Therapeutic methods and uses of antibodies against human MASP-3

Abstract

Methods for treating paroxysmal nocturnal hemoglobinuria, complement factor 3 glomerulopathy, or idiopathic immune complex-mediated glomerulonephritis using MASP-3 serine protease inhibitors are provided. In some embodiments, the MASP-3 serine protease inhibitor is an anti-MASP-3 antibody. Use of MASP-3 serine protease inhibitors in the treatment of paroxysmal nocturnal hemoglobinuria, complement factor 3 glomerulopathy, or idiopathic immune complex-mediated glomerulonephritis, and for the manufacture of a medicament for treating paroxysmal nocturnal hemoglobinuria, complement factor 3 glomerulopathy, or idiopathic immune complex-mediated glomerulonephritis, is also provided. TIFF2025537131000011.tif104156

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to the use of an antibody or antigen-binding fragment thereof that specifically binds to human MASP-3.

[0002] Sequence Listing Statement The sequence listing associated with this application is provided in XML format in lieu of a hard copy and is hereby incorporated by reference. The XML file containing this sequence listing is named MP_1_0337_SequenceListing_20231023_ST26.xml. This XML file is 19,552 bytes, was created on October 23, 2023, and has been submitted via the Patent Center along with the application herein. [Background technology]

[0003] background The complement system provides an early mechanism for initiating, amplifying, and orchestrating immune responses to microbial infections and other acute insults in humans and other vertebrates (M.K. Liszewski and J.P. Atkinson, in Fundamental Immunology, 3rd ed., W.E. Paul, Raven Press, Ltd., New York, 1993; non-patent literature 1) and also plays a role in immune surveillance against cancer (P. Macor, et al., Front. Immunol., 9:2203, 2018; non-patent literature 2). The complement system involves more than 30 fluid-phase and membrane-bound glycoproteins, cofactors, receptors, and regulatory proteins (S. Meyer, et al., mAbs, 6:1133, 2014; non-patent literature 3). Many of these are serine proteases, which form a highly regulated cascade of activation events. The complement system rapidly responds to molecular stress signals through a cascade of sequential proteolytic reactions initiated by the binding of pattern recognition receptors (PRRs) to unique structures on damaged cells, biomaterial surfaces, or invading microorganisms (Reis et al., Nat. Rev. Immunol., 18:5, 2018).

[0004] Activation of the complement cascade induces diverse immune effector functions, such as cell lysis, phagocytosis, chemotaxis, and immune activation (S. Meyer, et al., 2014). Furthermore, the complement system also acts as a bridge between the innate immune response and the subsequent activation of adaptive immunity. In addition to its anti-infective properties, the complement system is also involved in the clearance of immune complexes and apoptotic cells, tissue regeneration, hematopoietic progenitor cell recruitment, and angiogenesis (T.M. Pierpont et al., Front. Oncol., 8:163, 2018).

[0005] The complement system can be activated through three distinct pathways: the classical pathway, the alternative pathway, and the lectin pathway (see Figure 1). Activation of the classical pathway is triggered by a conformational change in the classical pathway initiation complex C1, which is composed of a hexamer of trimeric chains, C1q, and a heterotetramer of the C1q-related serine proteases C1r and C1s, as detailed below. Binding of C1q to a complex composed of host antibodies bound to foreign particles (i.e., antigens) initiates activation of the C1 complex. Because classical pathway activation largely depends on a prior adaptive immune response by the host, the classical pathway is an effector mechanism of the adaptive immune system. In contrast, both the lectin and alternative pathways are independent of adaptive immunity and are part of the innate immune system.

[0006] The classical pathway (CP) is primarily initiated by antibody-antigen complexes. Antibodies of the IgM and IgG subclasses bind to antigens on the surface of pathogens or target cells and recruit the C1 complex. The C1 complex consists of the multimolecular recognition subcomponent C1q (composed of six heterotrimers of C1qA, B, and C chains) and the C1q-related serine proteases C1r and C1s. Upon binding of C1q to the Fc region of either antigen-bound IgM or at least two IgGs bound to each antigen, the serine protease C1r converts from its zymogen form to its enzymatically active form and subsequently cleaves and activates its substrate C1s. Once activated, C1s cleaves C4 into its fragments C4a and C4b. C4b binds to complement component C2. This complex, C4bC2, is cleaved by C1s in a second cleavage step to release C2b, forming the complement C3 convertase complex, C4bC2a, the so-called C3 convertase, which cleaves the abundant plasma complement component C3 into C3a and C3b.

[0007] The lectin pathway is triggered by the binding of pattern recognition molecules, such as mannose-binding lectin (MBL), ficolins, or collectin-11 and collectin-10, to pathogen-associated molecular patterns (PAMPs) or apoptotic or distressed host cells. The recognition molecules form complexes with the MBL-related serine proteases MASP-1 and MASP-2, activating them upon binding, which leads to the cleavage of C2 and C4 and the formation of C3 convertase (C4bC2a).

[0008] The alternative pathway is initiated by spontaneous hydrolysis ("tickover") of C3 to C3(HO), which then binds to factor B (fB). The resulting conversion of the C3(HO)fB complex requires the enzymatic activity of another highly specific serine protease called factor D. The availability of enzymatically active factor D is thought to be the limiting factor in the alternative pathway amplification loop, and its availability requires the action of another enzyme, MASP-3, which converts pro-factor D (proCFD) to its active form, mature factor D (matCFD) (Dobo et al., Sci Rep 6:31877, 2016). Another serine protease, activated maturation factor D (matCFD), cleaves the C3(HO)-bound fB into Ba and Bb. Bb is also a serine protease and is involved in the formation of the alternative C3 pro-convertases C3(H2O)Bb and C3bBb, which cleave C3 into C3a and C3b. This mechanism maintains a constitutively low level of activity in the alternative pathway. Newly generated C3b, formed by C3(H2O)Bb or by the C3 convertases C4bC2a of the classical and lectin pathways, binds to the target surface and sequesters fB, forming the C3bfB complex, which is cleaved by matCFD to generate another C3 convertase complex, C3bBb, forming an AP amplification loop. This convertase can be further stabilized by properdin, which prevents disruption of this complex and conversion of C3b by factors H and I. C3bBb is the functional convertase of the alternative pathway.

[0009] These three pathways converge upon the formation of the C3 convertases C4bC2a and C3bBb. The cleavage fragment of C3, C3a, is an anaphylatoxin that promotes inflammation. C3b functions as an opsonin by covalently binding to the surface of target cells via a thioester bond, marking them for circulating complement receptor (CR)-displaying effector cells, such as NK cells and macrophages, which contribute to complement-dependent cellular cytotoxicity (CDCC) and complement-dependent cytophagocytosis (CDCP), respectively. C3b also binds to the C3 convertase (either C4bC2a or C3bBb) to form the C5 convertase (C4bC2a(C3b)n or C3bBb(C3b)n, respectively), which leads to MAC formation and subsequent CDC. Furthermore, the cell-associated cleavage fragments of C3b, iC3b and C3dg, can promote adaptive immune responses through complement receptor-mediated cytotoxicity (CDCC and CDCP) and B cell activation (MC Carroll, Nat. Immunol., 5:981, 2004 (Non-Patent Document 7)).

[0010] Formation of C5 convertase leads to the cleavage of C5 into C5a and C5b. C5a is another anaphylatoxin. C5b recruits C6-9 to form the membrane attack complex (MAC or C5b-9 complex). The MAC complex triggers pore formation, leading to membrane disruption and cytolysis of target cells (a process known as complement-dependent cytotoxicity, or CDC). While direct cytolysis via MAC formation has traditionally been recognized as the terminal effector mechanism of the complement system, C3b-mediated opsonization and proinflammatory signaling, as well as the anaphylatoxin function of C3a, are thought to play important roles in mediating complement-dependent inflammatory pathology.

[0011] Complement regulatory proteins (CRPs) prevent unnecessary complement activation and the consumption of complement components. These proteins are present in most cells and, through tight regulation, play an important role in protecting host cells from complement-mediated damage. CRPs can be soluble proteins (sCRP) or membrane-bound complement regulatory proteins (mCRP) (P.F. Zipfel and C. Skerka, Nat. Rev. Immunol. 9:729, 2009). One of the most abundant protease inhibitors in the circulation is C1 inhibitor (C1inh), with a mean plasma concentration of 0.25 g / L (H. Gregorek, Comp. and Inflamm. 8:310, 1991). C1inh binds to and inactivates C1r, C1s, and two MBL-related serine proteases, MASP-1 and MASP-2. It is therefore a major inhibitor of the classical and lectin pathways. Other sCRPs include C4-binding protein (C4BP) and factors H, B, D, and I (PF Zipfel and C. Skerka, 2009).

[0012] In contrast to sCRP, mCRP controls the complement pathway by targeting both C3 and C4 (P.F. Zipfel and C. Skerka, 2009). For example, CD46 (membrane cofactor protein; MCP) is a cofactor of factor I, which mediates the cleavage of C3b and C4b into their respective inactive degradation products, iC3b and iC4b, respectively, thereby inhibiting all three complement pathways. CD55 (decay-accelerating factor; DAF) promotes the decay of C3 and C5 convertases, which inhibits all three complement pathways. CD59 (protectin) prevents the assembly of MAC by inhibiting the polymerization of C9 and its subsequent binding to C5b-8, thereby inhibiting all three pathways.

[0013] Although complement activation provides a valuable first line of defense against potential pathogens, complement activation, which promotes a protective immune response, can also pose a potential threat to the host (K.R. Kalli, et al., Springer Semin. Immunopathol. 15:417-431, 1994; B.P.Morgan, Eur. J. Clinical Investig. 24:219-228, 1994). For example, C3 and C5 proteolytic products recruit and activate neutrophils. Activated neutrophils, while essential for host defense, can indiscriminately release destructive enzymes, causing organ damage. In addition, complement activation can trigger the deposition of lytic complement components not only on microbial targets but also on nearby host cells, resulting in host cell lysis. Thus, dysregulated and unabated complement activity can function as a major driver of disease, causing the uncontrollable spread of inflammation and tissue destruction.

[0014] The alternative complement pathway (AP) is typically described as a downstream amplifier of complement activity, increasing the host immune response after activation of complement via the classical and lectin pathways. However, the AP's ability to generate a positive feedback loop of active protease complexes that drive the formation of new complexes of the same type is unique within the complement pathway (Lachmann PJ, Adv Immunol 104:115-49, 2009). Activation of the AP is thought to be a key pathomechanism in several acute and chronic disease states and may represent an effective point for clinical management.

[0015] Increasing recognition of the importance of complement-mediated tissue injury in various disease states has highlighted the need for effective complement inhibitors. To date, few complement-targeting drugs have been approved for human use. Eculizumab (Soliris®) and the related molecule ravulizumab (Ultomiris®) are antibodies that selectively bind to C5. Avacopan (Tavneos®) is a small molecule drug that acts as a C5a receptor antagonist and selectively blocks the effects of C5a. Pegcetacoplan (Empaveli®) is a pegylated peptide that binds to and inhibits complement component C3. All of these currently approved drugs inhibit multiple complement pathways, which can lead to undesirable effects. Therefore, inhibitors that selectively block the initiation step of a single complement pathway, such as the alternative pathway, would offer significant advantages over existing treatment options.

[0016] The role of the complement system in contributing to tissue damage in many clinical conditions, and the lack of targeted treatments that block upstream complement activation, particularly AP activation, highlights the urgent need to develop therapeutically effective complement inhibitors to prevent these deleterious effects. [Prior art documents] [Non-patent literature]

[0017] [Non-Patent Document 1] M.K. Liszewski and J.P. Atkinson, in Fundamental Immunology, edited by W.E. Paul (3rd ed., Raven Press, Ltd., New York), 1993 [Non-patent document 2] P. Macor,et al.,Front.Immunol.,9:2203,2018 [Non-patent document 3] S. Meyer,et al.,mAbs,6:1133,2014 [Non-patent document 4] Reis et al.,Nat.Rev.Immunol.,18:5,2018 [Non-Patent Document 5] TMPierpont et al.,Front.Oncol.,8:163,2018 [Non-patent document 6] Dobo et al.,Sci Rep 6:31877,2016 [Non-Patent Document 7] MCCarroll, Nat. Immunol.,5:981,2004 [Non-patent document 8] PFZipfel and C.Skerka, Nat.Rev.Immunol.9:729,2009 [Non-Patent Document 9] H. Gregorek,Comp.and Inflamm.8:310,1991 [Non-Patent Document 10] KR Kalli,et al.,Springer Semin.Immunopathol.15:417 431,1994 [Non-Patent Document 11] BPMorgan,Eur.J.Clinical Investig.24:219 228,1994 [Non-Patent Document 12] Lachmann PJ,Adv Immunol 104:115-49,2009 Summary of the Invention

[0018] overview This Summary is provided to introduce some concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.

