Therapeutic antibodies that bind to the serine protease domain of MASP-2 and uses thereof

Abstract

Isolated monoclonal antibodies and antigen-binding fragments thereof are provided that specifically bind, to an epitope within the serine protease domain of human MASP-2. In some embodiments, the antibodies or antigen-binding fragments thereof inhibit lectin pathway complement activation. Also provided are polynucleotides encoding the disclosed monoclonal antibodies or antigen-binding fragments thereof, and cloning vectors or expression cassettes comprising such polynucleotides. Further provided are methods of inhibiting lectin pathway complement activation and methods of treating lectin pathway diseases and disorders.

Description

The terms “VH” and “VL” refer to the variable binding regions from an antibody heavy chain and an antibody light chain, respectively. A VL may be a kappa class chain or a lambda class chain The variable binding regions comprise discrete, well-defined sub-regions known as complementarity determining regions (CDRs) and framework regions (FRs). The CDRs are located within a hypervariable region (HVR) of the antibody and refer to sequences of amino acids within antibody variable regions which, in general, together confer the antigen As used herein, the term ’’antigen-binding fragment" refers to a polypeptide fragment that contains at least one CDR of an immunoglobulin heavy and / or light chains that specifically binds to the antigen to which the antibody was raised. An antigen-binding fragment may comprise 1, 2, 3, 4, 5, or all 6 CDRs of a VH and VL sequence from an antibody. A "Fab" (fragment antigen binding) is the part of an antibody that binds to antigens and includes the variable region and CH I of the heavy chain linked to the light chain via an inter-chain disulfide bond. Each Fab fragment is monovalent with respect to antigen binding, i.e., it has a single antigen-binding site. Pepsin treatment of an antibody yields a single large F(ab')2 fragment that roughly corresponds to two di sulfide-linked Fab fragments having divalent antigen-binding activity and is still capable of cross-linking antigen. Both the Fab and F(ab’)2 are examples of "antigen-binding fragments." Fab’ fragments differ from Fab fragments by having a few additional residues at the carboxy terminus of the CHI domain including one or more cysteines from the antibody hinge region. Fab'-SH is the designation herein for Fab' in which the cysteine residue(s) of the constant domains bear a free thiol group. F(ab’)2 antibody fragments are often produced as pairs of Fab’ fragments that have hinge cysteines between them. Other chemical couplings of antibody fragments are also known. Fab fragments may be joined, e.g., by a peptide linker, to farm a single chain Fab, also referred to herein as "scFab." In these embodiments, an inter-chain disulfide bond that is present in a native Fab may not be present, and the linker serves in full or in part to link or connect the Fab fragments in a single polypeptide chain. A heavy-chain derived Fab fragment (e.g., comprising, consisting of, or consisting essentially of VH + CHI, or "Fd") and a light chain-derived Fab fragment (e.g., comprising, consisting of or consisting essentially of VL + CL) may be linked in any arrangement to form a scFab. For example, a scFab may be arranged, in N-terminal to C-terminal direction, according to (heavy chain Fab fragmentlinker - light chain Fab fragment) or flight chain Fab fragment - linker - heavy chain Fab fragment). "Fv" is a small antibody fragment that contains a complete antigen-recognition and antigen-binding site. This fragment generally consists of a dimer of one heavy- and one light-chain variable region domain in tight, non-covaient association However, even a single variable domain (or half of an Fv comprising only three CDRs specific for an antigen) has the Nad. Acad. Sei. USA 83:8258 8262 (1986); U.S. Pat. No.4,935,233, and U.S. Pat. No. 4,751,180. Any suitable linker may be used, and in general can. be about 3, 4, 5, 6, 7, 8, 9, 10, 11., 12. 13. 14. 15, 16. 17. 18, 19. 20. 21, 22. 23. 24. 25. 26, 27. 28. 29, 30. 40. 50. 60. 70, 80, 90, 100 amino acids In length, or less than about 200 arnlno acids in length, and will preferably comprise a flexible structure (can provide flexibility and room for conformational movement between two regions, domains, motifs, fragments, or modules connected by the linker), and will preferably be biologically inert and / or have a low risk of immunogenicity in a human. Antibodies may be monospecific (e.g., binding to a single epitope) or multi specific (e.g., binding to multiple epitopes and / or target molecules). A bispecific or multispecific antibody or antigen-binding fragment may, in some embodiments, comprise one, two, or more antigen-binding domains (e.g., a VH and a VL). Two or more binding domains may be present that bind to the same or different epitopes, and a bispecific or multispecific antibody or antigen-binding fragment as provided herein can, in some embodiments, two or more binding domains, that bind to different antigens or pathogens altogether. Antibodies and antigen-binding fragments may be constructed in various formats. Exemplary antibody formats disclosed in Spiess et al., Moi. Immunol. 67(2):95 (2015), and in Brinkmann and Kontermann, mAbs 9(2)4 82-212 (2017), which formats and methods of making the same are incorporated herein by reference and include, for example, Bispecific I cell Engagers (BiTEs), DARTs, Knobs-Into-Holes (KIH) assemblies, scFv-CH3-KIH assemblies, KIH Common Light-Cham antibodies, TandAbs, Triple Bodies, Tri Bi Minibodies, Fab-sei - scFv-CH-CL-scFv, F(ab!)2-scFv2, tetravalent HCabs, Intrabodies, CrossMabs, Dual Action Fabs (DAFs) (two-in-one or four-in-one), DutaMabs, DT-IgG, Charge Pairs, Fab-arm Exchange, SEEDbodies, Triomabs, LUZ-Y assemblies, Fcabs, kX-bodies, orthogonal Fabs, DVD-Igs (e.g., US Patent No. 8,258,268, which formats are incorporated herein by reference in their entirety), IgG(H)-scFv, scFv-(H)IgG, IgGt L nscF' scFv-(L)IgG, IgG(L,H)-Fv, IgG(H)-V, V(H)-IgG, IgG(L)-V, V(L)-IgG, KIH IgG-scFab, 2scFv-IgG, lgG-2scFv, scFv4-lg, Zybody, and DVI-IgG (fbur-in-one), as well as so-called FIT-Ig (e.g., PCT 5 Publication No. WO 2015 / 103072, which formats are incorporated herein by reference in their entirety), so-called WuxiBody formats (e.g., PCT Publication No. WO 2019 / 057122, which formats are incorporated herein by reference in their entirety), and so- called feddbow-Insert Ig formats (lEi-Ig, e.g., PCT Publication Nos. WO 2019 / 024979 and WO 2019 / 025391, which formats are incorporated herein by reference in their entirety ). An antibody or antigen-binding fragment may comprise two or more VH domains, two or more VL domains, or both fte, two or more VH domains and two or more VL domains). In particular embodiments, an antigen-binding fragment comprises the format (N-terminal to C-terminal direction) VH-linker-VL-linker-VE3-linker-VL, wherein the two VH sequences can be the same or different and the two VL sequences can be the same or different. Such linked scFvs can include any combination of VH and VL domains arranged to bind to a given target, and in formats comprising two or more VH and / or two or more VL, one, two, or more different epitopes or antigens may be bound. It will be appreciated that formats incorporating multiple antigen-binding domains may include VH and / or VL sequences in any combination or orientation. For example, the antigen-binding fragment can comprise the format VL-iinker-VH-imker-VL-iinker-VH, VH-iinker~VL-hnker-VL-Hnker-VH, or VL-linker-VH-Iinker-VHdinker-VL. As used herein, the modifier "monoclonal" indicates the character of the antibody as being obtained from a substantially homogenous population of antibodies, and is not intended to be limited as regards the source of the antibody or the manner in which it is made (e.g., by hybridoma, phage selection, recombinant expression, transgenic animals, etc.). The term "monoclonal antibody" encompasses not only intact monoclonal antibodies and full-length monoclonal antibodies, but also fragments thereof (such as Fab, Fab', F(ab')2, Fv), single chain (ScFv), variants thereof, fusion proteins comprising an antigen-binding portion, humanized monoclonal antibodies, chimeric monoclonal antibodies, and any other modified configuration of the immunoglobulin molecule that comprises an antigen-binding fragment (epitope recognition site) of the required specificity and the ability to bind to an epitope. Monoclonal antibodies can be obtained using any technique that provides for the production of antibody molecules by continuous cell fines in culture, such as the hybridoma method described by Kohler, G., et al., Nature 256:495, 1975, or they may be made by recombinant DNA methods (see, e.g., U.S. Patent No. 4,816,567 to Cabiliy). Monoclonal antibodies may also be isolated from phage antibody libraries using the techniques described in Clackson, T., et al., Nature 352:624 628, 1991, and Marks, J.D., et ah, J. Mol. Biol. 222:581 597, 1991. Such antibodies can be of any immunoglobulin class including IgG, IgM, IgE, IgA, IgD and any subclass thereof. 1'250() / M428 ? .< M252V / S254T / 12561-¼ 1343 3 K / IS434F. M4281.. / IS434S would leave the complement classical path way intact to handle immune complex processing and to aid in. host defense against infection. One component of the complement system that is a possible target in the development of therapeutic agents to specifically inhibit the lectin pathway is MASP-2. Of all the known protein components of the lectin -dependent complement system (such as MBL, H ficolin, M ficolin, L fi colin, collecting, MASP-1, MASP-2, C4 and C2), only MASP-1 and MASP-2 are both unique to the lectin pathway and required for the system to function. The lectins (such as MBL, H ficolin, M ffeoiin, L ficoiin, collectin-10, and conectin-11) are also unique components in the lectin pathway. However, loss of any one of the lectin components would not necessarily inhibit activation of the system due to lectin redundancy. It would be necessary to inhibit all the lectins in order to guarantee inhibition of the lectin dependent complement activation system. Furthermore, since MBL and the ficolins are also known to have opsonic activity independent of complement, inhibition of lectin pathway function would result in the loss of this beneficial host defense mechanism against infection. In contrast, complement-independent opsonic activity remains intact when MASP-2 is the inhibitory target. An added benefit of MASP-2 as the therapeutic target to inhibit the lectin pathway is that the plasma concentration of MASP-2 is among the lowest of any complement protein fe 500 ng / ml); therefore, correspondingly low concentrations of high affinity inhibitors of MASP-2 may be sufficient to obtain full inhibition (Moller Kristensen, M , et al, J. Immunol Methods 282:159 167, 2003). This is in marked contrast to MASP-1, which has a plasma concentration, of - 10,000 ng / mL, and therefore substantially higher concentrations of high affinity inhibitors of MASP-1 are expected to be necessary to obtain full inhibition. HL. Antibodies and Antigen-Binding Fragments Provided herein are antibodies and antigen-binding fragments thereof that specifically bind to MASP-2. In some embodiments, the antibodies and antigen binding fragments thereof are isolated monoclonal antibodies or antigen-binding fragments thereof. In some embodiments, the antibodies and antigen-binding fragments thereof inhibit lectin pathway complement activation. The antibodies and antigen-binding fragments described herein may be human antibodies, humanized antibodies, chimeric antibodies, or murine antibodies, or an antigen-binding fragment of any of the foregoing. Additionally, the antibodies and antigen- at least 80%, 85%, 90%, 95%., 98%, 99% or 100% identical to SEQ ID NO:1 A summary of the sequences of the variable regions and CDRs for certain and-MASP-2 antibodies described herein is provided in TABLES 1 A, IB, and IC, below. C‘SIN” indicates SEQ ID NO.) TABLE 1A: Summary of MASP-2 antibody sequences Antibody Heavy chain variable region (a a) Light chain variable region (aa) Heavy chain variable region (DNA) Light chain variable region (DNA) OMS850 SIN: 7 SIN: 10 SIN: 69 SIN: 72 OMS852 SIN: 46 SIN: 47 SIN: 75 SIN: 76 0MS854 SIN: 48 SIN: 47 SIN: 77 SIN; 76 OMS856 SIN: 49 SIN: 47 SIN: 78 SIN; 76 OMS858 SIN: 50 SIN: 47 SIN: 79 SIN: 76 OMS860 SIN: 8 SIN: 11 SIN: 70 SIN: 73 OMS870 SIN; 9 SIN: 12 SIN: 71 SIN: 74 TABLE IB: Summary of MASP-2 high affinity inhibitory antibody sequences with CDRs Antibody Heavy chain variable region (aa) Light chain variable region (aa) Heavy chain CDR1; CDR2; CDR3 Light chain CDR1; CDR2; CDR3 OMS850 SIN; 7 SIN: 10 14., 16, 18 32, 34, 36 OMS860 SIN; 8 SIN: 11 14,22,18 39.. 