WO2025153000A1 - Anti-masp2 antibody or antigen-binding fragment and use thereof - Google Patents

Abstract

The present invention provides an anti-MASP2 antibody and an antigen-binding fragment thereof, and further provides a polynucleotide encoding the antibody, a vector and a host cell for expressing the antibody, a pharmaceutical composition comprising the antibody, and a method and a pharmaceutical use of the antibody for treating MASP2-related diseases.

Description

An anti-MASP2 antibody or antigen-binding fragment thereof and use thereof Technical Field

The present invention belongs to the field of biomedicine technology, and specifically relates to an anti-MASP2 antibody or an antigen-binding fragment thereof, a pharmaceutical composition and use thereof.

Background Art

The complement system is activated mainly through three pathways: classical, alternative, and lectin. Mannan-binding lectin-associated serine protease 2 (MASP2) is a key enzyme in the complement lectin pathway. Its encoding gene is located on chromosome 1p36 and encodes a 76kDa serine protease MASP2 (long isoform) highly expressed in the liver and a 19kDa alternative splicing product Map19 (short isoform) present in plasma. The MASP2 encoding gene consists of 12 exons, of which exons 2 and 3 encode the CUB1 domain, exon 4 encodes the EGFL domain, exons 6 and 7 encode the CUB2 domain, exons 8 to 11 encode two CCP domains, respectively, and exon 12 encodes the peptide activation region, SP domain, and C-terminal mRNA untranslated region of MASP2. The mature proenzyme form of MASP2 consists of 686 amino acid residues. Once the lectin recognizes and binds to the pathogen, the zymogen form of MASP2 will break between CCP2 and SP, forming an active form of two polypeptide chains connected by disulfide bonds. The peptide activation region and SP domain of the activated MASP2 can effectively bind to and cleave C2, and with the assistance of the CCP domain, bind to and cleave C4 to initiate the subsequent cascade reaction, forming C4bC2a (i.e., C3 convertase), and ultimately promoting the formation of a membrane-breaking complex composed of C5-C9, causing the lysis of the pathogen, thereby resisting pathogenic microorganisms such as bacteria, yeast, and viruses.

Clinical experiments and research evidence show that a variety of diseases are related to abnormal activation of the complement system, such as abnormal or overexpression of MASP2, including IgA nephropathy (Lafayette, Richard A et al. Kidney international reports vol. 5, 11 2032-2041. 13Aug. 2020), thrombotic microangiopathy (Elhadad, S et al. Clinical and experimental immunology vol. 203, 1 (2021): 96-104), systemic lupus erythematosus (Xu, Wang-Dong et al. Journal of cellular and m olecular medicine vol.24,18(2020):10432-10443), membranous nephropathy, lupus nephritis (Cai Y et al. PLoS One, 2013, 8(4):e62465), transplant rejection, antiphospholipid syndrome (Boldt AB, et al. Hum Immunol, 2011, 72(9):753-760), rheumatoid arthritis, hemolytic uremic syndrome, hereditary angioedema (Krarup A et al. PLoS One, 2007, 2(7):e623), myocardial infarction (Zhang M, et al. Int J Cardiol, 2013, 166(2):499-504), etc.

At present, a variety of anti-MASP2 antibodies are disclosed in patent documents such as CN103687620B, WO2022228364A1, CN114634575A, and CN116284412A. However, there is still a lack of new structure antibodies targeting MASP2 on the market, and further improving the affinity and biological activity of anti-MASP2 antibodies is still a technical problem that needs to be solved in this field.

Summary of the invention

In one aspect, the present invention provides an anti-MASP2 antibody or an antigen-binding fragment thereof, which can specifically bind to the MASP2 protein with high affinity, has no cross-reaction with other complement components (e.g., C1s, C1r, MASP1, MASP3), and effectively inhibits the activation of the downstream complement pathway mediated by MASP2.

In one aspect, the present invention provides an anti-MASP2 antibody or an antigen-binding fragment thereof, comprising a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH comprises HCDR1, HCDR2 and HCDR3 regions, and the VL comprises LCDR1, LCDR2 and LCDR3 regions, wherein:

(i) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of the VH as shown in any one of SEQ ID NOs: 1-2, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of the VL as shown in any one of SEQ ID NOs: 3-5, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom;

(ii) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of the VH as shown in any one of SEQ ID NOs: 6-8, 48-50, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of the VL as shown in any one of SEQ ID NOs: 9-11, 51-55, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom; or

(iii) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of the VH as shown in any one of SEQ ID NOs: 12-15, 56-59, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of the VL as shown in any one of SEQ ID NOs: 16-18, 60-63, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom.

In some embodiments, the VH comprises HCDR1, HCDR2, and HCDR3 regions, and the VL comprises LCDR1, LCDR2, and LCDR3 regions, wherein:

(i) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of the VH as shown in SEQ ID NO: 1, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of the VL as shown in SEQ ID NO: 3, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom;

(ii) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of the VH as shown in SEQ ID NO: 8, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of the VL as shown in any one of SEQ ID NOs: 11, 51-53, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom;

(iii) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of the VH as shown in SEQ ID NO: 50, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of the VL as shown in SEQ ID NO: 51 or 55, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom; or

(iv) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of the VH as shown in SEQ ID NO: 15, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of the VL as shown in SEQ ID NO: 18 or 63, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom.

The mutation is selected from insertion, deletion and/or substitution that does not affect the function, and the substitution is preferably a substitution of a conservative amino acid.

In some embodiments, the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 1, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 3 or 5; or, the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 2, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 4.

In some embodiments, the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 6, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 9; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 7, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 10 or 11; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 8, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in any one of SEQ ID NOs: 11, 51-53. CDR3; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 48, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 54; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 49, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 52; or, the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 50, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 51 or 55.

In some embodiments, the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 12, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 16; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 13, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 17; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 14, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 18; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 15, and the The VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 18 or 62; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 56, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 60; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in SEQ ID NO: 57, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 61; or, the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH shown in any one of SEQ ID NOs: 15, 57-59, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL shown in SEQ ID NO: 63.

In some preferred embodiments, the VH and VL have HCDR1-3 and LCDR1-3 of the same sequence as a VH, VL selected from the group consisting of:

(1) VH as shown in SEQ ID NO: 8 and VL as shown in SEQ ID NO: 51;

(2) VH as shown in SEQ ID NO: 8 and VL as shown in SEQ ID NO: 52;

(3) VH as shown in SEQ ID NO: 8 and VL as shown in SEQ ID NO: 53;

(4) VH as shown in SEQ ID NO: 50 and VL as shown in SEQ ID NO: 51;

(5) VH as shown in SEQ ID NO: 50 and VL as shown in SEQ ID NO: 55; or

(6) VH as shown in SEQ ID NO: 15 and VL as shown in SEQ ID NO: 63.

In some embodiments, the HCDR1, HCDR2 and HCDR3 of the VH, and the LCDR1, LCDR2 and LCDR3 of the VL are defined according to IMGT, Kabat, Chothia, AbM, Contact or any combination thereof. In some preferred embodiments, the combination of IMGT and Kabat is defined; the combination of AbM and Kabat is defined; or the combination of IMGT, Kabat, Chothia, AbM and Contact is defined.

In some embodiments, the VH has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any of SEQ ID NOs: 1-2, and/or the VL has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any of SEQ ID NOs: 3-5.

In some embodiments, the VH has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any of SEQ ID NOs: 6-8, 48-50, and/or the VL has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any of SEQ ID NOs: 9-11, 51-55.

In some embodiments, the VH has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any of SEQ ID NOs: 12-15, 56-59, and/or the VL has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any of SEQ ID NOs: 16-18, 60-63.

In some embodiments, the VH comprises the sequence shown in SEQ ID NO: 1, and the VL comprises the sequence shown in any one of SEQ ID NO: 3-5; or, the VH comprises the sequence shown in SEQ ID NO: 2, and the VL comprises the sequence shown in any one of SEQ ID NO: 3-5.

In some embodiments, the VH comprises the sequence shown in SEQ ID NO: 6, and the VL comprises the sequence shown in any one of SEQ ID NOs: 9-11 and 51-55; the VH comprises the sequence shown in SEQ ID NO: 7, and the VL comprises the sequence shown in any one of SEQ ID NOs: 9-11 and 51-55; the VH comprises the sequence shown in SEQ ID NO: 8, and the VL comprises the sequence shown in any one of SEQ ID NOs: 9-11 and 51-55; the VH comprises the sequence shown in SEQ ID NO: 48, and the VL comprises the sequence shown in any one of SEQ ID NOs: 9-11 and 51-55; the VH comprises the sequence shown in SEQ ID NO: 49, and the VL comprises the sequence shown in any one of SEQ ID NOs: 9-11 and 51-55; or, the VH comprises the sequence shown in SEQ ID NO: 50, and the VL comprises the sequence shown in any one of SEQ ID NOs: 9-11 and 51-55.

In some embodiments, the VH comprises the sequence shown in SEQ ID NO: 12, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63; the VH comprises the sequence shown in SEQ ID NO: 13, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63; the VH comprises the sequence shown in SEQ ID NO: 14, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63; the VH comprises the sequence shown in SEQ ID NO: 15, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63. Sequence; the VH comprises the sequence shown in SEQ ID NO: 56, and the VL comprises the sequence shown in any one of SEQ ID NOs: 16-18, 60-63; the VH comprises the sequence shown in SEQ ID NO: 57, and the VL comprises the sequence shown in any one of SEQ ID NOs: 16-18, 60-63; the VH comprises the sequence shown in SEQ ID NO: 58, and the VL comprises the sequence shown in any one of SEQ ID NOs: 16-18, 60-63; or, the VH comprises the sequence shown in SEQ ID NO: 59, and the VL comprises the sequence shown in any one of SEQ ID NOs: 16-18, 60-63.

In some preferred embodiments, the VH and VL are selected from the following groups: the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 1, 3; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 2, 4; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 1, 5; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 6, 9; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 7, 10; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 7, 11 column; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 8, 11; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 8, 51; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 8, 52; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 8, 53; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 48, 54; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 49, 52; the VH and VL respectively contain or are S The VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 50 and 51; the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 50 and 55; the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 12 and 16; the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 13 and 17; the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 14 and 18; the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 15 and 18; the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 56 , 60; the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 57, 61; the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 15, 62; the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 58, 63; the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 15, 63; the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 59, 63; or, the VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 57, 63.

In some preferred embodiments, the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 1 and 3; the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 8 and 11; the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 8 and 51; the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 8 and 52; the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 8 and 53; the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 50 and 51; the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 50 and 55; the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 15 and 63; or, the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 15 and 18.