[0019] In one aspect, the present disclosure provides a method of treatment using a MASP-3 serine protease inhibitor. In some embodiments, the MASP-3 serine protease inhibitor is an anti-MASP-3 antibody or antigen-binding fragment thereof. In some embodiments, the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising HCDR1, HCDR2, and HCDR3 having the sequences shown as SEQ ID NO:3, SEQ ID NO:4 or 11, and SEQ ID NO:5, respectively, and a light chain variable region comprising LCDR1, LCDR2, and LCDR3 having the sequences shown as SEQ ID NO:6 or 14, SEQ ID NO:7, and SEQ ID NO:8, respectively.

[0020] In some embodiments, MASP-3 serine protease inhibitors are used in treatment methods for diseases and disorders related to the alternative pathway of complement. In some embodiments, the disease or disorder is paroxysmal nocturnal hemoglobinuria (PNH). In some embodiments, the disease or disorder is complement factor 3 glomerulopathy (C3G). In some embodiments, the disease or disorder is idiopathic immune complex-mediated glomerulonephritis (ICGN). [Brief explanation of the drawings]

[0021] The foregoing aspects and many of the attendant advantages of the present invention will become more readily appreciated as they become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings as hereinafter described.

[0022] [Figure 1] FIG. 1 is a schematic diagram of the complement system. [Figure 2] FIG. 2 is a graphical representation of a Phase 1 trial of antibody 13B1-10-1-NA in healthy subjects. [Figure 3] FIG. 3 is a graph showing the percent change in mean mature complement factor D (CFD) over time following IV administration of antibody 13B1-10-1-NA at doses of 3 mg / kg or 5 mg / kg to healthy subjects compared to placebo. [Figure 4] FIG. 4 is a graphical representation of a phase 1b trial of antibody 13B1-10-1-NA in patients with PNH, showing initial adjuvant treatment with antibody 13B1-10-1-NA and ravulizumab followed by 13B1-10-1-NA monotherapy. [Figure 5] Figure 5 is a graph showing mean hemoglobin levels in PNH patients during a Phase 1b study of antibody 13B1-10-1-NA. Patients were complement inhibitor treatment-naive adults with a confirmed diagnosis of PNH. Antibody 13B1-10-NA was administered by subcutaneous injection at a dose of 5 mg / kg every 4 weeks. Data shown include 10 patients at various time points after the first dose. Horizontal lines indicate the lower limit of normal for men (LLN(M)) and women (LLN(F)), as indicated. The number of patients contributing to each data point is indicated below the x-axis. [Figure 6] Figure 6 is a graph showing hemoglobin levels in each of 10 PNH patients in a Phase 1b trial of antibody 13B1-10-1-NA. Patients, dosing, and time points are as described for Figure 5. Horizontal lines indicate the lower limit of normal for men (LLN(M)) and for women (LLN(F)), as indicated. Male patients are indicated by squares and female patients by circles. Patients 6 and 7, indicated by asterisks, also had myelodysplastic syndrome (MDS). [Figure 7] Figure 7 is a graph showing mean LDH levels in PNH patients during a Phase 1b study of antibody 13B1-10-1-NA. Patients, dosing, and time points are as described for Figure 5. Horizontal lines indicate the upper limit of normal (ULN) and 1.5 x upper limit of normal (ULN 1.5 x), as indicated. The number of patients contributing to each data point is indicated below the x-axis. [Figure 8]Figure 8 is a graph showing LDL levels in each of 10 PNH patients in a Phase 1b study of antibody 13B1-10-1-NA. Patients, dosing, and time points are as described for Figure 5. Horizontal lines indicate the upper limit of normal (ULN) and 1.5 x upper limit of normal (ULN 1.5 x), as indicated. [Figure 9] Figure 9 is a graph showing mean absolute reticulocyte counts in PNH patients during a Phase 1b study of antibody 13B1-10-1-NA. Patients, dosing, and time points are as described for Figure 5. Horizontal lines indicate the upper limit of normal (ULN) and lower limit of normal (LLN), as indicated. The number of patients contributing to each data point is shown below the x-axis. [Figure 10] Figure 10 is a graph showing absolute reticulocyte counts in each of 10 PNH patients in a Phase 1b study of antibody 13B1-10-1-NA. Patients, dosing, and time points are as described for Figure 5. Horizontal lines indicate the upper limit of normal (ULN) and lower limit of normal (LLN), as indicated. [Figure 11] Figure 11 is a graph showing the mean GPI-deficient erythrocyte clone size in PNH patients during a Phase 1b trial of antibody 13B1-10-1-NA. Patients, dosing, and time points are as described for Figure 5. The number of patients contributing to each data point is indicated below the x-axis. DETAILED DESCRIPTION OF THE INVENTION

[0023] Detailed Description I. Definition Unless specifically defined herein, all terms used herein have the same meaning as would be understood by a person skilled in the art of the present invention. The following definitions are provided to clarify the terms used in the specification and claims to describe the present invention. Additional definitions are set forth throughout this disclosure.

[0024] Any concentration range, percentage range, ratio range, or integer range herein shall be understood to include any integer value within the recited range, and fractions thereof, as appropriate (e.g., tenths and hundredths of an integer), unless otherwise indicated or otherwise clear from the context. Any numerical range recited herein with respect to any physical characteristic, such as polymer subunits, size, or thickness, shall be understood to include any integer within the recited range, and fractions thereof, as appropriate, unless otherwise indicated or otherwise clear from the context. As used herein, the term "about" shall specify that a given range or value may vary by ±10% of the stated range or value, unless otherwise indicated.

[0025] As used herein, the terms "a," "an," and "the" should be understood to refer to one or more of the referent components. The use of alternatives (e.g., "or") should be understood to mean one or both of the alternatives, or any combination thereof. As used herein, the terms "comprise," "have," and "include" are used synonymously, and these terms and variations thereof should be construed as open-ended.

[0026] "Optional" or "optionally" means that the subsequently described element, component, event, or circumstance may be present or occur, or may not be present or occur, and that the description encompasses the case where the element, component, event, or circumstance is present or occurs, as well as the case where it is not present or occurs.

[0027] It should be understood that each individual construct or group of constructs derived from the various combinations of structures and subunits described herein is disclosed by this application to the same extent as if each construct or group of constructs were described individually, and thus, selection of a particular structure or particular subunit is within the scope of this disclosure.

[0028] The term "consisting essentially of" is not equivalent to "comprising" and refers to a specified material or step in a claim or something that does not substantially affect the basic characteristics of the claimed subject matter. For example, a protein domain, region, or module (e.g., a binding domain) or protein "consists essentially of" a particular amino acid sequence if the amino acid sequence of the domain, region, module, or protein contains extensions, deletions, mutations, or combinations thereof (e.g., amino- or carboxy-terminal amino acids or inter-domain amino acids) that collectively occupy at most 20% of the length of the domain, region, module, or protein (e.g., at most 15%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, or 1%) and do not substantially affect (i.e., reduce) the activity of the domain, region, module, or protein (e.g., target binding affinity of a binding protein) (i.e., do not reduce activity by more than 50%, e.g., 40%, 30%, 25%, 20%, 15%, 10%, 5%, or 1%).

[0029] As used herein, the terms "treat," "treatment," or "ameliorate" refer to the medical management of a disease, disorder, or condition of interest. Generally, an appropriate dose or treatment regimen comprising a targeted complement-activating molecule or composition of the present disclosure is administered in an amount sufficient to elicit a therapeutic or prophylactic benefit. Therapeutic or prophylactic / preventative benefit includes improved clinical outcome, relief or alleviation of disease-related symptoms, reduced symptom occurrence, improved quality of life, prolonged disease-free state, reduced disease extent, stabilization of the disease state, delay or prevention of disease progression, remission, survival, extended survival, or any combination thereof.

[0030] A "therapeutically effective amount" or "effective amount" of a targeted complement-activating molecule, polynucleotide, vector, host cell, or composition of the present disclosure refers to that amount of composition or molecule sufficient to produce a statistically significant therapeutic benefit, including improved clinical outcome, reduction or alleviation of disease-related symptoms, reduction in symptom occurrence, improved quality of life, prolonged disease-free state, reduced extent of disease, stabilization of disease state, delayed disease progression, remission, survival, or prolonged survival. When referring to an individual active ingredient administered alone, a therapeutically effective amount refers to the effect of that ingredient or the effect of cells expressing that ingredient alone. When referring to a combination, a therapeutically effective amount refers to the combined amount of active ingredients, or of combined adjunct active ingredients and cells expressing the active ingredients, that produces a therapeutic effect, whether administered sequentially, sequentially, or simultaneously.

[0031] As used herein, a "subject" encompasses any mammal, including, but not limited to, humans, non-human primates, dogs, cats, horses, sheep, goats, cattle, rabbits, pigs, and rodents. Subjects may be male or female, and may be of any suitable age, including infant, juvenile, adolescent, adult, or geriatric subjects.

[0032] As used herein, "amino acid" refers to naturally occurring and synthetic amino acids, as well as amino acid analogs and amino acid mimetics that function similarly to naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, as well as those that are later modified, such as hydroxyproline, γ-carboxyglutamate, and O-phosphoserine. Amino acid analogs refer to compounds that have the same basic chemical structure as a naturally occurring amino acid, i.e., an α-carbon bonded to a hydrogen, a carboxyl group, an amino group, and an R group, such as homoserine, norleucine, methionine sulfoxide, and methionine methylsulfonium. Such analogs have modified R groups (e.g., norleucine) or modified peptide backbones, but retain the same basic chemical structure as a naturally occurring amino acid. Amino acid mimetics refer to chemical compounds that have a structure that is different from the general chemical structure of an amino acid, but that function similarly to a naturally occurring amino acid.

[0033] As used herein, a "mutation" refers to a change in the sequence of a nucleic acid molecule or polypeptide molecule when compared to a reference or wild-type nucleic acid molecule or polypeptide molecule, respectively. Mutations can result in several different types of changes in the sequence, including nucleotide or amino acid substitutions, insertions, or deletions.

[0034] In the broadest sense, natural amino acids can be grouped based on the chemical characteristics of each amino acid's side chain. By "hydrophobic" amino acid we mean any of Ile, Leu, Met, Phe, Trp, Tyr, Val, Ala, Cys, or Pro. By "hydrophilic" amino acid we mean any of Gly, Asn, Gln, Ser, Thr, Asp, Glu, Lys, Arg, or His.

[0035] "Conservative substitution" refers to an amino acid substitution that does not significantly affect or alter the binding characteristics of a particular protein. Generally, a conservative substitution is one in which the substituted amino acid residue is replaced with an amino acid residue having a similar side chain. Conservative substitutions include those found in one of the following groups: Group 1: alanine (Ala or A), glycine (Gly or G), serine (Ser or S), threonine (Thr or T); Group 2: aspartic acid (Asp or D), glutamic acid (Glu or Z); Group 3: asparagine (Asn or N), glutamine (Gln or Q); Group 4: arginine (Arg or R), lysine (Lys or K), histidine (His or H); Group 5: isoleucine (Ile or I), leucine (Leu or L), methionine (Met or M), valine (Val or V); and Group 6: phenylalanine (Phe or F), tyrosine (Tyr or Y), tryptophan (Trp or W). Additionally or alternatively, amino acids can be grouped into conservative substitution groups based on similar function, chemical structure, or composition (e.g., acidic, basic, aliphatic, aromatic, or sulfur-containing). For example, where substitution is desired, the aliphatic group can include Gly, Ala, Val, Leu, and Ile. Other conservative substitution groups include sulfur-containing: Met and cysteine ​​(Cys or C); acidic: Asp, Glu, Asn, and Gln; small aliphatic, nonpolar, or weakly polar residues: Ala, Ser, Thr, Pro, and Gly; polar, negatively charged residues and their amides: Asp, Asn, Glu, and Gln; polar, positively charged residues: His, Arg, and Lys; large aliphatic, nonpolar residues: Met, Leu, Ile, Val, and Cys; and large aromatic residues: Phe, Tyr, and Trp. Further information can be found in Creighton (1984) Proteins, WH Freeman and Company.

[0036] As used herein, "protein" or "peptide" or "polypeptide" refers to a polymer of amino acid residues. Protein applies to both naturally occurring amino acid polymers, amino acid polymers in which one or more amino acid residues are artificial chemical mimetics of corresponding naturally occurring amino acids, and non-naturally occurring amino acid polymers. Variants of the proteins, peptides, and polypeptides of the present disclosure are also contemplated. In certain embodiments, variant proteins, peptides, and polypeptides comprise or consist of an amino acid sequence that is at least 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 99.9% identical to the amino acid sequence of a given or reference amino acid sequence described herein.