34, 36 OMS870 SIN 9 SIN 12 25, 27, 29 41,43,45 TABLE IC: Summary of MASP-2 antibody OMS850 with humanized and modified versions Antibody Heavy chain variable region (aa) Light chain variable region (aa) Heavy chain CDR1; CDR2; CDR3 .Light chain CDR1; CDR2; CDR3 OMS850 SIN: 7 SIN: 10 14, 16, 18 32, 34, 36 OMS852 SIN: 46 SIN: 47 14, 16, 18 32, 34, 36 OMS854 SIN: 48 SIN: 47 14, 53,18 32, 34, 36 OMS856 SIN: 49 SIN: 47 56, 53, 18 32, 34, 36 OMS858 SIN: 50 SIN: 47 57, 53, 18 32, 34, 36 In certain embodiments, the antibodies and antigen-binding fragments described herein comprise one or more mutations in the Fc region. For example, the Fc region may comprise one or more mutations that enhance stability or effector function. In some embodiments, the Fc region comprises an S228P amino acid substitution. In some embodiments, the Fc region comprises one or more mutations that promote FcRn interactions at low pH. In some embodiments, the antibodies and antigen-binding fragments described herein bind to the serine protease domain of human M ASP-2 with an affinity of less than 0.2 nM, less than 0.3 nM, fess than 0.4 nM, less than 0.5 nM, fess than 0 6 nM, less than 0.7 nM, less than 0.8 nM, less than 0.9 nM, less than 1.0 nM, less than 1.2 nM, less than 1.4 nM, less than 1.6 nM, less than 1.8 nM, less than 2.0 nM, fess than 2.5 nM, less than 3.0 nM, fess than 3.5 nM, fess than 4.0 nM, less than 4.5 nM, less than 5.0 nM, less than 5.5 nM, less than 6.0 nM, less than 6.5 nM, fess than 7.0 nM, less than 7.5 nM, fess than 8.0 nM, less than 8.5 nM, less than 9.0 nM, less than 9.5 nM, less than 10.0 nM, fess than 12 nM, fess than 14 nM, less than 16 nM, less than 18 nM, less than 20 nM, less than 22 nM, less than 24 nM, fess than 26 nM, fess than 28 nM, or less than 30 nM. In some embodiments, the antibodies and antigen-binding fragments described herein inhibit the lectin pathway of complement activation. In some embodiments, the antibodies and antigen-binding fragments inhibit the lectin pathway in mammalian blood. In some embodiments, the lectin pathway inhibition comprises a decrease in deposition of complement components on target cells. In some embodiments, the lectin pathway inhibition comprises a decrease in C3b deposition, C4 deposition, or MAC deposition In some embodiments, the lectin pathway inhibition comprises a decrease in deposition of complement components under lectin pathway-specific assay conditions. In some embodiments, the antibodies and antigen-binding fragments described herein inhibit the producing the provided antibodies and antigen-binding fragments thereof, which methods comprise culturing a host cell for a sufficient time under conditions allowing for expression of the antibodies or antigen-binding fragments thereof and isolating the antibodies or antigenbinding fragments thereof. Methods userid for isolating and purifying recombinantly produced proteins include, for example, obtaining supernatant from suitable host cells that secrete the proteins into culture medium, concentrating the medium, and purifying the protein by passing the concentrate through a suitable purification matrix or series of matrices. Methods for purification of proteins are well known in the art. V. Pharmaceutical Compositions Also provided herein are compositions that comprise a therapeutic agent selected from any one or more of the presently disclosed antibodies or antigen-binding fragments thereof, polynucleotides, vectors, or host cells, singly or in any combination, and may also include other selected therapeutic agents. Such compositions may further comprise one or more pharmaceutically acceptable carriers, excipients, or diluents. A pharmaceutically acceptable carrier is non-toxic, biocompatible and is selected so as not to detrimentally affect the biological activity of the therapeutic agent (and any other therapeutic agents combined therewith). Examples of pharmaceutically acceptable carriers for peptides are described in U.S. Patent No. 5,211,657 to Yamada. The therapeutic agents described herein may be formulated into preparations in solid, semi solid, gel, liquid or gaseous forms such as tablets, capsules, powders, granules, ointments, solutions, depositories, inhalants and injections allowing for oral, parenteral, or surgical administration. Local administration of the compositions by coating medical devices and the like is also contemplated Suitable carriers for parenteral delivery via injectable, infusion or irrigation and topical delivery include distilled water, physiological phosphate buffered saline, normal or lactated Ringer's solutions, dextrose solution, Hank's solution, or propanediol. In addition, sterile, fixed oils may be employed as a solvent or suspending medium. For this purpose, any biocompatible oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of imectables. The carrier and agent US2018 / 0105604, WO2018 / 045054, WO2018 / 071701, WO2019 / 036460, WO2019 / 246,367, not limited to diabetic angiopathy, diabetic neuropathy, diabetic retinopathy or diabetic macular edema. In some embodiments, the lectin-pathway disease or disorder is a cardiovascular disease or disorder, including but not limited to, Henoch-Schonlein purpura nephritis, systemic lupus erythematosus-associated vasculitis, vasculitis associated with rheumatoid arthritis (also called malignant rheumatoid arthritis), immune complex vasculitis, antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis, Takayasu's disease, dilated cardiomyopathy, diabetic angiopathy, Kawasaki's disease (arteritis), venous gas embolus (VGE), and inhibition of restenosis following stent placement, rotational atherectomy and / or percutaneous transluminal coronary angioplasty (PTCA). In some embodiments, the lectin-pathway disease or disorder is an inflammatory gastrointestinal disorder, including but not limited to, pancreatitis, diverticulitis and bowel disorders including Crohn's disease, ulcerative colitis, irritable bowel syndrome and inflammatory bowel disease (IBD). In some embodiments, the I ectin-pathway disease or disorder is caused or exacerbated by fibrosis of the digestive tract. In some embodiments, the lectin-pathway disease or disorder is pancreatic fibrosis. In some embodiments, the lectin-pathway disease or disorder is a pulmonary disorder, including but not limited to, acute respiratory distress syndrome, transfusion-related acute lung injury, ischemia / reperfusion acute lung injury, chronic obstructive pulmonary disease, asthma, Wegener’s granulomatosis, anti glomerular basement membrane disease (Goodpasture's disease), meconium aspiration syndrome, aspiration pneumonia, bronchiolitis obliterans syndrome, idiopathic pulmonary fibrosis, acute lung injury secondary to burn, non-cardiogenic pulmonary edema, transfusion-related respiratory depression and emphysema. In some embodiments, the lectin-pathway disease or disorder is an extracorporeal exposure-triggered inflammatory reaction and the method comprises treating a subject undergoing an extracorporeal circulation procedure including, but not limited to, hemodialysis, plasmapheresis, leukopheresis, extracorporeal membrane oxygenation ri A MO} heparin-induced extracorporeal membrane oxygenation I tin . precipitation (HELP) and cardiopulmonary bypass (CPB), In some embodiments, the lectin-pathwav disease or disorder is an angiogenesis WO 2023 / 108028 PCT / US2022 / 081121 CoV-2 infection is an acute infection. In alternative embodiments, the SARS-CoV-2 infection is a chronic infection. In certain embodiments, the lectin-pathway disease or disorder is an ongoing chronic condition caused by a past SARS-CoV-2 infection. In some embodiments, the lectin-pathway disease or disorder is acute respiratory distress syndrome. In some embodiments, the lectin pathway disease or disorder is secondary to SARS-CoV-2 infection. In some embodiments, the antibodies or antigen-binding fragments thereof disclosed herein block binding of MASP-2 to SARS-CoV-2 S protein and / or N protein. Select examples of lectin-pathway diseases and disorders are described in additional detail below. Atypical hemolytic uremic syndrome (aHUS). Atypical hemolytic uremic syndrome (aHUS) is part of a group of conditions termed "thrombotic microangiopathies." In the atypical form of HUS (aHUS), the disease is associated with defective complement regulation and can be either sporadic or familial. Familial cases of aHUS are associated with mutations in genes coding for complement activation or complement regulatory proteins, including complement factor H, factor I, factor B, membrane-cofactor protein inhibitor (CD46) as well as complement factor H-related protein 1 (CFHR1) and complement factor H-related protein 3 (CFHR3). (Zipfel, P.F., et al., PloS Genetics 3(3):e41 (2007)). The unifying feature of this diverse array of genetic mutations associated with aHUS is a predisposition to enhanced complement activation on cellular or tissue surfaces. A subject is a risk for developing aHUS upon the onset of at least one or more symptoms indicative of aHUS (e.g., the presence of anemia, thrombocytopenia and / or renal insufficiency) and / or the presence of thrombotic microangiopathy in a biopsy obtained from the subject. The determination of whether a subject is at risk for developing aHUS comprises determining whether the subject has a genetic predisposition to developing aHUS, which may be carried out by assessing genetic information (e.g. from a database containing the genotype of the subject), or performing at least one genetic screening test on the subject to determine the presence or absence of a genetic marker associated with aHUS (i.e., determining the presence or absence of a genetic mutation associated with aHUS in the genes encoding complement factor H (CFH), factor I (CFI), factor B (CFB), membrane cofactor protein inhibitor(CI)46), C3, complement factor H-related protein 1 (CFHR1), or THBD (encoding the anticoagulant protein thrombomodulin) or complement factor H-related protein 3 (CFHR3), or complement factor H-related protein 4 (CFHR4)) either via genome Lupus Nephritis (LN) A main complication of systemic lupus erythematosus (SLE) is nephritis, also known as lupus nephritis, which is classified as a secondary form of glomerulonephritis. Up to 60% of adults with SLE have some form of kidney involvement later in the course of the disease (Koda-Kimble et ah, Koda-Kimble and Young's Applied Therapeutics: the clinical use of drugs, 10th Ed, Lippincott Williams & Wilkins: pages 792--9, 2012) with a prevalence of 2070 per 100,000 people in the US. Lupus nephritis often presents in patients with other symptoms of active SLE, including fatigue, fever, rash, arthritis, serositis, or central nervous system disease (Pisetsky D.S. et al., Med Clin North Am 81(1): 113-28, 1997). Some patients have asymptomatic lupus nephritis; however, during regular follow-up, laboratory abnormalities such as elevated serum creatinine levels, low albumin levels, or urinary protein or sediment suggest, active lupus nephritis. VL Sequences The sequences referred to within the present specification are summarized in TABLE TABLE 2 SEQ ID ML Description Sequence 1 Human MASP-2 MRLUrLLGLLCGSVATPLGPKWPEPVFGRLASPG FPGEYANDQERRWTLTAPPGYRLRLYFTHFDLEL SHLCEYDFVKLSSGAKVLATLCGQESTDTERAPG KDTF ¥ S LG S SL DIFF RSD YSNEKPFTGFE AF Y A AE DIDECQVAPGEAPTCDHHCHNffl.GGFYCSCRAG YVLHRNKRTCSALCSGQVFTQRSGELSSPEYPRP YPKLSSCTYSISLEEGFSVILDFVESFDVETHPETL CPYDFLKlQTDREEHGPFCGKTLPHRiETKSNTVU TFVTDESGDHTGWKIHYTSTAQPCPYPMAPPNGH VSPVQAKYILKDSFSIFCETGYELLQGHLPLKSFT AVCQKDGSWDRPMPACSIVDCGPPDDLPSGRYE YriXJPGVlTYIGAVIQYSCEElTYlAfKVNDGKYVC EADGFWTSSKGEKSLPVCEPVCGLSARTTGGRIY GGQKAKPGDF PWQ VLILGGTTAAG AL JL YDNW VL TAAHAVYEQKHDASALDIRMGTLKRLSPHYTQA WSEAVFniEGYTHDAGFDNDIALIKLNNKVVIYS NITPICLPRKEAESFMRTDDIGTASGWGLTQRGFL ARNLMYVDIPIVDHQKCTAAYEKPPYPRGSVTAN MLCAGLESGGKDSCRGDSGGALVFLDSETERWF VGGIVSWGSMNCGEAGQYGVYTKYYNYIPWIENI GDI 7 Mouse MASP-2 MRLLIFLGLLWSLVATLLGSKWPEPVFGRLVSPG FPEKYADHQDRSWTLIAPPGYREREYFTHFDEEL SYRCEYDFVKLSSGIXVLATLCGQESTDTEQAPG NOTFYSLGPSLKVTFHSDYSNEKPFTGFEAFYAAE DVDECRVSLGDSVPCDHYCHNYLGGYYCSCRAG-YVLHQNKHTCSALCSGQVFTGRSGYLSSPEYPQP YPKESSCTYSIREEDGFSVIEDFYTSFDVTYHPEAQ CPYDSLK1QTDKGEHGPFCGKTLPPRIETDSHKVTI TFATDESGNHTGWKIFIYTSTARPCPDPTAPPNGSI SPVQAIYVLKDRFSVFCKTGFELLQGSVPL VCQKDGSWDRPWECSI[DCGPPDDLPNGHVDYI TGPEVTTYKAVIQYSCEETFYTMSSNGKYVCEAD GFWTSSKGEKLPPVCEPVCGLSTHTIGGRIVGGQP AKPGIWWQVLLLGQTTAAAGAIJHDNWVLTAA HAVYEKRMAAS SLNIRMGILKRL SPHYTQ AWPEE IFIHIiGYTHGAG:FDNDIALIKL,KNKV'nNGSIMPV<' LPRKEAASLMRTDFTGTVAGWGLTQKGLLARNL MFVDIPIADHQKCTAWEKEYPGVRVSANMLCA GLETGGKDSCRGDSGGALVFLDNETQRWFVGGI VSWGSFNCGAADQYGWTKVINYIPWIENIISNF 3 Rat MASP-2 MRLLIV’LGLLWSLVATLLGSKWPEPVFGRLVSPG FP EK YGNHQDR S W TEI APPGF RI ,RL YF THFNL ,EL SYRCEYDFVKLTSGTKVLATLCGQESTDTERAPG NDl'FYS:L,GPSLK\rl'FEISDYSNEKPFl'GFEAFYAAE; DVDECRTSLGDSVPCDHYCHNYLGGYYCSCRVG YH.,HQNKHrrCSAI,CSGQVFTGRSGFLSSPEYP{)PY [FkLSSCAYNIR^^                        I ! 1.1'* A 14 Sl-.K-10I OXXl-A Xj’Pi'11. C.xX I1.- Pl'*      114 S N .0 V 11 i ! TRTTrH'SGNHTGWKTHYTST AOPCTIYPT APPNXIW' s | SPVQATYVLKDSFSVFCKTGFELLQGSVPLKSFTA | | VCOKriGSWDRPlPECSnDCGPPDDI .PNGHVDYIT 1 GPEVTTYKAVIQYSCEETFYTMSSNGKYVCEADG ! P w 1S* S4SA.3.E1V.Si—1' \ C-iAPA 0i.5i„■ S1 Pi 1 Si4 ^.iix^llxjGsP^i*s I KPGDFPWQVI.-LLGETTAAGALIEtDDWVLTAA.HA. | | VYGKTEAMSSLDIRMGILKRLSPHYTQ.AWPEAVF | IHEGYTHGAGFDNDIALIKLKNKVTINRNIMPICLP | | rkeaaslmktdfvgtvagwgltqkgflarnlm 1 1 F VOIP l VDHOKC AT 4 YTKOP YPG AK VT VNMI -C 4 1 GLDAGGKDSCRGDSGGALVFLDNETQRWFVGGI | | VSWGS1NCGGSEQYGVYTKVTNYIPWLEX11XNF | ! 4 t-vnonioimis nx | MRLLTLLGLLCGSVATPLGPKWPEPVFGRLASPG | MASP-2 !              'X'                                                  vX' 1^1        "S'F                          ; SHLCEYDFVKLSSG.AKVLATLCGHESTDTERAPG I NDTFYSLGSSLDITFRSDYSNEKPFTGFEAFYAAE | 1 D.LDECQV APGEAiY\CDHHCHNHLGGFYCSCRVG 1 1 YJLHRNJOtTCSALCSGQVFTQRSGELSSPEYPOPY 1 1 PKLSSC TYSIRL-EEGFSVILDFVESFDVETHPETLCP 1 | VTDE SGD H TGWKIH Y T S TAQPCPY7PMAPPNGHLS | PVQAKYILKDSFSIFCEPGYELLQGHLPLKSFAAV | CQKDGSWDQPMPSCSR''DCGPPDDLPSGRVEYIT 1 | GPEVTTYKAVIQYSCEETFYTMKVNDGKYVCEA | ! DGFW 1S S K GE RSPPVC E. PV C GLS ARTFGGR1Y GG 1 QKAKPGDFPWQVLILGGSTAAGALLYDNWVLTA | AR Al Y EQKHLJASSLDIRLGALKRESPHY TQAW AE 1 ’ AV FlFl EG’ Y 1H D AGP ON O A LJ Xl .