In some embodiments, the anti-MASP2 antibodies provided herein further comprise a heavy chain constant region and a light chain constant region. In some embodiments, the heavy chain constant region is selected from human IgG1, IgG2, IgG3, IgG4 constant regions or variants thereof, and the light chain constant region is selected from human κ and λ chain constant regions or variants thereof. In some embodiments, the heavy chain constant region is selected from IgG4 constant region variants having increased FcRn binding affinity. In some embodiments, the heavy chain constant region is selected from an IgG4 constant region having any one or more mutations of S228P (corresponding to the 108th amino acid residue of SEQ ID NO: 19), M428L (corresponding to the 308th amino acid residue of SEQ ID NO: 20), N434S (corresponding to the 314th amino acid residue of SEQ ID NO: 20), M252Y (corresponding to the 132nd amino acid residue of SEQ ID NO: 21), S254T (corresponding to the 134th amino acid residue of SEQ ID NO: 21) and T256E (corresponding to the 136th amino acid residue of SEQ ID NO: 21), and the above mutations are all EU numbering. In some preferred embodiments, the heavy chain constant region comprises a sequence as shown in any one of SEQ ID NOs: 19-21 or an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical thereto, and the light chain constant region comprises a sequence as shown in any one of SEQ ID NOs: 22-23 or an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical thereto.

In some embodiments, the anti-MASP2 antibody provided by the present invention comprises a heavy chain and a light chain, wherein the heavy chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NO: 37, 39, 42, and 43, and/or the light chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NO: 38, 40, and 41.

In some embodiments, the anti-MASP2 antibody provided by the present invention comprises a heavy chain and a light chain, wherein the heavy chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NO: 24, 28, 31, 44, 67, 69, 70, 80, 81, and/or the light chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71.

In some embodiments, the anti-MASP2 antibody provided by the present invention comprises a heavy chain and a light chain, wherein the heavy chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NO: 26, 32, 34, 36, 45, 72, 74, 77, 79, and/or the light chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NO: 27, 33, 35, 73, 75, 76, 78.

In some embodiments, the heavy chain comprises the sequence shown in SEQ ID NO:37 and the light chain comprises the sequence shown in any one of SEQ ID NO:38, 40, and 41; the heavy chain comprises the sequence shown in SEQ ID NO:39 and the light chain comprises the sequence shown in any one of SEQ ID NO:38, 40, and 41; the heavy chain comprises the sequence shown in SEQ ID NO:42 and the light chain comprises the sequence shown in any one of SEQ ID NO:38, 40, and 41; or, the heavy chain comprises the sequence shown in SEQ ID NO:43 and the light chain comprises the sequence shown in any one of SEQ ID NO:38, 40, and 41.

In some embodiments, the heavy chain comprises the sequence shown in SEQ ID NO:24 and the light chain comprises the sequence shown in any one of SEQ ID NO:25, 29, 30, 64, 65, 66, 68, and 71; the heavy chain comprises the sequence shown in SEQ ID NO:28 and the light chain comprises the sequence shown in any one of SEQ ID NO:25, 29, 30, 64, 65, 66, 68, and 71; the heavy chain comprises the sequence shown in SEQ ID NO:31 and the light chain comprises the sequence shown in any one of SEQ ID NO:25, 29, 30, 64, 65, 66, 68, and 71; the heavy chain comprises the sequence shown in SEQ ID NO:44 and the light chain comprises the sequence shown in any one of SEQ ID NO:25, 29, 30, 64, 65, 66, 68, and 71; the heavy chain comprises the sequence shown in SEQ ID NO:67 and the light chain comprises the sequence shown in SE The heavy chain comprises the sequence shown in SEQ ID NO: 69 and the light chain comprises the sequence shown in SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; the heavy chain comprises the sequence shown in SEQ ID NO: 70 and the light chain comprises the sequence shown in SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71. 5, 66, 68, and 71; the heavy chain comprises the sequence shown in SEQ ID NO:80 and the light chain comprises the sequence shown in SEQ ID NO:25, 29, 30, 64, 65, 66, 68, and 71; or, the heavy chain comprises the sequence shown in SEQ ID NO:81 and the light chain comprises the sequence shown in SEQ ID NO:25, 29, 30, 64, 65, 66, 68, and 71.

In some embodiments, the heavy chain comprises the sequence shown in SEQ ID NO:26 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, and 78; the heavy chain comprises the sequence shown in SEQ ID NO:32 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, and 78; the heavy chain comprises the sequence shown in SEQ ID NO:34 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, and 78; the heavy chain comprises the sequence shown in SEQ ID NO:36 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, and 78; the heavy chain comprises the sequence shown in SEQ ID NO:45 and the light chain comprises the sequence shown in The heavy chain comprises the sequence shown in SEQ ID NO: 72 and the light chain comprises the sequence shown in SEQ ID NO: 74 and the light chain comprises the sequence shown in SEQ ID NO: 78; the heavy chain comprises the sequence shown in SEQ ID NO: 77 and the light chain comprises the sequence shown in SEQ ID NO: 78; or the heavy chain comprises the sequence shown in SEQ ID NO: 79 and the light chain comprises the sequence shown in SEQ ID NO: 78.

In some preferred embodiments, the heavy chain and the light chain respectively comprise a sequence selected from the following groups: a sequence as shown in SEQ ID NO: 24, 25; a sequence as shown in SEQ ID NO: 26, 27; a sequence as shown in SEQ ID NO: 28, 29; a sequence as shown in SEQ ID NO: 28, 30; a sequence as shown in SEQ ID NO: 31, 30; a sequence as shown in SEQ ID NO: 31, 64; a sequence as shown in SEQ ID NO: 31, 65; a sequence as shown in SEQ ID NO: The sequence shown in SEQ ID NO: 31 and 66; the sequence shown in SEQ ID NO: 67 and 68; the sequence shown in SEQ ID NO: 69 and 65; the sequence shown in SEQ ID NO: 70 and 64; the sequence shown in SEQ ID NO: 70 and 71; the sequence shown in SEQ ID NO: 32 and 33; the sequence shown in SEQ ID NO: 34 and 35; the sequence shown in SEQ ID NO: 36 and 35; the sequence shown in SEQ ID NO: 37 and 38; the sequence shown in SEQ ID NO: NO:39, 40; NO:37, 41; NO:72, 73; NO:74, 75; NO:36, 76; NO:77, 78; NO:36, 78; NO:79, 78; NO:74 ... the sequence shown in SEQ ID NO:42, 38; the sequence shown in SEQ ID NO:43, 38; the sequence shown in SEQ ID NO:44, 30; the sequence shown in SEQ ID NO:44, 64; the sequence shown in SEQ ID NO:44, 65; the sequence shown in SEQ ID NO:44, 66; the sequence shown in SEQ ID NO:80, 68; the sequence shown in SEQ ID NO:81, 65; or, the sequence shown in SEQ ID NO:45, 35.

In some preferred embodiments, the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:31 and 30; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:31 and 64; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:31 and 65; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:31 and 66; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:70 and 64; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:70 and 71; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:36 and 78; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:36 and 35 The heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:37 and 38; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:42 and 38; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:43 and 38; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:44 and 30; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:44 and 64; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:44 and 65; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:44 and 66; or the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NO:45 and 35.

In one aspect, the present invention provides an anti-MASP2 antibody or an antigen-binding fragment thereof, which binds to or competes for binding to the same epitope as the aforementioned anti-MASP2 antibody or antigen-binding fragment thereof.

In some embodiments, the anti-MASP2 antibodies or antigen-binding fragments thereof provided herein have at least one of the following:

(1) The antibody or antigen-binding fragment thereof binds to human MASP2 with a KD of 10 nM or lower, and the KD can be detected, for example, by the method of Example 3 of the present invention;

(2) the antibody or antigen-binding fragment thereof inhibits complement lectin pathway MAC deposition in an in vitro assay with an IC50 of less than 1, less than 0.9, less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4, less than 0.3, less than 0.2, less than 0.1, less than 0.09, less than 0.08, less than 0.07, less than 0.06, less than 0.05, less than 0.04, less than 0.03, less than 0.02, less than 0.01 μg/mL or less, and _{the IC50} can be obtained by, for example, detecting the method of Example 4 of the present invention;

(3) the antibody or antigen-binding fragment thereof does not substantially inhibit the classical pathway and/or the alternative pathway;

(4) the antibody or antigen-binding fragment thereof does not substantially bind to complement components C1r, C1s, MASP1 and/or MASP3;

(5) when binding to human MASP2, the antibody or antigen-binding fragment thereof has a KD that is substantially the same as or better than a reference MASP2 antibody;

(6) When binding to human MASP2, the antibody or antigen-binding fragment thereof specifically inhibits or blocks the complement agglutinin pathway. Preferably, the inhibition or blocking effect of the antibody or antigen-binding fragment thereof is substantially the same as or better than that of a reference MASP2 antibody;

(7) When binding to human MASP2, the antibody or antigen-binding fragment thereof reduces or decreases C4b and/or MAC deposition. Preferably, the antibody or antigen-binding fragment thereof reduces or decreases C4b and/or MAC deposition at a level substantially the same as or better than a reference MASP2 antibody.

In some preferred embodiments, the reference MASP2 antibody is selected from Narsoplimab.

In some embodiments, the anti-MASP2 antibodies provided herein are chimeric antibodies, humanized antibodies, or fully human antibodies. In some embodiments, the anti-MASP2 antibodies are monoclonal antibodies.

In some embodiments, the antigen-binding fragment of the invention is selected from the group consisting of: Fab, F(ab')2, Fab', Fd, Fv, dsFv, scFv, Fab, and diabodies.

In some embodiments, the anti-MASP2 antibodies or antigen-binding fragments thereof provided herein contain one or more effector molecules selected from anti-tumor agents, drugs, toxins, biologically active proteins (e.g., enzymes), other antibodies or antibody fragments, synthetic or naturally occurring polymers, nucleic acids and fragments thereof such as DNA, RNA and fragments thereof, radionuclides (e.g., radioiodides), radioisotopes, chelated metals, nanoparticles and reporter groups (e.g., fluorescent compounds), or compounds detectable by NMR or ESR spectroscopy. In some specific embodiments, the effector molecules are conjugated or fused to the anti-MASP2 antibodies or antigen-binding fragments thereof of the present invention.

In one aspect, the present invention provides a bispecific or multispecific antibody or antigen-binding fragment thereof, comprising an anti-MASP2 antibody or antigen-binding fragment thereof of the present invention.

In one aspect, the present invention provides a polynucleotide encoding an anti-MASP2 antibody or antigen-binding fragment thereof of the present invention. The polynucleotide of the present invention may be, for example, DNA or RNA, and may or may not contain intronic sequences. In a preferred embodiment, the polynucleotide is a cDNA molecule. The polynucleotide of the present invention may be prepared or obtained by known means based on the information of the amino acid sequence of the anti-MASP2 antibody or antigen-binding fragment thereof of the present invention, for example, by automated DNA synthesis and/or recombinant DNA technology.

