Anti-MASP2 antibody or antigen-binding fragment and use thereof

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 uses thereof Technical Field

[0001] 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 uses thereof. Background Art

[0002] The complement system is activated primarily through three pathways: the classical, alternative, and lectin pathways. 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 the 76 kDa serine protease MASP2 (long isoform), which is highly expressed in the liver, and the 19 kDa alternatively spliced ​​product Map19 (short isoform), which is present in plasma. The MASP2 gene consists of 12 exons: exons 2 and 3 encode the CUB1 domain, exon 4 encodes the EGFL domain, exons 6 and 7 encode the CUB2 domain, and exons 8 to 11 encode two CCP domains, respectively. 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 breaks down between CCP2 and SP, forming the active form consisting of two polypeptide chains connected by a disulfide bond. The peptide activation region and SP domain of activated MASP2 effectively bind and cleave C2. With the assistance of the CCP domain, it binds and cleaves C4, initiating a subsequent cascade reaction to form C4bC2a (i.e., the C3 convertase). This ultimately facilitates the formation of a membrane-permeating complex composed of C5-C9, triggering the lysis of the pathogen and thereby defending against pathogenic microorganisms such as bacteria, yeast, and viruses.

[0003] Clinical experiments and research evidence show that many 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 molecular 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.

[0004] Currently, various anti-MASP2 antibodies are disclosed in patent documents such as CN103687620B, WO2022228364A1, CN114634575A, and CN116284412A. However, there is still a lack of new MASP2-targeting antibodies on the market, and further improving the affinity and biological activity of anti-MASP2 antibodies remains a technical problem that needs to be solved in this field. Summary of the Invention

[0005] In one aspect, the present invention provides an anti-MASP2 antibody or antigen-binding fragment thereof, which can specifically bind to the MASP2 protein with high affinity, has no cross-reactivity with other complement components (e.g., C1s, C1r, MASP1, MASP3), and effectively inhibits MASP2-mediated activation of downstream complement pathways.

[0006] In one aspect, the present invention provides 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:

[0007] (i) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of any one of the VH as shown in SEQ ID NOs: 1-2, or a sequence in which at most 5, 4, 3, 2 or 1 mutations have occurred therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of any one of the VL as shown in SEQ ID NOs: 3-5, or a sequence in which at most 5, 4, 3, 2 or 1 mutations have occurred therefrom;

[0008] (ii) the HCDR1, HCDR2 and HCDR3 regions have the same sequence as the HCDR1, HCDR2 and HCDR3 of any one of SEQ ID NOs: 6-8, 48-50, or a sequence in which at most 5, 4, 3, 2 or 1 mutations have occurred therefrom, and the LCDR1, LCDR2 and LCDR3 regions have the same sequence as the LCDR1, LCDR2 and LCDR3 of any one of SEQ ID NOs: 9-11, 51-55, or a sequence in which at most 5, 4, 3, 2 or 1 mutations have occurred therefrom; or

[0009] (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 have occurred 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 have occurred therefrom.

[0010] In some embodiments, the VH comprises HCDR1, HCDR2, and HCDR3 regions, and the VL comprises LCDR1, LCDR2, and LCDR3 regions, wherein:

[0011] (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 have occurred 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 have occurred therefrom;

[0012] (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 have occurred 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 have occurred therefrom;

[0013] (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 are present therein, 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 are present therein; or

[0014] (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.

[0015] 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.

[0016] 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.

[0017] In some embodiments, the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH of SEQ ID NO: 6, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL of SEQ ID NO: 9; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH of SEQ ID NO: 7, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL of SEQ ID NO: 10 or 11; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH of SEQ ID NO: 8, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL of any one of SEQ ID NOs: 11, 51-53; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH of SEQ ID NO: 48, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL of SEQ ID NO: 51-53. The VL shown in NO: 54 has the same sequence of LCDR1, LCDR2 and LCDR3; 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.

[0018] In some embodiments, the VH has the same HCDR1, HCDR2 and HCDR3 as the VH of SEQ ID NO: 12, and the VL has the same LCDR1, LCDR2 and LCDR3 as the VL of SEQ ID NO: 16; the VH has the same HCDR1, HCDR2 and HCDR3 as the VH of SEQ ID NO: 13, and the VL has the same LCDR1, LCDR2 and LCDR3 as the VL of SEQ ID NO: 17; the VH has the same HCDR1, HCDR2 and HCDR3 as the VH of SEQ ID NO: 14, and the VL has the same LCDR1, LCDR2 and LCDR3 as the VL of SEQ ID NO: 18; the VH has the same HCDR1, HCDR2 and HCDR3 as the VH of SEQ ID NO: 15, and the VL has the same LCDR1, LCDR2 and LCDR3 as the VL of SEQ ID NO: 16. NO: 18 or 62 has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH of SEQ ID NO: 56, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL of SEQ ID NO: 60; the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH of SEQ ID NO: 57, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL of SEQ ID NO: 61; or, the VH has the same sequence of HCDR1, HCDR2 and HCDR3 as the VH of any one of SEQ ID NOs: 15, 57-59, and the VL has the same sequence of LCDR1, LCDR2 and LCDR3 as the VL of SEQ ID NO: 63.

[0019] In some preferred embodiments, the VH and VL have HCDR1-3 and LCDR1-3 with the same sequence as a VH, VL selected from the group consisting of:

[0020] (1) VH as shown in SEQ ID NO: 8 and VL as shown in SEQ ID NO: 51;

[0021] (2) VH as shown in SEQ ID NO: 8 and VL as shown in SEQ ID NO: 52;

[0022] (3) VH as shown in SEQ ID NO: 8 and VL as shown in SEQ ID NO: 53;

[0023] (4) VH as shown in SEQ ID NO: 50 and VL as shown in SEQ ID NO: 51;

[0024] (5) VH as shown in SEQ ID NO: 50 and VL as shown in SEQ ID NO: 55; or

[0025] (6) VH shown in SEQ ID NO: 15 and VL shown in SEQ ID NO: 63.

[0026] 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, they are defined according to a combination of IMGT and Kabat; according to a combination of AbM and Kabat; or according to a combination of IMGT, Kabat, Chothia, AbM, and Contact.

[0027] 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 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.

[0028] 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 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.

[0029] 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 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.

[0030] 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 NOs: 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 NOs: 3-5.

[0031] In some embodiments, the VH comprises the sequence set forth in SEQ ID NO: 6, and the VL comprises the sequence set forth in any one of SEQ ID NOs: 9-11, 51-55; the VH comprises the sequence set forth in SEQ ID NO: 7, and the VL comprises the sequence set forth in any one of SEQ ID NOs: 9-11, 51-55; the VH comprises the sequence set forth in SEQ ID NO: 8, and the VL comprises the sequence set forth in SEQ ID NO: 9-11, 51-55; the VH comprises the sequence set forth in SEQ ID NO: 48, and the VL comprises the sequence set forth in SEQ ID NO: 9-11, 51-55; the VH comprises the sequence set forth in SEQ ID NO: 49, and the VL comprises the sequence set forth in SEQ ID NO: 9-11, 51-55; or, the VH comprises the sequence set forth in SEQ ID NO: 50, and the VL comprises the sequence set forth in SEQ ID NO: 9-11, 51-55.

[0032] In some embodiments, the VH comprises the sequence of SEQ ID NO: 12, and the VL comprises the sequence of any one of SEQ ID NOs: 16-18, 60-63; the VH comprises the sequence of SEQ ID NO: 13, and the VL comprises the sequence of any one of SEQ ID NOs: 16-18, 60-63; the VH comprises the sequence of SEQ ID NO: 14, and the VL comprises the sequence of any one of SEQ ID NOs: 16-18, 60-63; the VH comprises the sequence of SEQ ID NO: 15, and the VL comprises the sequence of any one of SEQ ID NOs: 16-18, 60-63; the VH comprises the sequence of SEQ ID NO: 56, and the VL comprises the sequence of any one of SEQ ID NOs: 16-18, 60-63; the VH comprises the sequence of SEQ ID NO: 57, and the VL comprises the sequence of SEQ ID NOs: 16-18, 60-63; the VH comprises the sequence of SEQ ID NO: 58, and the VL comprises the sequence of SEQ ID NO: 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 SEQ ID NO: 16-18, 60-63.