-NN R V V N S Nl 1 Pi CLPRKEAESFMRTDDIGTASGWGLTQRGLLARNL | MYVD1P.IVDRQKC1 AAYEKPPYSGGSVTANMLC | 30 OMS870 VH FR4 WGQGTSVTVSS 31 OMS850 VL FR1 QWLTQSPVIMSASPGEKVTMTC 32 OMS850 VL CDR1 SASSSVRYMY 33 OMS850 / 860 VL FR2 WYQQKPGSSPRLLIY 34 OMS850 / 860 VL CDR2 DTSNLAS 35 OMS850 / 860 VL FR3 GVPVRFSGSGSGTSNSLTISRMEAEDAATYYC 36 OMS850 / 860 VL CDR3 QQWSSYPLT 37 OMS850 / 860 / 870 VI. FR4 FGAGTKLELKR 38 OMS860 VL FR1 QIVLTQSPVIMSASPGEKVTITC 39 OMS860 VL CDR1 SASSSVSYMY 40 OMS870 VL FR1 D1VLTQSPASLAVSLGQRATISC 41 OMS870 VL CDR1 RASESVDSYGNSFMH 42 OMS870 VL FR2 W YQQKPGQAPKLL1Y 43 OMS870 VL CDR1 FASNL.ES 44 OMS870 VI. FR3 GVPARFSGSGSRrrDFH'.'nDPVEAI>DAATYF(j 45 OMS870 VL CDR3 OQSWDPLT 46 OMS852 VH QVQLVQSGAEVKKPGASVKVSCKASGYTFTNYW MHWLRQAPGQGLEW1GD1DPSDSETHYIEKFKDR ATI. TI DR S S STAYMELS S L.RSEDTA V YYC ARGDIT ri'LRYFDVWGQGrLVrVSS 47 OMS852 / 854 / 856 / 858 VL DIQLTQSPSSLSASVGDRVTn'CSASSSVRYM QQKPGKAPKLLIYDTSNLASGVPSRFSGSGSGTDN rrL.HSSLQPEDFAl'YYCQQWSSYPi;rFGQGTKVEI KR 48 OMS854 VH QVQLVQSGAEVKKPGASVKVSCKASGYTFTNYW MHWLRQAPGQGLEWIGDIDASDSETHVGEKFKDR ATLT1DKSSSTAYMELSSLRSEDTAVYY TTLRYFDVWGQGTLVTVSS 49 OMS856 VH QVQLVQSGAEVKKPGASVKVSCKASGYTFTNYH MHWLRQAPGQGLEW1GD1DASDSETHYIEKFKDR ATI. TI DR S S STAYMELS S LRSEDTAV YYC ARGDIT TTLRYFDVWGQGTLVTVSS 50 OMS858 VH QVQLVQSGAEVKKPGASVKVSCKASGYTFTNHH MHWLRQAPGQGLEWKHHDASDSETHYn / KFKDR ATLTIDKSSSTAYMELSSLRSEDTAVYYCARGDIT TTLRYFDVWGQGTLVTVSS 51 OMS852 / 854 / 856 / 858 VH FR1 QVQLVQSGAEVKKPGA S VKVSCKASGYTFT 52 OMS852 VH FR2 WLRQAPGQGLEWIG 53 OMS854 / 856 / 858 VH CDR2 D1DASDSETHYIEKFKD 5-4 OMS852 / 854 / 856 / 858 VH FR3 RATLTIDKSSSTAYMELSSLRSEDTAVYYCAR 55 OMS852 / 854 / 856 / 858 VH FR4 WGQGTLVTVSS 56 OMS856 VH CDR1 NYHMH 57 OMS858 VH CDR1 NHHMH 58 OMS852 VL FR1 DIQETQSPSSLSASVGDRVTITC 59 OMS852 VL FR2 WYQQKPGKAPKLLIY 60 OMS852 VL H<3 GVPSRFSGSGSGTDNTLTISSLQPEDFATYYC 61 OMS852 VL FR4 FGQGTKVEIKR 62 Not used 63 VH CDR2 consensus sequence for OMS850 / 852 / 854 / 856 / 858 / 860 DIDXSDSEXXYXXKFKD wherein X a.t position 4 is P or A; X at position 9 is T or I; X at position 10 is H or Y, X at position 12 is I or N; and X at position 13 is E or Q 64 VL CDR1 consensus sequence for OMS850 / 852 / 854 / 856 / 858 / 860 SASSSVXYMY wherein X at position 7 is R or S 65 human GG4 heavy chain constant region ASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPE PVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVV TVPSS$I-.GTKTYTCNVDHKPSHTKVDKRVESKYG PPCPSCPAPEFLGGPSVFLFPPKPKDTLMISRTPEV rCVVVDVSQEDPEVQFNWYVDGVEVHNAKrKl> REEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVS NKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMT KNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT TPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLGK 66 human IgG4 heavy chain constant region with stabilizing S228P mutation ASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPE PVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVV TVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYG PPCPPCPAPEFL.GGPSVFUPPKPKDTLMISR.TPEV TCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKP REEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVS NKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMT KNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT TPPVLDSDGSFFLYSRLTVTSKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLGK 67 human IgG4 heavy chain constant region with stabilizing S228P mutation and low pH FcRn interaction enhancing mutations ASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPE PVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVV TVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYG PPCPPCPAPEFLXjGPSVFUPPKPKDTI.MISR.TPEV TCVVVDVSQEDPEVQFNWYVL)GVEVHNAKTKP REEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVS NKGL,PSSIEK'nSKAKGQPREP()VYTi,PPSQEEMT KNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKT TPPVLDSDGSFFLYSRLTVTJKSRWQEGNVFSCSV LHEALHSHYTQKSLSLSLGK 68 human kappa light chain constant region TVAAPSVWPPSDEQLKSGTASVVCLLNNFYPRE AKVQWKVDNALQSGNSQESVTEQDSKDSTYSLS SIXTLSKADYEKHKVYACEVTEKX^SSPVTKSFN RGEC 69 DNA encoding OMS850 VH (mouse parental) CAGGTCCAACTGCAGCAGCCTGGGGCTGAGCT ggtgagg<:ctgckhx:ttcagtgaggctgtcctg CAAGGCTTCTGGCTACACCTTCACCAACTACTG G ATGC ATTGGTTG A AGC AG AGGCCTA'F AC AAG 1 AC A TGC A C TGGC TGC GC C A GGC GCC (J GGC C A G s 1 UG AC 1GU AU 1 GUA 1L GUGU A1A1 GG AG GC G 1G ; ! GGACTCCGAAACTCAIT 'ACATTGAGAAGTTCAA | 1 GGACAGGGCC ACCCTC ACC ATCGAT A AGAGCT 1 ! CC1 CGACL-UCC 1 AGA 1 GGAAC 1 GIGGAGCC 1 GA 1 1 GA 1 IAGAGGA'1 AC7 GC7 GIGI AC 1AG1 G'l GCGC i 1 GGTKjCGACA1 '1 ACAACGACCC1 G’CUG’YAU 1 '1CG’ ; 1 ACGTCTGCK^GAC AGGGC' ACCCTTGTG ACCGTGT 1 ! G-U1UU                                                       i 5 7Q DNA encoding OMI >8 I CAAC1TCC AACTCGTCCAGTCCGGAGCAGAAGT | VH | CAAGAAGCCGGGAGCCAGCGTGAAAGTG'l'CGT 1 1 GCAAAGCCTCCGGTTAC AU IT 1 'CA.CCAACUATC 1 ! ACATGCACTGGCTGCGCCAGGCGCCCGGCCAG- i I GGACTGGAGTGGATCGGGGA1 'ATCGACGCCTC | ! (KjAC- 1 LLGAAACTUA1 1 ACAYKjAGAAGflGAA 1 GGACAGGGCCACCCTCACCATCGATAAGAGCT 1 LL / A.GACCGCC1 ACATGGAACTG1 CCAGCC-'IUA ; ; KJ / 'Y G-                    ATtky C       J C? -*L G? A       J.      A C?                 ; ! (KKKaGG’AUAl .GXCAACGALL-GTGCGG1AG11 L-G i 1 ACGIXJlXJGGGACAGGGCACCCITGIXiACCGTGT s Example 2 and characterization of recombinant xioiibodies ID NO:67) which contains the S228P amino acid substitution and also contains certain mutations that promote FcRn interactions at low pH. It was determined that 26 clones were unique chimeric monoclonal antibodies. These chimeric monoclonal antibodies were expressed in transiently transfected Expi293F cells, purified and tested for binding affinity to human MASP-2 and for the ability to inhibit MASP-2-mediated lectin pathway activation. To measure binding of the 26 purified recombinant MASP-2 antibodies to human MASP-2 (CCPI -CCP2-SP fragment), a solid phase ELISA assay was carried out as follows. A MaxiSorp ELISA plate was coated with human MASP-2 (CCP1 / 2 / SP fragment) at 1.0 pg / mL in carbonate / bi-carbonate buffer overnight at 4°C. The plate was subsequently blocked with 1% BSA / PBS, washed in PBS and then incubated for one hour at room temperature with serial dilutions of recombinant MASP-2 mAbs in blocking buffer (PBST + 0.1% BSA). The plate was washed (PBS-T, 0.05%) and a detection antibody was added (goat anti-human IgG-HRP) for one hour at room temperature. After another wash (PBS-T, 0.05%) the plate was developed (5 minutes) with OPT EIA TMB (BD Biosciences #555214). Absorbance reading at A450 was measured using the Spectramax M5e plate reader. Of the 26 chimeric mAbs, 22 were found to have good binding to human MASP-2 (apparent Kd range of 0.1 nM to 1 nM). Four of the 26 chimeric mAbs were found to have weak / negligible binding to human MASP-2. To measure the ability of the 26 purified recombinant MASP-2 antibodies to block the lectin pathway of complement activation, a C3 deposition assay was carried out as follows. Mannan was diluted to a concentration of 50 pg / ml in 50 mM carbonate buffer (15 mM NagCOa + 35 mM NaHCOg + 1.5 mMNaNa), pH 9.6 and coated on an ELISA plate overnight at 4°C. The next day, 250 pl of 1% BSA in PBS was added to the wells and incubated for 2 hours a.t room temperature. The plates were washed 3X with 300 pl PBS containing 0.05% Tween-20 and stored on ice with 200 rd PBS until addition of the samples. Normal human serum was diluted to 1.0% in GVB / Ca / Mg buffer, and the 26 purified MASP-2 mAbs were added in a concentration range from 0.00001 to 100 nM to this buffer and preincubated 10 minutes on ice before addition to the blocked ELISA plate The complement activation reaction was initiated by transferring the preincubation mixtures into the wells of the mannan coated assay plate. Following incubation for 40 minutes at room temperature, the reaction was stopped by washing the plates thrice in ELISA wash buffer. C3b deposition was detected with an anti-hum an C3c antibody (Dako) followed by Goat a-Rabblt HRP (Southern Biotech). The negative control was buffer without serum (no C3 deposition), and the positive control was serum with no inhibitory antibody (Maximum C3b deposition). A cut-off criterion was set at haff of the activity of an irrelevant mAb and buffer alone. Of the 26 unique chimeric mAbs identified in the screen, it was determined that the three clones with the highest inhibitory LP activity in the C3b deposition assay were OMS850, OMS860 and OMS870. These three antibodies were selected for further characterization as described below. The sequences of the heavy chain variable regions and light chain variable regions of clones OMS850, OMS860 and OMS870 are shown in FIGURE 3 (“SIN” = “SEQ ID NO:” in FIGURE 3) and are included below. The complementarity determining regions (CDRs) and framework regions (FRs) of each are provided in TABLES 1 A, IB, and IC (above) and TABLES 3-6 (below). Presented below is the heavy chain variable region (VH) sequence for each high affinity MASP-2 inhibitory antibody. The Kabat CDRs are underimed. Ifey. OMS850 VH: SEQ ID NO:7 (mouse parental) OVOLOOPGAlff..¥RPGSSVRLSCKASGYTFT¥¥WMgWLK()RPIOGLEWKlDn)PSI)S ETHYIEKFKDKATLTIDKSSSTAYMHLSSLTSEDSAIYYCARGpiTTTLRVFpVWGT GTTVTVSS QMS860 VF1. SEQJD NO:8 (mouse..parental} QVQLQQPGAELVRPGSSVKLSCKASGYTEI'NYWMHWVRQRPIQGLEWIGMDFSDS EiYYNQKFKPKATI. / rVDKSSSTAYMI-ILSSI.;rSEDSAVYYCARGI)rri;TLRYFpyW GTGTTVTVSS EVQLOQPGTELVKPGASVKLSCKASGYTFTSWMHWVKORPGOGLEWIGNINPSN ggt^cnekfknk a tmt vdk s s st a yvol s sue sed s a v y yc ar waydampywg QGTSVTVSS TABLE 3: MASP-2 Antibody VH Sequences (CDRs and FR regions, Kabai) mouse parental Antibody VH FR1 VH CDR1 OMS850 QVQLQQPGAELVRPGSSVRLSCKASGYTFT (SIN 13) NYWMH (SIN 14) OMS860 QVQLQQPGAELVRPGSSVKLSCKASGYTFT (SIN 20) NYWMH (SIN 14) OMS870 EVQLQQPGTELVKPGASVKESCKASGYTFT (SIN 24) SYWMH (SIN 25) Antibody VH FR2 VH C»R2 OMS850 WLKQRPIQGLEWIG (SIN 15) DIDP SD SETH YIEKFKD (SIN 16) OMS860 WVRQRPIQGLEWIG (SIN 21) DIDPSDSEIYYNQKFKD (SIN 22) OMS870 WVKQRPGQGLEWIG (SIN 26) N1NPSNGGTNCNEKFK N (SIN 27) Antibody VH FR3 VH CDR3 OMS850 KATLTIDKSSSTAYMHLSSLTSEDSA1YYCA R(SIN 17) GDITTTLRYFDV (SIN 18) OMS860 K ATLT VDK S S ST A YMHL S SET SED S A VY YC AR (SIN 23 ) GDH1TLRYFDV (SIN 18) OMS870 KA1MTVDKSSSTAYMQLSSLTSEDSAVYYC AR (SIN 28) W A YD AMD Y (SIN 29) Antibody VH FR4 OMS850 WGTGTTV1VVSS (SIN 19) OMS860 WGTGTTVTVSS (SIN 19) OMS870 WGQGTSVTVSS (SIN 30) Presented below are the light chain variable region (VL) sequences for the high affinity M ASP-2 inhibitory antibodies. The Kabat CDRs are underlined. These regions are the same whether numbered by the Kabat or Chothia system. Light Chain Variable Region s: OIVLT0SPVIMSASPGEK.VTMTCSASSSyR¥MYWY0QKPGSSPRLLIYDTSNLASGV PVRFSGSGSGTSNSLTISRMEAEDAATYYCQQ.WSSYPLTFGAGTKLELKR OMS860 VE: SEQ II^NOT 01VLT0SPVIMSASPGEKVTITCSASSSVSYMYWYO0KPGSSPRLLIYDTSNLASGVP VRFSGSGSGTSNSLTISRNIEAEDAATYYCQQWSSYPLTFGAGTKLELKR <>IS870VI^ DIVLTOSPASLAVSLGORATISCRASESVDSYGNSFMHWYOQKPGOAPKLLIYFASN LESGVPARFSGSGSRTDFTLTIDPVEADDAATYFCQOSNEpPLTFGAGTKLELKR TABLE 4: MASP-2 Antibody VL Sequences (CDRs and FR regions, Kabat) mouse parental Antibody VL FR1 VL CDR1 OMS850 QIVLTQSPVIMSASPGEKVTMTC (SIN 31) SASSSVRYMY (SIN 32) OMS860 QIVLTQSPVIMSASPGEKVTHC (SIN 38) SASSSVSYMY (SIN 39) OMS870 DIVLTQSPASLAVSLGQRATISC (SIN 40) RASESVDSYGNSFMH (SIN 41) Antibody VL FR2 VLCDR2 OMS850 WYQQKPGSSPRLLIY (SIN 33) DTSNLAS (SIN 34) OMS860 WYQQKPGSSPRLLIY (SIN 33) DTSNLAS (SIN 34) OMS870 WYQQKPGQAPKLLIY (SIN 42) FASNLES (SIN 43) Antibody VL FR3 VL CDR3 OMS850 GVPVRF'SGSGSGTSNSLTISRMEAEDAATYYC (SIN 35) QQWSSYPLT (SIN 36) OMS860 GVPVRFSGSGSGTSNSLTISRMEAEDAATYYC (SIN 35) QQWSSYPLT (SIN 36) OMS870 GVPARFSGSGSRTDFTLTIDPVEADDAATYFC (SIN 44) QQSNEDPLT (SIN 45) Antibody VL FR4 OMS850 FGAGTKLELKR (SIN 37) OMS860 FGAGTKLELKR (SIN 37) OMS870 FGAGTKLELKR (SIN 37) TABLE 5: Consensus Sequences for OMS850 and OMS860 VH CD Rs: Antibody Region Sequence OMS850 VH-CDR1 \ V W VH (SIN 14) OMS860 VH-CDR1 NYWMH (SIN 14) OMS852 VH-CDR1 NYWMH (SIN 14) OMS8S4 VH-CDR1 NYWMH (SIN 14) OMS856 VH-CDR1 N YHMH (SIN 56) OMS858 HC-CDR1 NHHMH (SIN 57) Consensus VH-CDR1 NXXMH Wherein X at position 2 is H or Y and Wherein X at position 3 is H or W OMS850 V1-LCDR2 DIDPSDSETHYIEKFKD (SIN 16) OMS860 V1-LCDR2 DIDPSDSEIYYNQKFKD (SIN 22) OMS852 V1-LCDR2 DIDPSDSETHYIEKFKD (SIN 16) OMS854 VH-CDR2 DIDASDSETHYIEKFKD (SIN 53) OMS856 VH-CDR2 DIDASDSETHYIEKFKD (SIN 53) OMS858 VH-CDR2 DIDASDSETHYIEKFKD (SIN 53) Consensus VH-CDR2 D1DXSDSEXXYXXKFKD (SIN 63), Wherein X at position 4 is P or A; Wherein X at position 9 is T or I; X at position 10 is H or Y, X at position 12 is I or N; and X at position 13 is E or Q OMS850 VH-CDR3 GD1HTLRYFDV (SIN 18) OMS860 VH-CDR3 GDITTTLRYFDV (SIN 18) OMS852 VH-CDR3 GDITTTLRYFDV (SIN 18) OMS854 VH-CDR3 GDITTTLRYFDV (SIN 18) OMS856 VH-CDR3 GDITTTLRYFDV (SIN 18) OMS858 VH-CDR3 GDITTH.RYFDV (SIN 18) Consensus VH-CDR3 GDITTTLRYFDV (SIN 18) TABLE 6: Consensus Sequences for OMS850 and OMS860 VL CDRs: Antibody Region Sequence OMS850 VL-CDRi SASSSVRYMY (SIN 32) OMS860 VL-CDRi SASSSVSYMY (SIN 39) OMS852 VL-CDRi SASSSVRYMY (SIN 32) Consensus VL-CDR1 SASSSVXYMY, (SIN 64) Wherein X at position 7 is R or S OMS850 VL-CDR2 DTSNLAS (SIN 34) OMS860 VL-CDR2 DTSNLAS (SIN 34) OMS852 VL-CDR2 DTSNLAS (SIN 34) Consensus VL-CDR2 DTSNLAS (SIN 3-4) OMS850 VL-CDR3 QQWSSYPLT (SIN 36) OMS860 VL-CDR3 QQWSSYPLT (SIN 36) OMS852 VL-CDR3 QQWSSYPLT (SIN 36) Consensus VL-CBR3 QQWSSYPLT (SIN 36} Examnie 3 Further Characterization of the candidate MASP-2 inhibitory antibodies I. Binding to recombinant human MASP-2 A solid phase ELISA assay was carried out to measure binding of the three selected MASP-2 inhibitory antibodies to human MASP-2 (CCP1-CCP2-SP fragment), as described in Example 1. Results are shown in FIGURE 4A-D and summarized in TABLE 7, below. TABLE 7: Results of MASP-2 Binding Assay mAb ECss OMS850 0.25 nM OMS860 0.23 nM QMS 8 70 0.41 nM 2. C3b deposition assay in human, cynomolgus monkey, rat and mouse serum The three selected MASP-2 antibodies described in Example 2 were expressed, purified and diluted to the same stock concentration, which was again diluted in Caand Mg*"’ containing GVB buffer (4.0 mM barbital, Ml mM NaCl, 1.0 mM MgCb, 2.0 mM CaCQ, 0.1% gelatin, pH 7.4} to assure that all antibody clones had the same amount of buffer. A. C3b deposition assay in human serum C. C3 deposition assay in rat serum Mannan was diluted to a concentration of 50 p.g / ml in carbonate buffer (15 mM N&2CO3 + 35 mMNaHCOy + 1.5 mM NaN-^), pH 9.6 and coated on an ELISA plate overnight at 4°C. The next day, 250 id of 1% BSA blocking solution was then added to the wells and incubated for 2 hours at room temperature. The plates were washed 3X with 300 pl PBS / tween-20 Rat serum was diluted to 0.3% in GVB / Ca / Mg buffer, and MASP-2 mAb clones OMS850, OMS860 and OMS870 were added in a final concentration range from 0.00001 to 100 nM and preincubated 15 minutes on ice. The reaction was initiated by transferring the preincubation mixtures into the wells of the mannan coated, blocked assay plate followed by incubation for 40 minutes at room temperature. The reaction was stopped by washing the plate thrice with wash buffer. C3b deposition was detected with an anti-human C3c antibody (Dako) followed by Goat a-Rabbit HRP (Southern Biotech). The negative control was buffer without serum and antibody (resulting in no C3b deposition), and the positive control was serum without antibody (maximum C3b deposition). A cut-off criterion was set at half of the activity of an irrelevant mAh and buffer alone. I). C3b deposition assay in mouse serum Mannan was diluted to a concentration of 50 pg / mL in carbonate buffer (15 mM NagCOj + 35 mM NaHCOj + 1.5 mMNaNj), pH 9.6 and coated on an ELISA plate overnight at 4°C. The next day, 250 id of 1% BSA in PBS blocking solution was then added to the wells and incubated for 2 hours at room temperature. The plates were washed 3X with 300 yl PBS / tweem20. Mouse serum was diluted to 1.0% in GVB / Ca / Mg buffer, and MASP-2 mAb clones OMS850. OMS860 and OMS870 were added in a final concentration range from 0.00001 to 100 nM and preincubated 15 minutes on ice. The reaction was initiated by transferring the preincubation mixtures into the wells of the mannan coated, blocked assay plate followed by incubation for 40 minutes at room temperature. T he reaction was stopped by transferring the plates to an ice bath C3b deposition was detected with an anti-human C3c antibody (Dako) followed by Goat a-Rabbit HRP (Southern Biotech). The negative control was buffer without serum and antibody (resulting in no C3b deposition), and the positive control was serum without antibody (maximum C3b deposition ). A cut-off criterion was set at half of the activity of an irrelevant mAb and buffer alone. The results are shown in FIGURES 5A, 5B, 5C and 5D and summarized in TABLE 8, below. The data point indicated as “buffer” in FIGURES 5A-D is a buffer-only negative control. ''FABLE 8: Results of C3b Deposition Assay mAb Bum an (IC58 n M) Cynomolgus (ICw nM) Rat (ICw nM) Monse (ICso nM) OMS850 0.15 0.4 0.05 0.5 OMS860 0 6 26.2 0.3 5.8 QMS 8 70 0.13 18.9 0.6 >100 3. C4b deposition assay in 50% human serum Mannan was diluted to a concentration of 50 pg / ml in carbonate buffer (15 mM NagCOy + 35 mM NaHCOy + 1.5 mM NaNy), pH 9.6 and coated on an ELISA plate overnight at 4°C. The next day, 250 pl of 1% BSA in PBS blocking solution was then added to the wells and incubated for 2 hours at room temperature. The plates were washed 3X with 300 pl PBS / tween-20. Normal human serum was diluted to 50.0% in PBS, and MASP-2 mAb clones OMS850, OMS860 and OMS870 were added in a final concentration range from 0.0001 to 100 nM to this buffer and preincubated 15 minutes on ice. The reaction was initiated by transfer of the preincubation mixtures to the mannan-coated, blocked ELISA plate followed by incubation for 7 minutes at 4°C. C4b deposition was detected with an anti-human C4c antibody (Dako) followed by Goat a-Rabbit HRP (Southern Biotech) The negative control was buffer without serurn and antibody (= no C4b deposition). The background was determined in wells received buffer only. A cut-off criterion was set at half of the activity of an irrelevant mAh and buffer alone. Results are shown in FIGURE 6 and provided in TABLE 9, below. The data point indicated as ‘'buffer' in FIGURE 6 is a buffer-only negative control. TABLE 9: Results of C4b deposition assay mAh Human C4b deposition (ICA ag / mL) OMS850 0.07 OMS860 0.1 OMS870 0.09 Antibody OMS850 was chosen for humanization and further optimization in view of the good potency in human, mouse, rat and cynomolgus monkeys as described above Example 4 Humanization of MASP-2 mAh OMS850 and production of variants Before humanization, the anti-MASP-2 inhibitory mAh OMS850 was analyzed for post-translational modification. An Aspartic acid isomerization motif‘'DP” was identified in VH CDR2 (D1DPSDSETHYIEKFKD (SEQ ID NO: 16)) of OMS850. Variants of OMS850 were generated by site-directed mutagenesis to modify P53 to A, N, D, L, S and T. The variants were expressed and purified as described above. Affinity was determined by ELIS A and potency was assessed by C3 deposition assay in human serum using the intact IgG4 formats as described above. Results are shown in FIGURE 7 and provided in TABLE 10, below. TABLE 10: Results of C3b Deposition Assay mAb Human C3b deposition (ILA nM.) OMS850 0.09 OMS850 UHpu. A 0.07 OMS850 JTI P53 / N 0.53 OMS850 VH P53 D 0.16 As shown in FIGURE 7, it was determined in a C3b deposition assay that OMS850 VH P53A had the best potency in human serum as measured in the C3b deposition assay. Thus, this P53 A substitution was incorporated during the subsequent humanization described below. To reduce immunogenicity risk, representative high affinity M ASP-2 inhibitory antibody OMS850 was humanized by a CDR-grafting method. The CDRs of mAb OMS850 were grafted into the ciosest consensus human framework sequences. Some of the Vernier zone residues were modified by Quickchange site-directed mutagenesis (Agilent Technologies). The resulting humanized VH and VL regions were transferred into pcDNA3.1-based human IgG4 and IgK expression constructs, and the recombinant antibodies were expressed and purified as described above. Affinity of the humanized antibodies was determined by ELISA, and potency was assessed by C3 deposition assay using intact IgG4 formats in 1% human serum using the methods described above in Example 3. A first humanized prototype was developed and designated OMS852. The amino acid sequence of the OMS852 humanized heavy chain variable region and light chain variable region are provided below. The CDRs (Kabat) are underlined. Full sequence of OMS852 VH (humanized): (SEQ ID NO: 46) OVOLVQSGAEVKKPGASVKVSCKASGY1TTNY\¥MHWLRQAPGQGLEWIGDIDPSD SETHYIEKFKDRATLTIDKSSSTAYA4ELSSLRSEDTAVYYCARGDITTTLRYFDVWG0 GTLVTVSS DIQLTQSPSSLSASVGDRVTITCSASSSyRYMYWYQQKPGKAPFG..LIYDT^ SRFSGSGSGTDNTLTISSLQPEDFATYYCQQWSSYPLTFGQGTKVEIKR The results of the C3b deposition assay using various modified versions of OMS850 mAb as compared to the OMS850 parental mAh are shown in FIGURE SA and FIGURE SB and summarized in TABLE 11. TABLE 11: Results of C3b deposition Assay for humanized candidates of OMS850 mAb Human C3b deposition (ICso Ab OMS850 parent 0.15; 0.12 OMS852 (4-11) 0.16 OMS852 (4PA- 2) 0.12; 0.10 OMS852 (4PA- 4) 0.15 OMS852 (4PA- 1) 0.09 OMS852 (4PA- 6) 0.17 Monoclonal antibody OMS852 4PA-1, which is both humanized and incorporates the P53A modification previously identified, was selected for further development, and was designated OMS854. Amino acid sequences of the heavy chain, variable regions and light chain variable regions for humanized antibody OMS854 are provided below. The CDRs (Rabat) are underlined. Full sequence of OMS854 VH: (SEQ ID NO: 48) OVOLVOSGAEVKKPGASVKVSCKASGYTFTNYWMHWLRQAPGOGLEWIGDIDASD SETHYEKFKDRATLTIDKSSSTAYMELSSLRSEDTAVYYCARGDITTTLRYFDVWGQ GTLVTVSS Ful 1 sequence of OMS854 VL (humamzed) (SEQ ID NO: 47) D10LT0SPSSLSASVGDRVT1TCSASSSVRYMYWY00KPGKAPKLLIYDTSNLASGVP SRFSGSGSGTDNTLTISSLQPEDFATYYCQQWSSYPLTFGOGTKVEIKR As shown in TABLE 12, further modifications were made to the VH CDR1 such that it includes at least one, or optionally two, or optionally three histidines. A variant with two histidines was designated OMS856. A variant with three histidines was designated OMS858. Full sequence of OMS856 VH (REQ ID NO :49) ovolvosgaevkkpgasvkvsckasgytftnyhmhwlrqaikkiglewigdidasd SETHYIEKFKDRATLTIDKSSSTAYMELSSLRSEDTAVYYCARGDITTTLRYFDVWGQ GTLVTVSS QVQLVQSGAEVKKPGASVKVSCKASGYTFTNHHNfHWLRQAPGQGLEWIGDIDASD SETHYIEKFKDRATIfFIDKSSSTAYMELSSLRSEDTAVYYCARGDITTTLRYFDVWGQ GTLVTVSS TABLE 12: MASP-2 Antibody VH Sequences (CDRs and FR regions, Kabat) Antibod y VH FRI VH CDR1 OMS850 QVQLQQPGAELVRPGSSVRLSCKASGYTFT (SIN 13) NYWMH (SIN 14) OMS852 QVQL VQSGAE VKKPGAS VK VSCK A SOW FT (SIN 51) NYWMH (SIN 14) OMS854 QVQLVQSGAEVKKPGASVKVSCKASGYTFT (SIN 51) NYWMH (SIN 14) OMS856 QVQLVQSGAEVKKPGASVKVSCKASGYTFT (SIN 51) NYHMH (SIN 56) OMS858 QVQLVQSGAEVKKPGASVKVSCKASGYTFT (SIN 51) NFIFIMH (SIN 57) Antibed y VH FR2 VH CDR2 OMS850 WLKQRPIQGLEWIG (SIN 15) DIDPSDSETHY1EKFK D(SIN 16) OMS852 WLRQAPGQGLEWIG (SIN 52) DIDPSDSETHYIEKFK D (SIN 16) OMS854 WLRQAPGQGLEWIG (SIN 52) D ID ASD SETH YIE KF K D(SIN 53) OMS856 WLRQAPGQGLEWIG (SIN 52) DIDASDSETHYIEKF'K D(SIN 53) OMS858 WLRQAPGQGLEWIG (SIN 52) DID ASD SETH YIEKFK D(SIN 53) Antibod y VH FR3 VH CDR3 OMS850 K ATLTIDKS S STA YMHLS SLTSEDS AIYYC AR (SIN 17) GDITTTLRYFDV (SIN 18) OMS852 RATLTIDKSSSTAYMELSSLRSEDTAVYYCA R ( SIN 54) GDITTTLRYFDV (SIN 18) OMS854 RATLTIDKSSSTAYMELSSLRSEDTAVYYCA R (SIN 54} GDITTTLRYFDV (SIN 18) OMS856 RATLTIDKSSSTAYMELSSLRSEDTAVYYCA R(SIN 54) GDITTTLRYFDV (SIN 18) OMS858 R ATLTIDKS SST A YMELS SLRSEDT A VY YC A R(SIN 54) GDITTTLRYFDV (SIN 18) Antibod y VH FR4 OMS850 WGTGTTVTVSS (SIN 19) OMS852 WGQGTLVTVSS (SIN 55) OMS854 WGQGTLVTVSS (SIN 55) OMS856 WGQGTLVTVSS (SIN 55) OMS858 WGQGTLVIVSS (SIN 55) TABLE Lx MASP-2 Antibody VL Sequences (CDRs and FR regions, Rabat) Antibody EL FR1 VL CDR1 OMS850 QIVLTQSPVIMSASPGEKVTMTC (SIN 31) SASSSVRYMY(SIN 32) OMS852 DIQLTQSPSSLSASVGDRVTn'C (SIN 58) SASSSVRYMY (SIN 32) Antibody VL FR2 VI. CDR2 OMS850 WYQQKPGSSPRLLIY (SIN 33) DTSNLAS (SIN 34) OMS852 W YQQKPGKAPKLLIY (SIN 59) DTSNLAS (SIN 34) Antibody VL FR3 VL CDRS OMS850 GVPVRFSGSGSGTSNSLTISRMEAEDAAT'YYC (SIN 35) QQWSSYPLT (SIN 36) OMS852 GVPSRFSGSGSGTDNTLTISSLQPEDFATYYC (SIN 60) QQWSSYPLT(SIN 36) Antibody VL FR4 OMS850 FGAGTKLELKR (SIN 37) OMS852 FGQGTKVEKR (SIN 61) SEQ ID NO:65: human IgG4 constant region AS1XGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQ SSGLYSLSSVVTVTSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPSCPAPEFLG GPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPR EEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVY TLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVI..DSDGSFFL YSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLGK SEaiDNO,..66; human. lgG4 constant region with S228P mutation ASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQ SSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVrESKYGPPCPPCPAPEFLG GPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPR EEQFNSTYRVVS^XTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVY TLPPSQEEMTKNQVSIGXIXKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSRLTV’DKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLGK SEQ ID NO: 67: human IgG4 constant region with S228P mutation and also a mutation (Xtend) that promotes FcRn interactions at low pH ASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQ SSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKV^ GPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEYHNAKTKPR EEQFNS1'YRVVSVL1'VLH(;>DWLNGKEYKCKVSNKGL.PSSIEKIISKAKGQPREPQVY TLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFL YSRLTVDK SRWQEGN VF SC S VLHEALHSHYTQK SLSLSLGK SEQ ID NO :68: human IgK constant region TVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTE QDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC SEQIDNO,:69;DNA encoding OM CAGGTCXAACTGCAGCAGCCTGGGGCTGAGCTGGTGAGGtXlTGGGTCm AGGCTGTCCTGCAAGGCTTCTGGCTACACCTTCACCAACTACTGGATGCATTGGT TGAAGCAGAGGCCTATACAAGGCCTTGAATGGATTGGTGACATTGACCCTTCTGA TAGTGAAACTCACTACATTGAAAAGTTCAAGGACAAGGCCACATTGACTATAGA CAAATCCTCCAGCACAGCCTATATGCACCTCAGCAGCCTGACATCTGAGGACTCT GCGATCTATFACI'GTGCAAGAGGGGA’l^ATTACTACGACCCTT'AGGTACnEiGAlG TCTGGGGCACAGGGACCACGGTCACCGTCTCCTCA SEQ ID NQ:70: DNA encoding OMS860 VH (mouse parental) CAGGTCCAACTGCAGCAGCCTGGGGCTGAGCTGGTGAGGCCTGGGTCT’rcAGlG AAGCTGTCCTGCAAGGCTTCTGGCTACACCTTCACCAACTACTGGATGCATTGGG n)AGACAGAGGCCTATACAAGG(X7FrGAATGGATlXiGTGACATTGACCCTTCTGA