[0037] A "nucleic acid molecule" or "oligonucleotide" or "polynucleotide" or "polynucleic acid" refers to an oligomeric or polymeric compound containing covalently linked nucleotides, which may be composed of natural subunits (e.g., purine or pyrimidine bases) or non-natural subunits (e.g., morpholine rings). Purine bases include adenine, guanine, hypoxanthine, and xanthine, while pyrimidine bases include uracil, thymine, and cytosine. Nucleic acid molecules include polyribonucleic acid (RNA), including, for example, mRNA, microRNA, siRNA, viral genomic RNA, and synthetic RNA, and polydeoxyribonucleic acid (DNA), including, for example, cDNA, genomic DNA, and synthetic DNA. Both RNA and DNA can be single-stranded or double-stranded. If single-stranded, the nucleic acid molecule can be the coding strand or the non-coding strand (antisense strand). A nucleic acid molecule encoding an amino acid sequence includes all nucleotide sequences that encode the same amino acid sequence. Some versions of a nucleotide sequence may also contain introns, provided that the introns can be removed by co-transcriptional or post-transcriptional mechanisms. In other words, different nucleotide sequences can encode the same amino acid sequence as a result of redundancy or degeneracy in the genetic code, or due to splicing.

[0038] Variants of the nucleic acid molecules of the present disclosure are also contemplated. Variant nucleic acid molecules are at least 70%, 75%, 80%, 85%, 90%, and preferably 95%, 96%, 97%, 98%, 99%, or 99.9% identical to a given or reference polynucleotide nucleic acid molecule described herein, or hybridize to the polynucleotide under stringent hybridization conditions of 0.015 M sodium chloride, 0.0015 M sodium citrate at about 65-68°C, or 0.015 M sodium chloride, 0.0015 M sodium citrate, and 50% formamide at about 42°C. Nucleic acid molecule variants retain the ability to encode a binding domain having the functionality described herein, such as binding a target molecule.

[0039] "Percent sequence identity" refers to the relationship between two or more sequences, as determined by comparing the sequences. Preferred methods for determining sequence identity are designed to give the best match between the compared sequences. For example, sequences are aligned for optimal comparison (e.g., gaps can be introduced in one or both of the first and second amino acid or nucleic acid sequences for optimal alignment). Furthermore, non-homologous sequences can be ignored for comparison purposes. Percent sequence identity referred to herein is calculated over the entire length of the reference sequence, unless otherwise indicated. Methods for determining sequence identity and sequence similarity can be found in publicly available computer programs. Sequence alignment and percent identity calculations can be performed using BLAST programs (e.g., BLAST2.0, BLASTP, BLASTN, or BLASTX) or Megalign (DNASTAR) software. The mathematical algorithm used in BLAST programs can be found in Altschul et al., Nucleic Acids Res. 25:3389-3402, 1997. Appropriate parameters for measuring alignment can be determined by known methods, including any algorithms needed to achieve maximal alignment over the full-length of the sequences being compared.

[0040] The term "isolated" means that the material is removed from its original environment (e.g., the natural environment if it is naturally occurring). For example, a naturally occurring nucleic acid or naturally occurring polypeptide present in a living animal is not isolated, but the same nucleic acid or polypeptide separated from some or all of the coexisting materials in the natural system is isolated. Such a nucleic acid may be part of a vector, and / or such a nucleic acid or polypeptide may be part of a composition (e.g., a cell lysate), but is still isolated in that such a vector or composition is not part of the natural environment for the nucleic acid or polypeptide. "Isolated" can, in some embodiments, also describe an antibody, antigen-binding fragment, polynucleotide, vector, host cell, or composition that is outside the human body.

[0041] The term "gene" refers to a segment of DNA or RNA involved in producing a polypeptide chain; the term, in certain contexts, encompasses regions preceding and following the coding region (e.g., the 5' untranslated region (UTR) and the 3' UTR) as well as intervening sequences (introns) between individual coding segments (exons).

[0042] "Functional variant" refers to a polypeptide or polynucleotide that is structurally similar or substantially structurally similar to a parent or reference compound of the present disclosure, but differs slightly in composition (e.g., one or more bases, atoms, or functional groups are different or added or removed) such that the polypeptide or encoded polypeptide can perform at least one function of the parent polypeptide with at least 50% efficiency, preferably at least 55%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, 100% of the activity level of the parent polypeptide, or at an activity level greater than the activity level of the parent polypeptide. In other words, a functional variant of a polypeptide of the disclosure or the encoded polypeptide has "similar binding," "similar affinity," or "similar activity" if the functional variant exhibits improved performance, or no more than a 50% reduction in performance, compared to the parent or reference polypeptide in a selected assay, such as an assay for measuring enzymatic activity or binding affinity.

[0043] As used herein, a "functional portion" or "functional fragment" refers to a polypeptide or polynucleotide that comprises only a domain, portion, or fragment of a parent or reference compound, wherein the polypeptide or encoded polypeptide retains at least 50% of the activity associated with the domain, portion, or fragment of the parent or reference compound, preferably at least 55%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, 100%, or a higher activity level than the activity level of the parent polypeptide, or confers a biological benefit (e.g., an effector function). A "functional portion" or "functional fragment" of a polypeptide of the present disclosure or the encoded polypeptide has "similar binding" or "similar activity" if the functional portion or fragment exhibits improved performance or exhibits no more than a 50% reduction in performance compared to the parent or reference polypeptide in a chosen assay (for affinity, the reduction is preferably no more than 20% or 10%, or no more than a 1 log difference compared to the parent or reference).

[0044] As used herein, the terms "engineered," "recombinant," or "non-naturally occurring" refer to an organism, microorganism, cell, protein, polypeptide, nucleic acid molecule, or vector that contains at least one genetic modification or has been modified by the introduction of a foreign or heterologous nucleic acid molecule, where such modification or alteration is introduced by genetic engineering (i.e., human intervention). Genetic modifications include, for example, modifications that introduce expressible nucleic acid molecules encoding functional RNA, proteins, fusion proteins, or enzymes, or modifications that introduce the addition, deletion, or substitution of other nucleic acid molecules, or other functional disruption of the genetic material of a cell. Additional modifications include, for example, non-coding regulatory regions, where modifications alter the expression of a polynucleotide, gene, or operon.

[0045] As used herein, "heterologous" or "non-endogenous" or "foreign" refers to any gene, protein, compound, nucleic acid molecule, or activity that is not native to a host cell or subject, or any gene, protein, compound, nucleic acid molecule, or activity that is native to a host cell or subject, but that has been modified. Heterologous, non-endogenous, or foreign includes genes, proteins, compounds, or nucleic acid molecules that have been mutated or otherwise modified such that the structure, activity, or both differ between the native and modified gene, protein, compound, or nucleic acid molecules. In certain embodiments, a heterologous, non-endogenous, or foreign gene, protein, or nucleic acid molecule (e.g., a receptor, ligand, etc.) is not endogenous to a host cell or subject, and a nucleic acid encoding such a gene, protein, or nucleic acid molecule has been added to the host cell by conjugation, transformation, transfection, electroporation, etc., where the added nucleic acid molecule may be integrated into the host cell genome or may exist as extrachromosomal genetic material (e.g., as a plasmid or other self-replicating vector). "Homologous" or "homolog" refers to a gene, protein, compound, nucleic acid molecule, or activity found in or derived from a given host cell, species, or strain. For example, a heterologous or foreign polynucleotide or gene encoding a polypeptide may be homologous to a native polynucleotide or gene and encode a homologous polypeptide or activity, but the polynucleotide or polypeptide may have an altered structure, sequence, expression level, or any combination thereof. The non-endogenous polynucleotide or gene and the encoded polypeptide or activity may be derived from the same species, a different species, or a combination thereof.

[0046] In certain embodiments, a nucleic acid molecule native to a host cell, or a portion thereof, would be considered heterologous to that host cell if it has been modified or mutated. Alternatively, a nucleic acid molecule native to a host cell may be considered heterologous if it has been modified with heterologous expression control sequences or with endogenous expression control sequences not normally associated with the nucleic acid molecule native to the host cell. In addition, the term "heterologous" can refer to a biological activity that is different, modified, or not endogenous to the host cell. As described herein, multiple heterologous nucleic acid molecules can be introduced into a host cell as separate nucleic acid molecules, as individually regulated multiple genes, as a polycistronic nucleic acid molecule, as a single nucleic acid molecule encoding an antibody or antigen-binding fragment (or other polypeptide), or any combination thereof.

[0047] As used herein, the term "endogenous" or "native" refers to a polynucleotide, gene, protein, compound, molecule, or activity that is normally present in a host cell or subject.

[0048] The term "expression," as used herein, refers to the process by which a polypeptide is produced based on a coding sequence, e.g., a gene, of a nucleic acid molecule. This process can include transcription, post-transcriptional control, post-transcriptional modification, translation, post-translational control, post-translational modification, or any combination thereof. An expressed nucleic acid molecule is typically operably linked to an expression control sequence (e.g., a promoter).

[0049] The term "operably linked" refers to the association of two or more nucleic acid molecules on a single nucleic acid fragment so that the function of one is affected by the other. For example, a promoter is operably linked to a coding sequence if it is capable of affecting the expression of that coding sequence (i.e., that the coding sequence is under the transcriptional control of the promoter). "Unlinked" means that the associated genetic elements are not closely related to each other so that the function of one does not affect the other.

[0050] As described herein, multiple heterologous nucleic acid molecules can be introduced into a host cell as separate nucleic acid molecules, as individually regulated multiple genes, as a polycistronic nucleic acid molecule, as a single nucleic acid molecule encoding a protein (e.g., the heavy chain of an antibody), or any combination thereof. When two or more heterologous nucleic acid molecules are introduced into a host cell, it is understood that the two or more heterologous nucleic acid molecules can be introduced as a single nucleic acid molecule (e.g., on a single vector), on separate vectors, integrated into a single site or multiple sites on a host chromosome, or any combination thereof. The number of heterologous nucleic acid molecules or protein activities referred to refers to the number of different encoding nucleic acid molecules or the number of different protein activities, not the number of separate nucleic acid molecules introduced into the host cell.

[0051] The term "construct" refers to any polynucleotide (or, if the context makes clear, a fusion protein of the present disclosure) containing a recombinant nucleic acid molecule. The (polynucleotide) construct may be present in a vector (e.g., a bacterial vector, a viral vector) or integrated into a genome. A "vector" is a nucleic acid molecule capable of transporting another nucleic acid molecule. A vector can be, for example, a plasmid, a cosmid, a virus, an RNA vector, or a linear or circular DNA or RNA molecule, which may contain chromosomal, non-chromosomal, semisynthetic, or synthetic nucleic acid molecules. Vectors of the present disclosure also include transposon systems (see, e.g., Sleeping Beauty, e.g., Geurts et al., Mol. Ther. 8:108, 2003; Mates et al., Nat. Genet. 41:753, 2009). Exemplary vectors are capable of autonomous replication (episomal vectors), delivery of polynucleotides to a cellular genome (e.g., viral vectors), or expression of nucleic acid molecules to which they are linked (expression vectors).

[0052] As used herein, "expression vector" or "vector" refers to a DNA construct containing a nucleic acid molecule operably linked to suitable control sequences capable of achieving expression of the nucleic acid molecule in a suitable host. Such control sequences typically include a promoter to effect transcription, an optional operator sequence to control such transcription, a sequence encoding suitable mRNA ribosomal binding sites, and sequences that control the termination of transcription and translation. A vector can be a plasmid, a phage particle, a virus, or simply a potential genomic insert. Upon transformation into a suitable host, the vector can replicate and function independently of the host genome, or, in some cases, can integrate into the genome itself or deliver a polynucleotide contained in the vector to the genome without vector sequences. As used herein, the terms "plasmid," "expression plasmid," "virus," and "vector" are often used interchangeably.

[0053] The term "introduced" in the context of inserting a nucleic acid molecule into a cell means "transfection," "transformation," or "transduction," and includes reference to the incorporation of a nucleic acid molecule into a eukaryotic or prokaryotic cell, where the nucleic acid molecule may be integrated into the cell's genome (e.g., chromosome, plasmid, plastid, or mitochondrial DNA), converted into an autonomous replicon, or transiently expressed (e.g., transfected mRNA).

[0054] In certain embodiments, a polynucleotide of the present disclosure may be operably linked to certain elements of a vector. For example, polynucleotide sequences required to affect the expression and processing of a ligated coding sequence may be operably linked. Expression control sequences may include appropriate transcription initiation, termination, promoter, and enhancer sequences, efficient RNA processing signals such as polyadenylation signals, sequences that stabilize cytoplasmic mRNA, sequences that increase translation efficiency (i.e., Kozak consensus sequences), sequences that increase protein stability, and, in some cases, sequences that enhance protein secretion. Expression control sequences may be operably linked if they are contiguous with a gene of interest. Expression control sequences that act in trans or at a distance to regulate a gene of interest may also be considered operably linked.