As is well known in the art, multiple codons can encode the same amino acid. Therefore, nucleic acids encoding protein sequences include nucleic acids with codon degeneracy. The amino acid sequence of the present invention can be encoded by a variety of nucleic acids. The genetic code is universal and well known. Nucleic acids encoding any amino acid sequence of the present invention can be easily conceived based on the common knowledge in the art, and can be optimized for production. Although the possible number of nucleic acid sequences encoding a given amino acid is very large, given the standard table of the genetic code, and with the assistance of a calculator, those skilled in the art can easily produce every possible combination of nucleic acid sequences encoding a given amino acid.

In one aspect, the present invention provides an expression vector comprising a polynucleotide of the present invention, wherein the expression vector comprises a eukaryotic expression vector, a prokaryotic expression vector, a viral vector, such as a bacterial plasmid, a bacteriophage, a yeast plasmid, a plant cell virus, a mammalian cell virus such as an adenovirus, a retrovirus, or other vectors.

On the one hand, the present invention provides a host cell comprising a polynucleotide or an expression vector of the present invention. The host cell comprises a prokaryotic cell, a fungal cell or a mammalian cell, such as a CHO cell, a NS0 cell or other mammalian cell, an Escherichia coli or other prokaryotic cell, a yeast cell or other fungal cell.

In one aspect, the present invention provides a pharmaceutical composition comprising an anti-MASP2 antibody or antigen-binding fragment thereof, or a bispecific or multispecific antibody or antigen-binding fragment thereof, or a polynucleotide, or an expression vector, or a host cell of the present invention, and one or more pharmaceutically acceptable carriers.

In some preferred embodiments, the pharmaceutical composition contains a therapeutically effective amount of the aforementioned anti-MASP2 antibody or antigen-binding fragment thereof, or the aforementioned nucleic acid molecule, and one or more pharmaceutically acceptable carriers, diluents, buffers or excipients.

In some embodiments, the pharmaceutical composition may include any number of excipients. Excipients that may be used include carriers, surfactants, thickeners or emulsifiers, solid binders, dispersion or suspension aids, solubilizers, colorants, flavoring agents, coating agents, disintegrants, lubricants, sweeteners, preservatives, isotonic agents, or combinations thereof. The selection and use of suitable excipients are taught in Gennaro, ed., Remington: The Science and Practice of Pharmacy, 20th edition (Lippincott Williams & Wilkins 2003), the disclosure of which is incorporated herein by reference.

In some embodiments, the pharmaceutical composition further comprises one or more additional therapeutic agents.

In one aspect, the present invention provides a kit comprising the aforementioned anti-MASP2 antibody or antigen-binding fragment thereof.

In one aspect, the present invention provides the use of the aforementioned anti-MASP2 antibody or antigen-binding fragment thereof in detecting MASP2 protein or preparing a reagent for detecting MASP2 protein. MASP2 protein can be detected in vivo or in vitro, preferably human MASP2 protein, and the purpose may be non-disease diagnosis.

In one aspect, the invention provides a method for preventing and/or treating a disease or condition associated with MASP2 in a subject, comprising administering to a subject in need thereof a therapeutically or prophylactically effective amount of an anti-MASP2 antibody or antigen-binding fragment thereof, a bispecific or multispecific antibody or antigen-binding fragment thereof, a polynucleotide, an expression vector, a host cell, a pharmaceutical composition or a kit of the invention.

In one aspect, the present invention provides use of the aforementioned anti-MASP2 antibody or antigen-binding fragment thereof, or the aforementioned bispecific or multispecific antibody or antigen-binding fragment thereof, or the aforementioned polynucleotide, or the aforementioned expression vector, or the aforementioned host cell, or the aforementioned pharmaceutical composition, or the aforementioned kit in the preparation of a medicament for preventing and/or treating a disease or condition associated with MASP2 in a subject.

In some embodiments, the disease or condition associated with MASP2 is a disease or condition caused by abnormal expression of MASP2. In some embodiments, the disease associated with MASP2 is selected from the disease or condition caused by overexpression of MASP2. In some preferred embodiments, the disease associated with MASP2 is selected from IgA nephropathy, thrombotic microangiopathy, systemic lupus erythematosus, membranous nephropathy, lupus nephritis, transplant rejection, antiphospholipid syndrome, rheumatoid arthritis, hemolytic uremic syndrome, hereditary angioedema, myocardial infarction, etc.

In one aspect, the present invention provides use of the aforementioned anti-MASP2 antibody or antigen-binding fragment thereof, or the aforementioned bispecific or multispecific antibody or antigen-binding fragment thereof, or the aforementioned polynucleotide, or the aforementioned expression vector, or the aforementioned host cell, or the aforementioned pharmaceutical composition, or the aforementioned kit in the preparation of a medicament, wherein the medicament is used for:

(1) specifically inhibiting or blocking the complement lectin pathway; and/or

(2) Reduce or decrease C4b and/or MAC deposition.

The present invention also provides a method for preparing the anti-MASP2 antibody or antigen-binding fragment thereof of the present invention:

The anti-MASP2 antibody or antigen-binding fragment thereof of the present invention can be obtained by conventional techniques, such as the Cold Spring Harbor Guide to Antibody Experimental Techniques, Chapters 5-8 and 15. For example, mice can be immunized with human MASP2 or a fragment thereof, and the resulting antibody can be renatured, purified, and amino acid sequenced by conventional methods. Antigen-binding fragments can also be prepared by conventional methods. The antibody or antigen-binding fragment of the present invention is prepared by adding one or more human FR regions to the non-human CDR region using genetic engineering methods. The human FR germline sequence can be obtained from the website of ImMunoGeneTics (IMGT) by comparing the IMGT human antibody variable region germline gene database and MOE software, or from the Journal of Immunoglobulin, 2001 ISBN012441351. Alternatively, for example, the cDNA sequences encoding the heavy chain and the light chain are cloned into an expression vector. The recombinant immunoglobulin expression vector can be stably transfected into CHO cells. Stable clones are obtained by expressing antibodies that specifically bind to human MASP2. Positive clones are expanded in serum-free medium in a bioreactor to produce antibodies.

The anti-MASP2 antibody or antigen-binding fragment thereof of the present invention can be expressed intracellularly, on the cell membrane, or secreted outside the cell. If necessary, the recombinant protein can be separated and purified by various separation methods using its physical, chemical and other properties. These methods are well known to those skilled in the art. Generally, the transformed host cells are cultured under conditions suitable for the expression of the antibody of the present invention, and then purified by conventional immunoglobulin purification steps, such as protein A-Sepharose affinity chromatography, ion exchange chromatography, hydrophobic chromatography, molecular sieve chromatography, hydroxyapatite chromatography, gel electrophoresis, dialysis and other conventional separation and purification means and a combination of these methods to obtain the anti-MASP2 antibody or antigen-binding fragment thereof of the present invention. The antibody can be filtered and concentrated by conventional methods.

As a preferred embodiment of the method for preparing the anti-MASP2 antibody or antigen-binding fragment thereof of the present invention, the method for separating and purifying the anti-MASP2 antibody or antigen-binding fragment thereof is protein A affinity chromatography, cation exchange method or anion exchange method.

The resulting monoclonal antibodies or bispecific antibodies can be identified by conventional means. For example, the binding specificity of the antibody can be determined by immunoprecipitation or in vitro binding assays such as enzyme-linked immunosorbent assay (ELISA) or radioimmunoassay (RIA). The binding affinity of the antibody can be determined, for example, by Scatchard analysis of Munson et al., Anal. Biochem., 107:220 (1980), or by surface plasmon resonance (Biacore).

For the sake of clarity, general terms used in the description of the compounds are defined herein.

Unless otherwise indicated, the following terms and phrases used herein are intended to have the following meanings. A particular term or phrase should not be considered to be uncertain or unclear in the absence of a special definition, but should be understood in accordance with the ordinary meaning. When a trade name appears in this article, it is intended to refer to its corresponding commodity or its active ingredient. The term "pharmaceutically acceptable" used here refers to those compounds, materials, compositions and/or dosage forms that are within the scope of reliable medical judgment and are suitable for use in contact with human and animal tissues without excessive toxicity, irritation, allergic reactions or other problems or complications, and are commensurate with a reasonable benefit/risk ratio.

The terms "mannan-binding lectin-associated serine protease 2", "MASP2 protein", "MASP2 antigen" and "MASP2" are used interchangeably and refer to any MASP2 molecule known to those skilled in the art and its functional homologs, unless otherwise specified, including but not limited to those derived from humans, rodents, mice, rats, primates, monkeys and guinea pigs. The term also refers to a fragment or variant of native MASP2 that retains at least one in vivo or in vitro activity of native MASP2. The term encompasses the full-length unprocessed precursor form of MASP2 as well as the mature form resulting from post-translational cleavage of the signal peptide. MASP2 as used herein also refers to a specific polypeptide expressed in a cell via a naturally occurring DNA sequence variation of the MASP2 gene, such as a single nucleotide polymorphism of the MASP2 gene. Examples include amino acid sequences corresponding to human MASP2 registered with Genbank Accession No. NP_006601.2, mouse MASP2 registered with Genbank Accession No. NP_001003893.1, rat MASP2 registered with Genbank Accession No. NP_742040.1, and monkey MASP2 registered with Genbank Accession No. XP_045236890.1 or XP_005544871.1. Other examples of amino acid sequences of MASP2 can be obtained using, for example, GenBank, UniProt, or OMIM.

The term "antibody" as referred to herein includes complete antibodies and any antigen-binding fragments thereof (i.e., "antigen-binding portions") or single chains thereof. Complete antibodies are glycoproteins comprising two heavy (H) chains and two light (L) chains connected by disulfide bonds. Each heavy chain consists of a heavy chain variable region (abbreviated herein as VH) and a heavy chain constant region (abbreviated herein as CH). The heavy chain constant region consists of three domains CH1, CH2, and CH3. Each light chain consists of a light chain variable region (abbreviated herein as VL) and a light chain constant region (abbreviated herein as CL). The light chain constant region consists of one domain CL. The VH region and the VL region can be further subdivided into hypervariable regions (called complementary determining regions (CDRs)), separated by more conserved regions called framework regions (FRs). Each VH and VL consists of three CDRs and four FRs, arranged in the following order from the amino terminus to the carboxyl terminus: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The three CDR regions of the light chain refer to LCDR1, LCDR2, and LCDR3; the three CDR regions of the heavy chain refer to HCDR1, HCDR2, and HCDR3. The variable regions of the heavy and light chains contain binding domains that interact with antigens. The constant region of the antibody can mediate the binding of immunoglobulins to host tissues or factors, including various cells of the immune system (e.g., effector cells) and the first component (C1q) of the classical complement system.