TAGTGAAATTTACTACAATCAAAAGTTCAAGGACAAGGCCACATTGACTGTAGA caaat(x:tccagcaccg(x:tataixx:acctca(X)agcctgacatctgaggactct WO 2023 / 108028 PCT / US2022 / 081121 WO 2023 / 108028 PCT / US2022 / 081121 ACTCCGAAACTCATTACATTGAGAAGTTCAAGGACAGGGCCACCCTCACCATCG ATAAGAGCTCCTCGACCGCCTACATGGAACTGTCCAGCCTGAGATCAGAGGATA CTGCTGTGT.ACTACTGTGCGCGGGG€GA.C.ATTACAACGA(XX:TGC^^^^ CGTCTGGGGACAGGGCACCCTTGTGACCGTGTCCTCC SEQ ID NO:79: GNA encoding OMS858 CAAGTCCAACTCGTCCAGTCCGGAGCAGAAGTCAAGAAGCCGGGAGCCAGCGTG AAAGTGTCGTGCAAAGCCTCCGGTTACACTTrCACCAACCATCACATGCACTGGC TGGGCCAGGCGCCCGGCCAGGGACTGGAGTGGATCGGGGATATCGACGCCTCGG ACTCCGAAACTCATTACATTGAGAAGTTCAAGGACAGGGCCACCCTCACCATCG ATAAGAGCTCCTCGACCGCCTACATGGAACTGTCCAGCCTGAGATCAGAGGATA ctgctgtGtactactgt(x?gcg(jG(x:gacattacaacgaccctc}(:ggtactt(:ga CGTCTGGGGACAGGGCACCCTTGTGACCGTGTCCTCC Antibody OMS8SS specifically blocks the lectin pathway The effect of nt Ab OMS858 on membrane attack complex (MAC) deposition was analyzed using pathway-specific conditions for the lectin pathway, the classical pathway and the alternative pathway. For this purpose, the Wieslab COMPL300 complement screening kit (Wieslab, Lund, Sweden) was used following the manufacturer’s instructions. For the classical pathway, complement was activated on IgM. For the lectin pathway, complement was activated on mannan, and for the alternative pathway, complement was activated on EPS. FIGURE 9A graphically illustrates the level of MAC deposition in the presence or absence of an ti-M ASP-2 antibody OMS858 under classical pathway-specific assay conditions. FIGURE 9B graphically illustrates the level of MAC deposition in the presence or absence of anti-MASP-2 antibody OMS858 under lectin pathway-specific assay conditions. FIGURE 9C graphically illustrates the level of MAC deposition in the presence or absence of anti-MASP-2 antibody OMS858 under alternative pathway-specific assay conditions. As shown in FIGURE 9B, mAh OMS858 blocks lectin pathway-mediated activation of MAC deposition with an IC50 value of approximately 1 nM. However, mAb OMS858 had no effect on MAC deposition initiated by classical pathway-mediated activation (FIGURE 9A) or from alternative pathway-mediated activation (FIGURE 9C) An anti-Cis antibody (TNT003), which is known to inhibit the classical pathway, is included as a control in FIGURE 9A An ami-Factor B antibody, which is known to inhibit the alternative pathway, is included as a control in FIGURES 9B and 9C. Example 6 Analysis of MASP-2 binding epitopes for antibodies OMS850, OMS858, OMS860, OMS870 Antibody OMS858 was biotinylated and tested for the ability to bind concurrently with several different MASP-2 antibodies in an Octet biolayer interferometry binding assay as follows. Antibody OMS858 was biotinylated using EZ-link Sulfo-NHS-LC-Biotin (Fischer Scientific, A39257). Super Streptavidin (SSA) Biosensor (Fortebio 18-5057) was hydrated in PBS for 15 minutes at room temperature. 3 mL of 50 nM biotinylated OMS858was captured on the BLI chip, followed by capture of hMASP-2-CCPl-CCP2-SP. A500 nM solution of one of five test anti-MASP-2 antibodies were prepared in immobilization buffer (PBS, 0.02% BSA, 0.05% Tween-20, pH 7.4). The test antibodies used were OMS850, OMS860, and OMS870. the production of which is described above, and previously identified anti-MASP-2 antibodies OMS721, and 4A8. Plate wells in the first column received 200 nL of biotinylated OMS858 and the wells in the following column received 200 pL of hMASP-2-CCPl-CCP2-SP. In a separate column on the plate, 200 pL of 500 nM test antibodies were added to each well. Controls were also carried out using unbiotinylated OMS858 or buffer alone in place of a test antibody. The binding assay was carried out on the Octet using the following steps, baseline establishment (60s), loading of biotinylated OMS858 (180s), baseline establishment (60s), loading of hMASP-2-CCPl-CCP2-SP (180s), followed by association of test antibody (300s) and dissociation (300s). As shown in FIGURE 10, armbodies OMS850, OMS860 and OMS870 were unable to bind to MASP-2 captured by OMS858, indicating that these antibodies bind to the same or a partially overlapping epitope on MASP-2. In contrast, previously identified ann-MASP-2 antibodies OMS72I and 4A8 were able to bind to MASP-2 captured by OMS858, indicating that these two antibodies bind to a different epitope on MASP-2 than OMS850, OMS860, OMS870 andOMS858. Example 7 Crystallization of MASP-2 protein and Fab mAh OMS858 complex 1. MASP-2 Protein Preparation Recombinant MASP-2 protein, based on UniProt 000187, human mannan-binding lectin serine protease 2, was prepared as follows. Expression constructs for human MASP-2 CCP2-SP and CCP2-SP-6HIS were generated for recombinant expression in Aco / ? cells. Recombinant, expression of MASP-2 inKcoZf as inclusion bodies and protein purification was carried out according to methods described in Ambrus G. et al., 2003, with minor modifications. For the HIS tagged version, the MASP-2 protein (CCP2-SP-6HIS) was purified under denaturing conditions according to the methods described in Ni-NTA Superflow Cartridge Handbook, Qiagen, March 2007. Purification of MASP-2 included extraction, unfolding, refolding and chromatography using standard methods as described by Hann at et ah, J Moi. Biol. 2004;342:1533-1546; and Gai et al., J. Biol. Chern. 2005;280:33435-33444; and Ambrus et al. J Immunol. 2003 Feb I;170(3). 1374-82. After size exclusion chromatography, the recombinant MASP-2 protein was concentrated from 5 mg / mL to 20 mg / mL with spin concentrator (Ammon NMWL lOkDa). Concentrated MASP-2 protein samples were flash-frozen and stored until thawing for complex formation Purification and cleavage were monitored by SDS-PAGE stained by Commassie Blue Simply Blue™ Safe Stain (Invitrogen). the structure 1Q3X and portions of 3C08 as search models and partially refined with Buster 2.10.2 or Retinae 5.8 Electron densities were inspected with Coot (Ernsley et al., 2010) and subjected to iterative model building and refinement cycles until the density of MASP-2 and Fab mAb OMS858 was clearly visible and R-factors sufficient; at this point the partial refinement was deemed completed and models for ligand, solvent and protein were inspected. TABLE 14. Summary of crystal parameters, data collection;, and refinement statistics for MASP-2- Fab mAb OMS858 complex crystals Data collection and refinement statistics Space group C I 2 1 Unit cell parameters a - 169.37.A, b === 69.04A, c === 8L76A, «.===90.0°, 6===98.172 7===90.0° Data collection Wavelength (A) 1.0 Resolution range (A) 39.6-2.90 (3.08-2.90) No. of observations 85,344 No of unique reflections 20.232 Completeness (%) 96.9 (94.0) Mean I / o(I) 7.0 (1.0) Rmerge on I (%) 12.1 (132.0) Rmeas on I (%) 13.9 (152.0) Rp rm on 1' (%) 6.7(74.1) Model and refinement statistics Resolution range (A) 39.6-2.90 No. of reflections (total) 19,207 No. of reflections (test) 963 Completeness (% total) 96.27% Cutoff criteria F>0 Rcryst Rfree 26.9 30.7 Stereochemical parameters Restraints RMSD bond length (A) 0.007 Restraints RMSD bond angle (°) 1.71 Average isotropic B value, protein (A2) 94.9 Coordinate error (maximum-likelihood based, A) 0 47 Protein residues 689 Ramachandran plot: residues (%) in tavored / aliowed 71.7% / 15.7% Example 9 Crystal structure analysis Refined structures were analyzed for protein-protein and -solvent interaction types and distances, using LigPlot+ (Laskowski and Swindells, 2011) with parameters set for 3,35 A for the maximum distance between hydrogen bond donor and acceptor; and non-bonded contact parameters between hydrophobic to any contacts, such as van der Waals interactions with maximum contact distance of 3.90 A. TABLE 15 shows H-bonds between atoms of m Ah OMS858 and M ASP-2. TABLE 16 shows van der 'Waals interactions of MASP-2 atoms with those of Fab mAb OMS858 atoms that result by LigPlot+ -based analysis of the crystallographic structure, using "Antibody'' setting. LigPlot+ calls these ’nonbonded contacts’ or 'hydrophobic contacts'. Despite the name, there are atom pairings that include possible H-bonds. Thus, in some instances, the TABLE 16 also contains H-bond interactions. FIGURE 11 is a schematic diagram showing the arrangement of and contacts between the MASP-2 Serine Protease domain and the Fab mAb OMS858. FIGURE 12A is a schematic diagram showing the MASP-2 epitope to which mAb OMS858 binds, which includes the following residues in the SP domain of MASP-2: ASP496; LYS503; SER506; PRO507; HIS508 and TRP5B. As shown in FIGURE 12A, the epitope to which OMS858 binds encompasses two patches, the first including ASP496 and TRP513 and the second including LYS503; SER506; PRO507 and HIS508. FIGURE 12B is a schematic diagram showing the paratope of mAb OMS858 that binds to the MASP-2 epitope shown in FIGURE 12A. As shown in FIGURE 1213, the paratope encompasses two connected, corresponding patches with contributions from the heavy and light chain and in particular, heavy chain residues HIS33, ASP50, ASP52; ASP55; GLU'57, HIS59 and light chain residues TYR31; ARG30 and TRP90. It was determined that there are three hydrogen bonds and 36 van der Waals contacts as follows: 'FABLE 15: 3 H-bonds between atoms of mAb OMS858 and MASP-2: Donor MASP-2 d atom Acceptor Chain $ atom Distance HIS A 508 NE2 ASP H 50 OD2 2.36 LYS A 503 RZ ASP H 55 OD2 3.01 LYS A 503 NZ ASP H 52 OD2 3.17 TABLE 16: 36 van der Waals contacts between atoms of mAb OMS858 ami MASP-2: mAb Chain Atom MASP-2 Chain d Atom distance ARG L 30 CB Hip A 513 CZ2 3.34 TYE. I.. 31 CE2 HtP A 513 CHO 3.83 ARG L 30 CB TRP A 513 CE2 3.88 HIS H 59 CD2 HIS A 508 CD2 3.71 HIS H 59 NE2 HIS A. 508 CD2 3 73 HISS H 59 CE1 HIS A 508 CD2 3.81 HIS H 59 ND1 HIS A 508 CD2 3.82 HIS H 59 CG HIS A 508 CD2 3.75 ASP H 50 OD2 HIS A 508 CD2 3.23 UM L 90 CH2 HIS A 508 NE2 3.83 HIS H 59 CD2 HIS A. 508 NE2 3 69 HIS H 59 CG HIS A 508 NE2 3.34 HIS H 59 CB HIS A 508 NE2 3.56 ASP H 50 CG HIS A 508 NE2 3.41 TRP L 90 CZ2 HIS A 508 CE1 3.89 HIS H 59 CE1 HIS A 508 CEI 3.88 HIS H 59 ND1 HIS A 508 CE1 3.22 HIS H 59 CG HIS A. 508 CE1 3.33 HIS H 59 CB HIS A 508 CE1 3.46 ASP H 50 OD2 HIS A 508 CE1 3.42 HIS H 59 CE1 HIS A 508 ND1 3.46 HIS H 59 CG HIS A 508 ND1 3.70 HIS H 59 NE2 HIS A 508 CG 3.73 HIS H 59 CE1 HIS A. 508 CG 3.39 HIS H 59 ND1 HIS A 508 CG 3.52 HIS H 59 CE1 HIS A 508 CB 3.76 HIS H 33 CE1 PRO A 507 CD 3.72 HIS H 33 ND I PRO A 507 CD 3.70 HIS H 33 CE1 SER A 506 CA 3.70 GEL H 57 CB LYS A. 503 NZ 3.1 ASP H 55 CG LYS A 503 NZ 3.49 ASP H 52 CB LYS A 503 NZ 3.86 ASP H 55 OD2 LYS A 503 CE 3.29 ASP H 52 OD2 LYS A 503 CE 3.57 ASP H 52 OD2 LYS A 503 CD 3.18 TYR L 31 CE2 ASP A. 496 OD2 3.73 FIGURE 13 illustrates the interactions between the mAb OMS858 paratope and the MASP-2 epitope as computed by LigPIot+ software, using ‘Antibody’ mode with settings for hydrogen-bond calculation parameters (3.35 A for maximum distance between hydrogen bond donor and acceptor; and non-bonded contact parameters between hydrophobic to any contacts, such as van der Waals interactions with maximum contact distance of 3.90 A) employing models derived from the corresponding crystallographic MASP-2-compound costructures. Hydrogen bonds and polar contacts are depicted as broken lines with distances provided in units of Angstrom. Atoms for amino acids that interact with compound atoms as well as compound atoms that have sufficient 2fo-fc electron density from crystallographic data are depicted. MASP-2 amino acid residue numbering (MASP-2 AA#) is according to Uniprot accession code 000187, atom numbering for amino acids (AA atom) according to conventions established by the Protein Data Bank and correspond to those in TABLES 15 and 16. OMS858 amino acid residue numbering is according to the VH set forth as SEQ ID NO:50 and the VL set forth as SEQ ID NO:47. The OMS858 paratope, including the heavy chain variable region (Loop HL Loop H2) and the light chain variable region (Loop L3, Loop LI) is depicted above the dashed line in FIGURE 13 and the MASP-2 epitope is depicted below the dashed line in FIGURE 13. Certain of the amino acids shown in FIGURE 13 have arcs with radiating lines, which indicate that they have van der Waals interactions (dotted lines) with atoms of other amino acids. Hydrogen bonds and polar contacts are depicted as broken lines with distances provided in units of Angstroms. Carbon atoms are shown as solid circles, nitrogen atoms are shown as open circles with a cross; and oxygen atoms are shown as open circles with an x. Side chains of amino acids Giu57 and Arg30 of OMS858 were only partially resolved in the X-ray structure. Hence, additional hydrogen bonds and ionic interactions of the OMS858 are likely to exist between VH GLU57 and VL ARG30 of OMS858 with opposing residues on MASP-2. given the dose proximity of the backbone. Specifically, VL ARG30 of OMS858 may form an ionic bond to ASP496 of MASP-2 and VL ARG30 of OMS858 may form a a n-stacking interaction with the aromatic moiety of TRP513 of MASP-2 and VH GLU57 of OMS858 may form an ionic bond or a hydrogen bond with the amino group of LYS5O3 of MASP-2). As shown in FIGURE 13, OMS858 binds to MASP-2 via 3 H-bonds with residues: ASP52 and ASP55 in the VH binding to LYS5O3 in MASP-2 and ASP50 in the VL binding to HIS508 in MASP-2. As further shown in FIGURE 13, OMS858 binds to MASP-2 via van der Waals contacts between HIS33 of the VH to SER506 and PRO507 of MASP-2; ASP52, ASP55 and GLU57 of the VH to LYS503 of MASP-2; HIS59 and ASP50 of the VH to HIS508 of MASP-2, TRP90 of the VI. to HIS5O8, ARG30 of the VI. to TRP513 of MASP-2 and TYR31 of the VL to TRP513 and ASP496 of MASP-2. In certain aspects, the MASP-2 inhibitory antibody interacts via van der Waals contacts to 1. 