[0033] In some preferred embodiments, the VH and VL are selected from the following groups: 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: 2 and 4; the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 1 and 5; the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 6 and 9; the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 7 and 10; the VH and VL respectively comprise or are the sequences shown in SEQ ID NOs: 7 and 11; 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: NO: 48, 54; the VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 49, 52; the VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 50, 51; the VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 50, 55; the VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 12, 16; the VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 13, 17; the VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 14, 18; the VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 15, 18; the VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 56, 60; the VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 57, 61; the VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 15, 62; the VH and VL respectively comprise or are the sequences shown in SEQ ID NO: NO: 58, 63; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 15, 63; the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 59, 63; or, the VH and VL respectively contain or are the sequences shown in SEQ ID NO: 57, 63.

[0034] 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.

[0035] 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 kappa and lambda chain constant regions or variants thereof. In some embodiments, the heavy chain constant region is selected from an IgG4 constant region variant with 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 amino acid residue 108 of SEQ ID NO: 19), M428L (corresponding to amino acid residue 308 of SEQ ID NO: 20), N434S (corresponding to amino acid residue 314 of SEQ ID NO: 20), M252Y (corresponding to amino acid residue 132 of SEQ ID NO: 21), S254T (corresponding to amino acid residue 134 of SEQ ID NO: 21) and T256E (corresponding to amino acid residue 136 of SEQ ID NO: 21), all of which are EU numbering mutations. 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 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 at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical thereto.

[0036] In some embodiments, the anti-MASP2 antibodies provided herein comprise a heavy chain having an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 37, 39, 42, 43, and / or a light chain having an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 38, 40, 41.

[0037] In some embodiments, the anti-MASP2 antibodies provided herein comprise a heavy chain having an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 24, 28, 31, 44, 67, 69, 70, 80, 81, and / or a light chain having an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 25, 29, 30, 64, 65, 66, 68, 71.

[0038] In some embodiments, the anti-MASP2 antibodies provided herein comprise a heavy chain having an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 26, 32, 34, 36, 45, 72, 74, 77, 79, and / or a light chain having an amino acid sequence that is at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identical to any one of SEQ ID NOs: 27, 33, 35, 73, 75, 76, 78.

[0039] 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 NOs: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 NOs: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 NOs: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 NOs:38, 40, and 41.

[0040] 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 NOs: 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 NOs: 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 NOs: 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 NOs: 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 SEQ ID NO: 68. 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; or, 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.

[0041] 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 NOs: 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 NOs: 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 NOs: 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 NOs: 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 any one of SEQ ID NOs: 27, 33, 35, 73, 75, 76, and 78; The sequence shown in NO:72 and the light chain comprises the sequence shown in any one of SEQ ID NOs:27, 33, 35, 73, 75, 76, and 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 NOs:27, 33, 35, 73, 75, 76, and 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 NOs:27, 33, 35, 73, 75, 76, and 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 NOs:27, 33, 35, 73, 75, 76, and 78.

[0042] In some preferred embodiments, the heavy chain and light chain each comprise a sequence selected from the group consisting of: a sequence as shown in SEQ ID NOs: 24 and 25; a sequence as shown in SEQ ID NOs: 26 and 27; a sequence as shown in SEQ ID NOs: 28 and 29; a sequence as shown in SEQ ID NOs: 28 and 30; a sequence as shown in SEQ ID NOs: 31 and 30; a sequence as shown in SEQ ID NOs: 31 and 64; a sequence as shown in SEQ ID NOs: 31 and 65; a sequence as shown in SEQ ID NOs: 31 and 66; a sequence as shown in SEQ ID NOs: 67 and 68; a sequence as shown in SEQ ID NOs: 69 and 65; a sequence as shown in SEQ ID NOs: 70 and 64; a sequence as shown in SEQ ID NOs: 70 and 71; a sequence as shown in SEQ ID NOs: 32 and 33; a sequence as shown in SEQ ID NOs: 34 and 35; a sequence as shown in SEQ ID NOs: 36 and 35; a sequence as shown in SEQ ID NOs: 37 and 38; a sequence as shown in SEQ ID NOs: 39 and 40; a sequence as shown in SEQ ID NOs: 41 and 42. NO:37, 41; the sequence shown in SEQ ID NO:72, 73; the sequence shown in SEQ ID NO:74, 75; the sequence shown in SEQ ID NO:36, 76; the sequence shown in SEQ ID NO:77, 78; the sequence shown in SEQ ID NO:36, 78; the sequence shown in SEQ ID NO:79, 78; the sequence shown in SEQ ID NO:74, 78; 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.

[0043] In some preferred embodiments, the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 31 and 30, respectively; the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 31 and 64, respectively; the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 31 and 65, respectively; the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 31 and 66, respectively; the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 70 and 64, respectively; the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 70 and 71, respectively; the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 36 and 78, respectively; the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 36 and 35, respectively; the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 37 and 38, respectively; the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 42 and 38, respectively; the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 43 and 38, respectively; the heavy chain and light chain comprise the sequences shown in SEQ ID NOs: 44 and 45, respectively; The heavy chain and light chain respectively comprise the sequences shown in SEQ ID NOs: 44 and 30; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NOs: 44 and 64; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NOs: 44 and 65; the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NOs: 44 and 66; or the heavy chain and light chain respectively comprise the sequences shown in SEQ ID NOs: 45 and 35.

[0044] In one aspect, the present invention provides an anti-MASP2 antibody or antigen-binding fragment thereof that binds to or competes for binding to the same epitope as the aforementioned anti-MASP2 antibody or antigen-binding fragment thereof.

[0045] In some embodiments, the anti-MASP2 antibodies or antigen-binding fragments thereof provided herein have at least one of the following:

[0046] (1) The antibody or antigen-binding fragment thereof binds to human MASP2 with a KD of 10 nM or less, and the KD can be determined, for example, by the method of Example 3 of the present invention;

[0047] (2) The antibody or antigen-binding fragment thereof has an IC 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 50 In an in vitro assay, the IC 50For example, the method of Example 4 of the present invention can be used to detect and obtain;

[0048] (3) the antibody or antigen-binding fragment thereof does not substantially inhibit the classical pathway and / or the alternative pathway;

[0049] (4) the antibody or antigen-binding fragment thereof does not substantially bind to complement components C1r, C1s, MASP1 and / or MASP3;

[0050] (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 that of a reference MASP2 antibody;

[0051] (6) When bound to human MASP2, the antibody or antigen-binding fragment thereof specifically inhibits or blocks the complement lectin pathway. Preferably, the inhibitory 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;

[0052] (7) When bound 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 equivalent to or better than a reference MASP2 antibody.

[0053] In some preferred embodiments, the reference MASP2 antibody is selected from Narsoplimab.

[0054] In some embodiments, the anti-MASP2 antibodies provided herein are chimeric, humanized, or fully human antibodies. In some embodiments, the anti-MASP2 antibodies are monoclonal antibodies.

[0055] 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.

[0056] 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 provided herein.

[0057] In one aspect, the invention provides a bispecific or multispecific antibody or antigen-binding fragment thereof comprising an anti-MASP2 antibody or antigen-binding fragment thereof of the invention.

[0058] 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 can 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 can be prepared or obtained by known means based on information about 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.

[0059] 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. The nucleic acid 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.

[0060] In one aspect, the present invention provides an expression vector comprising a polynucleotide of the present invention, including 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.

[0061] In one aspect, the present invention provides a host cell comprising a polynucleotide or expression vector of the present invention, wherein the host cell comprises a prokaryotic cell, a fungal cell, or a mammalian cell, such as a CHO cell, a NSO cell, or other mammalian cell, an Escherichia coli or other prokaryotic cell, a yeast cell, or other fungal cell.

[0062] 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.

[0063] 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.

[0064] In some embodiments, the pharmaceutical composition can include any number of excipients. Operable excipients include carriers, surfactants, thickeners or emulsifiers, solid binders, dispersion or suspension aids, solubilizers, coloring agents, flavorings, coatings, disintegrants, lubricants, sweeteners, preservatives, isotonic agents, or combinations thereof. Selection and use of suitable excipients are taught in the following, Gennaro writes, Remington: The Science and Practice of Pharmacy, 20th edition (Lippincott Williams & Wilkins 2003), the disclosure of which is incorporated herein by reference.