For the determination or definition of CDR, the deterministic depiction of CDR and the identification of residues comprising the binding site of the antibody can be completed by resolving the structure of the antibody and/or resolving the structure of the antibody-ligand complex. This can be achieved by any of the various techniques known to those skilled in the art, such as X-ray crystallography. A variety of analytical methods (combinations of methods) can be used to identify CDR, including but not limited to Kabat, Chothia, AbM, IMGT, Contact definitions, conformational definitions. All of these techniques are well known in the art, see, for example, Kabat, EA et al. (1991) Sequences of Proteins of Immunological Interest, 5th Edition, U.S. Department of Health and Human Services, NIH Publication No. 91-3242, Chothia et al. (1989) Nature 342:877; Chothia, C. et al. (1987) J. Mol. Biol. 196:901-917, Al-lazikani et al. (1997) J. Molec. Biol. 273:927-948; and Almagro, J. Mol. Recognit. 17:132-143 (2004). The software programs used include, but are not limited to, AbRSA (http://cao.labshare.cn/AbRSA/cdrs.php), abYsis (www.abysis.org/abysis/sequence_input/key_annotation/key_annotation.cgi), and IMGT (http://www.imgt.org/3Dstructure-DB/cgi/DomainGapAlign.cgi#results). The positions of amino acid residues included in an exemplary defined CDR are listed in the following table:

Note 1: The definitions in different literatures vary slightly, especially the Chothia definition scheme;

Note 2: Except for the Contact definition that uses the Chothia numbering or Martin numbering scheme, other definition schemes are compatible with various numbering schemes;

Note 3: When Kabat numbering is used, the end of the Chothia HCDR1 varies between H32 and H34 depending on the length of the loop (this is because the Kabat numbering scheme places the insertion at H35A and H35B).

Note: The amino acid numbering on the heavy chain is represented by "H+number", and the amino acid numbering on the light chain is represented by "L+number"; for example, L24-L34 in the second row and second column of the table refers to the amino acid sequence determined from the 24th to the 34th residue according to the Kabat coding scheme starting from the N-terminus of the antibody light chain variable region; and the same applies to the others.

The term "antigen-binding fragment" (or simply "antibody portion") refers to one or more fragments of an antibody that specifically binds to an antigen (e.g., a MASP2 protein). It has been shown that the antigen-binding function of an antibody can be achieved by fragments of a full-length antibody. Examples of binding fragments encompassed by the term "antigen-binding fragment" of an antibody include: (i) a Fab fragment, a monovalent fragment consisting of the VL, VH, CL, and CH1 domains; (ii) a F(ab')2 fragment, a bivalent fragment comprising two Fab fragments linked by a disulfide bond at the hinge region; (iii) a Fd fragment consisting of the VH and CH1 domains; (iv) a Fv fragment consisting of the VL and VH domains of a single arm of an antibody; (v) a dAb fragment consisting of a VH domain (Ward et al., (1989) Nature 341:544-546); (vi) an isolated complementarity determining region (CDR); and (vii) a nanobody, a heavy chain variable region comprising a single variable domain and two constant domains. In addition, although the two domains VL and VH of the Fv fragment are encoded by separate genes, they can be connected by a linker using recombinant methods to make them a single protein chain, in which the VL region and the VH region are paired to form a monovalent molecule (called single-chain Fv (scFv); see, for example, Bird et al., (1988) Science 242: 423-426; and Huston et al., (1988) Proc. Natl. Acad. Sci. USA 85: 5879-5883). Such single-chain antibodies are also included in the term "antigen-binding fragment" of an antibody. These antibody fragments can be obtained by conventional techniques known to those skilled in the art, and the fragment screening for use is the same as that for intact antibodies.

As used herein, the term "monoclonal antibody" refers to a preparation of antibody molecules of single molecular composition. A monoclonal antibody composition displays a single binding specificity and affinity for a particular epitope.

The term "murine antibody" refers to a monoclonal antibody against human MASP2 prepared according to the knowledge and skills in the art. During preparation, a test subject may be injected with a MASP2 antigen, and then a hybridoma expressing an antibody having the desired sequence or functional properties may be isolated. The murine anti-MASP2 antibody or antigen-binding fragment thereof may further comprise a light chain constant region of a murine κ, λ chain or a variant thereof, or further comprise a heavy chain constant region of a murine IgG1, IgG2, IgG3 or a variant thereof.

The term "chimeric antibody" refers to an antibody formed by fusing the variable region of a heterologous (e.g., mouse) antibody with the constant region of a parent antibody (e.g., human antibody), which can reduce the immune response induced by the heterologous antibody. For example, human-mouse chimeric antibodies, to establish chimeric antibodies, it is necessary to first establish a hybridoma that secretes mouse-specific monoclonal antibodies, then clone the variable region genes from mouse hybridoma cells, and then clone the constant region genes of human antibodies as needed, connect the mouse variable region genes with the human constant region genes into chimeric genes, and then insert them into an expression vector, and finally express the chimeric antibody molecule in a eukaryotic system or a prokaryotic system.

The term "humanized antibody", also known as CDR-grafted antibody, refers to an antibody produced by transplanting mouse CDR sequences into the human antibody variable region framework, that is, different types of human germline antibody framework sequences. It can overcome the heterologous response induced by chimeric antibodies carrying a large amount of mouse protein components. Such framework sequences can be obtained from public DNA databases including germline antibody gene sequences or published references. For example, the germline DNA sequences of human heavy chain and light chain variable region genes can be obtained in the "VBase" human germline sequence database, and in Kabat, E.A. et al., 1991 Sequences of Proteins of Immunological Interest, 5th edition. In order to avoid a decrease in activity caused by a decrease in immunogenicity, the human antibody variable region framework sequence can be subjected to minimal reverse mutations or back mutations to maintain activity.

The term "bispecific" or "multispecific" refers to an antibody and/or antigen binding molecule that can specifically bind to two or more different antigenic determinants. Typically, a bispecific antibody or antigen binding molecule comprises two antigen binding sites, each of which is specific for a different antigenic determinant. In certain embodiments, the bispecific or multispecific antibody or antigen binding molecule can simultaneously bind to two or more antigenic determinants, particularly two or more antigenic determinants expressed on two or more different cells.

The terms "variants" of the heavy chain constant region and the light chain constant region refer to variants of the heavy chain constant region or the light chain constant region that are derived from humans and do not change the structure and function of the antibody variable region and have been disclosed in the prior art. Exemplary variants include IgG1, IgG2, IgG3 or IgG4 heavy chain constant region variants with site-directed modification and amino acid substitutions in the heavy chain constant region. Specific substitutions include YTE mutations, L234A and/or L235A mutations, S228P mutations, and/or mutations to obtain knob-into-hole structures (such that the antibody heavy chain has a combination of knob-Fc and hole-Fc) known in the prior art. These mutations have been shown to impart new properties to the antibody without changing the function of the antibody variable region.

As used herein, the terms "include", "comprising", and "having" are used interchangeably and are intended to indicate the inclusiveness of the solution, meaning that the solution may have other elements besides the listed elements. At the same time, it should be understood that the use of "include", "comprising", and "having" descriptions in this article also provides a "consisting of..." solution.

The term "antibody" herein includes, but is not limited to, a monoclonal antibody, a polyclonal antibody, a monospecific antibody, a multispecific antibody (e.g., a bispecific antibody), a monovalent antibody, a multivalent antibody, a whole antibody, an antigen-binding fragment, a naked antibody, a conjugated antibody, a humanized antibody, or a fully human antibody.

The term "conservative amino acid" herein generally refers to amino acids belonging to the same class or having similar characteristics (e.g., charge, side chain size, hydrophobicity, hydrophilicity, main chain conformation, and rigidity). Exemplarily, the amino acids within each of the following groups are conservative amino acid residues of each other, and the replacement of the amino acid residues within the group is a replacement of conservative amino acids:

1) Alanine (A), serine (S), threonine (T);

2) Aspartic acid (D), glutamic acid (E);

3) Asparagine (N), glutamine (Q);

4) Arginine (R), Lysine (K), Histidine (H);

5) isoleucine (I), leucine (L), methionine (M), valine (V); and

6) Phenylalanine (F), tyrosine (Y), tryptophan (W).

The terms "identity" and "sequence ... identity" are interchangeable herein and are calculated in the following manner: To determine the percentage of "identity" of two amino acid sequences or two nucleic acid sequences, the sequences are aligned for optimal comparison purposes (e.g., gaps may be introduced in one or both of the first and second amino acid sequences or nucleic acid sequences for optimal alignment or non-homologous sequences may be discarded for comparison purposes). The amino acid residues or nucleotides at corresponding amino acid positions or nucleotide positions are then compared. When a position in the first sequence is occupied by the same amino acid residue or nucleotide at the corresponding position in the second sequence, then the molecules are identical at this position.

When the term "compete" is used in the context of antigen binding proteins (e.g., neutralizing antigen binding proteins or neutralizing antibodies) that compete for the same epitope, it means competition between antigen binding proteins as determined by an assay in which the antigen binding protein (e.g., antibody or immunologically functional fragment thereof) to be tested prevents or inhibits (e.g., reduces) specific binding of a reference antigen binding protein (e.g., ligand or reference antibody) to a common antigen (e.g., MASP2 antigen or fragment thereof). Numerous types of competitive binding assays can be used to determine whether one antigen binding protein competes with another, such as: solid phase direct or indirect radioimmunoassays (RIA), solid phase direct or indirect enzyme immunoassays (EIA), sandwich competition assays (see, e.g., Stahli et al., 1983, Methods in Enzymology 9:242-253); solid phase direct biotin-avidin EIA (see, e.g., Kirkland et al., 1986, J. Immunol. 137:3614-3619), solid phase direct labeled assays, solid phase direct labeled sandwich assays (see, e.g., Harlow and Lane, 1988, Antibodies, A Laboratory Manual, Cold Spring Harbor Press); solid phase direct labeling RIA with I-125 label (see, e.g., Morel et al., 1988, Molec. Immunol. 25: 7-15); solid phase direct biotin-avidin EIA (see, e.g., Cheung et al., 1990, Virology 176: 546-552); and directly labeled RIA (Moldenhauer et al., 1990, Scand. J. Immunol. 32: 77-82). Typically the assay involves the use of purified antigen bound to a solid surface or cells bearing either an unlabeled test antigen binding protein or a labeled reference antigen binding protein. Competitive inhibition is measured by measuring the amount of label bound to the solid surface or cells in the presence of the antigen binding protein being tested. Typically the antigen binding protein being tested is present in excess. Antigen binding proteins identified by competitive assays (competing antigen binding proteins) include: antigen binding proteins that bind to the same epitope as a reference antigen binding protein; and antigen binding proteins that bind to adjacent epitopes that are sufficiently close to the binding epitope of the reference antigen binding protein that the two epitopes sterically interfere with each other in binding. Typically, when the competing antigen binding protein is present in excess, it will inhibit (e.g., reduce) at least 40-45%, 45-50%, 50-55%, 55-60%, 60-65%, 65-70%, 70-75%, or 75% or more of the specific binding of the reference antigen binding protein to the common antigen. In some cases, binding is inhibited by at least 80-85%, 85-90%, 90-95%, 95-97%, or 97% or more.