2, 3, 4, 5, 6, or ail of the following residues of MASP-2: SER506, PRO507, LYS503, HIS508; TRP513; ASP496 and combinations thereof. In certain aspects the MASP-2 inhibitory antfoody interacts via hydrogen bonds to 1 or 2 of the following residues of MASP-2- LYS5O3 and HIS508. FIGURE 14 A illustrates the three-dimensional structure of the MASP-2 epitope comprising ASP496, LYS5O3, SER506, PRO507, HIS508 and TRP513 to which OMS858 binds. As shown in FIGURE 14A, the entire MASP-2 epitope set forth as DIRMGTLKRLSPHYTQAW (SEQ II) NO:6), corresponding to ammo acid residues 496513 of human MASP-2 (SEQ ID NO:1) is located on a single anti-parallel beta strand-loop-beta strand element FIGURE 14B illustrates the three-dimensional structure of the OMS858 paratope comprising HIS33, ASP50, ASP52, ASP55, GLU57, and HIS59 of the hea vy chain and ARG30, TYR31 and TRP90 of the light chain to which MASP-2 binds. HIS33 is located on loop Hl. ASP50, ASP52, ASP55, GLU57, HIS59 form an and-parallel beta strand-loop-beta strand element. TYR31 and ARG30 are on loop 1 of the light chain, and TRP90 is on the L3 loop of the light chain. FIGURE 15 illustrates the contacts between the MASP-2 epitope DIRMGTLKRLSPHYTQAW (SEQ ID NO:6) and the heavy chain variable region and light chain variable region of OMS858. In particular, as shown in FIGURE 15, the heavy chain variable region residues ASP55, GLU57 and ASP52 interact with LYS503 of MASP-2; and heavy chain variable region residues HIS33, FI IS 5 9 and ASP50 interact with SER506, HIS508 and PRO507 of MASP-2. As further shown in FIGURE 15, the light chain variable region residue TRP90 interacts with PRO507 and HIS508 of MASP-2 and light chain variable region residues ARG30 and TYR31. interact with ASP496 and TRP513 of MASP-2. In certain aspects, MASP-2 SP amino acid residues 496-513 of SEQ ID NO;1 (DIRMGTLKRLSPHYTQAW set forth as SEQ ID NO:6) interact with OMS858 through van der Waals interactions. Van der Waals interactions include weak, short-range electrostatic attractive forces between uncharged molecules, arising from the interaction of permanent or transient electric dipole moments. As shown in TABLE 16, OMS858 EC ARG30 atom CB interacts with MASP-2 atoms CZ2 and CE2 in TRP513 LC TYR31 atom CE2 interacts with MASP-2 atom CH2 of TRP513. HC HIS59 atoms CD2, NE2, CEI, ND1 and CG interact with MASP-2 atom CD2 in HIS508. HC ASP50 atom OD2 interacts with MASP-2 atom CD2 in HIS508. LC TRP90 atom CH2 interacts with MASP-2 atom NE2 in HIS508. HC HIS59 atoms CD2, CG and CB interact with MASP-2 atom NE2 in HIS508. HC ASP50 atom OD2 interacts with MASP-2 atoms CD2 and CEI in HIS508. LC TRP90 atom CZ2 interacts with MASP-2 atom CE1 of HIS508. HC HIS59 atoms CE1, ND1, CG, CB and OD2 interact with MASP-2 atom CEI in HIS508. HC HIS59 atoms CEI and CG interact with MASP-2 atom ND1 in HIS508. HC HIS59 atoms NE2, CEI and HD1 interact with MASP-2 atom CG in HIS508. HC HIS59 atom ND1 interact with MASP-2 atom CG in HIS508. HC HIS59 atom CEI interacts with Generation of a Dog-dike Human MASP-2 to analyze the role of HIS508 in OMS858 binding As described in Example 9, the structural observation of the MASP-2 / OMS858 complex shows that HIS508 is a key side chain of the binding epitope since it interacts with both the heavy and light chain of the variable domain of OMS858 via a H-bridge to ASP50 and pi "interaction to TR.P90 and HIS59. FIGURE 16 is an amino acid alignment of the MASP-2 serine protease (SP) domains of human MASP-2 (aa 445 to 686 of SEQ ID NO:1); cynomolgus monkey MASP-2 (aa 445 to 686 of SEQ ID NO:4); dog MASP-2 (aa 445 to 686 of SEQ ID NO:5); mouse MASP-2 (aa 444 to 685 of SEQ ID NO:2): and rat MASP-2 (aa 444 to 685 of SEQ ID NO:3). SliQJPNOj k. human MAS^^       006601.2) MRLLTLLGLLCGSVATPLGPKWPEPVFGRLASPGFPGEYANDQERRWTLTAPPGYRL RLYFTHFDLELSHECEYDFVKLSSGAKVLATLCGQESTDTERAPGKDTFYSLGSSLDI TFRSDYSNEKPFTGFEAFYAAEDIDECQVAPGEA1HGDHHCHNHLGGF YCSCRAGYV LHR.NKRTCSALCSGQVFTQRSGELSSPEYPRPYPKLSSCTYSISLEEGFSVILDFVESFD VETHPETLCPYDFLKIQTDREEHGPFCGKTLPHRIETKS'NTVTn'FVTDESGDHTGWKI HYTSTAQPCPYPMAPPNGFIVSPVQAKYn.ADSFSIFCETGYELLQGHLPLKSFl'AVCQ KDGSVYDRPMPACSIVDCGPPDDLPSGRVEYrrGPGVTl'YKAVIQYSCEEIFYYMKVN DGKYVCEADGFWTSSKGEKSLPVCEPVCGLSARTTGGRIYGGQKAKPGDFPWQVLI LGGTTAAGALLYDNWVLTAAEIAVYEQKHDASALDIRMGTLKRLSPHYTQAWSEAV FIHEGYTHDAGFDNDIALIKLNNKVVINSNITPICLPRKEAESFMRTDDIGTASGWGLT QRGFLARNLMYVDIPIVDHQKCTAAYEKPPYPRGSVTANMLCAGLESGGKDSCRGD SGGALVFLDSETERWFVGGIVSWGSMACGEAGQYGVYT'KVINYIPWIENnSDF SEQ ID NO:2: mouse MASP-2 (NP 001003893.1) MRELIFLGLLWSIAA.TLEGSKWPEPVFGRLVSPGFPEKYADHQDRSWTETAPPGYRL RLYFTHFDLELSYRCEYDFVKLSSGIKVLATLCGQESTDTEQAPGNDTFYSLGPSLK VTFHSDYSNEKPFTGFEAFYAAEDVDECRVSLGDSVPCDHYCHNYLGGYYCSCRAG Y VI AIQNKHTC S ALC SGQ VFTGRSG YES SPEYPQP YOKES SCT YSIRLEDGFS VILDF VE SEQ ID NO:4: cyno MASP-2 (XP 005544869.1) predicted MRLLTLLGIACGSVATPIAtPKWPEPVFGRLASPGFPGEYANDQERRWTLTAPPGYRL RLYFTHFDLELSHLCEYDFVKLSSGAKVLA 1 LCG.HES1 'DTERAPGNDTF YSLGSSLD1 introduced by PCR-based site-directed mutagenesis using PfuUltra II fusion HS DNA polymerase (Agilent). Based on the crystal structure data, it was expected that OMS858 would have a lower affinity to this MASP-2 H508Q mutation as compared to wild-type human H508. Ail expression constructs were transformed into BL21(DE3)pLysS E. co# (Invitrogen) and recombinant proteins were expressed according to the manufacture’s protocol and purified by immobilized metal affinity chromatography (IMAC) using a nickel column. Protein integrity and enzymatic activity of the purified proteins were assessed by SDS-PAGE and a peptide cleavage assay, respectively. Bio-layer interferometry (BLI) was applied to analyze OMS858 antibody binding to the multiple MASP-2 proteins. All measurements were conducted with the Octet RED96 system (ForteBio) using PBS containing 1% BSA and 0.02% Tween 20 as assay buffer. OMS858 (50 nM) was first loaded onto anti-human Fc capture biosensors (ForteBio). After one step of baseline, the captured sensors were submerged into wells containing different-concentrations of the target proteins (1.6--50 nM) for the association step (120 sec), and then transferred to empty wells for the dissociation step (200 sec). In all experiments, the captured sensor was also dipped in a well containing no analyte to allow single reference subtraction to compensate for the natural dissociation of the captured antibody. The recorded binding sensorgrams were analyzed with Octet data analysis software (ForteBio) to determine binding affinity (KD). TABLE 17: OMS858 binding to MASP-2 MA SP-2 protein OMS858 KD Human MASP-2 CCP1 / CCP2 / SP 4.52 nM Human MASP-2 CCP1 / CCP2 / SP H508Q “dog-like” -2 uM Cyno MASP-2 CCP1 / CCP2 / SP 8.23 nM Mouse MASP-2 CCP1 / CCP2 / SP 32.9 nM As shown in TABLE 17, the human MASP-2 with the H508Q “dog-like” mutation reduced the binding affinity by approximately 450-fold. Example 11 Cynomolgus Monkey Study: PK / PD of OMS856 and OMS858 Naive cynomolgus monkeys (n=3) were administered OMS856 and OMS858 at 1.5 mg / kg either iv or sc. Blood samples were collected from each animal on Day -7 and then at 0.083, 1,4, 24, 72, 168, 240, 336, 504, 672, 840 and 1008 hours post-dose and tested for the presence of lectin pathway activity and for the amount of the administered antibody. The lectin pathway assay was carried out in ELISA plates coated with 5 pg / ml mannan for overnight at 4°C Plates were then blocked with 1% BSA in PBS tor 2 hours at room temperature. Cynomolgus serum was two-fold diluted in PBS and added to mannan coated wells and mcubated at 4CC for 14 minutes. After that, plates were washed thrwe in PBS / tween-20 and C4 deposition was probed by rabbit anti-human C4c (Dako) followed by adding Goat a-R.abb.ii HRP (Southern Biotech). FIGURE 17A and FIGURE 17B graphically illustrate the lectin pathway activity versus time of cynomolgus monkeys following iv administration of 1.5 mg / kg OMS856 or OMS858, respectively. FIGURE 18A and FIGURE 18B graphically illustrate the lectin pathway activity versus time of cynomolgus monkeys following sc administration of 1.5 mg / kg OMS856 or OMS858, respectively. As shown in FIGURE 17A and FIGURE 18A, cynomolgus monkeys exhibit sustained systemic lectin pathway inhibition following iv and sc administration of 1.5 mg / kg OMS856. As shown in FIGURE 17B and FIGURE 18B, cynomolgus monkeys exhibit sustained systemic lectin pathway inhibition following iv and sc administration of 1.5 mg / kg OMS85S. Example 12 Analysis of OMS858 in a Mouse Model of Thrombosis A study was carried out to determine the minimally effective dose and the maximal effect of OMS858 in the ferric chloride-induced carotid artery occlusion model in mice. The left carotid artery of male C57B1 / 6 mice was exposed and a miniature flowprobe (0.7mm) from Transonic was installed around the vessel. Following test compound administration, thrombus formation was induced by applying a piece of filter paper (1 5mm x Imm) saturated with 3.5% FeCh. The filter paper was placed directly on the carotid artery in contact with the adventitial surface of the vessel After 3 minutes of exposure, the filter paper was removed, and the vessel was washed with saline. Carotid blood flow was continuously recorded until complete occlusion of the vessel or for a maximum period of 45 minutes. The time to occlusion (TTO) was defined as the time from application of FeCl-j until the blood flow dropped below 0.1 mL / min for at least 30 seconds or until the signal amplitude was reduced enough to prevent heartbeat visualization by the probe. Vessels not occluded at the end of the 45 min observation period were scored with a TTO of 45 min. Mice (n=8 for each dose group) were administered OMS858 by sc injection 24 hours prior to the study at the following dosages: 1 mg / kg, 3 mg / kg, lOmg / kg and 30 mg / kg. Acetylsalicylic acid (ASA) at 30 mg / kg administered one hour prior to FeCft challenge was used as the positive control. An unrelated antibody was used as a negative control. Results are shown in TABLE 18 and graphically illustrated in FIGURE 19. As shown in TABLE 18 and FIGURE 19. the maximal effect of OMS858 was comparable to ASA. As further shown in TABLE 18 and FIGURE 19, OMS858 was effective at the lowest test dosage (1 mg / kg) The TTO in vehicle-treated control mice was 14.7 -1-. 4.6 minutes. As expected, pretreatment with ASA significantly prolonged TTO to 36.4 ± 5.7 minutes, whereas pretreatment with isotype control antibody did not significantly prolong TTO (9.3 ± 1.5 minutes), confirming suitability of the test system. Pretreatment of mice with OMS858 at doses of 1,3, 10 and 30 mg / kg significantly prolonged TTO (40.4 ± 4.6, 37.0 ± 5.2, 39.1 ± 3.9 minutes and 37.4 ± 5.0, respectively) as compared to vehicle group No clear doseresponse relationship could be observed among the OMS858 doses evaluated, indicating that the maximal pharmacologic effect could be achieved at a dose level of Img / kg SC In this mouse model. TABLE 18: Time to occlusion of the carotid artery following FeCh -induced vascular injury Test Article Dose (mg / kg) TTO (minutes) Mean ± SEM N p Value versus Vehicle Vehicle 14.7 • 4.6 8 ASA 30 36.4 ± 5.7* 8 0.010 OMS858 1 40.4 ± 4.6* 8 0.002 OMS858 3 37.0 ± 5.2* 8 0.006 OMS858 10 39.1 ± 3.9* 8 0.001 OMS858 30 37.4 ± s o* 8 0.005 Isotype control 10 9.3 i 1.5 8 0.286 * p < 0.05 compared to vehicle control; p values were generated using a one-tailed, unpaired t-test; ASA = Aspirin; N = number of mice / treatment group; SEM = standard error of the mean; TTO :::: time to occlusion Example 13 Effect of OMS858 on Classical, Lectin, and Alternative Pathway-Induced C5b-9 Activation in Human Serum To assess the functional selectivity of lectin pathway inhibition by OMS858 the Wieslab® complement system screening kit was used. The functional activity of O.MS858 was assessed by pre-incubating human serum samples with serially diluted OMS858 followed by complement activation under pathway-sped tie assay conditions and quanti.fication of C5b-9 deposition. Human serum samples diluted in pathway specific assay buffers were pre-incubated with serial dilutions of OMS858, followed by incubation on the appropriate Wieslab® assay wells pre-coated with classical pathway-specific (A), lectin pathway-specific (B) or alternative pathway-specific (C) complement activator for 1 hour at 37°C. Deposition of terminal complement activation product C5b-9 (also referred to as MAC} was quantified using alkaline phosphatase conjugated antibody specific for the C5b-9 neoantigen. As shown in FIGURES 20A-20C, OMS858 inhibited lectin pathway-induced activation of C5b-9 with an IC50 value of 0 81 nM (121.5 ng / mL) without affecting classical or alternative pathway- induced activation of C5b-9 at concentrations up to 500nM. Example 14 Further Characterization of Monoclonal Antibody OMS858 Binding to Human MASP-2 Surface plasmon resonance (SPR) was used to determine the association and dissociation rate constants (kon and koffi respectively) for the interaction of fluid phase zymogen and catalytically active forms of human MASP-2 with immobilized OMS858. Optimized methodologies and concentration series were used for a detailed