[0065] In some embodiments, the pharmaceutical composition further comprises one or more additional therapeutic agents.

[0066] In one aspect, the present invention provides a kit comprising the aforementioned anti-MASP2 antibody or antigen-binding fragment thereof.

[0067] In one aspect, the present invention provides the use of the aforementioned anti-MASP2 antibodies or antigen-binding fragments thereof in detecting MASP2 protein or preparing a reagent for detecting MASP2 protein. The detection of MASP2 protein, preferably human MASP2 protein, can be performed in vivo or in vitro, and can be for non-disease diagnosis purposes.

[0068] In one aspect, the present 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, bispecific or multispecific antibody or antigen-binding fragment thereof, polynucleotide, expression vector, host cell, pharmaceutical composition, or kit of the present invention.

[0069] 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.

[0070] In some embodiments, the MASP2-associated disease or condition is a disease or condition caused by abnormal MASP2 expression. In some embodiments, the MASP2-associated disease is selected from a disease or condition caused by overexpression of MASP2. In some preferred embodiments, the MASP2-associated disease 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, and the like.

[0071] 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:

[0072] (1) specifically inhibiting or blocking the complement lectin pathway; and / or

[0073] (2) Reduce or decrease C4b and / or MAC deposition.

[0074] The present invention also provides a method for preparing the anti-MASP2 antibody or antigen-binding fragment thereof of the present invention:

[0075] The anti-MASP2 antibodies or antigen-binding fragments described herein can be obtained using conventional techniques, such as those described in Chapters 5-8 and 15 of the Cold Spring Harbor Laboratory Manual of Antibody Laboratory Techniques. For example, mice can be immunized with human MASP2 or a fragment thereof, and the resulting antibodies can be renatured, purified, and subjected to amino acid sequencing using conventional methods. Antigen-binding fragments can also be prepared using conventional methods. The antibodies or antigen-binding fragments described herein are prepared by genetically engineering non-human CDR regions with one or more human FR regions. Human FR germline sequences can be obtained from the ImMunoGeneTics (IMGT) website by comparing the IMGT Human Antibody Variable Region Germline Gene Database with MOE software, or from the Journal of Immunoglobulins, 2001 ISBN 012441351. Alternatively, for example, cDNA sequences encoding heavy and light chains can be cloned into expression vectors. The recombinant immunoglobulin expression vectors can be stably transfected into CHO cells. Stable clones expressing antibodies that specifically bind to human MASP2 are obtained. Positive clones are expanded in serum-free culture medium in bioreactors to produce antibodies.

[0076] The anti-MASP2 antibodies or antigen-binding fragments thereof of the present invention can be expressed intracellularly, on the cell membrane, or secreted extracellularly. If desired, the recombinant protein can be isolated and purified by various separation methods utilizing its physical, chemical, and other properties. These methods are well known to those skilled in the art. Typically, the transformed host cells are cultured under conditions suitable for expression of the antibodies of the present invention, and then purified using conventional immunoglobulin purification procedures, 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 methods, or combinations thereof, to obtain the anti-MASP2 antibodies or antigen-binding fragments thereof of the present invention. The antibodies can be filtered and concentrated using conventional methods.

[0077] 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.

[0078] The resulting monoclonal antibodies or bispecific antibodies can be characterized 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 as described in Munson et al., Anal. Biochem., 107:220 (1980), or by surface plasmon resonance (Biacore).

[0079] For the sake of clarity, general terms used in the description of the compounds are defined herein.

[0080] 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 as undefined or unclear in the absence of a specific definition, but should be understood according to its ordinary meaning. When a trade name appears in this article, it is intended to refer to its corresponding commercial product or its active ingredient. The term "pharmaceutically acceptable" as used herein refers to those compounds, materials, compositions and / or dosage forms that are suitable for use in contact with human and animal tissues within the scope of sound medical judgment without excessive toxicity, irritation, allergic reaction or other problems or complications, commensurate with a reasonable benefit / risk ratio.

[0081] The terms "mannan-binding lectin-associated serine protease 2," "MASP2 protein," "MASP2 antigen," and "MASP2" are used interchangeably to refer to any MASP2 molecule known to those skilled in the art and its functional homologs, including, but not limited to, those derived from humans, rodents, mice, rats, primates, monkeys, and guinea pigs, unless otherwise indicated. The term also refers to fragments or variants of native MASP2 that retain 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. As used herein, MASP2 also refers to specific polypeptides expressed in cells as a result of naturally occurring DNA sequence variations in the MASP2 gene, such as single nucleotide polymorphisms of the MASP2 gene. Examples include the amino acid sequence corresponding to human MASP2 registered as Genbank Accession No. NP_006601.2, the amino acid sequence corresponding to mouse MASP2 registered as Genbank Accession No. NP_001003893.1, the amino acid sequence corresponding to rat MASP2 registered as Genbank Accession No. NP_742040.1, and the amino acid sequence corresponding to monkey MASP2 registered as Genbank Accession No. XP_045236890.1 or XP_005544871.1. Other examples of the amino acid sequence of MASP2 can be obtained using, for example, GenBank, UniProt, or OMIM.

[0082] The term "antibody" as used herein includes intact antibodies and any antigen-binding fragments thereof (i.e., "antigen-binding portions") or single chains thereof. An intact antibody is a glycoprotein comprising two heavy (H) chains and two light (L) chains connected by disulfide bonds. Each heavy chain is composed 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 is composed of three domains, CH1, CH2, and CH3. Each light chain is composed 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 is composed of one domain, CL. The VH and VL regions can be further subdivided into hypervariable regions, called complementarity determining regions (CDRs), separated by more conserved regions, called framework regions (FRs). Each VH and VL is composed of three CDRs and four FRs, arranged from amino-terminus to carboxyl-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. The three CDR regions of the light chain are referred to as LCDR1, LCDR2, and LCDR3; the three CDR regions of the heavy chain are referred to as HCDR1, HCDR2, and HCDR3. The variable regions of the heavy and light chains contain binding domains that interact with antigens. The constant region of an antibody can mediate the binding of the immunoglobulin 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.

[0083] For the determination or definition of CDRs, the deterministic depiction of CDRs and the identification of residues comprising the binding site of the antibody can be accomplished by resolving the structure of the antibody and / or resolving the structure of the antibody-ligand complex. This can be accomplished by any of the various techniques known to those skilled in the art, such as X-ray crystallography. A variety of analytical methods (including combinations of methods) can be used to identify CDRs, including but not limited to Kabat, Chothia, AbM, IMGT, Contact definitions, and 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 ed., 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 the amino acid residues included in an exemplary defined CDR are listed in the table below:

[0084] Note 1: Definitions vary slightly in different literature, especially the Chothia definition scheme;

[0085] Note 2: Except for the Contact definition that uses the Chothia or Martin numbering scheme, other definition schemes are compatible with various numbering schemes;

[0086] Note 3: When using Kabat Numbering, 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).

[0087] Note: The amino acid numbers on the heavy chain are represented by "H+numbers", and the amino acid numbers on the light chain are represented by "L+numbers"; for example, L24-L34 in the second row and second column of the table refers to the amino acid sequence determined from residues 24 to 34 according to the Kabat numbering scheme starting from the N-terminus of the antibody light chain variable region; and the same applies to the others.

[0088] 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 performed 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 form a single protein chain, wherein 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 within the scope of 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.

[0089] 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.

[0090] The term "murine antibody" refers to a monoclonal antibody against human MASP2 prepared according to the knowledge and skill in the art. These antibodies can be prepared by injecting a test subject with a MASP2 antigen, followed by isolation of hybridomas expressing antibodies with the desired sequence or functional properties. The murine anti-MASP2 antibody or antigen-binding fragment thereof may further comprise a light chain constant region of a murine kappa or lambda chain, or variants thereof, or a heavy chain constant region of a murine IgG1, IgG2, IgG3, or variants thereof.

[0091] 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). This antibody can mitigate the immune response induced by the heterologous antibody. For example, human-mouse chimeric antibodies are created by first establishing a hybridoma that secretes mouse-specific monoclonal antibodies. The variable region genes are then cloned from the mouse hybridoma cells. Furthermore, the constant region genes of the human antibody are cloned as needed. The mouse variable region genes and the human constant region genes are then connected to form a chimeric gene, which is then inserted into an expression vector. Finally, the chimeric antibody molecule is expressed in a eukaryotic or prokaryotic system.