[0055] In certain embodiments, the vector comprises a plasmid vector or a viral vector (e.g., a lentiviral vector or a gamma-retroviral vector). Viral vectors include retroviruses, adenoviruses, parvoviruses (e.g., adeno-associated viruses), coronaviruses, negative-strand RNA viruses, such as orthomyxoviruses (e.g., influenza viruses), rhabdoviruses (e.g., rabies and vesicular stomatitis viruses), paramyxoviruses (e.g., measles and Sendai viruses), positive-strand RNA viruses, such as picornaviruses and alphaviruses, and double-stranded DNA viruses, such as adenoviruses, herpesviruses (e.g., herpes simplex virus types 1 and 2, Epstein-Barr virus, cytomegalovirus), and poxviruses (e.g., vaccinia, fowlpox, and canarypox). Other viruses include, for example, Norwalk virus, togavirus, flavivirus, reovirus, papovavirus, hepadnavirus, and hepatitis virus. Examples of retroviruses include avian leukosis sarcoma, mammalian type C, type B, type D viruses, the HTLV-BLV complex, lentiviruses, and spumaviruses (Coffin, JM, "Retroviridae: The viruses and their replication," in "Fundamental Virology," 3rd ed., BN Fields et al., eds., Lippincott-Raven Publishers, Philadelphia, 1996).Methods for using retroviral and lentiviral viral vectors and packaging cells to transduce mammalian host cells with viral particles containing a transgene are known in the art and have been previously described, for example, in U.S. Patent No. 8,119,772; Walchli et al., PLoS One 6:327930, 2011; Zhao et al., J. Immunol. 174:4415, 2005; Engels et al., Hum. Gene Ther. 14:1155, 2003; Frecha et al., Mol. Ther. 18:1748, 2010; and Verhoeyen et al., Methods Mol. Biol. 506:97, 2009. Retroviral and lentiviral vector constructs and expression systems are also commercially available. Other viral vectors, including DNA viral vectors, such as adenovirus-based vectors and adeno-associated virus (AAV)-based vectors, herpes simplex virus (HSV)-derived vectors, such as amplicon vectors, replication-deficient HSV, and attenuated HSV, can also be used for polynucleotide delivery (Krisky et al., Gene Ther. 5:1517, 1998).

[0056] Other vectors that can be used in the compositions and methods of the present disclosure include those derived from baculovirus and alphavirus (Jolly, D J. 1999. "Emerging Viral Vectors," in Friedmann T. (ed.), The Development of Human Gene Therapy, New York: Cold Spring Harbor Lab, pp. 209-40), or plasmid vectors (e.g., Sleeping Beauty or other transposon vectors).

[0057] When the viral vector genome contains multiple polynucleotides to be expressed as separate transcripts in a host cell, the viral vector may also contain additional sequences between the two (or more) transcripts that enable bicistronic or polycistronic expression. Examples of such sequences used in viral vectors include an internal ribosome entry site (IRES), a furin cleavage site, a viral 2A peptide, or any combination thereof.

[0058] Plasmid vectors are also known in the art, including DNA-based plasmid vectors for expressing one or more proteins in vitro or for direct administration to a subject. Such vectors may contain a bacterial replication origin, a viral replication origin, genes encoding components necessary for plasmid replication, and / or one or more selection markers. Such vectors may also contain additional sequences that allow bicistronic or polycistronic expression.

[0059] As used herein, the term "host" refers to a cell or microorganism that is targeted for genetic modification with a heterologous nucleic acid molecule to produce a polypeptide of interest (e.g., an antibody of the present disclosure).

[0060] A host cell can include any individual cell or cell culture that can incorporate a vector or nucleic acid or express a protein. The term also encompasses the progeny of the host cell, whether genetically or phenotypically the same or different. Suitable host cells depend on the vector and can include mammalian cells, animal cells, human cells, simian cells, insect cells, yeast cells, and bacterial cells. These cells can be induced to incorporate vectors or other materials by transformation using viral vectors, calcium phosphate precipitation, DEAE-dextran, electroporation, microinjection, or other methods. See, e.g., Sambrook et al., Molecular Cloning: A Laboratory Manual, 2nd ed. (Cold Spring Harbor Laboratory, 1989).

[0061] As used herein, "antigen" refers to an immunogenic molecule that elicits an immune response. This immune response may involve antibody production, activation of specific immune-competent cells, complement activation, antibody-dependent cellular cytotoxicity, or any combination thereof. An antigen (immunogenic molecule) may be, for example, a peptide, glycopeptide, polypeptide, glycopolypeptide, polynucleotide, polysaccharide, lipid, etc. It is apparent that antigens may be synthesized, recombinantly produced, or derived from a biological sample. Exemplary biological samples that may contain one or more antigens include tissue samples, fecal samples, cells, biological fluids, or combinations thereof. An antigen may be expressed by cells that have been modified or genetically engineered to express the antigen. An antigen may also be present in or on an infectious agent, e.g., present in a virion, or expressed or displayed on the surface of a cell infected with the infectious agent.

[0062] The term "epitope" or "antigenic epitope" includes any molecule, structure, amino acid sequence, or protein determinant that is recognized and specifically bound by a cognate binding molecule, e.g., an immunoglobulin, or other binding molecule, domain, or protein. Epitopic determinants generally contain chemically active surface groups of molecules, such as amino acids or sugar side chains, and can have specific three-dimensional structural and charge characteristics. When the antigen is or comprises a peptide or protein, the epitope can be composed of contiguous amino acids (e.g., a linear epitope), or of amino acids from different parts or regions of the protein that become adjacent due to protein folding (e.g., a discontinuous or conformational epitope), or of noncontiguous amino acids that remain adjacent regardless of protein folding.

[0063] The term "antibody" refers to an immunoglobulin molecule consisting of one or more polypeptides that specifically bind to an antigen through at least one epitope recognition site. For example, the term "antibody" encompasses intact antibodies comprising at least two heavy chains and two light chains connected by disulfide bonds, as well as any antigen-binding portion or fragment of an intact antibody, such as an scFv, Fab, or Fab'2 fragment, that has or retains the ability to bind to the antigen target molecule recognized by the intact antibody. The term also encompasses full-length or fragments of antibodies of any class or subclass, including IgG and its subclasses (e.g., IgG1, IgG2, IgG3, and IgG4), IgM, IgE, IgA, and IgD.

[0064] The term "antibody" is used herein in the broadest sense and includes antibodies and antibody fragments thereof derived from any antibody-producing mammal (e.g., mouse, rat, rabbit, and primate, including human), or derived from hybridoma, phage selection, recombinant expression, or transgenic animals (or other methods for producing antibodies or antibody fragments). The term "antibody" is not intended to be limiting as to the source of the antibody or the manner in which it is made (e.g., by hybridoma, phage selection, recombinant expression, transgenic animals, peptide synthesis, etc.). Exemplary antibodies include polyclonal, monoclonal, and recombinant antibodies, multispecific antibodies (e.g., bispecific antibodies), humanized antibodies, fully human antibodies, murine antibodies, chimeric, mouse-human, mouse-primate, primate-human monoclonal antibodies, and anti-idiotypic antibodies; exemplary antibodies can be any intact molecule or a fragment thereof. As used herein, the term "antibody" encompasses not only intact polyclonal or monoclonal antibodies, but also fragments thereof (e.g., dAb, Fab, Fab', F(ab')2, Fv), single chain (ScFv), synthetic variants thereof, naturally occurring variants thereof, fusion proteins comprising an antibody portion with an antigen-binding fragment of the required specificity, humanized antibodies, chimeric antibodies, and any other modified configuration of immunoglobulin molecule containing an antigen-binding site or fragment (epitope recognition site) of the required specificity. The term also encompasses genetically engineered and otherwise modified forms of immunoglobulins containing antigen-binding fragments thereof, such as intrabodies, peptibodies, diabodies, triabodies, tetrabodies, tandem di-scFv, tandem tri-scFv, etc.

[0065] The terms "VH" and "VL" refer to the variable binding regions from antibody heavy chains and antibody light chains, respectively. VL can be a kappa-class chain or a lambda-class chain. The variable binding region comprises discrete, clearly defined subregions known as complementarity-determining regions (CDRs) and framework regions (FRs). CDRs are located within the hypervariable regions (HVRs) of an antibody and generally refer to the sequence of amino acids within the antibody variable region that, as a whole, confers antigen specificity and / or binding affinity to the antibody. Consecutive CDRs (i.e., CDR1 and CDR2, and CDR2 and CDR3) are separated from each other by framework regions in the primary structure.

[0066] As used herein, a "chimeric antibody" is a recombinant protein that contains variable domains and complementarity-determining regions derived from a non-human species (e.g., a rodent), with the remainder of the antibody molecule derived from a human antibody. In some embodiments, a chimeric antibody is composed of an antigen-binding fragment of one antibody operably linked to or otherwise fused to a heterologous Fc portion of a different antibody. For example, a mouse-human chimeric antibody may comprise an antigen-binding fragment of a mouse antibody fused to an Fc portion derived from a human antibody. In some embodiments, the heterologous Fc domain may be derived from a different Ig class than the parent antibody, such as IgA (including subclasses IgA1 and IgA2), IgD, IgE, IgG (including subclasses IgG1, IgG2, IgG3, and IgG4), and IgM.

[0067] As used herein, a "humanized antibody" is a molecule having an antigen-binding site derived from an immunoglobulin of a non-human species, with the remainder of the molecule's immunoglobulin structure based on human immunoglobulin structure and / or sequence, typically prepared using recombinant techniques. Humanized antibodies differ from chimeric antibodies in that typically only the CDRs from the non-human species are used and grafted onto appropriate framework regions in a human variable domain. The antigen-binding site may be wild-type or modified by one or more amino acid substitutions. In some embodiments, a humanized antibody retains all CDR sequences (e.g., a humanized mouse antibody containing all six CDRs from a mouse antibody). In other embodiments, a humanized antibody has one or more CDRs (one, two, three, four, five, six) that are altered compared to the original antibody, also referred to as one or more CDRs "derived from" one or more CDRs from the original antibody.

[0068] As used herein, the term "antibody fragment" refers to a portion derived from or related to a full-length antibody, generally including the antigen-binding or variable region thereof. Specific examples of antibody fragments include Fab, Fab', F(ab)2, F(ab')2, and Fv fragments, scFv fragments, diabodies, linear antibodies, single-chain antibody molecules, and multispecific antibodies formed from antibody fragments.

[0069] As used herein, the term "antigen-binding fragment" refers to a polypeptide fragment containing at least one CDR of an immunoglobulin heavy and / or light chain that specifically binds to the antigen from which the antibody was raised. An antigen-binding fragment may contain one, two, three, four, five, or all six CDRs of the VH and VL sequences from an antibody.

[0070] "Fab" (fragment antigen binding) is the antigen-binding portion of an antibody. It contains the variable region and the CH1 region of a heavy chain linked to a light chain by an interchain disulfide bond. Each Fab fragment is monovalent with respect to antigen binding; i.e., each Fab fragment has a single antigen-binding site. Pepsin treatment of an antibody yields a single large F(ab')2 fragment, which roughly corresponds to two disulfide-linked Fab fragments with bivalent antigen-binding activity and still retains the ability to cross-link antigen. Both Fab and F(ab')2 are examples of "antigen-binding fragments." Fab' fragments differ from Fab fragments by possessing several additional residues at the carboxy terminus of the CH1 domain, including one or more cysteines from the antibody hinge region. Fab'-SH is the designation used herein for Fab' fragments in which the cysteine ​​residues in the constant domains bear free thiol groups. F(ab')2 antibody fragments are often produced as pairs of Fab' fragments with hinge cysteines between them. Other chemical couplings of antibody fragments are also known.

[0071] Fab fragments may be joined, for example, by a peptide linker, to form a single-chain Fab, also referred to herein as an "scFab." In these embodiments, the interchain disulfide bonds present in native Fabs may be absent, and the linker serves, in whole or in part, to link or connect the Fab fragments into a single polypeptide chain. A Fab fragment derived from a heavy chain (e.g., comprising, consisting of, or consisting essentially of VH+CH1, or "Fd") and a Fab fragment derived from a light chain (e.g., comprising, consisting of, or consisting essentially of VL+CL) may be linked in any configuration to form an scFab. For example, scFabs may be arranged, from N-terminus to C-terminus, as follows: (heavy chain Fab fragment-linker-light chain Fab fragment) or (light chain Fab fragment-linker-heavy chain Fab fragment).