characterization of the interaction, and the rate constants obtained were used to calculate the dissociation equilibrium constant (KD) for the OMS858-MASP-2 interaction. The kon and koa for catalytically active MASP-2 binding to OMS858 were 3.38 x lO^tw'1 and 9.71 x. 10'3 s’1 respectively; yielding a Kd value of 287pM. The konand Wfor zymogen MASP-2 binding to OMS858 were 2 41 x KfMV and 1.72 x 1 (TV1 respectively, yielding a KD value of 715pM. See TABLE 19. TABLE 19: Binding of OMS858 with zymogen and active forms of human MASP-2 MASP-2 form k™ (tM s3| kotf (s’1) Kb (pM) Catalytically active MASP-2 3.38 x 107 9.71 x 10’} 287 Zymogen MASP-2 2.41 x 10s 1.72 x 10-4 715 The binding specificity of OMS858 for MASP-2 was evaluated by solid phase enzyme-linked immunosorbent assay (ELISA). Recombinant human MASP-2 or Clr, Cis, CFD, MASP-1 and MASP-3 were immobilized on polystyrene plates, and the dose-response of OMS858 binding was measured. The apparent dissociation constant (KD) was estimated by nonlinear regression using a 4-parameter logistic model. Two different lots of OMS858 were tested. The mean apparent KD of OMS858 binding to human MASP-2 was 0.047 pg / mL. No significant binding to Clr, Cis, MASP-1, MASP-3 or factor D was observed at OMS858 concentrations up to 100 pg / raL, indicating that OMS858 has at least 2000-fold selectivity for MASP-2 over closely related serine proteases of the complement system. Fold selectivity calculated as Kufreiated serine protease) / mean km \1 \SP-21 See TABLE 20. TABLE 20: Selectivity of OMS858 binding to MASP-2 compared to related serine proteases of the complement system Apparent KD values of OMS858 binding [ug / roL] MASP-2 MASP-1 MASP-3 Clr cis CFO LotM 0.042 >100 >100 >100 >100 >100 f oi #2 0.051 >100 >100 >100 >100 >100 Mean 0.047 >100 >100 >100 >100 >100 Fold selectivity >2000 >2000 >2000 >2000 >2000 Example 15 Characterization of Monoclonal Antibody OMS858 Functional Activity in Various Mammalian Species An Enzyme-Linked Immunosorbent Assay (ELISA) measuring lectin-dependent C4 activation in 50% serum was used to characterize the functional potency of OMS858 in serum from human, cynomolgus monkey, dog, rabbit and in mouse hirudin plasma. The functional activity of OMS858 was assessed by pre-incubating serum or hirudin plasma samples from the respective species with serially diluted OMS858 followed by addition of the mixture to mannan-coated ELISA plate wells which drive lectin-dependent C4 activation in vimo. The functional potency of OMS858 inhibition of MASP-2 activity was estimated by analyzing the lectin pathway inhibition concentration-response curve and determining the ICso value. In human serum, OMS858 demonstrated potent inhibition of lection-dependent complement activation, with a mean IC50 value of 1.09 nM (164 ng / mL). The mean IC50 values of OMS858 for inhibition of lectin pathway activation measured in cynomolgus monkey serum and mouse plasma were 44.1 nM (6.620 pg / mL) and 11.9 nM (1.79 ng / mL), respectively By contrast, OMS858 did not appreciably inhibit lectin-dependent complement activation in sera from rabbit and dog at concentrations up to 500nM. See TABLE 21. Comparison of the mouse and cynomolgus monkey functional potencies to that of human demonstrated that OMS858 has 10.9-fold and 40.5-fold lower functional potency in these species as compared to the human,, respectively. Potency relative to human was calculated as the ratio of the ICso value of the query species to the [C50 obtained with human serum. See TABLE 22. TABLE 21. IC50 values for lectin pathway inhibition by OMS858 in mouse, rabbit, dog, and cynomolgus monkey serum as compared to human IC50 value (nM) iiiOiiiiiii Rabbit lllililllll iiiiiiiiiiiiii Expenmem 1 0.89 9.59 >500 >500 42.8 Experiment 2 0.86 11.2 >500 >500 44 Experiment 3 1.52 14.8 >500 >500 45.5 MEAN 1.09 n.9 N / A N / A 44.1 TABLE 22: Potencies across species Maine to human Test Spewes Ratio nCA-Query / ICM-Human) Human i Mouse 10.9 Rabbit AZA. A summary of PK parameters measured following a single administration of OMS858 by SC or IV injection to mice and monkeys is shown in TABLE 23. Plots of mean OMS858 serum concentration over time following a single IV or SC administration to mice (left panel) and monkeys (right panel) are shown in FIGURE 23. Following a single SC administration, the median time at which maximum concentration was reached (Wx) was 24 to 168 hours post dose in mice and 72 or 168 hours post dose in monkeys. Following a single SC or IV administration, the elimination tvs of OMS858 was 203 to 409 hours in mice arid 196 to 487 hours in monkeys. Maximum observed concentration (Cmax) and total exposure (area under the time-concentration curve extrapolated to infinity [AUCw]) generally increased with dose in a dose-proportional manner in mice and monkeys Bioavailability determined using total exposure (AUC / nf) following a single SC administration of 1 mg / kg OMS858 was 85.7% in mice and 93.0% in monkeys. 'FABLE 23: Pharmacokinetic parameters following single administration of OMS858 by SC and IV injection to mice and monkeys Species Parameter 0.1 mg Ay SC 0.3 mg / kg SC 1.0 mg / kg SC 3.9 mg / kg SC 1 wg / kg IV Mouse® Co(pg / mL)b NA NA NA NA 24.3 W (G 24.0 168 72.0 72.0 0.0830 fox (ugmiL) 1.19 2.54 8.54 23.1 24.3 V .-m ax?'' O 0 L C (^g / inL) / (mg / kg) 1 1 .9 8.47 8.54 7.71 24.3 A.UC;0.336V (h*pg / mL) 282 716 2170 6040 2570 AUGo-x^v / Dese (h*pg / mL) / (mg / kg) 2820 2390 2170 2010 2570 W (h) 1340 1340 1340 1340 1340 AUGo-o (hGgdnL) 519 1220 4540 14100 5300 AU Gn? (h*p^mL) 526 1230 4810 16000 5610 Species Parameter 0.1 mg / kg SC 0.3 mg / kg SC 1..() mg / kg SC 3.0 mg / kg SC 1 mg / kg IV Vss (mL / kg)b NA NA NA NA 36.7 Bioavailability« NA NA 93.0% NA NA a Serum parameters reported for male mice based on composite mean concentration versus time data. b Determined for IV group only at the 1 mg / kg dose level, c Bioavailability == AUCinf SC / AUCinf IV. d Mean serum parameters reported for male monkeys. AUCjousfih):::: area under the time-concentration curve from 0 to 336 hours postdose, AUQo 336h> / Dose = dose normalized area under the time-concentration curve from 0 to 336 hours postdose; AUCwa ::: area under the time-concentration curve from 0 to t hours (last measured timepoint), AUCinf :::: area under the time-concentration curve extrapolated to infinity; Co ::: estimated concentration at time 0; Cffiax =; maximum observed concentration; C;!;3X / Dose =; dose-normalized maximum observed concentration; h =: hour(s); NA =: not applicable, SC =: subcutaneous; IV == intravenous; 1½ == terminal half-life; =; last measurable timepoint; W == time at which maximum concentration is reached, Vss ::: volume of distribution at steady state; Vz = volume of distribution based on terminal elimination phase Example IS Phase 1 Single-Dose Clinical Study of OMS858 in Healthy Human Subjects A single ascending-dose blind study of intravenous (IV) and subcutaneous (SC) administration of OMS858 in healthy subjects is carried out to assess safety, tolerability, PK, PD, and immunogenicity as compared to a placebo. A total of 48 healthy human volunteers are divided into 6 cohorts of 8 subjects each. In each cohort, 6 subjects are administered OMS858 and 2 subjects are administered placebo. Both the subjects and the medical staff administering the doses are blinded with respect to which subjects receive OMS858 and which receive placebo. The dosing of the 6 cohorts is as follows: • Cohort I: single IV dose of 0.01 mg / kg OMS858 or placebo ♦ Cohort 2: single IV dose of 0.03 mg / kg OMS858 or placebo All publications, patent applications, and patents mentioned in this specification are herein incorporated by reference. While certain embodiments of the invention have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. Although the invention has been described in connection with specific embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the specific embodiments described that are obvious to those skilled in the fields of medicine, immunology, pharmacology, or related fields are intended to be within the scope of the Invention. Accordingly, the following numbered paragraphs describing specific embodiments are provided for clarity, but should not be construed to limit the claims. 1. An isolated monoclonal armbody or antigen-binding fragment thereof that specifically binds to an epitope located within the serine protease domain of human MASP-2, wherein said epitope is located within ammo acids wsDIRMGTLKRLAPHYTQAWsw (SEQ ID NO:6), wherein the antibody or ami gen-binding fragment thereof inhibits lectin pathway complement activation. 2. The isolated antibody or antigen-binding fragment thereof of paragraph 1, wherein the antibody or antigen-binding fragment competes with C4 binding to MASP-2. 3. The isolated antibody, or antigen-binding fragment thereof of paragraph 1, wherein the antibody or antigen-binding fragment thereof forms a hydrogen bond with least one of human MASP-2 Lys 503 and / or His 508. 4. The isolated antibody or antigen-binding fragment thereof of paragraph 1, wherein the antibody or antigen-binding fragment thereof forms a hydrogen bond with human MASP-2 His 508. 5. The isolated armbody or antigen-binding fragment thereof of paragraph 1, wherein the antibody or antigen-binding fragment thereof forms a van-der-Waals contact with one or more of the following human MASP-2 amino acids: Asp 496, Lys 503, Ser 506, Pro 507, His 508 and Trp 513. 6. An isolated antibody or antigen-binding fragment thereof of paragraph 1, wherein the antibody or antigen-binding fragment thereof comprises: (a) a heavy chain variable region comprising a HC-CDRl having the sequence NXXMH, wherein X at position 2 is H or Y and wherein X at position 3 is H or W; a HC-CDR2 set forth as SEQ ID NO:63 (D1DXSDSEXXYXXKFKD) wherein X at position 4 is P or A; and wherein X at position 9 is T or 1, and wherein X at position 10 is H or Y, and wherein X at position 12 is I or N, and wherein X at position 13 is E or Q; and a HC-CDR3 set forth as SEQ ID \O fo (GDITTTLRYFDV); and ib) a light chain variable region comprising a LC-CDR1 set forth as SEQ ID NO:64 (SASSSVXYMY) wherein X at position 7 is R or S; a LC-CDR2 set forth as SEQ ID NO:34 (DTSNLAS) and a LC-CDR3 set forth as SEQ ID NO:36 (QQWSSYPLT); or (b) a heavy chain variable region comprising a HC-CDRl set forth as SEQ ID NO:25 (SYWMH), a HC-CDR2 set fords as SEQ ID NO:27 (NINPSNGGTNCNEKFKN) and a HC-CDR3 set forth as SEQ ID NO:29 (WAYDAMDY) and a LC-CDR1 set forth as SEQ ID NO-41 (RASESVDSYGNSFMH), a LC-CDR2 set forth as SEQ ID NO:43 (FASNLES) and a LC-CDR3 set forth as SEQ ID NO:45 (QQSNEDPLT). 7. The isolated antibody or antigen-binding fragment thereof of paragraph 6(a), wherein the HC-CDRl comprises SEQ ID NO: 14 (NYWMH), 8. The isolated antibody or antigen-binding fragment thereof of paragraph 6(a), wherein the HC-CDRl comprises SEQ 1DNO:56 (NYHMH). 9. The isolated antibody or antigen-binding fragment thereof of paragraph 6(a), wherein the HC-CDRl comprises SEQ ID NO: 57 (NHHMH). 10. The isolated antibody or antigen-binding fragment thereof of paragraph 6(a), wherein, the HC-CDR2 comprises SEQ ID NO: 16 (DIDPSDSETHYIEKFKD) 11. The isolated antibody or antigen-binding fragment thereof of paragraph 6(a), wherein the HC-CDR2 comprises SEQ ID NO:22 (DIDPSDSEIYYNQKFKD). N():32 (SASSSVRYMY) the LC-CDR2 comprises STQ ID NO:34 (DTSNLAS) and the LC-CDR3 comprises SEQ ID NO:36 (QQWSSYPLT). 19. The isolated antibody or antigen-binding fragment thereof of paragraph 6(a), wherein the HC-CDR1 comprises SEQ ID NO: 14 (NYWM); the HC-CDR2 comprises SEQ ID NO: 16 (D1DPSDSETHYEKFKD), and the HC-CDR3 comprises SEQ ID NO: 18 (GDITTTLRYFDV) and theLC-CDRl comprises SEQ ID NO:32 (SASSSVRYMY), the LC-CDR2 comprises SEQ ID NO:34 (DTSNLAS), and the LC-CDR3 comprises SEQ ID NO. 3 6 (QQWSSYPLT). 20. The isolated antibody or antigen-binding fragment thereof of paragraph 6(a), wherein the HC-CDR1 comprises SEQ ID NO: 14 (NYWM); the HC-CDR2 comprises SEQ ID NO:53 (DIDASDSETHYIEKFKD), and the HC-CDR3 comprises SEQ ID NO:18 (GDITTTLRYFDV) and the LC-CDR1 comprises SEQ ID NO:32 (SASSSVRYMY), the LC-CDR2 comprises SEQ ID NO:34 (DTSNLAS), and the LC-CDR3 comprises SEQ ID NO:36 (QQWSSYPLT). 21. The i solated antibody or antigen-binding fragment thereof of paragraph 6(a), wherein the HC-CDR1 comprises SEQ ID NO:56 (NYHMH); the HC-CDR2 comprises SEQ ID NO:53 (DIDASDSETHYIEKFKD), and the HC-CDR3 comprises SEQ ID NO: 18 (GDITTTLRYFDV ) and the LC-CDR1 comprises SEQ ID NO:32 (SASSSVRYMY), the LC-CDR2 comprises SEQ ID NO:34 (DTSNLAS), and the LC-CDR3 comprises SEQ ID NO:36 (QQWSSYPLT). 22. The isolated antibody or antigen-binding fragment thereof of paragraph 6(a), wherein the HC-CDR1 comprises SEQ ID NO:57 (NHHMH); the HC-CDR2 comprises SEQ ID NO:53 ((DIDASDSETHYIEKFKD) and the HC-CDR3 comprises SEQ ID NO'18 (GDITTTLRYFDV) and the LC-CDR1 comprises SEQ ID NO:32 (SASSSVRYMY) the LC-CDR.2 comprises SEQ IDNO:34 (DTSNLAS) and the LC-CDR3 comprises SEQ ID NO:36 (QQWSSYPLT). 23. The isolated antibody or antigen-binding fragment thereof of paragraph 6(a), wherein the HC-CDR1 comprises SEQ ID NO: 14 (NYWM), die HC-CDR2 comprises SEQ ID NO:22 (DIDPSDSEIYYNQKFKD) and the HC-CDR3 comprises SEQ ID NO: 18 (GDITTTLRYFDV ) and the LC-CDR1 comprises SEQ ID NO'39 (SASSSVSYMY ) the WO 2023 / 108028 PCT / US2022 / 081121 WO 2023 / 108028 PCT / US2022 / 081121