[0092] The term "humanized antibody", also known as CDR-grafted antibody, refers to an antibody produced by transplanting the CDR sequence of a mouse into the antibody variable region framework of a human, i.e., different types of human germline antibody framework sequences. This can overcome the heterologous reactions induced by chimeric antibodies due to the large amount of mouse protein components they carry. Such framework sequences can be obtained from public DNA databases or published references including germline antibody gene sequences. For example, the germline DNA sequences of human heavy and light chain variable region genes can be obtained in the "VBase" human germline sequence database, as well as in Kabat, EA et al., 1991 Sequences of Proteins of Immunological Interest, 5th edition. In order to avoid a decrease in immunogenicity and the resulting decrease in activity, the human antibody variable region framework sequence can be subjected to minimal reverse mutation or back mutation to maintain activity.

[0093] The term "bispecific" or "multispecific" refers to an antibody and / or antigen-binding molecule that is capable of specifically binding 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 is capable of simultaneously binding to two or more antigenic determinants, particularly two or more antigenic determinants expressed on two or more different cells.

[0094] 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 that have been disclosed in the prior art and do not change the structure and function of the antibody variable region. Exemplary variants include IgG1, IgG2, IgG3 or IgG4 heavy chain constant region variants that have undergone 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 that obtain a knob-into-hole structure (so that the antibody heavy chain has a knob-Fc and hole-Fc combination) 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.

[0095] As used herein, the terms "include," "comprising," and "having" are used interchangeably and are intended to indicate the inclusiveness of a solution, meaning that other elements may be present in addition to the listed elements. It should also be understood that the use of "include," "comprising," and "having" in this document also provides a "consisting of" solution.

[0096] The term "antibody" herein includes, but is not limited to, monoclonal antibodies, polyclonal antibodies, monospecific antibodies, multispecific antibodies (e.g., bispecific antibodies), monovalent antibodies, multivalent antibodies, whole antibodies, antigen-binding fragments, naked antibodies, conjugated antibodies, humanized antibodies, or fully human antibodies.

[0097] The term "conservative amino acid" herein generally refers to amino acids that belong to the same class or have similar characteristics (e.g., charge, side chain size, hydrophobicity, hydrophilicity, main chain conformation, and rigidity). For example, the amino acids within each of the following groups are conservative amino acid residues of each other, and substitutions of amino acid residues within the group are substitutions of conservative amino acids:

[0098] 1) Alanine (A), serine (S), threonine (T);

[0099] 2) Aspartic acid (D), glutamic acid (E);

[0100] 3) Asparagine (N), glutamine (Q);

[0101] 4) Arginine (R), Lysine (K), Histidine (H);

[0102] 5) Isoleucine (I), Leucine (L), Methionine (M), Valine (V); and

[0103] 6) Phenylalanine (F), tyrosine (Y), tryptophan (W).

[0104] The terms "identity" and "sequence ... identity" are used interchangeably herein and are calculated as follows: To determine the percent "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 that position.

[0105] 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 refers to competition between antigen binding proteins as determined by an assay in which the antigen binding protein (e.g., antibody or immunologically functional fragment thereof) being 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 label assays, solid phase direct label sandwich assays (see, e.g., Harlow and Lane, 1988, Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory Press, 1992).

[0013] The present invention relates to a method for the determination of the competitive inhibition of antigen binding proteins by direct solid-phase labeling of antigens, such as immunoprecipitants, antigen-binding proteins, and antigen-binding proteins. The method also includes methods ... 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 sufficiently close to the binding epitope of the reference antigen binding protein that the two epitopes sterically hinder each other from 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.

[0106] The term "subject" includes any human or non-human animal. The term "non-human animal" includes all vertebrates, such as mammals and non-mammals, for example, non-human primates, rodents, rabbits, pigs, dogs, cats, chickens, amphibians and reptiles, although mammals such as non-human primates and rodents are preferred.

[0107] 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 lessen 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.

[0108] The antibodies of the present invention are monoclonal antibodies that are structurally and chemically characterized 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.

[0109] 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.

[0110] Table 2 Heavy chain / light chain constant region sequences of anti-MASP2 antibodies of the present invention

[0111] 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:

[0112] >Narsoplimab heavy chain (SEQ ID NO:46):

[0113] >Narsoplimab light chain (SEQ ID NO:47):

[0114] The heavy chain variable region and light chain variable region CDR sequences in Table 1 as defined by Kabat, Chothia, IMGT, AbM, and Contact using abYsis are shown in Table 3.

[0115] Table 3 CDR sequences of anti-MASP2 antibodies of the present invention

[0116] By 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

[0117] 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.

[0118] 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.

[0119] Figure 3 shows the binding of antibodies 11W0, 11W1, and 11W3 to complement homologous members, with Narsoplimab used as a control antibody. The complement homologous member involved in Figure 3A is human complement component C1s, the complement homologous member involved in Figure 3B is human complement component C1r, the complement homologous member involved in Figure 3C is human complement component MASP-1, and the complement homologous member involved in Figure 3D is human complement component MASP-3.

[0120] FIG4 shows the inhibitory activity of antibodies 20W30, 11W3 and their long-acting modified antibodies on the complement lectin pathway in vitro.

[0121] Figure 5A shows the inhibitory activity of the long-acting modified antibody 11W4-LS on the complement lectin pathway in vitro (human complement serum), with Narsoplimab as the control antibody; the IC 50 <0.01μg / mL.

[0122] Figure 5B 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.

[0123] Figure 5C shows the inhibitory activity of the long-acting modified antibodies 11W5-LS, 11W6-LS, 11W7-LS, and 11W8-LS on the complement lectin pathway in vitro (human complement serum), with Narsoplimab serving as a control antibody; the IC 50 <0.05μg / mL.

[0124] FIG6 shows the results of ELISA affinity determination of some antibodies.

[0125] FIG7 shows the results of MAC assay of some antibodies using the complement lectin pathway (human complement serum).

[0126] FIG8 shows the effects of some antibodies on the classical and alternative pathways of complement (human complement serum).

[0127] FIG9 shows the effects of some antibodies on C4b deposition (human complement serum). Specific embodiments

[0128] Example 1 Immunization of mice to produce anti-MASP2 antibodies

[0129] 1.1 Preparation of mouse antibodies

[0130] Twelve Balb / C mice (Vitamin B) and twelve C57 mice (Vitamin B) were immunized via protein injection with huMASP-2A-chis, cynoMASP-2A-chis, musMASP-2A-chis, and ratMASP-2A-chis. The adjuvant used was Freund's complete adjuvant (100 μg / mouse), while the adjuvant used was Freund's incomplete adjuvant (50 μg / mouse) for the second, third, and fourth immunizations. A 100 μg / mouse boost was administered for the second, third, and fourth immunizations. Three days after the boost, spleens and orbital blood were collected for titer analysis. The spleens were ground and stored in Trizol.

[0131] After the sprint immunization, the spleen of the mouse was taken and total RNA was extracted by Trizol method. The extracted total RNA was reverse transcribed into cDNA. Based on the germline of the Fab heavy chain and light chain, the variable region genes of the mouse heavy chain and light chain were amplified and then cloned into the phage display vector using enzyme digestion. The recombinant vector was transformed into competent Escherichia coli SS320 (Lucigen, MC1061F) to construct an antibody gene phage display library with a library capacity of 5×10 8 .

[0132] The library is screened using magnetic bead and immunotube methods. Magnetic bead screening involves biotin-labeling the antigen protein hu 10AA-CCP1-CCP2-SP-A-chis, binding it to streptavidin-coupled magnetic beads, and then incubating the antigen-bound magnetic beads with the antibody gene phage display library, followed by washing and elution. Three rounds of panning are typically performed, resulting in the enrichment of large quantities of monoclonal antibodies specific for the antigen. Immunotube screening involves coating 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 on the surface of an immunotube with high adsorption capacity. The phage-displayed antibody library is then added to the immunotube and incubated with the antigen proteins adsorbed on the surface of the immunotube, followed by a panning process of washing and eluting. After three rounds of panning, specific monoclonal antibodies Fab targeting the antigen are ultimately enriched.

