zinc salt in the control medium. The production fermentation run starts with an initial cell count of 0.3-0.45×10⁶ cells/ml at 37 ± 1°C, the first 3-4 days are dedicated to grow the cells in batch phase. Next step involves lowering the temperature to 31±1 °C and continuing the run till 7th day. Lactate reduces by almost 10-40% throughout the run. The produced fusion protein is then collected from the media using the technique of affinity chromatography.

Example 10

The cell culture is performed in a feed-batch mode is employed. In the cell cultures the mammalian host cells and culture medium which is Hyclone CDM4Mab are supplied initially. The salts (zinc) is also added in the medium (0.3mM). The production fermentation run starts with an initial cell count of 0.3-0.45×10⁶ cells/nil at 37 ± 1° C, the first 3-4 days are dedicated to growing the cells in batch phase. Next step involves lowering the temperature to 31+1-1 °C and continuing the run till 7th day.

Example 11

Purification of antibody-peptide fusion immunostimulatory molecules using protein A column. Supernatant culture secreted from recombinant CHO cell line containing the fusion monoclonal antibodies is tested for titer and endotoxins under sterile conditions. The supernatant is subjected to affinity chromatography using Mab Select Xtra Protein A affinity resin, washed and equilibrated with binding buffer. The pH of the supernatant is adjusted using 0.5M phosphate to the same pH as the column; the supernatant is allowed to bind to the column/ pass through the column at the flow rate of 0.5 ml/minute to achieve the maximum binding. All the Antibody-proteins fusion molecules bind through the Fc region while impurities are eliminated as flow through.. The column is washed with equilibration buffer and the bound fusion molecules are eluted using 0.1 M glycine at pH 3.0. The pH of the eluted proteins is adjusted to neutral pH or the stable formulation pH and the purified protein are stored at -20°C or at 2-8°C.

Example 12

The following example is not according to the invention and is present for illustration purposes only. Differentiating Trastuzumab from Trastuzumab-TGF βRII receptor fusion molecule

A breast cancer tumor overexpressing the ErbB2 receptor will either by constitutive activation or heterodimerization with other members of the ErbB family of receptors lead to tumor progression. This will involve the binding of growth factors associated with the ErbB signaling pathway. In addition to this, the tumor creates a milieu wherein the immune system is suppressed by activating TGF β and specific cytokines involved in the subdued immune response. A novel molecule is generated wherein Trastuzumab (anti ErbB2) is fused with the TGF βRII receptor as a fusion protein. While it is hypothesized that Trastuzumab will act as a targeted molecule homing into the ErbB2 overexpressing breast cancer cells, the TGFβRII receptor will sequester TGFβ leading to immune activation. The experiment will utilize the growth of Herceptin resistant ErbB2 expressing cell lines (selected by growing BT474 cells in the presence of Herceptin) in the presence of TGFβ, cytotoxic CD8 positive cells and NK cells. While Trastuzumab will be ineffective in inducing cytotoxicity Trastuzumab TGFβRII receptor fusion molecule will sequester the TGFβ thereby preventing the inhibition of cytotoxic CD8 and NK cells. This will lead to enhanced cytotoxicity observed in Trastuzumab -TGFβRII receptor fusion treated cells over cells treated with Trastuzumab alone. The readout for the experiment will use Alamar Blue a resazurin dye which will get activated directly proportional to live cells present. Another method could be to measure cytotoxicity by using cytotox glo which measures protease release which directly corresponds to proportional dead cells. Yet another method could be the use of the flow cytometer directly measuring apoptotic and necrotic cell population by using Annexin V and propidium iodide. Results from these multiple experiments will elucidate understanding of the activity of the conjugate molecule as compared to Trastuzumab alone.

Although the invention has been described with reference to the above example, it will be understood that modifications and variations are encompassed within the scope of the invention. Accordingly, the invention is limited only by the following claims.

Claims

A bi-specific chimeric fusion protein consisting of a targeting moiety that binds to CTLA4 and an immunomodulating moiety that binds to PD-L1, wherein the targeting moiety and the immunomodulating moiety are linked by an amino acid spacer selected from SEQ ID NO: 3 or SEQ ID NO: 11, wherein the immunomodulating moiety is PD1 consisting of the amino acid sequence of SEQ ID NO: 10, wherein the targeting moiety is anti-CTLA4 antibody consisting of heavy chain SEQ ID NO: 7 and light chain SEQ ID NO: 8; wherein SEQ ID NO: 10 is attached via the amino acid spacer to the C-terminus of SEQ ID NO 7 or SEQ ID NO: 8.