[0072] "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 domain in tight, non-covalent association. However, even a single variable domain (i.e., half of an Fv containing only the three antigen-specific CDRs) has the ability to recognize and bind to antigen, although typically with lower affinity than the entire binding site.

[0073] A "single-chain Fv," also abbreviated as "sFv" or "scFv," is an antibody fragment comprising a VH antibody domain and a VL antibody domain connected into a single polypeptide chain. The scFv polypeptide may contain a polypeptide linker disposed between the VH and VL domains, connecting them and enabling the scFv to maintain or form the desired structure for antigen binding. However, a linker is not required. Such a peptide linker can be incorporated into a fusion polypeptide using standard techniques known in the art. Additionally or alternatively, the Fv can have a disulfide bond formed between the VH and VL domains to stabilize the VH and VL domains. For a description of scFvs, see the review by Plückthun (1994) in The Pharmacology of Monoclonal Antibodies, vol. 113, edited by Rosenburg and Moore, Springer-Verlag, New York, pp. 269-315. In certain embodiments, the antibody or antigen-binding fragment comprises an scFv comprising a VH domain, a VL domain, and a peptide linker linking the VH domain to the VL domain. In particular embodiments, the scFv comprises a VH domain linked to the VL domain by a peptide linker, which can be in a VH-linker-VL or VL-linker-VH orientation. Any of the scFvs of the present disclosure can be engineered so that the C-terminus of the VL domain is linked to the N-terminus of the VH domain by a short peptide sequence, or vice versa (i.e., (N)VL(C)-linker-(N)VH(C) or (N)VH(C)-linker-(N)VL(C)). Alternatively, in some embodiments, a linker can be linked to the N-terminal portion or N-terminus of the VH domain, VL domain, or both.

[0074] Peptide linker sequences for use in scFvs or other fusion proteins, such as the targeted complement-activating molecules described herein, can be selected based on, for example, the following criteria: (1) the ability to adopt an extended, flexible conformation; (2) the inability or inability to adopt secondary structures that could interact with functional epitopes on the first and second polypeptides and / or the target molecule; and / or (3) the lack of, or relatively few hydrophobic or charged residues that might react with the polypeptides and / or the target molecule. Other considerations regarding linker design (e.g., length) can include the conformation or range of conformations in which the VH and VL can form a functional antigen-binding site. In certain embodiments, the peptide linker sequence contains, for example, Gly, Asn, and Ser residues. Other near-neutral amino acids, such as Thr and Ala, can also be included in the linker sequence. Other amino acid sequences that may be useful as linkers include those disclosed in Maratea et al., Gene 40:39 46 (1985), Murphy et al., Proc. Natl. Acad. Sci. USA 83:8258 8262 (1986), U.S. Patent No. 4,935,233, and U.S. Patent No. 4,751,180. Other illustrative and non-limiting examples of linkers include, for example, pentamer TIFF2025537131000002.tif4128, which may be repeated once or may be repeated 1-5 or more times, e.g. The linker may begin or end in the middle of a repeat, such as TIFF2025537131000003.tif4128. Any suitable linker may be used, and suitable linkers will generally be about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 15 23, 24, 25, 26, 27, 28, 29, 30, 40, 50, 60, 70, 80, 90, 100 amino acids in length, or less than about 200 amino acids in length, preferably comprise a flexible structure (which can provide flexibility and room for conformational movement between the two regions, domains, motifs, fragments, or modules connected by the linker), and preferably be biologically inert and / or have a low risk of immunogenicity in humans.

[0075] Antibodies can be monospecific (e.g., bind to a single epitope) or multispecific (e.g., bind to multiple epitopes and / or target molecules). Bispecific or multispecific antibodies or antigen-binding fragments, in some embodiments, can comprise one, two, or more antigen-binding domains (e.g., a VH and a VL). There can be two or more binding domains that bind to the same epitope or different epitopes, and bispecific or multispecific antibodies or antigen-binding fragments provided herein, in some embodiments, can comprise two or more binding domains that bind to different antigens or pathogens as a whole.

[0076] Antibodies and antigen-binding fragments can be constructed in a variety of formats. Exemplary antibody formats are disclosed in Spiess et al., Mol. Immunol. 67(2):95 (2015) and Brinkmann and Kontermann, mAbs 9(2):182-212 (2017).These formats and methods for making them are incorporated herein by reference and include, for example, Bispecific T Cell Engagers (BiTEs), DARTs, Knobs-Into-Holes (KIH) Assembly, scFv-CH3-KIH Assembly, KIH Common Light Chain Antibodies, TandAbs, Triple Bodies, TriBi Minibodies, Fab-scFvs, scFv-CH-CL-scFvs, 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 Assembly, Fcabs, κλ-bodies, orthogonal Fabs, Fab), DVD-Ig (e.g., U.S. Pat. No. 8,258,268, these formats are incorporated herein by reference in their entireties), IgG(H)-scFv, scFv-(H)IgG, IgG(L)-scFv, scFv-(L)IgG, IgG(L,H)-Fv, IgG(H)-V,V(H)-IgG, IgG(L)-V,V(L)-IgG, KIH IgG-scFab, 2scFv-IgG, IgG-2scFv, scFv4-Ig, Zybody, and DVI-IgG (Four-in-One), as well as the so-called FIT-Ig (e.g., PCT Publication No. WO 2015 / 103072, these formats are incorporated herein by reference in their entireties), the so-called WuxiBody format (e.g., PCT Publication No. WO 2019 / 057122, which formats are incorporated herein by reference in their entireties), and the so-called In-Elbow-Insert Ig format (IEI-Ig, e.g., PCT Publication Nos. WO 2019 / 024979 and WO 2019 / 025391, which formats are incorporated herein by reference in their entireties).

[0077] An antibody or antigen-binding fragment can contain two or more VH domains, two or more VL domains, or both (i.e., two or more VH domains and two or more VL domains). In particular embodiments, an antigen-binding fragment comprises the format (from N-terminus to C-terminus): VH-linker-VL-linker-VH-linker-VL, where 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 comprise any combination of VH and VL domains configured to bind to a given target. In formats comprising two or more VHs and / or two or more VLs, one, two, or more different epitopes or antigens can be bound. It will be understood that formats incorporating multiple antigen-binding domains can comprise VH and / or VL sequences in any combination or orientation. For example, antigen-binding fragments can comprise the formats VL-linker-VH-linker-VL-linker-VH, VH-linker-VL-linker-VL-linker-VH, or VL-linker-VH-linker-VH-linker-VH-linker-VL.

[0078] As used herein, the modifier "monoclonal" indicates the character of the antibody as being obtained from a substantially homogeneous population of antibodies, and is not intended to be limited as to 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 and full-length monoclonal antibodies, but also fragments thereof (e.g., Fab, Fab', F(ab')2, Fv), single chain (ScFv), variants thereof, fusion proteins comprising the antigen-binding portion, humanized monoclonal antibodies, chimeric monoclonal antibodies, and immunoglobulin molecules of any other modified configuration containing an antigen-binding fragment (epitope recognition site) with the required specificity and binding ability for the epitope. Monoclonal antibodies may be obtained using any technique which provides for the production of antibody molecules by continuous cell lines in culture, such as the hybridoma method described by Kohler, G., et al., Nature 256:495, 1975, or may be made by recombinant DNA methods (see, e.g., U.S. Pat. No. 4,816,567 to Cabilly). Monoclonal antibodies may also be isolated from phage antibody libraries using the techniques described by Clackson T. et al., Nature 352:624-628, 1991 and Marks JD, et al., J. Mol. Biol. 222:581-597, 1991. Such antibodies may belong to any immunoglobulin class, including IgG, IgM, IgE, IgA, and IgD, and any subclass thereof.

[0079] Recognized immunoglobulin polypeptides include kappa and lambda light chains, and alpha, gamma (IgG1, IgG2, IgG3, IgG4), delta, epsilon, and mu heavy chains, or equivalents in other species. Full-length immunoglobulin "light chains" (about 25 kDa or about 214 amino acids) contain a variable region of about 110 amino acids at the NH2-terminus and a kappa or lambda constant region at the COOH-terminus. Full-length immunoglobulin "heavy chains" (about 50 kDa or about 446 amino acids) similarly contain a variable region (about 116 amino acids) and one of the heavy chain constant regions mentioned above, e.g., gamma (about 330 amino acids).

[0080] The basic four-chain antibody unit is a heterotetrameric glycoprotein composed of two identical light (L) chains and two identical heavy (H) chains. IgM antibodies differ from the above configuration in that they consist of five basic heterotetrameric units along with an additional polypeptide called the J chain, thus providing ten antigen-binding sites. Secretory IgA antibodies also differ from the basic structure in that they polymerize to form multivalent assemblies containing two to five basic four-chain units along with the J chain. Each L chain is linked to an H chain by one covalent disulfide bond, while the two H chains are linked to each other by one or more disulfide bonds, depending on the H chain isotype. Each H chain and each L chain also have regularly spaced intrachain disulfide bridges. The pairing of a VH and a VL together forms a single antigen-binding site.

[0081] Each H chain has an N-terminal variable domain (VH) followed by three constant domains (CH1, CH2, CH3) in the case of alpha, gamma, and delta chains, and four CH domains (CH1, CH2, CH3, CH4) in the case of mu and epsilon chains.

[0082] Each L chain has a variable domain (VL) at the N-terminus followed by a constant domain (CL) at the other end. When an L chain and an H chain pair, the VL aligns with the VH, and the CL aligns with the first constant domain (CH1) of the heavy chain. L chains of any vertebrate species can be assigned to one of two types, called kappa (κ) and lambda (λ), based on the amino acid sequence of their constant domain (CL).

[0083] Immunoglobulins can be assigned to different classes or isotypes depending on the amino acid sequence of the constant domain (CH) of their heavy chains. There are five classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM, which have heavy chains designated alpha (α), delta (δ), epsilon (ε), gamma (γ), and mu (μ), respectively. The γ and α classes are further divided into subclasses based on subtle differences in CH sequence and function. For example, humans express the following subclasses: IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2.

[0084] For a discussion of the structure and properties of these various classes of antibodies, see, e.g., page 71 and chapter 6 of Basic and Clinical Immunology, 8th ed. (Daniel P. Stites, Abba I. Terr and Tristram G. Parslow (eds.), Appleton and Lange, Norwalk, CT, 1994).

[0085] The term "variable" refers to the fact that the sequences of certain segments of the V domain vary widely among antibodies. The V domain mediates antigen binding and defines the specificity of a particular antibody for its particular antigen. However, variability is not evenly distributed throughout the 110-amino acid span of the variable domain. Rather, the V region consists of relatively invariant stretches of 15-30 amino acids called framework regions (FRs), separated by shorter, more highly variable regions called "hypervariable regions," each 9-12 amino acids long. The variable domains of native heavy and light chains each contain four FRs, largely arranged in a beta-sheet configuration, connected by three hypervariable regions. These three hypervariable regions form loops that connect and, in some cases, form part of the n-sheet structure. The hypervariable regions in each chain are held in close proximity by FRs, and the hypervariable regions from the other chain contribute to the formation of the antigen-binding site of antibodies (see Kabat, et al., "Sequences of Proteins of Immunological Interest," 5th ed., Public Health Service, National Institutes of Health, Bethesda, MD (1991)). The constant domains are not directly involved in binding of antibodies to antigens but exhibit various effector functions.

[0086] As used herein, "effector function" refers to a biological activity attributable to the Fc region of an antibody. Examples of antibody effector functions include antibody-dependent cellular cytotoxicity (ADCC), C1q binding and complement-dependent cytotoxicity, Fc receptor binding, phagocytosis, downregulation of cell surface receptors, and participation in B-cell activation. Modifications, such as amino acid substitutions, can be made to the Fc domain to modify (e.g., enhance or reduce) one or more functions of an Fc-containing polypeptide. Such functions include, for example, Fc receptor binding, modulation of antibody half-life, ADCC function, protein A binding, protein G binding, and complement binding. Amino acid modifications that modify Fc function include, for example, T250Q / M428L, M252Y / S254T / T256E, H433K / N434F, M428L / N434S, E233P / L234V / L235A / G236Δ / A327G / A330S / P331S, E333A, S239D / A330L / I332E, P257I / Q311, K326W / E333S, S239D / I332E / G236A, N297Q, K322A, S228P, L235E / E318A / K320A / K322A, L234A / L235A, and L234A / L235A / P329G mutations. Other Fc modifications and their effects on Fc function are known in the art.