[0133] 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 and subjected to ELISA, and the method was as follows: 1) Coating: 2 μg / mL antigen huMASP-2A-chis, cynoMASP-2A-chis, ratMASP-2A-chis, musMASP-2A-chis, 30 μL per well, 4°C overnight, PBST wash 3 times; 2) Blocking: 5% PBSM blocking at room temperature for 1 hour, PBST wash 3 times; 3) Primary antibody: add monoclonal phage expression supernatant, negative control (IgG) diluted to 5 μg / mL, 30 μL / well, room temperature for 1 hour, PBST wash 3 times; 4) Secondary antibody: add secondary antibody Anti-M13-HRP diluted 1:20000, 5% Dilute with PBSM, add the secondary antibody Anti-human-Fab-HRP diluted 1:5000 in PBS to the negative control (IgG) sample, 30 μL / well, incubate at room temperature for 1 hour, and wash 6 times with PBST; 5) Stop: add 30 μL / well TMB to develop at room temperature for 5-10 minutes, then add 30 μL / well 2M stop solution to terminate the reaction. 450 Read the data. For the positive clones screened, extract the plasmid and perform next-generation sequencing. The amino acids of the heavy chain variable region and light chain variable region of the murine anti-MASP2 antibody obtained in this example are shown in Table 4.

[0134] 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.

[0135] 1.2 Preparation of chimeric antibodies

[0136] The heavy chain variable region sequence of the murine anti-MASP2 antibody was cloned into a GSV0 vector containing a human heavy chain constant region (IgG4SP with an Fc modification at S228P to stabilize the hinge). 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 murine anti-MASP2 antibody was cloned into a GSV0 vector containing a human light chain constant region (κ chain). The light chain constant region sequence is shown in SEQ ID NO:23. The above vectors were co-transfected into CHO cells for expression using the ExpiCHOs expression system. The expression supernatant was collected and purified to obtain the complete chimeric antibody. The heavy and light chain sequences of the chimeric antibodies 11W0 (11W-VH1-VL1) and 12W0 (12W-VH1-VL1) targeting MASP2 are as follows:

[0137] >11W0 heavy chain (SEQ ID NO: 24):

[0138] >11W0 light chain (SEQ ID NO: 25):

[0139] >12W0 heavy chain (SEQ ID NO: 26):

[0140] >12W0 light chain (SEQ ID NO: 27):

[0141] 1.3 Preparation of humanized antibodies

[0142] The structure of the parent antibody was modeled using the MOE homology modeling program, and then CDR grafting was used to design humanized antibodies. In short, the CDRs of the parent antibody were grafted onto the human antibody backbone to obtain humanized light and heavy chains for each parent antibody. In addition, post-transcriptional modification (PTM) sites, such as glycosylation sites, deamidation sites, and isomerization sites, were identified based on the humanized sequence, and mutations were designed to remove PTM sites to optimize the antibody sequence, thereby avoiding adverse effects on protein conformation and function.

[0143] 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).

[0144] 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, 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:

[0145] >11W1 heavy chain (SEQ ID NO: 28):

[0146] >11W1 light chain (SEQ ID NO: 29):

[0147] >11W2 heavy chain: SEQ ID NO: 28

[0148] >11W2 light chain (SEQ ID NO: 30):

[0149] >11W3 heavy chain (SEQ ID NO:31):

[0150] >11W3 light chain: SEQ ID NO: 30

[0151] >11W4 heavy chain (SEQ ID NO:31):

[0152] >11W4 light chain (SEQ ID NO: 64):

[0153] >11W5 heavy chain: SEQ ID NO: 31

[0154] >11W5 light chain (SEQ ID NO: 65):

[0155] >11W6 heavy chain: SEQ ID NO: 31

[0156] >11W6 light chain (SEQ ID NO: 66):

[0157] >11W7 heavy chain (SEQ ID NO: 67):

[0158] >11W7 light chain (SEQ ID NO: 68):

[0159] >11W8 heavy chain (SEQ ID NO: 69):

[0160] >11W8 light chain: SEQ ID NO: 65

[0161] >11W9 heavy chain (SEQ ID NO:70):

[0162] >11W9 light chain: SEQ ID NO: 64

[0163] >11W10 heavy chain: SEQ ID NO: 70

[0164] >11W10 light chain (SEQ ID NO:71):

[0165] >12W1 heavy chain (SEQ ID NO: 32):

[0166] >12W1 light chain (SEQ ID NO: 33):

[0167] >12W2 heavy chain (SEQ ID NO: 34):

[0168] >12W2 light chain (SEQ ID NO: 35):

[0169] >12W3 heavy chain (SEQ ID NO: 36):

[0170] >12W3 light chain: SEQ ID NO: 35

[0171] >12W4 heavy chain (SEQ ID NO: 72):

[0172] >12W4 light chain (SEQ ID NO: 73):

[0173] >12W5 heavy chain (SEQ ID NO: 74):

[0174] >12W5 light chain (SEQ ID NO: 75):

[0175] >12W6 heavy chain: SEQ ID NO: 36

[0176] >12W6 light chain (SEQ ID NO: 76):

[0177] >12W7 heavy chain (SEQ ID NO: 77):

[0178] >12W7 light chain (SEQ ID NO: 78):

[0179] >12W8 heavy chain: SEQ ID NO: 36

[0180] >12W8 light chain: SEQ ID NO: 78

[0181] >12W9 heavy chain (SEQ ID NO: 79):

[0182] >12W9 light chain: SEQ ID NO: 78

[0183] >12W10 heavy chain: SEQ ID NO: 74

[0184] >12W10 light chain: SEQ ID NO: 78

[0185] Example 2 Preparation of fully human antibodies targeting MASP2

[0186] Get Ficoll-Paque density gradient separation liquid (purchased from GE company, catalog number: 17144003S) and separate the peripheral blood mononuclear cell (Peripheral Blood Mononuclear Cell, PBMC) of normal human blood, by conventional method self-isolated PBMC cell extraction total RNA.Use reverse transcription kit (purchased from TaKaRa company, catalog number: 6210A) the total RNA extracted is reverse transcribed into cDNA.Based on the sequence similarity of heavy chain and light chain germline gene, respectively at the V district front end and the first constant region rear end design degenerate primers of heavy chain and light chain, obtain the heavy chain variable region gene fragment and the light chain variable region gene fragment of antibody after PCR, construct corresponding human antibody gene phage display library and carry out screening, the selection of monoclonal in library according to the method recorded in embodiment 1.1.The positive clone selected is further carried out antibody affinity maturation transformation, obtained antibody 20W30, 20W51 and 20W78, the amino acid sequence of each antibody is as shown in Table 5.

[0187] Table 5 Heavy chain / light chain sequences of fully human antibodies targeting MASP2

[0188] Example 3

[0189] Evaluation of the binding ability of anti-MASP2 antibodies

[0190] 3.1 Determination of antibody affinity at the kinetic level (ForteBio)

[0191] The affinity constant (KD) of human MASP2 for antibodies was determined kinetically. The antibody was immobilized onto a Protein A sensor, and the human MASP2 protein was serially diluted. The antibody and antigen underwent equilibrium (baseline), association (association), and disassociation (disassociation) steps. The Protein A sensor was then regenerated and neutralized. 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 showed that the KD of the 11W and 12W series antibodies of the present invention for MASP2 protein was less than 10 -8 It can be seen that the affinity of the 11W and 12W series antibodies of the present invention for binding to human MASP2 protein is superior to that of the control antibody Narsoplimab (Table 6).

[0192] Table 6 Affinity test results of 11W and 12W series antibodies binding to human MASP2 protein

[0193] 3.2 ELISA determination of antibody affinity

[0194] The relative binding activity of each antibody against human MASP2 protein was determined using an ELISA method. Specifically, recombinant human MASP2 protein (2 μg / mL) was coated onto an ELISA plate at 100 μL / well and incubated overnight at 4°C. The plate was then blocked with 1% BSA in PBST (containing 0.05% Tween-20) for 2 hours at 37°C (200 μL / well), washed three times with PBST, and each antibody was serially diluted in PBST containing 1% BSA and added to the ELISA plate (100 μL / well). The working concentration of the antibody was 10,000 ng / mL, followed by 8 dilutions in 4 steps. The plate was incubated at 37°C for 1 hour, and 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 h, washed three times with PBST, and then 100 μL of 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 using a microplate reader.