The term "subject" includes any human or non-human animal. The term "non-human animal" includes all vertebrates, such as mammals and non-mammals, such as non-human primates, rodents, rabbits, pigs, dogs, cats, chickens, amphibians and reptiles, although mammals such as non-human primates and rodents are preferred.

The term "therapeutically effective amount" refers to an amount of an anti-MASP2 antibody or antigen-binding fragment thereof of the invention sufficient to prevent or ameliorate symptoms associated with a disease or condition (e.g., IgA nephropathy) and/or reduce the severity of the disease or condition. A therapeutically effective amount should be understood in the context of the condition being treated, wherein one skilled in the art can readily identify the actual effective amount.

The antibodies of the present invention are monoclonal antibodies characterized structurally and chemically as described below and in the following examples. The amino acid sequence ID numbers of the heavy chain/light chain variable regions of exemplary antibodies are summarized in Table 1, and the heavy chain and light chain constant region sequence ID numbers are summarized in Table 2.

Table 1 Heavy chain/light chain variable region sequences of anti-MASP2 antibodies of the present invention


Note: The underlined amino acid residues are the CDR regions defined by Kabat.

Table 2 Heavy chain/light chain constant region sequences of anti-MASP2 antibodies of the present invention

The positive control antibody Narsoplimab used in the present invention was synthesized according to WO2012151481A, and its heavy chain/light chain amino acid sequence is as follows:

>Narsoplimab heavy chain (SEQ ID NO:46):

>Narsoplimab light chain (SEQ ID NO:47):

The heavy chain variable region and light chain variable region CDR sequences in Table 1 defined by Kabat, Chothia, IMGT, AbM, and Contact using abYsis are shown in Table 3.

Table 3 CDR sequences of anti-MASP2 antibodies of the invention

Through the following detailed description and examples, other features and advantages disclosed by the present invention will become apparent, which should not be construed as limiting. The contents of all references, Genbank entries, patents and published patent applications cited throughout this application are expressly incorporated herein by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 shows the effects of antibodies 11W0 and 11W3 on the classical complement pathway, wherein an isotype IgG antibody (IgG4SP) was used as a negative control.

FIG2 shows the effects of antibodies 11W0 and 11W3 on the alternative pathway, wherein an isotype IgG antibody (IgG4SP) was used as a negative control.

Figure 3 shows the binding of antibodies 11W0, 11W1 and 11W3 to complement homologous family members, and Narsoplimab is used as a control antibody. Among them, the complement homologous family member involved in Figure 3A is human complement component C1s, the complement homologous family member involved in Figure 3B is human complement component C1r, the complement homologous family member involved in Figure 3C is human complement component MASP-1, and the complement homologous family member involved in Figure 3D is human complement component MASP-3.

FIG4 shows the inhibitory activity of antibodies 20W30, 11W3 and their long-acting modified antibodies on the complement agglutinin pathway in vitro.

FIG5A shows the inhibitory activity of the long-acting modified antibody 11W4-LS on the complement lectin pathway in vitro (human complement serum), wherein Narsoplimab was used as a control antibody; the _IC50 of 11W4-LS was <0.01 μg/mL.

FIG5B shows the inhibitory activity of the long-acting modified antibody 11W4-LS on the complement lectin pathway in vitro (cynomolgus monkey complement serum), wherein Narsoplimab was used as a control antibody.

Figure 5C shows the inhibitory activity (human complement serum) of the long-acting modified antibodies 11W5-LS, 11W6-LS, 11W7-LS, and 11W8-LS on the complement lectin pathway in vitro, wherein Narsoplimab was used as a control antibody; the IC ₅₀ of 11W5-LS, 11W6-LS, 11W7-LS, and 11W8-LS was <0.05 μg/mL.

FIG6 shows the results of ELISA affinity determination of some antibodies.

FIG. 7 shows the results of MAC assay of some antibodies using the complement agglutinin pathway (human complement serum).

FIG8 shows the effects of some antibodies on the classical complement pathway and the alternative complement pathway (human complement serum).

FIG. 9 shows the effects of some antibodies on C4b deposition (human complement serum).

Specific embodiments

Example 1 Immunization of mice to prepare anti-MASP2 antibodies

1.1 Preparation of mouse antibodies

A total of 12 Balb/C mice (Vitolver) and 12 C57 mice (Vitolver) were immunized by protein injection. The proteins used were huMASP-2A-chis, cynoMASP-2A-chis, musMASP-2A-chis, and ratMASP-2A-chis. The adjuvant for the first immunization was Freund's complete adjuvant, injected at 100 μg/mouse. The adjuvant for the second, third, and fourth immunizations was Freund's incomplete adjuvant, injected at 50 μg/mouse. The sprint immunization was injected at 100 μg/mouse. After the sprint immunization, the spleen and orbital blood of the mice were taken on the third day for titer detection, and the spleen was ground and stored in Trizol.

The spleen of mice after sprint immunization was taken, and total RNA was extracted by Trizol method, and the extracted total RNA was reverse transcribed into cDNA. Based on the germline of Fab heavy chain and light chain, the variable region genes of mouse heavy chain and light chain were amplified, and then cloned into phage display vector by restriction enzyme, and the recombinant vector was transformed into competent Escherichia coli SS320 (Lucigen, MC1061F) to construct antibody gene phage display library with a library capacity of 5×10 ⁸ .

The library was screened by magnetic bead method and immunotube method. The magnetic bead method screening is based on the biotin labeling of the antigen protein hu 10AA-CCP1-CCP2-SP-A-chis, and then binding it to magnetic beads coupled with streptavidin. The antigen-bound magnetic beads and the antibody gene phage display library were incubated, washed and eluted in the panning process. Usually, three rounds of panning were performed, so that specific monoclonal antibodies against the antigen could be enriched in large quantities. Immunotube screening is a process in which the antigen proteins hu 10AA-CCP1-CCP2-SP-A-chis, cyno 10AA-CCP1-CCP2-SP-A -chis2, mus 10AA-CCP1-CCP2-SP-A-chis and rat 10AA-CCP1-CCP2-SP-A-chis are coated on the surface of an immunotube with high adsorption capacity, and the phage-displayed antibody library is added to the immunotube and incubated with the antigen protein adsorbed on the surface of the immunotube, washed and eluted. After three rounds of panning, the specific monoclonal antibody Fab against the antigen is finally enriched.

The phage pool eluted in each round was tested by ELISA to evaluate the enrichment effect, and the third round was selected for monoclonal selection. The monoclonal phage supernatant was centrifuged for ELISA, and the method was as follows: 1) Coating: 2μg/mL antigen huMASP-2A-chis, cynoMASP-2A-chis, ratMASP-2A-chis, musMASP-2A-chis, 30μL per well, 4°C overnight, PBST wash plate 3 times; 2) Blocking: 5% PBSM blocking at room temperature for 1h, PBST wash plate 3 times; 3) Primary antibody: add monoclonal phage expression supernatant, negative control (IgG) diluted to 5μg/mL, 30μL/well, room temperature for 1h, PBST wash plate 3 times; 4) Secondary antibody: add 1:20000 diluted secondary antibody Anti-M13-HRP, 5% Diluted with PBSM, negative control (IgG) samples were added with 1:5000 dilution of secondary antibody Anti-human-Fab-HRP, diluted with PBS, 30 μL/well, room temperature for 1h, washed 6 times with PBST; 5) Termination: Add 30 μL/well TMB to color at room temperature for 5min to 10min, then add 30 μL/well 2M stop solution to terminate the reaction. The data was read at OD ₄₅₀ by microplate reader. For the positive clones screened out, the plasmid was extracted for second generation sequencing. The amino acids of the heavy chain variable region and light chain variable region of the mouse anti-MASP2 antibody obtained in this example are shown in Table 4.

Table 4 Heavy chain/light chain variable region sequences of murine anti-MASP2 antibodies


Note: The underlined amino acid residues are the CDR regions defined by the Kabat numbering system/method.

1.2 Preparation of chimeric antibodies

The heavy chain variable region sequence of the mouse anti-MASP2 antibody was cloned into a GSV0 vector containing a human heavy chain constant region (IgG4SP, which has an Fc modification of S228P to stabilize the hinge), and the amino acid sequence of the heavy chain constant region is shown in SEQ ID NO: 19; the light chain variable region sequence of the mouse anti-MASP2 antibody was cloned into a GSV0 vector containing a human light chain constant region (κ chain), and the light chain constant region sequence is shown in SEQ ID NO: 23. Using the ExpiCHOs expression system, the above vectors were co-transfected into CHO cells for expression, and the expression supernatant was collected and purified to obtain complete chimeric antibodies. The chimeric antibodies 11W0 (11W-VH1-VL1) and 12W0 (12W-VH1-VL1) targeting MASP2, the heavy chain and light chain sequences are as follows:

>11W0 heavy chain (SEQ ID NO:24):

>11W0 light chain (SEQ ID NO:25):

>12W0 heavy chain (SEQ ID NO:26):

>12W0 light chain (SEQ ID NO: 27):

1.3 Preparation of humanized antibodies

The structure of the parent antibody was modeled by the MOE homology modeling program, and then the humanized antibody was designed using CDR transplantation. In short, the CDR of the parent antibody was transplanted into the human antibody backbone to obtain the humanized light chain and heavy chain of each parent antibody. In addition, based on the humanized sequence, post-transcriptional modification (PTM) sites, such as glycosylation sites, deamidation sites, isomerization sites, etc., were identified, and mutations were designed to remove PTM sites to optimize the antibody sequence, thereby avoiding adverse effects on protein conformation and function.

According to different degrees of humanized replacement, multiple humanized sequences can be generated simultaneously based on the parent sequence. Exemplary humanized heavy chain variable region and light chain variable region sequences are shown in Table 1, which shows 5 humanized VHs designed for 11W-VH1 (i.e., 11W-VH2 to 11W-VH6), and 7 humanized VLs designed for 11W-VL1 (i.e., 11W-VL2 to 11W-VL8); 7 humanized VHs designed for 12W-VH1 (i.e., 12W-VH2 to 12W-VH8), and 6 humanized VLs designed for 12W-VL1 (i.e., W12-VL2 to 12W-VL7).