[0087] As used herein, the term "hypervariable region" refers to the amino acid residues of an antibody that are responsible for antigen binding. The hypervariable region contains several "complementarity-determining regions" (CDRs). The heavy chain contains three CDR sequences (CDRH1, CDRH2, and CDRH3), and the light chain contains three CDR sequences (CDRL1, CDRL2, and CDRL3). Various systems exist for identifying and numbering the amino acids that make up the CDRs. For example, the hypervariable regions generally include CDRs at about residues 24-34 (L1), 50-56 (L2), and 89-97 (L3) in the light chain variable domain and about residues 31-35 (H1), 50-65 (H2), and 95-102 (H3) in the heavy chain variable domain, when numbered according to the Kabat numbering system described in Kabat, et al., "Sequences of Proteins of Immunological Interest," 5th ed., Public Health Service, National Institutes of Health, Bethesda, MD (1991), and / or the CDRs at about residues 102-1104 (H1), 102-1106 (H2), 102-1108 (H3) in the heavy chain variable domain. The CDRs comprise CDRs at approximately residues 24-34 (L1), 50-56 (L2), and 89-97 (L3) in the light chain variable domain and residues 26-32 (H1), 52-56 (H2), and 95-102 (H3) in the heavy chain variable domain, when numbered according to the Chothia numbering system described in Lefranc, J.P., et al., Nucleic Acids Res 27:209-212; Ruiz, M., et al., Nucleic Acids Res 28:219-221 (2000), the CDRs are contained at approximately residues 27-38 (L1), 56-65 (L2), and 105-117 (L3) in VL, and 27-38 (H1), 56-65 (H2), and 105-117 (H3) in VH.The Antigen Receptor Numbering And Receptor Classification (ANARCI) software tool (2016, Bioinformatics 15:298-300) can be used to annotate and compare equivalent residue positions for different molecules. Thus, the identification of the CDRs of an exemplary variable domain (VH or VL) sequence provided herein according to one numbering scheme does not exclude antibodies containing CDRs of the same variable domain determined using a different numbering scheme.

[0088] As used herein, "specifically binds" refers to an antibody or antigen-binding fragment that binds to an antigen with a particular affinity while not significantly associating or combining with any other molecules or components in a sample. Affinity can be defined as the equilibrium association constant (Ka), calculated as the ratio of k / k, with units of 1 / M, or as the equilibrium dissociation constant (K), calculated as the ratio of k / k, with units of M.

[0089] In some contexts, antibodies and antigen-binding fragments may be described in terms of their affinity and / or avidity for the antigen. Unless otherwise indicated, avidity refers to the overall binding strength of an antibody or antigen-binding fragment for an antigen, which reflects the binding affinity of the antibody or antigen-binding fragment, the valency (e.g., whether the antibody or antigen-binding fragment contains 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more binding sites), and, for example, whether other agents are present that can affect binding (e.g., noncompetitive inhibitors of the antibody or antigen-binding fragment).

[0090] Each embodiment herein applies mutatis mutandis to every other embodiment, unless expressly stated otherwise. It is contemplated that any embodiment discussed in this specification can be implemented with respect to any method, kit, reagent, or composition of the invention, and vice versa. Furthermore, compositions of the invention can be used to achieve methods of the invention.

[0091] II. Overview The alternative pathway of the complement system has been implicated in the pathogenesis of numerous acute and chronic disease states, including paroxysmal nocturnal hemoglobinuria (PNH), complement factor 3 glomerulopathy (C3G), and idiopathic immune complex-mediated glomerulonephritis (ICGN). This disclosure describes the use of alternative pathway inhibitors, particularly MASP-3 inhibitors, to treat these alternative pathway-associated diseases.

[0092] A. The role of MASP-3 in the complement system Mannan-binding lectin-associated serine protease-3 (MASP-3) is an activator of the alternative complement pathway (AP). MASP-3 is one of three possible products of the MASP1 gene. The primary transcript of MASP1 can be spliced ​​to form mRNAs encoding MASP-1, MASP-3, or MAp44. Interestingly, each of these three gene products has distinct activities. MASP-1 is a component of the lectin pathway of the complement system, MAp44 is a nonproteolytic protein, and MASP-3 is an activator of the AP. MASP-1 and MASP-3 proteins share five structural domains in their N-terminal regions but possess a unique serine protease domain at the C-terminus (Ammitzboll et al., PLos One 8(9):e73317, 2013). The amino acid sequence of human MASP-3, including a 19-amino acid leader sequence, is provided as SEQ ID NO: 17. The serine protease domain of human MASP-3 comprises amino acids 450 to 728 of SEQ ID NO:17.

[0093] One of the earliest upstream steps in AP activation is the conversion of complement factor D (CFD) from an inactive zymogen to a cleaved or mature form with serine protease activity (Dobo et al., Sci Rep 6:31877, 2016; Oroszlan et al., J Immunol 162(2):857, 2016). See Figure 1. MASP-3 is responsible for this conversion of CFD from the zymogen to the mature form, thus overseeing a critical upstream regulatory step in AP activation (WO2018 / 026722). Due to the role of MASP-3 in the early stages of AP activation, inhibition of MASP-3 may provide an efficient, targeted inhibition of AP activation.

[0094] B. Paroxysmal nocturnal hemoglobinuria Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired disorder characterized by hemolytic anemia caused by uncontrolled activity of AP on red blood cells (RBCs). Hemolysis results from the spontaneous loss of complement regulatory proteins CD55 and CD59 on a clonally derived subset of RBCs, which is caused by the comprehensive loss of all cell surface proteins attached by GPI anchors. If left untreated, PNH is associated with debilitating anemia, a high risk of thrombosis, and significantly reduced survival (Risitano et al., Front Immunol. 10:1157, 2019).

[0095] Eculizumab and its second-generation variant, ravulizumab, block terminal complement activation by binding to complement C5 and preventing its cleavage. Both mAbs are approved in the United States for the treatment of patients with PNH, and they are effective in reducing hemolysis and the risk of thrombosis and death. However, hemolysis is not completely blocked by targeting C5, and most patients remain persistently anemic. Patients experience low hemoglobin levels and fatigue, and 25%–50% of individuals still require transfusions (Al-Ani et al., Therapeutics and Clinical Risk Management 12:1161, 2016). The incomplete therapeutic benefit of C5 inhibitors is due to the extravascular hemolytic pathway, in which C3b-opsonized RBCs are destroyed by phagocytes. Indeed, extravascular clearance is exacerbated in patients treated with C5-blocking mAbs because unlysed PNH RBCs serve as targets for persistent C3b adhesion until they are destroyed by phagocytes found in the spleen (Berentsen et al., Ther Adv Hematol 10:2040620719873321, 2019). In some early cases, drastic measures such as splenectomy have been used to ameliorate this condition, but this is no longer considered standard of care (Risitano et al., 2019). Therefore, C3b-mediated extravascular hemolysis is a concern in the treatment of PNH with terminal pathway inhibitors.

[0096] More recently, pegcetacoplan, a pegylated peptide that binds to C3 and blocks its enzymatic cleavage by convertases from the three complement pathways, has been shown to be superior to eculizumab in managing extensive hemolysis in patients with PNH (Hillmen et al., N Engl J Med 384:1028, 2021). Pegcetacoplan treatment improved hemoglobin and other hematological measures, consistent with inhibiting not only intravascular but also extravascular hemolysis. However, pegcetacoplan is administered as a twice-weekly subcutaneous infusion, which poses a relatively large burden to patients.

[0097] Therefore, there remains a need for effective and convenient treatments for PNH. Proximal complement inhibitors, such as MASP-3 inhibitors, could improve patient experience by blocking both intravascular and extravascular hemolysis by inhibiting only the alternative pathway, while leaving the classical and lectin pathways intact.

[0098] C. Complement factor 3 glomerulopathy Complement factor 3 glomerulopathy (C3G) is a disorder associated with dysregulation of AP in the plasma and glomerular microenvironment. AP hyperactivation leads to the deposition of C3 and its cleavage products within the glomerulus, leading to inflammation and progressive renal disease (Smith et al., Nat Rev Nephrol 15:129, 2019; Nephrol Dial Transpl 32(3):459, 2017). The causes of AP hyperactivation can vary among patients, including underlying genetic abnormalities in complement genes and autoantibodies against complement components (Iatropoulos et al., Mol Immunol 71:131, 2016; Corvillo et al., Front Immunol 10:886, 2019). If untreated, the clinical manifestations of C3G range from proteinuria with relatively preserved renal function to rapidly progressive renal failure. Although the disease can remain stable for several years despite persistent proteinuria, almost half of patients will develop end-stage renal disease within five years of clinical diagnosis (Bomback et al., Kidney Int 93(4):977, 2018).

[0099] Although several treatments are available to help manage symptoms, there are currently no approved medications for C3G. Eculizumab, an anti-C5 monoclonal antibody, has been tested for the treatment of C3G, but responses have been highly heterogeneous. For example, in one study, only three of ten patients achieved a significant reduction in 24-hour proteinuria, suggesting that upstream components of the complement pathway may play a role in C3G (Ruggenenti et al., Am J Kidney Dis 74(2):224, 2019). Therefore, improved treatments for patients with C3G remain needed.

[0100] D. Idiopathic immune complex-mediated glomerulonephritis Idiopathic immune complex-mediated glomerulonephritis (ICGN), sometimes called immune complex membranoproliferative glomerulonephritis (IC-MPGN), has similar symptoms to C3G but a different etiology. In both diseases, excessive activation of the complement system causes damage to the glomerulus, but in ICGN, the initiating event is the deposition of immune complexes, which trigger complement activation. In some cases, this immune complex deposition appears to be associated with mutations in complement component proteins (Iatropoulos et al., 2016). ICGN is a progressive disease, with approximately 50% of patients progressing to end-stage renal disease within 10 years.

[0101] Although several treatments are available to help manage symptoms, there are currently no approved medications for ICGN. Systemic immunosuppressive treatments have been proposed, but these carry the risk of significant side effects.

[0102] III. Antibodies and Antigen-Binding Fragments Antibodies against MASP-3 have been previously described, including various high-affinity antibodies with serine protease inhibitory activity, see PCT Patent Publications WO2013 / 180834, WO2013 / 192240, and WO2018 / 026722, which are incorporated herein by reference.

[0103] The antibodies described in WO2018 / 026722, including those designated 13B1, 10D12, 35C1, 4D5, 1F3, 4B6, and 1A10, as well as variants and modified versions of these antibodies, are particularly interesting for therapeutic applications. While several such variants are described in WO2018 / 026722, those skilled in the art will be able to construct additional variants containing the same or similar CDR sequences, and such additional variants are also contemplated for use as described herein. The sequences of certain antibodies and their variants are listed in the sequence listing in Table 1.

[0104] It is also contemplated that antigen-binding fragments of high-affinity antibodies with MASP-3 serine protease inhibitory activity may be used for the therapeutic purposes described herein. Such fragments are known in the art and include single-chain antibodies, ScFvs, Fab fragments, Fab' fragments, F(ab')2 fragments, and monovalent antibodies lacking the hinge region.

[0105] In some embodiments, the antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence set forth as SEQ ID NO:3. In some embodiments, the antibody or antigen-binding fragment thereof comprises an HCDR2 having the sequence set forth as SEQ ID NO:4 or 11. In some embodiments, the antibody or antigen-binding fragment thereof comprises an HCDR3 having the sequence set forth as SEQ ID NO:5. In some embodiments, the antibody or antigen-binding fragment thereof comprises an LCDR1 having the sequence set forth as SEQ ID NO:6 or 14. In some embodiments, the antibody or antigen-binding fragment thereof comprises an LCDR2 having the sequence set forth as SEQ ID NO:7. In some embodiments, the antibody or antigen-binding fragment thereof comprises an LCDR3 having the sequence set forth as SEQ ID NO:8.

[0106] In some embodiments, the antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence set forth as SEQ ID NO:3, an HCDR2 having the sequence set forth as SEQ ID NO:4, an HCDR3 having the sequence set forth as SEQ ID NO:5, an LCDR1 having the sequence set forth as SEQ ID NO:6, an LCDR2 having the sequence set forth as SEQ ID NO:7, and an LCDR3 having the sequence set forth as SEQ ID NO:8. In some embodiments, the antibody or antigen-binding fragment thereof comprises a VH having the sequence set forth as SEQ ID NO:1 and a VL having the sequence set forth as SEQ ID NO:2. In some embodiments, the antibody or antigen-binding fragment thereof is antibody 13B1. In some embodiments, the antibody or antigen-binding fragment thereof comprises a VH having the sequence set forth as SEQ ID NO:12 and a VL having the sequence set forth as SEQ ID NO:10. In some embodiments, the antibody or antigen-binding fragment thereof is antibody 13B1-10-1.