[0195] The experimental results are shown in Table 7 and FIG6 , which show that the 12W and 20W series antibodies of the present invention have a higher affinity for binding to human MASP2 protein than the control antibody Narsoplimab.

[0196] Table 7 Affinity test results of 20W series antibodies binding to MASP2 protein

[0197] Example 4 Specificity of Anti-MASP2 Antibodies in Inhibiting the Complement Lectin Pathway in Vitro

[0198] 4.1 Determination of MAC by the complement lectin pathway

[0199] The inhibitory effect of candidate antibodies was determined using the WIESLAB Complement System MBL pathway screening kit (COMPLMP320RUO). Plates were pre-coated with mannan, an MBL pathway activator. Antibodies were serially diluted in assay buffer, along with human complement serum (Quidel, Al12), which was also diluted in assay buffer. The plates were then incubated on ice for 30 minutes. The antibody-serum mixture was added to the plates and incubated at 37°C for 120 minutes. After washing, deposited MAC (membrane attack complex, C5b-9) was detected using an alkaline phosphatase-conjugated specific antibody.

[0200] The experimental results are shown in Tables 8-9 and Figure 7. It can be seen that the antibodies of the present invention have better inhibitory activity on the complement lectin pathway than the control antibody Narsoplimab. In addition, 11W1 and 12W0 also have comparable inhibitory activity to the control antibody Narsoplimab.

[0201] Table 8 Inhibition of the complement lectin pathway by anti-MASP2 antibodies

[0202] Table 9.1 Inhibition of the complement lectin pathway by anti-MASP2 antibodies

[0203] Table 9.2 Inhibition of the complement lectin pathway by anti-MASP2 antibodies

[0204] 4.2 Determination of MAC of the classical and alternative complement pathways

[0205] The WIESLAB Complement System Classical Pathway Screening Kit (COMPLCP310RUO) and the Complement System Alternative Pathway Screening Kit (COMPLAP330RUO) assess the selectivity of candidate antibodies for the complement system. Plates are pre-coated with IgM as a classical pathway activator and LPS as an alternative pathway activator. Antibodies are serially diluted in assay buffer, along with human complement serum (Quidel, Al12) and incubated on ice for 30 minutes. The antibody-serum mixture is then added to the plate and incubated at 37°C for 120 minutes. After washing, deposited MACs are detected using an alkaline phosphatase-conjugated specific antibody.

[0206] The experimental results are shown in Figures 1-2. It can be seen 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, but can specifically inhibit the complement lectin pathway.

[0207] Example 5 Cross-reactivity determination of anti-MASP2 antibodies

[0208] 5.1 MASP2 cross-species reactivity testing

[0209] The relative binding activity of each antibody against MASP2 protein was determined using an ELISA method. Recombinant human, mouse, and monkey MASP2 proteins (2 μg / mL) were coated onto ELISA plates at 100 μL / well and incubated overnight at 4°C. Plates were then blocked with 1% BSA in PBST (containing 0.05% Tween-20) for 2 hours at 37°C (200 μL / well). The plates were washed three times with PBST. Candidate antibodies were serially diluted in PBST containing 1% BSA and added to the ELISA plates (100 μL / well). The working concentration of the antibodies was 10,000 ng / mL followed by 4 dilutions. Narsoplimab was used as a positive control, and an isotype IgG antibody was used as a negative control. Plates were incubated at 37°C for 1 hour and 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 h, washed three times with PBST, and then 100 μL of TMB (SURMOPICS) was added to react. The reaction was terminated with 2M HCl, and the OD value was measured at 450 nm-570 nm by a microplate reader. The experimental results are shown in Table 10.

[0210] 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.

[0211] 5.2 Complement family member cross-reactivity test

[0212] The relative binding activity of each antibody against complement family members C1r, C1s, MASP1, and MASP3 was determined using ELISA. C1r, C1s, MASP1, and MASP3 proteins (2 μg / mL) were coated onto ELISA plates at 100 μL / well and incubated overnight at 4°C. Plates were then blocked with 1% BSA in PBST (containing 0.05% Tween-20) for 2 hours at 37°C (200 μL / well), washed three times with PBST, and serially diluted with 1% BSA in PBST. The candidate antibodies were then added to the ELISA plates (100 μL / well) at a working concentration of 10,000 ng / mL, diluted in multiples of 4, for eight steps. Narsoplimab was used as a positive control. Plates were incubated at 37°C for 1 hour, and 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, and washed three times with PBST. Then, 100 μL of TMB (SURMOPICS) was added for reaction. The reaction was terminated with 2M HCl, and the OD value was measured on a microplate reader at 450-570 nm. The experimental results are shown in Figure 3, indicating that the antibodies of the present invention have essentially no binding activity against members of the complement family.

[0213] Example 6: Modification of Anti-MASP2 Antibodies for Longer-Term Effects

[0214] In order to improve the PK characteristics of humanized antibodies, mutations are introduced in the Fc region to extend the half-life of the antibody. The M428L / N434S mutation (LS mutation) and the M252Y / S254T / T256E mutation (YTE mutation) have been shown to extend the half-life of antibodies 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). Therefore, humanized antibodies with extended half-lives were generated, and the heavy chain / light chain amino acid sequences of each antibody are as follows:

[0215] >20W30-LS heavy chain (SEQ ID NO:42):

[0216] >20W30-LS light chain: SEQ ID NO: 38

[0217] >20W30-YTE heavy chain (SEQ ID NO: 43):

[0218] >20W30-YTE light chain: SEQ ID NO: 38

[0219] >11W3-LS heavy chain (SEQ ID NO:44):

[0220] >11W3-LS light chain: SEQ ID NO: 30

[0221] >11W4-LS heavy chain (SEQ ID NO:44):

[0222] >11W4-LS light chain (SEQ ID NO: 64):

[0223] >12W3-LS heavy chain (SEQ ID NO:45):

[0224] >12W3 light chain: SEQ ID NO: 35

[0225] >11W5-LS heavy chain (SEQ ID NO:44):

[0226] >11W5-LS light chain: SEQ ID NO: 65

[0227] >11W6-LS heavy chain (SEQ ID NO:44):

[0228] >11W6-LS light chain: SEQ ID NO: 66

[0229] >11W7-LS heavy chain (SEQ ID NO:80):

[0230] >11W7-LS light chain: SEQ ID NO: 68

[0231] >11W8-LS heavy chain (SEQ ID NO:81):

[0232] >11W8-LS light chain: SEQ ID NO: 65

[0233] The affinity constant (KD) of antibodies for FcRn was measured using a kinetic assay (ForteBio). Human FcRn was immobilized on a Protein A sensor, and the antibody was serially diluted. The antibody and FcRn were subjected to equilibrium (baseline), association (association), and disassociation (disassociation) steps. The Protein A sensor was then regenerated and neutralized. After multiple cycles, the affinity constant (KD), association rate constant (Kon), and dissociation rate constant (Kdis) of human FcRn for the antibodies were analyzed. The affinity test results for each antibody for human FcRn are shown in Tables 11-12. Modification of 20W30 with either the LS or YTE mutation increased its affinity for FcRn, with the LS mutation being more effective (Table 11). Modification of 11W3 with the LS mutation increased its affinity for FcRn by approximately 10-fold (Table 12).

[0234] Table 11 Affinity test results of anti-MASP2 antibodies to human FcRn

[0235] Table 12 Affinity test results of anti-MASP2 antibodies to human FcRn

[0236] 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. The inhibitory activity of the modified antibody remains 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. 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 basically does not affect the bypass and classical pathways (Figure 8).

[0237] The species cross-reactivity of the long-acting modified antibodies against MASP2 was determined according to the method of Example 5, and the results are shown in Table 13. It can be seen that the LS mutation or the YTE mutation did not affect the species cross-reactivity of the antibody.

[0238] Table 13 Binding of anti-MASP2 antibodies to various MASP2 proteins Note: Murine MASP2 protein refers specifically to mouse MASP2 protein.