Claims

1. An isolated monoclonal antibody or antigen-binding fragment thereof that specifical ly binds to an epitope located within the serine protease domain of human MASP-2, wherein said epitope is located within amino acids 4%DIRMGTLKRLSPHYTQAW5b ("SEQ ID NO:6), wherein the antibody or antigen -binding fragment thereof inhibits lectin pathway complement activation.2 The isolated antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment competes with C4 binding to MASP-2.

3. The isolated antibody, or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof forms a hydrogen bond with least one of human MASP-2 Lys 503 and / or His 508.

4. The isolated antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof forms a hydrogen bond with human. MASP-2 His 508.

5. The isolated antibody or antigen-binding fragment thereof of claim 1, wherein, the antibody or antigen-binding fragment thereof forms a van-der-Waals contact with one or more of the following human MASP-2 amino acids: Asp 496, Lys 503, Ser 506, Pro 507, His 508 and Trp 513.

6. An isolated antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof comprises:(a) a heavy chain variable region comprising a HC-CDRI having the sequence NXXMH, wherein X at position 2 is H or Y and wherein X at position 3 is H or W; a HC-CDR2 set forth as SEQ ID NO:63 (DIDXSDSEXXYXXKFKD) wherein X at position 4 is P or A; and wherein X at position 9 is T or I, and wherein X at position 10 is H or Y, and wherein X at position 12 is I or N, and wherein X at position 13 is E or Q: and a HC-CDR3 set forth as SEQ ID NO: 18 (GDITTTLRYFDV), and (b) a light chain variable region comprising a LC-CDR1 set forth as SEQ ID NO:64 (SASSSVXYMY) wherein X at position 7 is R or S: a LC-CDR2 comprises SEQ ID NO:34 (DTSNLAS) and the LC-CDR3 comprises SEQ ID N():36 (QQWSSYPLT).

16. The isolated antibody or antigen-binding fragment thereof of claim 6(a), wherein the HC-CDR1 comprises SEQ ID NO: 14 (NYWMH); the HC-CDR2 comprises SEQ ID NO: 16 (DIDPSDSETHYIEKFKD) or SEQ ID NO:53 (DIDASDSETHYIEKFKD) and the HC-CDR3 comprises SEQ ID NO: 18 (GDITTTI.,RYFDV) and the LC-CDR1 comprises SEQ ID NO:32 (SASSSVRYMY) the LC-CDR2 comprises SEQ ID NO:34 (DTSNLAS) and the EC-CDR.3 comprises SEQ IDNO:36 (QQWSSYPLT).

17. The isolated antibody or antigen-binding fragment thereof of claim 6(a), wherein the HC-CDR1 comprises SEQ ID NO:56 (NYHMH); the HC-CDR2 comprises SEQ ID NO: 16 (DIDPSDSETHYIEKFKD) or SEQ ID NO:53 (DIDASDSETHYIEKFKD) and the HC-CDR3 comprises SEQ ID NO'18 (GDITTTLRYFDV) and the LC-CDR1 comprises SEQ ID NO:32 (SASSSVRYMY) the LC-CDR2 comprises SEQ ID NO:34 (DTSNLAS) and the LC-CDR3 comprises SEQ ID NO.36 (QQWSSYPLT).

18. The isolated antibody or antigen-binding fragment thereof of claim 6(a), wherein the HC-CDR1 comprises SEQ ID NO:57 (NHHMH); the HC-CDR2 comprises SEQ ID NO: 16 (DIDPSDSETHYIEKFKD) or SEQ ID NO:53 (DIDASDSETHYIEKFKD) and the HC-CDR3 comprises SEQ ID NO: 18 (GDITTTLRYFDV) and the LC-CDR1 comprises SEQ ID NO.32 (SASSSVRYMY) the LC-CDR2 comprises SEQ ID NO:34 (DTSNLAS) and the IC-CDR3 comprises SEQ ID NO:36 (QQWSSYPLT).

19. The isolated antibody or antigen-binding fragment thereof of claim 6(a), wherein the HC-CDR1 comprises SEQ ID NO: 14 (NYWM): the HC-CDR2 comprises SEQ ID NO: 16 (DIDPSDSETHYIEKFKD), and the HC-CDR3 comprises SEQ ID NO: 18 (GDITTTLRYFDV) and the LC-CDR1 comprises SEQ ID NO:32 (SASSSVRYMY), the LC-CDR2 comprises SEQ ID NO:34 (DTSNLAS), and the LC-CDR3 comprises SEQ ID NO:36 (QQWSSYPLT).

20. The isolated antibody or antigen-binding fragment thereof of claim 6(a), wherein the HC-CDR1 comprises SEQ ID NO: 14 (NYWM); the HC-CDR2 comprises SEQ 1DNO:53 (DIDASDSETHYIEKFKD), and the HC-CDR3 comprises SEQ ID NO: 18 (GDITTTLRYFDV) and the LC-CDR1 comprises SEQ ID NO.32 (SASSSVRYMY), the(D1DASDSETHYIEKFKD),SEO ID(GDITTTLRYFDV ) and the LC-CDR1 comprises SEO ID NO:39 (SASSSVSYMY ) the2 comprises SEO ID NO;34 fDTSNLAS) and the LC-CDR3 comprises SEO IDQ5% $8% 00% nj- 100% Oentk'O to SFO TP 10 or SFO ID NO26. The isolated antibody or antigen-binding fragment of claim 6(a), wherein the antibody or antigen-binding fragment thereof comprises a heavy chain comprising at least 80%, 85%, 90%, 95%, 98%, 99% or 100% identical to SEQ ID NO:8 and a right chain comprising at least 80%, 85%, 90%, 95%, 98%, 99% or 100% identical to SEQ ID NO: 11.

27. The isolated antibody or antigen-binding fragment of claim 6(b), wherein the antibody or antigen-binding fragment thereof comprises a heavy chain comprising at least 80%, 85%, 90%, 95%, 98%, 99% or 100% identical to SEQ ID NO:9 and a light chain comprising at least 80%, 85%, 90%, 95%, 98%, 99% or 100% identical to SEQ ID NO; 12.

28. The isolated antibody or antigen binding fragment thereof of any of claims 1-27, wherein the antibody or antigen-binding fragment is selected from the group consisting of a human antibody, a humanized antibody, a chimeric antibody, a murine antibody, and an antigenbinding fragment of any of the foregoing.

29. The isolated antibody or antigen-binding fragment thereof of any of claims 1-27, wherein the antibody or antigen binding fragment thereof is selected from the group consisting of a single chain antibody, an ScFv, a Fab fragment, an Fab’ fragment, an F(ab’)2 fragment, a univalent antibody lacking a hinge region and a whole antibody.

30. The isolated antibody or antigen-binding fragment thereof of any of claims 1-27, further comprising an immunoglobulin constant region.

31. The isolated antibody or antigen binding fragment thereof of any one of claims 1-27, wherein the antibody or antigen-binding fragment thereof is humanized.

32. The isolated antibody or antigen-binding fragment thereof of any one of claims 1-27, wherein the antibody or antigen-binding fragment thereof is an IgG immunoglobulin selected from the group consisting of IgG 1, lgG2, and IgG4.

33. The isolated antibody or antigen-binding fragment thereof of any one of claims 1-27, wherein the antibody or antigen-binding fragment thereof comprises one or more mutations m the Fc region.

34. The isolated antibody or antigen-binding fragment thereof of claim 33, wherein the Fc region comprises an S228P amino acid substitution.

35. The isolated antibody or antigen-binding fragment thereof of any of claims 1--34, wherein the antibody or antigen-binding fragment thereof binds to the serine protease domain of human MAS P-2 with an affinity of less than 20 nM.

36. The isolated antibody or antigen-binding fragment thereof of claim 35, wherein the antibody or antigen-binding fragment thereof binds to the serine protease domain of human MASP-2 with an affinity of less than 10 nM.

37. The isolated antibody or antigen-binding fragment thereof of any of claims 1-34, wherein the antibody or antigen-binding fragment thereof inhibits the lectin pathway in mammalian blood.

38. The isolated antibody or antigen-binding fragment thereof of claim 37, wherein lectin pathway inhibition comprises a decrease in C3b deposition under lectin pathway-specific assay conditions.

39. The isolated antibody or antigen-binding fragment thereof of claim. 37, wherein lectin pathway inhibition comprises a decrease in C4 deposition under lectin pathway-specific assay conditions.

40. The isolated antibody or antigen-binding fragment thereof of claim 37, wherein lectin pathway inhibition comprises a decrease in MAC deposition under lectin pathway-specific assay conditions.

41. The isolated antibody or antigen-binding fragment thereof of any of claims 1-34, wherein the antibody or antigen-binding fragment thereof does not inhibit the classical pathway in mammalian blood.

42. A composition comprising the antibody or antigen-binding fragment thereof of any of claims 1-34 and a pharmaceutically acceptable excipient.

43. The composition of claim 42, wherein said composition is formulated for subcutaneous administration.

44. An isolated polynucleotide encoding the heavy and light chain variable regions of an antibody or antigen-binding fragment thereof from any one of claims 1-34.

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