[0107] In some embodiments, the antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence set forth as SEQ ID NO:3, an HCDR2 having the sequence set forth as SEQ ID NO:11, an HCDR3 having the sequence set forth as SEQ ID NO:5, an LCDR1 having the sequence set forth as SEQ ID NO:6, an LCDR2 having the sequence set forth as SEQ ID NO:7, and an LCDR3 having the sequence set forth as SEQ ID NO:8. In some embodiments, the antibody or antigen-binding fragment thereof comprises a VH having the sequence set forth as SEQ ID NO:9 and a VL having the sequence set forth as SEQ ID NO:10. In some embodiments, the antibody or antigen-binding fragment thereof is antibody 13B1-9-1.

[0108] In some embodiments, the antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence set forth as SEQ ID NO:3, an HCDR2 having the sequence set forth as SEQ ID NO:11, an HCDR3 having the sequence set forth as SEQ ID NO:5, an LCDR1 having the sequence set forth as SEQ ID NO:14, an LCDR2 having the sequence set forth as SEQ ID NO:7, and an LCDR3 having the sequence set forth as SEQ ID NO:8. In some embodiments, the antibody or antigen-binding fragment thereof comprises a VH having the sequence set forth as SEQ ID NO:9 and a VL having the sequence set forth as SEQ ID NO:13. In some embodiments, the antibody or antigen-binding fragment thereof is antibody 13B1-9-1-NA.

[0109] In some embodiments, the antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence set forth as SEQ ID NO:3, an HCDR2 having the sequence set forth as SEQ ID NO:4, an HCDR3 having the sequence set forth as SEQ ID NO:5, an LCDR1 having the sequence set forth as SEQ ID NO:14, an LCDR2 having the sequence set forth as SEQ ID NO:7, and an LCDR3 having the sequence set forth as SEQ ID NO:8. In some embodiments, the antibody or antigen-binding fragment thereof comprises a VH having the sequence set forth as SEQ ID NO:12 and a VL having the sequence set forth as SEQ ID NO:13. In some embodiments, the antibody or antigen-binding fragment thereof comprises a light chain having the sequence set forth as SEQ ID NO:15 and a heavy chain having the sequence set forth as SEQ ID NO:16. In some embodiments, the antibody or antigen-binding fragment thereof is antibody 13B1-10-1-NA.

[0110] IV. Pharmaceutical Compositions The above-mentioned MASP-3 antibodies may be incorporated into compositions comprising one or more pharmaceutically acceptable carriers, excipients, or diluents.

[0111] Pharmaceutically acceptable carriers are selected so as to be non-toxic, biocompatible, and not to adversely affect the biological activity of the therapeutic agent (and any other therapeutic agents with which it is combined). Examples of pharmaceutically acceptable carriers for peptides are described in U.S. Patent No. 5,211,657 to Yamada. The therapeutic agents described herein can be formulated into solid, semi-solid, gel, liquid, or gaseous preparations, such as tablets, capsules, powders, granules, ointments, solutions, depositories, inhalants, and injectables, that allow for oral, parenteral, or surgical administration. Local administration of the composition by coating a medical device is also contemplated.

[0112] Suitable carriers for parenteral delivery by injection, infusion, irrigation, or topical application include distilled water, physiological phosphate-buffered saline, normal or lactated Ringer's solution, dextrose solution, Hank's solution, or propanediol. Additionally, sterile, fixed oils can be used as solvents or suspending media. Any biocompatible oil, including synthetic mono- or diglycerides, can be used for this purpose. Additionally, fatty acids such as oleic acid are useful in the preparation of injectable solutions. The carrier and active ingredient can be formulated as a liquid, suspension, polymeric or non-polymeric gel, paste, or salve.

[0113] The carrier may also include a delivery vehicle to sustain (i.e., extend, delay, or control) the delivery of an active agent or to enhance the delivery, uptake, stability, or pharmacokinetics of a therapeutic agent. Non-limiting examples of such delivery vehicles include microparticles, microspheres, nanospheres, or nanoparticles composed of proteins, liposomes, carbohydrates, synthetic organic compounds, inorganic compounds, polymer or copolymer hydrogels, and polymeric micelles. Suitable hydrogel and micelle delivery systems include the PEO:PHB:PEO copolymer and copolymer / cyclodextrin complexes disclosed in WO 2004 / 009664 A2 and the PEO and PEO / cyclodextrin complexes disclosed in U.S. Patent Application Publication No. 2002 / 0019369 A1. Such hydrogels may be injected locally at the intended site of action or subcutaneously or intramuscularly to form sustained-release depots.

[0114] The compositions of the present invention may be formulated for delivery by any suitable method, including, but not limited to, oral, topical, transdermal, sublingual, buccal, subcutaneous, intramuscular, intravenous, intraarterial, or as an inhalant. The compositions of the present invention may also include biocompatible excipients, such as dispersing or wetting agents, suspending agents, diluents, buffers, penetration enhancers, emulsifiers, binders, thickeners, flavoring agents (for oral administration).

[0115] Pharmaceutical compositions according to certain embodiments of the present invention are formulated so that the active ingredients contained therein are bioavailable when the composition is administered to a patient. The composition to be administered to a subject may be in the form of one or more dosage units. And, the containers of the therapeutic agents described herein may hold multiple dosage units. Actual methods for preparing such dosage forms will be known or apparent to those skilled in the art. See, for example, "Remington: The Science and Practice of Pharmacy," 20th Edition (Philadelphia College of Pharmacy and Science, 2000). In any event, the composition to be administered will contain an effective amount of the therapeutic agent or composition of the present disclosure for treating the disease or condition of interest, in accordance with the teachings herein.

[0116] The composition can be in solid or liquid form.In some embodiments, the carrier is granular, and thus the composition is in the form of, for example, tablet or powder.The carrier can also be liquid, and in this case, the composition is, for example, oral oil, injectable liquid, or aerosol that is useful for inhalation administration.When intended for oral administration, pharmaceutical composition is preferably in solid or liquid form, and herein, semi-solid, semi-liquid, suspension and gel form are included in the form that is considered as solid or liquid in this specification.

[0117] As a solid composition for oral administration, the pharmaceutical composition may be formulated into powder, granules, compressed tablets, pills, capsules, chewing gum, wafers, etc. Such solid compositions typically contain one or more inert fillers or diluents, such as sucrose, corn starch, or cellulose. In addition, one or more of the following may be present: binders, such as carboxymethylcellulose, ethylcellulose, microcrystalline cellulose, tragacanth, or gelatin; excipients, such as starch, lactose, or dextrin; disintegrants, such as alginic acid, sodium alginate, Primogel, corn starch, etc.; lubricants, such as magnesium stearate or Sterotex; glidants, such as colloidal silicon dioxide; sweeteners, such as sucrose or saccharin; flavorings, such as peppermint, peppermint, methyl salicylate, or orange flavoring; and coloring agents. When the composition is in the form of a capsule, eg, a gelatin capsule, it may contain, in addition to materials of the above type, a liquid carrier such as polyethylene glycol or oil.

[0118] The composition can be in the form of a liquid, such as an elixir, syrup, solution, emulsion, or suspension. Two examples of liquids can be for oral administration or for delivery by injection. When intended for oral administration, a preferred composition contains one or more of the following in addition to the compound: sweetener, preservative, dye / colorant, and flavor enhancer. The composition intended for administration by injection can contain one or more of surfactant, preservative, wetting agent, dispersant, suspending agent, buffer, stabilizer, and isotonicity agent.

[0119] Liquid pharmaceutical compositions, whether in solution, suspension, or other similar form, may contain one or more of the following excipients: sterile diluents, such as water for injection, saline solution, preferably saline, Ringer's solution, isotonic sodium chloride, fixed oils, synthetic mono- or diglycerides, polyethylene glycol, glycerin, propylene glycol, and other solvents that can serve as solvents or suspending media; antibacterial agents, such as benzyl alcohol or methylparabens; antioxidants, such as ascorbic acid or sodium bisulfite; chelating agents, such as ethylenediaminetetraacetic acid; buffers, such as acetates, citrates, or phosphates, and agents for adjusting tonicity, such as sodium chloride or dextrose. Parenteral preparations can be enclosed in glass or plastic ampoules, disposable syringes, or multiple-dose vials. Saline is the preferred excipient. Injectable pharmaceutical compositions are preferably sterile.

[0120] Liquid compositions intended for either parenteral or oral administration should contain an amount of the therapeutic agent described herein so that an appropriate dosage will be obtained. The term "parenteral" includes subcutaneous, intravenous, intramuscular, intrasternal, or intraarterial injection or infusion. Typically, the therapeutic agent is at least 0.01% of the composition. When intended for oral administration, this amount can vary and be between about 0.1% and about 70% by weight of the composition. Certain oral pharmaceutical compositions contain about 4% to about 75% of the therapeutic agent.

[0121] The composition may be intended for topical administration, in which case the carrier may suitably comprise a solution, emulsion, ointment, or gel base. The base may, for example, comprise one or more of the following: petrolatum, lanolin, polyethylene glycol, beeswax, mineral oil, diluents such as water and alcohol, and emulsifiers and stabilizers. A thickener may be present in a composition for topical administration. If intended for transdermal administration, the composition may comprise a transdermal patch or iontophoresis device. Pharmaceutical compositions may also be intended for rectal administration in the form of, for example, a suppository that melts in the rectum to release the drug. Compositions for rectal administration may contain an oily base as a suitable non-irritating excipient. Examples of such bases include, but are not limited to, lanolin, cocoa butter, and polyethylene glycol.

[0122] The composition may contain various materials that modify the physical form of the solid or liquid dosage unit. For example, the composition may contain a material that forms a coating shell around the active ingredient. The material that forms the coating shell is typically inert and may be selected from, for example, sugar, shellac, and other enteric coating agents. Alternatively, the active ingredient may be encapsulated in a gelatin capsule. The solid or liquid composition may contain an agent that binds to the therapeutic agent of the present disclosure, thereby assisting in the delivery of the compound. Suitable agents that can perform this function include one or more proteins or liposomes.

[0123] The composition may consist essentially of a dosage unit that can be administered as an aerosol. The term aerosol is used to describe a variety of systems, from colloidal to systems consisting of pressurized packages. Delivery can be by liquefied or compressed gas, or by a suitable pump system that dispenses the active ingredient. The aerosol may be delivered in a single-phase, two-phase, or three-phase system to deliver the active ingredient. The aerosol delivery includes the necessary container, activator, valve, subcontainer, etc., which may collectively form a kit. Those skilled in the art can determine a preferred aerosol without undue experimentation.

[0124] Pharmaceutical compositions can be prepared by methods well known in the pharmaceutical field. For example, compositions intended for administration by injection can be prepared by mixing a composition containing a therapeutic agent described herein and, optionally, one or more salts, buffers, and / or stabilizers with sterile distilled water to form a solution. A surfactant may be added to facilitate the formation of a uniform solution or suspension. A surfactant is a compound that non-covalently interacts with the composition to facilitate dissolution or uniform suspension in an aqueous delivery system.

[0125] The pharmaceutical composition may comprise a MASP-3 inhibitory antibody or its antigen-binding fragment in an aqueous solution. In some embodiments, the pharmaceutical composition comprises a MASP-3 inhibitory antibody or its antigen-binding fragment in an aqueous solution comprising a buffer system having a pH of 6.0±5%, 20±5% mM histidine, 100±5% mg / mL sucrose, and 0.035±5% polysorbate 80 (w / w). In some embodiments, the MASP-3 inhibitory antibody or its antigen-binding fragment is contained at a concentration of 110 mg / mL±5%. In some embodiments, the MASP-3 inhibitory antibody, or antigen-binding fragment thereof, comprises a heavy chain variable region comprising an HC-CDR1 comprising SEQ ID NO:3, an HC-CDR2 comprising SEQ ID NO:4 or SEQ ID NO:11, and an HC-CDR3 comprising SEQ ID NO:5, and a light chain variable region comprising an LC-CDR1 comprising SEQ ID NO:6 or SEQ ID NO:14, an LC-CDR2 comprising SEQ ID NO:7, and an LC-CDR3 comprising SEQ ID NO:8. In some embodiments, the pharmaceutical composition is sterile. In some embodiments, the MASP-3 inhibitory antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising a sequence at least 80%, 85%, 90%, 95%, 98%, 99% or 100% identical to SEQ ID NO:1, SEQ ID NO:9, or SEQ ID NO:12, and a light chain variable region comprising a sequence at least 80%, 85%, 90%, 95%, 98%, 99% or 100% identical to SEQ ID NO:2, SEQ ID NO:10, or SEQ ID NO:13. In some embodiments, the MASP-3 inhibitory antibody or antigen-binding fragment thereof is selected from the group consisting of a human antibody, a humanized antibody, a chimeric antibody, a murine antibody, and an antigen-binding fragment of any of the foregoing. In some embodiments, the MASP-3 inhibitory antibody or antigen-binding fragment thereof is selected from the group consisting of a single-chain antibody, an ScFv, an Fab fragment, an Fab' fragment, an F(ab')2 fragment, a monovalent antibody lacking a hinge region, and a complete antibody. In some embodiments, the MASP-3 inhibitory antibody further comprises an immunoglobulin constant region. In some embodiments, the MASP-3 inhibitory antibody comprises a human IgG4 constant region.In some embodiments, the MASP-3 inhibitory antibody comprises a human IgG4 constant region with an S228P mutation. In some embodiments, the MASP-3 inhibitory antibody comprises a mutation that promotes FcRn interaction at low pH.