The heavy chain constant region of the antibody can be selected from the constant region of human IgG1, IgG2, IgG3, IgG4 or variants thereof, and the light chain constant region can be selected from the light chain constant region of human κ, λ chain or variants thereof. The heavy chain/light chain constant regions shown in Table 2 are combined with the heavy chain/light chain variable regions shown in Table 1 to form a complete anti-MASP2 antibody. Exemplary heavy chain/light chain sequences of humanized antibodies are as follows:

>11W1 heavy chain (SEQ ID NO:28):

>11W1 light chain (SEQ ID NO:29):

>11W2 heavy chain: SEQ ID NO:28

>11W2 light chain (SEQ ID NO:30):

>11W3 heavy chain (SEQ ID NO:31):

>11W3 light chain: SEQ ID NO:30

>11W4 heavy chain (SEQ ID NO:31):

>11W4 light chain (SEQ ID NO:64):

>11W5 heavy chain: SEQ ID NO:31

>11W5 light chain (SEQ ID NO:65):

>11W6 heavy chain: SEQ ID NO:31

>11W6 light chain (SEQ ID NO:66):

>11W7 heavy chain (SEQ ID NO:67):

>11W7 light chain (SEQ ID NO:68):

>11W8 heavy chain (SEQ ID NO:69):

>11W8 light chain: SEQ ID NO:65

>11W9 heavy chain (SEQ ID NO:70):

>11W9 light chain: SEQ ID NO:64

>11W10 heavy chain: SEQ ID NO:70

>11W10 light chain (SEQ ID NO:71):

>12W1 heavy chain (SEQ ID NO:32):

>12W1 light chain (SEQ ID NO:33):

>12W2 heavy chain (SEQ ID NO:34):

>12W2 light chain (SEQ ID NO:35):

>12W3 heavy chain (SEQ ID NO:36):

>12W3 light chain: SEQ ID NO:35

>12W4 heavy chain (SEQ ID NO:72):

>12W4 light chain (SEQ ID NO:73):

>12W5 heavy chain (SEQ ID NO:74):

>12W5 light chain (SEQ ID NO:75):

>12W6 heavy chain: SEQ ID NO:36

>12W6 light chain (SEQ ID NO:76):

>12W7 heavy chain (SEQ ID NO:77):

>12W7 light chain (SEQ ID NO:78):

>12W8 heavy chain: SEQ ID NO:36

>12W8 light chain: SEQ ID NO:78

>12W9 heavy chain (SEQ ID NO:79):

>12W9 light chain: SEQ ID NO:78

>12W10 heavy chain: SEQ ID NO:74

>12W10 light chain: SEQ ID NO:78

Example 2 Preparation of fully human antibodies targeting MASP2

Ficoll-Paque density gradient separation solution (purchased from GE, catalog number: 17144003S) was used to separate peripheral blood mononuclear cells (PBMC) from normal human blood, and total RNA was extracted from the isolated PBMC cells by conventional methods. The extracted total RNA was reverse transcribed into cDNA using a reverse transcription kit (purchased from TaKaRa, catalog number: 6210A). Based on the sequence similarity of the heavy chain and light chain germline genes, degenerate primers were designed at the front end of the V region of the heavy chain and light chain and the back end of the first constant region, respectively. After PCR, the heavy chain variable region gene fragment and the light chain variable region gene fragment of the antibody were obtained. According to the method described in Example 1.1, the corresponding human antibody gene phage display library was constructed, and the library was screened and the monoclonal selection was performed. The selected positive clones were further subjected to antibody affinity maturation transformation to obtain antibodies 20W30, 20W51 and 20W78, and the amino acid sequences of each antibody are shown in Table 5.

Table 5 Heavy chain/light chain sequences of fully human antibodies targeting MASP2

Example 3

Evaluation of the binding capacity of anti-MASP2 antibodies

3.1 Kinetic level (ForteBio) determination of antibody affinity

The affinity constant (KD) of human MASP2 and antibody was detected by kinetic level. The antibody was immobilized on Protein A sensor, and the human MASP2 protein was gradiently diluted. The antibody and antigen were subjected to the steps of equilibrium (Baseline), association (Association), and dissociation (Disassociation). The Protein A sensor was then regenerated (Regeneration) and neutralized (Neutralisation). After multiple cycles, the affinity constant (KD), association rate constant (Kon), and dissociation rate constant (Kdis) of MASP2 for the antibody were analyzed. The experimental results show that the affinity KD of the 11W and 12W series antibodies of the present invention for the MASP2 protein is lower than 10 ^-8 M. It can be seen that the affinity of the 11W and 12W series antibodies of the present invention for binding to the human MASP2 protein is better than that of the control antibody Narsoplimab (Table 6).

Table 6 Affinity test results of 11W and 12W series antibodies binding to human MASP2 protein

3.2 ELISA to determine antibody affinity

The relative binding activity of each antibody to human MASP2 protein was determined by ELISA method. The specific operation was as follows: recombinant human MASP2 protein (2μg/mL) was coated on the ELISA plate at 100μL/well and incubated at 4°C overnight. Then, the plate was blocked with PBST containing 1% BSA (containing 0.05% Tween-20) at 37°C for 2 hours (200μL/well), washed three times with PBST, and each antibody was first serially diluted with PBST containing 1% BSA, and then added to the ELISA plate in sequence (100μL/well). The working concentration of the antibody was: 10000ng/ml was diluted in 4 times for 8 points. Incubated at 37°C for 1 hour, washed three times with PBST. Then, Anti-Human IgG-FC-HRP (JACSON; 109-035-170) was added at 100 μL/well, incubated at 37°C for 1 h, washed three times with PBST, and then 100 μL TMB (SURMOPICS) was added for reaction. The reaction was terminated with 2 M HCl, and the OD value was measured at 450nm-570nm with a microplate reader.

The experimental results are shown in Table 7 and FIG6 , which show that the affinity of the 12W and 20W series antibodies of the present invention for binding to human MASP2 protein is superior to that of the control antibody Narsoplimab.

Table 7 Affinity test results of 20W series antibodies binding to MASP2 protein

Example 4 Specificity of anti-MASP2 antibodies in inhibiting the complement lectin pathway in vitro

4.1 Determination of MAC by complement lectin pathway

The inhibitory effect of candidate antibodies was determined using the WIESLAB Complement System MBL pathway screening kit (Complement System MBL pathway: COMPLMP320RUO). The plate was pre-coated with a layer of mannan as an activator of the MBL pathway, and the antibody was serially diluted with the assay solution, and human complement serum (Quidel, Al12) was also diluted with the assay solution and then incubated on ice for 30 minutes. The antibody-serum mixture was added to the plate and incubated at 37°C for 120 minutes. After washing the plate, the deposited MAC (membrane attack complex, C5b-9) was detected with a specific antibody labeled with alkaline phosphatase.

The experimental results are shown in Tables 8-9 and Figure 7. It can be seen that the inhibitory activity of the antibodies of the present invention on the complement agglutinin pathway is better than that of the control antibody Narsoplimab. In addition, 11W1 and 12W0 also have inhibitory activity comparable to that of the control antibody Narsoplimab.

Table 8 Inhibition of complement lectin pathway by anti-MASP2 antibodies

Table 9.1 Inhibition of the complement lectin pathway by anti-MASP2 antibodies

Table 9.2 Inhibition of the complement lectin pathway by anti-MASP2 antibodies

4.2 Determination of MAC of the classical complement pathway and the alternative complement pathway

The WIESLAB Complement System Classical pathway screening kit (Complement System Classical pathway: COMPLCP310RUO) and the alternative pathway screening kit (Complement System Alternative pathway: COMPLAP330RUO) determine the selectivity of candidate antibodies for the complement system. The plates were pre-coated with IgM as an activator of the classical pathway and LPS as an activator of the alternative pathway. The antibodies were serially diluted with the assay solution, and human complement serum (Quidel, Al12) was also diluted with the assay solution and then incubated on ice for 30 minutes. The antibody-serum mixture was added to the plate and incubated at 37°C for 120 minutes. After washing the plates, the deposited MAC was detected with a specific antibody labeled with alkaline phosphatase.

The experimental results are shown in Figures 1-2, which show that the anti-MASP2 antibody of the present invention has substantially no significant inhibitory effect on the classical complement pathway and the alternative complement pathway, and can specifically inhibit the complement lectin pathway.

Example 5 Cross-reactivity assay of anti-MASP2 antibodies

5.1 MASP2 cross-species reactivity test

The relative binding activity of each antibody to MASP2 protein was determined by ELISA. Recombinant human, mouse, and monkey MASP2 proteins (2 μg/mL) were coated on ELISA plates at 100 μL/well and incubated overnight at 4°C. Afterwards, the plates were blocked with PBST containing 1% BSA (containing 0.05% Tween-20) at 37°C for 2 hours (200 μL/well), washed three times with PBST, and the candidate antibodies were serially diluted with PBST containing 1% BSA and added to the ELISA plates (100 μL/well) in sequence. The working concentration of the antibodies was: 10,000 ng/ml, diluted in multiples of 4 for 8 points, Narsoplimab was used as a positive control, and isotype IgG antibodies were used as negative controls. Incubated at 37°C for 1 hour, washed three times with PBST. Then, Anti-Human IgG-FC-HRP (JACSON; 109-035-170) was added at 100 μL/well and incubated at 37°C for 1 h. The cells were washed three times with PBST and 100 μL TMB (SURMOPICS) was added for reaction. The reaction was terminated with 2 M HCl and the OD value was measured at 450 nm-570 nm by a microplate reader. The experimental results are shown in Table 10.

Table 10 Binding of anti-MASP2 antibodies to various MASP2 proteins


Note: “√” means that it has binding activity with the antigen protein; “×” means that it has no binding activity with the antigen protein; mouse MASP2 protein specifically refers to mouse MASP2 protein.

5.2 Complement family member cross-reactivity test

The relative binding activity of each antibody to complement homologous family members C1r, C1s, MASP1, and MASP3 was determined by ELISA method. C1r, C1s, MASP1, and MASP3 proteins (2 μg/mL) were coated on ELISA plates at 100 μL/well and incubated overnight at 4°C. After that, the plates were blocked with PBST containing 1% BSA (containing 0.05% Tween-20) at 37°C for 2 hours (200 μL/well), washed three times with PBST, and the candidate antibodies were serially diluted with PBST containing 1% BSA and added to the ELISA plates in sequence (100 μL/well). The working concentration of the antibodies was: 10000 ng/ml, diluted in multiples of 4 for 8 points, and Narsoplimab was used as a positive control. Incubated at 37°C for 1 hour, washed three times with PBST. Then, 100 μL/well of Anti-Human IgG-FC-HRP (JACSON; 109-035-170) was added, incubated at 37°C for 1 hour, washed three times with PBST, and then 100 μL of TMB (SURMOPICS) was added for reaction. The reaction was terminated with 2M HCl, and the OD value was measured by an enzyme marker at 450nm-570nm. The experimental results are shown in FIG3 , which shows that the antibody of the present invention has basically no binding activity to complement homologous family members.