[0239] In addition, the 11W series of antibodies were further tested for their ability to recognize rat MASP2 protein. Using an ELISA assay, biotinylated recombinant rat MASP2 protein (2 μg / mL) was coated onto streptavidin (SA)-precoated ELISA plates at 100 μL / well and incubated overnight at 4°C. The candidate antibodies were then serially diluted in PBS containing 2% BSA and added to the ELISA plates (100 μL / well). The working concentration of the antibodies was 10,000 ng / mL followed by eight dilutions in multiples of four. The plates were incubated at 37°C for 1 hour and washed five times with PBST. Then, 100 μL / well of Anti-Human IgG (JACSON; 109-035-003) diluted 1:10,000 in PBS containing 2% BSA was added. The cells were incubated at 37°C for 1 hour and washed five times with PBST. Then, 100 μL of TMB (SURMOPICS) was added for reaction, and the cells were incubated at room temperature. The reaction was terminated with 1 M H₂SO₄ and the OD value was measured at 450 nm using a microplate reader. The results showed that the antibody 11W4-LS also had binding activity to rat MASP2 protein.

[0240] Example 7 Effect of Anti-MASP2 Antibodies on C4b Deposition

[0241] 10 μg / ml mannan (Sigma, M7504) was added to the ELISA plate wells 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 antibody diluent, incubated on ice for 45 min, and then added to the ELISA plate and incubated at 37°C for approximately 2 h. After washing, 100 μL / well of a 1:700 dilution of detection antibody (ASSAYPRO, #11223-05021) was added and incubated at room temperature for 60 min. After washing, 100 μL / well of a 1:200 dilution of 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 approximately 2 min. Finally, 1 M H2SO4 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 values ​​of the 11W series optimized antibodies in FIG9 for inhibiting C4b deposition are calculated. 50 The values ​​were all no higher than 0.01 μg / ml, which was significantly improved compared with the inhibitory activity of Narsoplimab.

[0242] 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 description is intended to cover all substitutions, modifications and variations 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 in their entirety.

Claims

1. An anti-MASP2 antibody or an antigen-binding fragment thereof, wherein the anti-MASP2 antibody or the antigen-binding fragment thereof comprises a heavy-chain variable region (VH) and a light-chain variable region (VL), 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 sequences as the HCDR1, HCDR2 and HCDR3 of the VH shown in any one of SEQ ID NOs: 1-2, or sequences with at most 5, 4, 3, 2 or 1 mutation(s) compared thereto, and the LCDR1, LCDR2 and LCDR3 regions have the same sequences as the LCDR1, LCDR2 and LCDR3 of the VL shown in any one of SEQ ID NOs: 3-5, or sequences with at most 5, 4, 3, 2 or 1 mutation(s) compared thereto; (ii) The HCDR1, HCDR2 and HCDR3 regions have the same sequences as the HCDR1, HCDR2 and HCDR3 of the VH shown in any one of SEQ ID NOs: 6-8, 48-50, or sequences with at most 5, 4, 3, 2 or 1 mutation(s) compared thereto, and the LCDR1, LCDR2 and LCDR3 regions have the same sequences as the LCDR1, LCDR2 and LCDR3 of the VL shown in any one of SEQ ID NOs: 9-11, 51-55, or sequences with at most 5, 4, 3, 2 or 1 mutation(s) compared thereto; or (iii) The HCDR1, HCDR2 and HCDR3 regions have the same sequences as the HCDR1, HCDR2 and HCDR3 of the VH shown in any one of SEQ ID NOs: 12-15, 56-59, or sequences with at most 5, 4, 3, 2 or 1 mutation(s) compared thereto, and the LCDR1, LCDR2 and LCDR3 regions have the same sequences as the LCDR1, LCDR2 and LCDR3 of the VL shown in any one of SEQ ID NOs: 16-18, 60-63, or sequences with at most 5, 4, 3, 2 or 1 mutation(s) compared thereto; The mutations are selected from insertions, deletions and / or substitutions that do not affect the function, and the substitutions are preferably conservative amino acid substitutions.

2. The antibody or antigen-binding fragment thereof according to claim 1, wherein the VH has HCDR1, HCDR2 and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 1, and the VL has LCDR1, LCDR2 and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 3 or 5; The VH has HCDR1, HCDR2 and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 2, and the VL has LCDR1, LCDR2 and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 4; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 6, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 9; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 7, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 10 or 11; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 8, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in any one of SEQ ID NO: 11, 51 - 53; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 48, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 54; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 49, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 52; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 50, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 51 or 55; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 12, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 16; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 13, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 17; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 14, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 18; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 15, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 18 or 62; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 56, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 60; The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in SEQ ID NO: 57, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO: 61; or, The VH has HCDR1, HCDR2, and HCDR3 with the same sequences as those of the VH shown in any one of SEQ ID NOs: 15, 57 - 59, and the VL has LCDR1, LCDR2, and LCDR3 with the same sequences as those of the VL shown in SEQ ID NO:

63.

3. The antibody or its antigen-binding fragment according to claim 1 or 2, wherein the VH has an amino acid sequence having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity with the sequence shown in any one of SEQ ID NOs: 1 - 2, and / or the VL has an amino acid sequence having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity with the sequence shown in any one of SEQ ID NOs: 3 - 5; The VH has an amino acid sequence having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity with the sequence shown in any one of SEQ ID NOs: 6 - 8, 48 - 50, and / or the VL has an amino acid sequence having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity with the sequence shown in any one of SEQ ID NOs: 9 - 11, 51 - 55; or The VH has an amino acid sequence having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity with the sequence shown in any one of SEQ ID NOs: 12 - 15, 56 - 59, and / or the VL has an amino acid sequence having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity with the sequence shown in any one of SEQ ID NOs: 16 - 18, 60 - 63.

4. The antibody or its antigen-binding fragment according to any one of claims 1 - 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 NOs: 3 - 5; The VH contains the sequence shown in SEQ ID NO: 2, and the VL contains the sequence shown in any one of SEQ ID NOs: 3-5; The VH contains the sequence shown in SEQ ID NO: 6, and the VL contains the sequence shown in any one of SEQ ID NOs: 9-11, 51-556; The VH contains the sequence shown in SEQ ID NO: 7, and the VL contains the sequence shown in any one of SEQ ID NOs: 9-11, 51-55; The VH contains the sequence shown in SEQ ID NO: 8, and the VL contains the sequence shown in any one of SEQ ID NOs: 9-11, 51-55; The VH contains the sequence shown in SEQ ID NO: 48, and the VL contains the sequence shown in any one of SEQ ID NOs: 9-11, 51-55; The VH contains the sequence shown in SEQ ID NO: 49, and the VL contains the sequence shown in any one of SEQ ID NOs: 9-11, 51-55; The VH contains the sequence shown in SEQ ID NO: 50, and the VL contains the sequence shown in any one of SEQ ID NOs: 9-11, 51-55; The VH contains the sequence shown in SEQ ID NO: 12, and the VL contains the sequence shown in any one of SEQ ID NOs: 16-18, 60-63; The VH contains the sequence shown in SEQ ID NO: 13, and the VL contains the sequence shown in any one of SEQ ID NOs: 16-18, 60-63; The VH contains the sequence shown in SEQ ID NO: 14, and the VL contains the sequence shown in any one of SEQ ID NOs: 16-18, 60-63; The VH contains the sequence shown in SEQ ID NO: 15, and the VL contains the sequence shown in any one of SEQ ID NOs: 16-18, 60-63; The VH contains the sequence shown in SEQ ID NO: 56, and the VL contains the sequence shown in any one of SEQ ID NOs: 16-18, 60-63; The VH contains the sequence shown in SEQ ID NO: 57, and the VL contains the sequence shown in any one of SEQ ID NOs: 16-18, 60-63; The VH contains the sequence shown in SEQ ID NO: 58, and the VL contains the sequence shown in any one of SEQ ID NOs: 16-18, 60-63; or, The VH contains the sequence shown in SEQ ID NO: 59, and the VL contains the sequence shown in any one of SEQ ID NOs: 16-18, 60-63.

5. The antibody or antigen-binding fragment thereof according to any one of claims 1-4, wherein the VH and VL are selected from the following groups: The VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 1 and 3; The VH and VL respectively contain or are the sequences shown in SEQ ID NOs: 2 and 4; The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 1 and 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; The 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 comprise or are the sequences shown in SEQ ID NO: 59 and 63; or, The VH and VL respectively comprise or are the sequences shown in SEQ ID NO: 57 and 63.