Example 6: Long-acting modification of anti-MASP2 antibodies

In order to improve the PK characteristics of humanized antibodies, mutations were introduced into the Fc region to extend the antibody half-life. The M428L/N434S mutation (LS mutation) and the M252Y/S254T/T256E mutation (YTE mutation) have been shown to extend the antibody half-life by increasing FcRn binding affinity (Booth et al., MAbs 10(7): 1098-1110, 2018; Dall'acqua WF et al., J Biol Chem 281: 23514-24, 2006). Thus, humanized antibodies with extended half-lives were generated, and the heavy chain/light chain amino acid sequences of each antibody are as follows:

>20W30-LS heavy chain (SEQ ID NO:42):

>20W30-LS light chain: SEQ ID NO:38

>20W30-YTE heavy chain (SEQ ID NO:43):

>20W30-YTE light chain: SEQ ID NO:38

>11W3-LS heavy chain (SEQ ID NO:44):

>11W3-LS light chain: SEQ ID NO:30

>11W4-LS heavy chain (SEQ ID NO:44):

>11W4-LS light chain (SEQ ID NO:64):

>12W3-LS heavy chain (SEQ ID NO:45):

>12W3 light chain: SEQ ID NO:35

>11W5-LS heavy chain (SEQ ID NO:44):

>11W5-LS light chain: SEQ ID NO:65

>11W6-LS heavy chain (SEQ ID NO:44):

>11W6-LS light chain: SEQ ID NO:66

>11W7-LS heavy chain (SEQ ID NO:80):

>11W7-LS light chain: SEQ ID NO:68

>11W8-LS heavy chain (SEQ ID NO:81):

>11W8-LS light chain: SEQ ID NO:65

The affinity constant (KD) between FcRn and antibody was detected by kinetic level (ForteBio). Human FcRn was fixed to Protein A sensor, and the antibody was graded diluted. The antibody and FcRn went through the steps of equilibrium (Baseline), association (Association), and dissociation (Disassociation). Protein A sensor was then regenerated (Regeneration) and neutralized (Neutralisation). After multiple cycles, the affinity constant (KD), association rate constant (Kon), and dissociation rate constant (Kdis) of human FcRn for antibody were analyzed. The affinity test results of each antibody and human FcRn are shown in Tables 11-12. It can be seen that the affinity of 20W30 to FcRn increased after LS mutation or YTE mutation modification, and the LS mutation had a better effect (Table 11); the affinity of 11W3 to FcRn increased by about 10 times after LS mutation modification (Table 12).

Table 11 Affinity test results of anti-MASP2 antibodies and human FcRn

Table 12 Affinity test results of anti-MASP2 antibodies and human FcRn

According to the method of Example 4, the effect of the long-acting modified antibody on the complement agglutinin pathway MAC was determined. The results are shown in Figures 4 and 5. It can be seen that the long-acting modification does not substantially affect the inhibitory activity of the antibody, and the inhibitory activity of the modified antibody is maintained at a level comparable to that before modification, and is superior to the control antibody Narsoplimab. Figures 5A to 5C show the inhibitory activity of other modified antibodies, and Figures 5A and 5B show that the antibody 11W4-LS has a complement agglutinin pathway inhibitory activity far exceeding that of Narsoplimab, wherein the inhibitory activity is increased by nearly 100 times under 1% human serum conditions (Figure 5A), and substantially does not affect the bypass and classical pathways (Figure 8).

According to the method of Example 5, the species cross-reactivity of the long-acting modified antibody to MASP2 was determined, and the results are shown in Table 13. It can be seen that the LS mutation or the YTE mutation has no effect on the species cross-reactivity of the antibody.

Table 13 Binding of anti-MASP2 antibodies to various MASP2 proteins

Note: Mouse MASP2 protein refers specifically to mouse MASP2 protein.

In addition, the 11W series antibodies were further tested to see if they recognized rat MASP2 protein. The ELISA method was used to determine whether the biotinylated recombinant rat MASP2 protein (2 μg/mL) was coated on a streptavidin (SA) pre-coated ELISA plate at 100 μL/well and incubated overnight at 4°C. After that, the candidate antibodies were serially diluted with PBS containing 2% BSA and added to the ELISA plate (100 μL/well) in sequence. The working concentration of the antibody was: 10,000 ng/ml and then diluted in multiples of 4 for 8 points. Incubate at 37°C for 1 hour and wash 5 times with PBST. Then, Anti-Human IgG (JACSON; 109-035-003) was diluted 1:10000 in PBS containing 2% BSA, and then added at 100 μL/well, incubated at 37°C for 1 hour, washed five times with PBST, and then 100 μL TMB (SURMOPICS) was added for reaction, incubated at room temperature, terminated with 1M H ₂ SO ₄ , and the OD value was measured at 450nm by a microplate reader. The results showed that the antibody 11W4-LS also had rat MASP2 protein binding activity.

Example 7 Effect of anti-MASP2 antibodies on C4b deposition

10 μg/ml mannan (Sigma, M7504) was added to the wells of the ELISA plate and coated overnight at 4°C; after washing, 200 μL/well of blocking solution was added and blocked at room temperature for 2 h; 1% human complement serum (Creative Biolabs, CTS-006) was mixed with the antibody diluent, incubated on ice for 45 min, and then added to the ELISA plate and incubated at 37°C for about 2 h; after washing, 100 μL/well of 1:700 diluted detection antibody (ASSAYPRO, #11223-05021) was added and incubated at room temperature for 60 min; after washing, 100 μL/well of 1:200 diluted peroxidase-streptavidin (R&D, DY998) was added and incubated at room temperature for 45 min; after washing, TMB color development solution was added and color was developed at 37°C in the dark for about 2 min; finally, 1M H ₂ SO ₄ was added to terminate the reaction and the OD value was read. The results are shown in FIG9 , which shows that the antibodies of the present invention can better reduce C4b deposition in the blood. The IC ₅₀ values of the 11W series optimized antibodies in FIG9 for inhibiting C4b deposition are calculated to be no higher than 0.01 μg/ml, which is significantly higher than the inhibitory activity of Narsoplimab.

Although the present invention has been described by one or more embodiments, it should be understood that the present invention is not limited to these embodiments, and the present invention description is intended to cover all substitutions, modifications and changes that fall within the spirit and broad scope of the appended claims. All references cited in the present invention are incorporated into the present invention by reference as a whole.

Claims (19)