6. The antibody or antigen-binding fragment thereof according to any one of claims 1-5, 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 IgG4 constant regions having any one or more mutations among S228P, M428L, N434S, M252Y, S254T and T256E, and the above mutations are all EU numberings; 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 having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity 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 having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity thereto.

7. The antibody or antigen-binding fragment thereof according to any one of claims 1-6, wherein the anti-MASP2 antibody comprises a heavy chain and a light chain, (i) the heavy chain has an amino acid sequence having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity to the sequence shown in any one of SEQ ID NOs: 37, 39, 42, 43, and / or the light chain has an amino acid sequence having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity to the sequence shown in any one of SEQ ID NOs: 38, 40, 41; (ii) the heavy chain has an amino acid sequence having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity 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 having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity 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 having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity 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 having at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% identity to the sequence shown in any one of SEQ ID NOs: 27, 33, 35, 73, 75, 76, 78.

8. The antibody or antigen-binding fragment thereof according to any one of claims 1-7, 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 a sequence as shown in any one of SEQ ID NOs: 38, 40, 41; The heavy chain contains the sequence shown in SEQ ID NO: 39 and the light chain contains the sequence shown in any one of SEQ ID NO: 38, 40, 41; The heavy chain contains the sequence shown in SEQ ID NO: 42 and the light chain contains the sequence shown in any one of SEQ ID NO: 38, 40, 41; The heavy chain contains the sequence shown in SEQ ID NO: 43 and the light chain contains the sequence shown in any one of SEQ ID NO: 38, 40, 41; The heavy chain contains the sequence shown in SEQ ID NO: 24 and the light chain contains the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; The heavy chain contains the sequence shown in SEQ ID NO: 28 and the light chain contains the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; The heavy chain contains the sequence shown in SEQ ID NO: 31 and the light chain contains the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; The heavy chain contains the sequence shown in SEQ ID NO: 44 and the light chain contains the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; The heavy chain contains the sequence shown in SEQ ID NO: 67 and the light chain contains the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; The heavy chain contains the sequence shown in SEQ ID NO: 69 and the light chain contains the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; The heavy chain contains the sequence shown in SEQ ID NO: 70 and the light chain contains the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; The heavy chain contains the sequence shown in SEQ ID NO: 80 and the light chain contains the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; The heavy chain contains the sequence shown in SEQ ID NO: 81 and the light chain contains the sequence shown in any one of SEQ ID NO: 25, 29, 30, 64, 65, 66, 68, 71; The heavy chain contains the sequence shown in SEQ ID NO: 26 and the light chain contains the sequence shown in any one of SEQ ID NO: 27, 33, 35, 73, 75, 76, 78; The heavy chain contains the sequence shown in SEQ ID NO: 32 and the light chain contains 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 any one of the sequences shown in 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 any one of the sequences shown in 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 any one of the sequences shown in 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 any one of the sequences shown in 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 any one of the sequences shown in 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 any one of the sequences shown in 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 any one of the sequences shown in SEQ ID NO: 27, 33, 35, 73, 75, 76, 78.

9. An antibody or antigen-binding fragment thereof according to any one of claims 1-8, wherein the heavy chain and the light chain respectively comprise sequences selected from the group consisting of: the sequences shown in SEQ ID NO:24 and 25; the sequences shown in SEQ ID NO:26 and 27; the sequences shown in SEQ ID NO:28 and 29; the sequences shown in SEQ ID NO:28 and 30; the sequences shown in SEQ ID NO:31 and 30; the sequences shown in SEQ ID NO:31 and 64; the sequences shown in SEQ ID NO:31 and 65; the sequences shown in SEQ ID NO:31 and 66; the sequences shown in SEQ ID NO:67 and 68; the sequences shown in SEQ ID NO:69 and 65; the sequences shown in SEQ ID NO:70 and 64; the sequences shown in SEQ ID NO:70 and 71; the sequences shown in SEQ ID NO:32 and 33; the sequences shown in SEQ ID NO:34 and 35; the sequences shown in SEQ ID NO:36 and 35; the sequences shown in SEQ ID NO:37 and 38; the sequences shown in SEQ ID NO:39 and 40; the sequences shown in SEQ ID NO:37 and 41; the sequences shown in SEQ ID NO:72 and 73; the sequences shown in SEQ ID NO:74 and 75; the sequences shown in SEQ ID NO:36 and 76; the sequences shown in SEQ ID NO:77 and 78; the sequences shown in SEQ ID NO:36 and 78; the sequences shown in SEQ ID NO:79 and 78; the sequences shown in SEQ ID NO:74 and 78; the sequences shown in SEQ ID NO:42 and 38; the sequences shown in SEQ ID NO:43 and 38; the sequences shown in SEQ ID NO:44 and 30; the sequences shown in SEQ ID NO:44 and 64; the sequences shown in SEQ ID NO:44 and 65; the sequences shown in SEQ ID NO:44 and 66; the sequences shown in SEQ ID NO:80 and 68; the sequences shown in SEQ ID NO:81 and 65; or, the sequences shown in SEQ ID NO:45 and 35.

10. An anti-MASP2 antibody or antigen-binding fragment thereof that binds or competes for binding to the same epitope as the anti-MASP2 antibody or antigen-binding fragment thereof according to any one of claims 1-9.

11. The anti-MASP2 antibody or antigen-binding fragment thereof according to any one of claims 1-10, having 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; (2) The antibody or its antigen-binding fragment inhibits the deposition of complement lectin pathway MAC in an in vitro assay at an IC 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 lower; 50 inhibits the deposition of complement lectin pathway MAC in an in vitro assay; (3) The antibody or antigen-binding fragment thereof substantially does not inhibit the classical pathway and / or the alternative pathway; (4) The antibody or its antigen-binding fragment substantially does not bind to complement components C1r, C1s, MASP1, and / or MASP3; (5) When binding to human MASP2, the KD of the antibody or its antigen-binding fragment is substantially the same as or better than that of a reference MASP2 antibody; (6) When binding to human MASP2, the antibody or its antigen-binding fragment specifically inhibits or blocks the complement lectin pathway. Preferably, the inhibitory or blocking effect of the antibody or its antigen-binding fragment is substantially the same as or better than that of a reference MASP2 antibody; (7) When binding to human MASP2, the antibody or its antigen-binding fragment reduces or decreases C4b and / or MAC deposition. Preferably, the antibody or its antigen-binding fragment reduces or decreases C4b and / or MAC deposition at a level substantially the same as or better than that of a reference MASP2 antibody.

12. The anti-MASP2 antibody or its antigen-binding fragment according to any one of claims 1-11, further comprising one or more effector molecules. Preferably, the effector molecule is selected from anti-tumor agents, drugs, toxins, bioactive proteins, other antibodies or antibody fragments, synthetic or naturally occurring polymers, nucleic acids and their fragments, radionuclides, radioisotopes, chelating metals, nanoparticles, and reporter groups, or compounds detectable by NMR or ESR spectroscopy.

13. A bispecific or multispecific antibody or its antigen-binding fragment, comprising the anti-MASP2 antibody or its antigen-binding fragment according to any one of claims 1-11.

14. A polynucleotide encoding the anti-MASP2 antibody or its antigen-binding fragment according to any one of claims 1-12, or encoding the bispecific or multispecific antibody or its antigen-binding fragment according to claim 13.

15. An expression vector comprising the polynucleotide according to claim 14.

16. A host cell comprising the polynucleotide according to claim 14 or the expression vector according to claim 15.

17. A pharmaceutical composition comprising the anti-MASP2 antibody or its antigen-binding fragment according to claims 1-12, or the bispecific or multispecific antibody or its antigen-binding fragment according to claim 13, or the polynucleotide 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.

18. A kit comprising the anti-MASP2 antibody or its antigen-binding fragment according to claims 1-12.

19. A method for preventing and / or treating a MASP2-related disease or disorder 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 according to any one of claims 1-12, the bispecific or multispecific antibody or antigen-binding fragment thereof according to claim 13, the polynucleotide according to claim 14, the expression vector according to claim 15, the host cell according to claim 16, the pharmaceutical composition according to claim 17, or the kit according to claim 18; preferably, the MASP2-related disease or disorder is IgA nephropathy.

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