An anti-MASP2 antibody or antigen-binding fragment thereof, comprising a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH comprises HCDR1, HCDR2 and HCDR3 regions, and the VL comprises LCDR1, LCDR2 and LCDR3 regions, wherein: (i) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of the VH as shown in any one of SEQ ID NOs: 1-2, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of the VL as shown in any one of SEQ ID NOs: 3-5, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom; (ii) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of the VH as shown in any one of SEQ ID NOs: 6-8, 48-50, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of the VL as shown in any one of SEQ ID NOs: 9-11, 51-55, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom; or (iii) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of the VH as shown in any one of SEQ ID NOs: 12-15, 56-59, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of the VL as shown in any one of SEQ ID NOs: 16-18, 60-63, or a sequence in which at most 5, 4, 3, 2 or 1 mutations occur therefrom; The mutation is selected from insertion, deletion and/or substitution that does not affect the function, and the substitution is preferably a substitution of a conservative amino acid. The antibody or antigen-binding fragment thereof according to claim 1, wherein the VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 1, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 3 or 5; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 2, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 4; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 6, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 9; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 7, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 10 or 11; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 8, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in any one of SEQ ID NOs: 11, 51-53; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 48, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 54; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 49, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 52; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 50, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 51 or 55; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 12, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 16; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 13, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 17; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 14, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 18; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 15, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 18 or 62; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 56, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 60; The VH has HCDR1, HCDR2 and HCDR3 of the same sequence as the VH shown in SEQ ID NO: 57, and the VL has LCDR1, LCDR2 and LCDR3 of the same sequence as the VL shown in SEQ ID NO: 61; or, The VH has HCDR1, HCDR2 and HCDR3 with the same sequence as the VH shown in any one of SEQ ID NOs: 15, 57-59, and the VL has LCDR1, LCDR2 and LCDR3 with the same sequence as the VL shown in SEQ ID NO: 63. The antibody or antigen-binding fragment thereof according to claim 1 or 2, wherein the VH has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 1-2, and/or the VL has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 3-5; The VH has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 6-8, 48-50, and/or the VL has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 9-11, 51-55; or The VH has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 12-15, 56-59, and/or the VL has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 16-18, 60-63. The antibody or antigen-binding fragment thereof according to any one of claims 1 to 3, wherein the VH comprises the sequence shown in SEQ ID NO: 1, and the VL comprises the sequence shown in any one of SEQ ID NO: 3 to 5; The VH comprises the sequence shown in SEQ ID NO: 2, and the VL comprises the sequence shown in any one of SEQ ID NO: 3-5; The VH comprises the sequence shown in SEQ ID NO: 6, and the VL comprises the sequence shown in any one of SEQ ID NO: 9-11, 51-556; The VH comprises the sequence shown in SEQ ID NO: 7, and the VL comprises the sequence shown in any one of SEQ ID NO: 9-11, 51-55; The VH comprises the sequence shown in SEQ ID NO: 8, and the VL comprises the sequence shown in any one of SEQ ID NO: 9-11, 51-55; The VH comprises the sequence shown in SEQ ID NO: 48, and the VL comprises the sequence shown in any one of SEQ ID NO: 9-11, 51-55; The VH comprises the sequence shown in SEQ ID NO: 49, and the VL comprises the sequence shown in any one of SEQ ID NO: 9-11, 51-55; The VH comprises the sequence shown in SEQ ID NO: 50, and the VL comprises the sequence shown in any one of SEQ ID NO: 9-11, 51-55; The VH comprises the sequence shown in SEQ ID NO: 12, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63; The VH comprises the sequence shown in SEQ ID NO: 13, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63; The VH comprises the sequence shown in SEQ ID NO: 14, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63; The VH comprises the sequence shown in SEQ ID NO: 15, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63; The VH comprises the sequence shown in SEQ ID NO: 56, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63; The VH comprises the sequence shown in SEQ ID NO: 57, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63; The VH comprises the sequence shown in SEQ ID NO: 58, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63; or, The VH comprises the sequence shown in SEQ ID NO: 59, and the VL comprises the sequence shown in any one of SEQ ID NO: 16-18, 60-63. The antibody or antigen-binding fragment thereof according to any one of claims 1 to 4, wherein the VH and VL are selected from the following groups: The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 1, 3; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 2 and 4; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 1, 5; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 6 and 9; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 7 and 10; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 7 and 11; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 8 and 11; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 8 and 51; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 8 and 52; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 8 and 53; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 48 and 54; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 49 and 52; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 50 and 51; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 50 and 55; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 12 and 16; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 13 and 17; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 14 and 18; Said VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 15 and 18; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 56 and 60; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 57 and 61; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 15 and 62; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 58 and 63; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 15 and 63; The VH and VL respectively contain or are the sequences shown in SEQ ID NO: 59 and 63; or, The VH and VL respectively contain or are the sequences shown in SEQ ID NO: 57 and 63. The antibody or antigen-binding fragment thereof according to any one of claims 1 to 5, wherein the anti-MASP2 antibody further comprises a heavy chain constant region and a light chain constant region; Preferably, the heavy chain constant region is selected from human IgG1, IgG2, IgG3, IgG4 constant regions or variants thereof, and the light chain constant region is selected from human κ and λ chain constant regions or variants thereof; More preferably, the heavy chain constant region is selected from an IgG4 constant region having any one or more mutations of S228P, M428L, N434S, M252Y, S254T and T256E, wherein the above mutations are EU numbering; Most preferably, the heavy chain constant region comprises a sequence as shown in any one of SEQ ID NOs: 19-21 or an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical thereto, and the light chain constant region comprises a sequence as shown in any one of SEQ ID NOs: 22-23 or an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical thereto. The antibody or antigen-binding fragment thereof according to any one of claims 1 to 6, wherein the anti-MASP2 antibody comprises a heavy chain and a light chain, (i) the heavy chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 37, 39, 42, and 43, and/or the light chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 38, 40, and 41; (ii) the heavy chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 24, 28, 31, 44, 67, 69, 70, 80, 81, and/or the light chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 25, 29, 30, 64, 65, 66, 68, 71; or (iii) the heavy chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 26, 32, 34, 36, 45, 72, 74, 77, 79, and/or the light chain has an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence shown in any one of SEQ ID NOs: 27, 33, 35, 73, 75, 76, 78. The antibody or antigen-binding fragment thereof according to any one of claims 1 to 7, wherein the anti-MASP2 antibody comprises a heavy chain and a light chain, the heavy chain comprises the sequence shown in SEQ ID NO: 37 and the light chain comprises the sequence shown in any one of SEQ ID NO: 38, 40, and 41; The heavy chain comprises the sequence shown in SEQ ID NO:39 and the light chain comprises the sequence shown in any one of SEQ ID NO:38, 40, and 41; The heavy chain comprises the sequence shown in SEQ ID NO:42 and the light chain comprises the sequence shown in any one of SEQ ID NO:38, 40, and 41; The heavy chain comprises the sequence shown in SEQ ID NO:43 and the light chain comprises the sequence shown in any one of SEQ ID NO:38, 40, and 41; The heavy chain comprises the sequence shown in SEQ ID NO: 24 and the light chain comprises the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; The heavy chain comprises the sequence shown in SEQ ID NO: 28 and the light chain comprises the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; The heavy chain comprises the sequence shown in SEQ ID NO:31 and the light chain comprises the sequence shown in any one of SEQ ID NO:25, 29, 30, 64, 65, 66, 68, 71; The heavy chain comprises the sequence shown in SEQ ID NO:44 and the light chain comprises the sequence shown in any one of SEQ ID NO:25, 29, 30, 64, 65, 66, 68, 71; The heavy chain comprises the sequence shown in SEQ ID NO:67 and the light chain comprises the sequence shown in any one of SEQ ID NO:25, 29, 30, 64, 65, 66, 68, 71; The heavy chain comprises the sequence shown in SEQ ID NO:69 and the light chain comprises the sequence shown in any one of SEQ ID NO:25, 29, 30, 64, 65, 66, 68, 71; The heavy chain comprises the sequence shown in SEQ ID NO:70 and the light chain comprises the sequence shown in any one of SEQ ID NO:25, 29, 30, 64, 65, 66, 68, 71; The heavy chain comprises the sequence shown in SEQ ID NO:80 and the light chain comprises the sequence shown in any one of SEQ ID NO:25, 29, 30, 64, 65, 66, 68, 71; The heavy chain comprises the sequence shown in SEQ ID NO:81 and the light chain comprises the sequence shown in any one of SEQ ID NO:25, 29, 30, 64, 65, 66, 68, 71; The heavy chain comprises the sequence shown in SEQ ID NO: 26 and the light chain comprises the sequence shown in any one of SEQ ID NO: 27, 33, 35, 73, 75, 76, 78; The heavy chain comprises the sequence shown in SEQ ID NO:32 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, 78; The heavy chain comprises the sequence shown in SEQ ID NO:34 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, 78; The heavy chain comprises the sequence shown in SEQ ID NO:36 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, 78; The heavy chain comprises the sequence shown in SEQ ID NO:45 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, 78; The heavy chain comprises the sequence shown in SEQ ID NO:72 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, 78; The heavy chain comprises the sequence shown in SEQ ID NO:74 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, 78; The heavy chain comprises the sequence shown in SEQ ID NO:77 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, 78; or, The heavy chain comprises the sequence shown in SEQ ID NO:79 and the light chain comprises the sequence shown in any one of SEQ ID NO:27, 33, 35, 73, 75, 76, 78. According to the antibody or antigen-binding fragment thereof according to any one of claims 1-8, the heavy chain and the light chain respectively comprise a sequence selected from the following groups: a sequence as shown in SEQ ID NO: 24, 25; a sequence as shown in SEQ ID NO: 26, 27; a sequence as shown in SEQ ID NO: 28, 29; a sequence as shown in SEQ ID NO: 28, 30; a sequence as shown in SEQ ID NO: 31, 30; a sequence as shown in SEQ ID NO: 31, 64; a sequence as shown in SEQ ID NO: 31, 65 ; Sequences as shown in SEQ ID NOs:31 and 66; Sequences as shown in SEQ ID NOs:67 and 68; Sequences as shown in SEQ ID NOs:69 and 65; Sequences as shown in SEQ ID NOs:70 and 64; Sequences as shown in SEQ ID NOs:70 and 71; Sequences as shown in SEQ ID NOs:32 and 33; Sequences as shown in SEQ ID NOs:34 and 35; Sequences as shown in SEQ ID NOs:36 and 35; Sequences as shown in SEQ ID NOs:37 and 38; The sequences shown in SEQ ID NOs: 39 and 40; the sequences shown in SEQ ID NOs: 37 and 41; the sequences shown in SEQ ID NOs: 72 and 73; the sequences shown in SEQ ID NOs: 74 and 75; the sequences shown in SEQ ID NOs: 36 and 76; the sequences shown in SEQ ID NOs: 77 and 78; the sequences shown in SEQ ID NOs: 36 and 78; the sequences shown in SEQ ID NOs: 79 and 78; the sequences shown in SEQ ID NOs: 74 and 78; the sequences shown in The sequence shown in SEQ ID NO:42, 38; the sequence shown in SEQ ID NO:43, 38; the sequence shown in SEQ ID NO:44, 30; the sequence shown in SEQ ID NO:44, 64; the sequence shown in SEQ ID NO:44, 65; the sequence shown in SEQ ID NO:44, 66; the sequence shown in SEQ ID NO:80, 68; the sequence shown in SEQ ID NO:81, 65; or, the sequence shown in SEQ ID NO:45, 35. An anti-MASP2 antibody or an antigen-binding fragment thereof, which binds to or competes for binding to the same epitope as the anti-MASP2 antibody or antigen-binding fragment thereof according to any one of claims 1 to 9. The anti-MASP2 antibody or antigen-binding fragment thereof according to any one of claims 1 to 10, which has at least one of the following: (1) the antibody or antigen-binding fragment thereof binds to human MASP2 with a KD of 10 nM or less; (2) the antibody or antigen-binding fragment thereof inhibits complement lectin pathway MAC deposition in an in vitro assay with an IC50 of less than 1, less than 0.9, less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4, less than 0.3, less than 0.2, less than 0.1, less than 0.09, less than 0.08, less than 0.07, less than 0.06, less than 0.05, less than 0.04, less than 0.03, less than _0.02 , less than 0.01 μg/mL or less; (3) the antibody or antigen-binding fragment thereof does not substantially inhibit the classical pathway and/or the alternative pathway; (4) the antibody or antigen-binding fragment thereof does not substantially bind to complement components C1r, C1s, MASP1 and/or MASP3; (5) when binding to human MASP2, the antibody or antigen-binding fragment thereof has a KD that is substantially the same as or better than a reference MASP2 antibody; (6) When binding to human MASP2, the antibody or antigen-binding fragment thereof specifically inhibits or blocks the complement agglutinin pathway. Preferably, the inhibition or blocking effect of the antibody or antigen-binding fragment thereof is substantially the same as or better than that of a reference MASP2 antibody; (7) When binding to human MASP2, the antibody or antigen-binding fragment thereof reduces or decreases C4b and/or MAC deposition. Preferably, the antibody or antigen-binding fragment thereof reduces or decreases C4b and/or MAC deposition at a level substantially the same as or better than a reference MASP2 antibody. The anti-MASP2 antibody or antigen-binding fragment thereof according to any one of claims 1 to 11, further comprising one or more effector molecules, preferably, the effector molecules are selected from anti-tumor agents, drugs, toxins, biologically active proteins, other antibodies or antibody fragments, synthetic or naturally occurring polymers, nucleic acids and fragments thereof, radionuclides, radioisotopes, chelated metals, nanoparticles and reporter groups, or compounds detectable by NMR or ESR spectroscopy. A bispecific or multispecific antibody or antigen-binding fragment thereof, comprising the anti-MASP2 antibody or antigen-binding fragment thereof according to any one of claims 1 to 11. A polynucleotide encoding the anti-MASP2 antibody or antigen-binding fragment thereof according to any one of claims 1 to 12, or encoding the bispecific or multispecific antibody or antigen-binding fragment thereof according to claim 13. An expression vector comprising the polynucleotide according to claim 14. A host cell comprising the polynucleotide according to claim 14 or the expression vector according to claim 15. A pharmaceutical composition comprising the anti-MASP2 antibody or antigen-binding fragment thereof according to claims 1-12, or the bispecific or multispecific antibody or antigen-binding fragment thereof according to claim 13, or the polynucleotide or antigen-binding fragment thereof according to claim 14, or the expression vector according to claim 15, or the host cell according to claim 16, and one or more pharmaceutically acceptable carriers. A kit comprising the anti-MASP2 antibody or antigen-binding fragment thereof according to claims 1-12. A method for preventing and/or treating a disease or condition associated with MASP2 in a subject, comprising administering to a subject in need thereof a therapeutically or prophylactically effective amount of the anti-MASP2 antibody or antigen-binding fragment thereof of any one of claims 1 to 12, the bispecific or multispecific antibody or antigen-binding fragment thereof of claim 13, the polynucleotide of claim 14, the expression vector of claim 15, the host cell of claim 16, the pharmaceutical composition of claim 17, or the kit of claim 18; preferably, the disease or condition associated with MASP2 is IgA nephropathy.