[0126] The pharmaceutical composition may be present in a unit dosage form suitable for therapeutic administration to a human subject in an article of manufacture containing a pharmaceutical composition comprising a MASP-3 inhibitory antibody or its antigen-binding fragment, for example, in a unit dosage ranging from 10 mg to 1000 mg of MASP-3 inhibitory antibody (e.g., 50 mg to 800 mg, or 75 mg to 500, e.g., 100 mg to 300 mg, e.g., 125 to 275 mg, e.g., 150 to 200 mg, e.g., 150±5% mg, 155±5% mg, 160±5% mg, 165±5% mg, 170±5% mg, 175±5% mg, 180±5% mg, 185±5% mg or 190±5% mg). In some embodiments, the MASP-3 inhibitory antibody, or antigen-binding fragment thereof, comprises a heavy chain variable region comprising an HC-CDR1 comprising SEQ ID NO:3, an HC-CDR2 comprising SEQ ID NO:4 or SEQ ID NO:11, and an HC-CDR3 comprising SEQ ID NO:5, and a light chain variable region comprising an LC-CDR1 comprising SEQ ID NO:6 or SEQ ID NO:14, an LC-CDR2 comprising SEQ ID NO:7, and an LC-CDR3 comprising SEQ ID NO:8.

[0127] V. Methods and Uses Also provided herein are methods of using an antibody or its antigen-binding fragment to treat a disease or disorder associated with AP. In some embodiments, the method comprises administering to a mammalian subject in need thereof an amount of a MASP-3 antibody or its antigen-binding fragment, or a composition comprising a MASP-3 antibody or its antigen-binding fragment, sufficient to inhibit the alternative complement pathway in the subject. In some embodiments, the subject is human. In some embodiments, the method can further comprise determining that the subject is suffering from a disease or disorder associated with AP before administering a compound or composition of the present disclosure to the subject. In some embodiments, the disease or disorder associated with AP is paroxysmal nocturnal hemoglobinuria (PNH), complement factor 3 glomerulopathy (C3G), or idiopathic immune complex-mediated glomerulonephritis (ICGN).

[0128] In some embodiments, the MASP-3 antibody or antigen-binding fragment has serine protease inhibitory activity. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof includes antibodies referred to in PCT Publication WO2018 / 026722, including antibodies designated 13B1, 10D12, 35C1, 4D5, 1F3, 4B6, and 1A10, as well as variants and modified versions of these antibodies. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof includes an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4 or 11, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:6 or 14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8.

[0129] In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered intravenously. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered subcutaneously. The MASP-3 antibody or antigen-binding fragment may be administered once or multiple times. If administered multiple times, the timing of administration may be at predetermined intervals or may be determined based on biomarker measurements or the patient's condition / quality of life. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at intervals of 4 to 16 weeks. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at intervals of 6 to 12 weeks. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at intervals of 6 weeks. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at intervals of 8 weeks. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at intervals of 10 weeks. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at intervals of 12 weeks. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at intervals of 14 weeks. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at 16-week intervals. The MASP-3 antibody or antigen-binding fragment thereof is administered in an amount sufficient to inhibit activation of the alternative pathway of complement in the subject.In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at a dose of 0.001 mg / kg to 100 mg / kg, for example, 0.05 mg / kg to 50 mg / kg, or 0.1 mg / kg to 25 mg / kg, or 0.1 mg / kg to 15 mg / kg, or 0.1 mg / kg to 10 mg / kg, or 0.1 mg / kg to 5 mg / kg, or 0.1 mg / kg to 3 mg / kg, or 0.1 mg / kg to 1 mg / kg, or or .3mg / kg to 25mg / kg, or .3mg / kg to 15mg / kg, or .3mg / kg to 10mg / kg, or .3mg / kg to 5mg / kg, or .3mg / kg to 3mg / kg, or .3mg / kg to 1mg / kg, or .5mg / kg to 25mg / kg, or .5mg / kg to 15mg / kg, or .5mg / kg to 10mg / kg, or .5mg / kg to 5mg / kg, or or .5mg / kg to 3mg / kg, or .5mg / kg to 1mg / kg, or .8mg / kg to 25mg / kg, or .8mg / kg to 15mg / kg, or .8mg / kg to 10mg / kg, or .8mg / kg to 5mg / kg, or .8mg / kg to 3mg / kg, or .8mg / kg to 1mg / kg, or 1mg / kg to 25mg / kg, or 1mg / kg to 15mg / kg, or 1 The drug is administered at a dosage ranging from 1 mg / kg to 10 mg / kg, or 1 mg / kg to 5 mg / kg, or 1 mg / kg to 3 mg / kg, or 3 mg / kg to 25 mg / kg, or 3 mg / kg to 15 mg / kg, or 3 mg / kg to 10 mg / kg, or 3 mg / kg to 5 mg / kg, or 5 mg / kg to 25 mg / kg, or 5 mg / kg to 15 mg / kg, or 5 mg / kg to 10 mg / kg. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at a dosage of approximately 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11, 11.5, 12, 12.5, 13, 13.5 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, or 20 mg / kg.In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at a dosage of greater than 20 mg / kg. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at a dosage of about 1.0 mg / kg. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at a dosage of about 3.0 mg / kg. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at a dosage of about 5.0 mg / kg. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at a dosage of about 10 mg / kg. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at a dosage of about 12 mg / kg. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at a dosage of about 15 mg / kg. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at a dosage of about 17 mg / kg. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is administered at a dosage of about 20 mg / kg. In some embodiments, the dosage of the MASP-3 antibody or antigen-binding fragment thereof is determined based on biomarker measurements of the patient's condition / quality of life.

[0130] In some embodiments, the disease or disorder related to AP is paroxysmal nocturnal hemoglobinuria (PNH). In some embodiments, the subject has a hemoglobin level of less than 10.5 g / dL. In some embodiments, the subject is being treated or has been treated with a C5 inhibitor, such as ravulizumab or eculizumab. In another embodiment, the subject has not been treated with a C5 inhibitor. In some embodiments, the subject has a hemoglobin level of less than 10.5 g / dL despite treatment with a C5 inhibitor. The MASP-3 antibody or antigen-binding fragment thereof can be an adjunctive therapy or a monotherapy. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof is an adjunctive therapy in combination with a C5 inhibitor, such as ravulizumab or eculizumab. Treatment with the MASP-3 antibody or antigen-binding fragment thereof may be initiated as an adjunctive therapy and later used as a monotherapy. In some embodiments, a subject is treated with a MASP-3 antibody or its antigen-binding fragment together with a C5 inhibitor, such as ravulizumab or eculizumab, for a period of time, and then, if the subject shows improvement in PNH symptoms or biomarkers during the adjunctive treatment period, the subject is switched to monotherapy with the MASP-3 antibody or its antigen-binding fragment. In some embodiments, improvement is identified as an increase in baseline hemoglobin levels. In some embodiments, the subject receives 1, 2, 3, 4, 5, 6, 7, or 8 doses of adjunctive treatment before switching to monotherapy. The subject may continue treatment with the MASP-3 antibody or its antigen-binding fragment, either as adjunctive treatment or as monotherapy, for as long as necessary to provide continued relief from PNH symptoms. In some embodiments, treatment with the MASP-3 antibody or its antigen-binding fragment is continued indefinitely.

[0131] Measurements and biomarkers relevant to improving PNH symptoms and / or determining the efficacy of MASP-3 antibody treatment include hemoglobin levels, indicators of hemolysis (including reticulocytes and lactate dehydrogenase), evidence of ADA, serum concentrations of MASP-3 antibodies, serum concentrations of CFD, C3 opsonization of PNH red blood cells (RBCs), PNH RBC clonal size, systemic MASP-3 levels, C-reactive protein, D-dimer, number and / or frequency of transfusions, and subject scores on the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale.

[0132] In some embodiments, the disease or disorder associated with AP is C3 glomerulopathy (C3G) and idiopathic immune complex-mediated glomerulonephritis (ICGN). The subject may continue treatment with a MASP-3 antibody or antigen-binding fragment thereof, either as adjunctive therapy or as monotherapy, for as long as necessary to provide continued relief from the symptoms of C3G or idiopathic ICGN. In some embodiments, treatment with a MASP-3 antibody or antigen-binding fragment thereof is continued indefinitely.

[0133] Measurements and biomarkers relevant to improving symptoms of C3G or idiopathic ICGN and / or determining the efficacy of MASP-3 antibody treatment include proteinuria levels, serum creatinine levels, glomerular filtration rate, evidence of ADA, serum concentrations of MASP-3 antibodies, serum concentrations of CFD, levels of MASP-3, complement factors Bb, C3, and C3a, kidney injury molecule-1 (KIM1), neutrophil gelatinase-associated lipocalin (NGAL), collectin 11, soluble complement complex C5b-9, soluble CD163, MCP-1, and / or clusterin, kidney biopsy analysis, and subject scores on the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale.

[0134] Further provided herein is an antibody, antigen-binding fragment, or composition of the present disclosure for use in a method for treating a disease or disorder associated with AP. In some embodiments, the use comprises administering to a mammalian subject in need thereof an amount of a MASP-3 antibody or antigen-binding fragment thereof, or a composition comprising a MASP-3 antibody or antigen-binding fragment thereof, sufficient to inhibit the alternative complement pathway in the subject. In some embodiments, the subject is human. In some embodiments, the use may further comprise determining that the subject is suffering from a disease or disorder associated with AP before administering a compound or composition of the present disclosure to the subject. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4 or 11, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:6 or 14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. In some embodiments, the disease or disorder associated with AP is paroxysmal nocturnal hemoglobinuria (PNH), complement factor 3 glomerulopathy (C3G), or idiopathic immune complex-mediated glomerulonephritis (ICGN).

[0135] Also provided herein is an antibody, antigen-binding fragment, or composition of the present disclosure for use in a method for manufacturing or preparing a medicament for treating a disease or disorder related to AP. In some embodiments, the medicament comprises an amount of a MASP-3 antibody or antigen-binding fragment thereof, or a composition comprising a MASP-3 antibody or antigen-binding fragment thereof, sufficient to inhibit the alternative pathway of complement in a mammalian subject. In some embodiments, the subject is human. In some embodiments, the MASP-3 antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4 or 11, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:6 or 14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. In some embodiments, the disease or disorder associated with AP is paroxysmal nocturnal hemoglobinuria (PNH), complement factor 3 glomerulopathy (C3G), or idiopathic immune complex-mediated glomerulonephritis (ICGN).

[0136] VI. Arrays The sequences referred to herein are summarized in Table 1.

[0137] [Table 1] TIFF2025537131000005.tif244166TIFF2025537131000006.tif247166TIFF2025537131000007.tif65166 [Example]

[0138] VII. Working Examples Example 1 Phase 1 single ascending dose study in healthy subjects A phase 1 clinical trial was conducted to evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of antibody 13B1-10-1-NA in healthy human subjects. The phase 1 trial was a randomized, double-blind, placebo-controlled, single-center study.

[0139] The subjects were healthy men and women aged 18-64 years at the time of screening, with a body mass index (BMI) of 20-32 kg / m 2 and weighed at least 50 kg. Of the 72 subjects in this study, 37 were women and 35 were men. The median age was 42 years, ranging from 20 to 63 years. The median BMA was 27.2 kg / m 2 and the range is 21.0 to 31.4 kg / m 2 The median weight was 77.0 kg, with a range of 50.8 to 105.7 kg. The racial breakdown of subjects was as follows: 40 Caucasians, 22 Black or African American, 3 Asian, 2 American Indian or Alaska Native, and 5 reporting multiple races. Of the 72 subjects, 4 reported Hispanic or Latino ethnicity.

[0140] Antibody 13B1-10-1-NA was administered intravenously (IV) at 0.1 mg / kg, 0.3 mg / kg, 1.0 mg / kg, 3.0 mg / kg, or 5.0 mg / kg, or subcutaneously (SC) at 3.0 mg / kg, 5.0 mg / kg, or 8.0 mg / kg, or subjects received an IV or SC placebo. A graphical representation of the study design is shown in Figure 2.

[0141] In this study, serum 13B1-10-1-NA concentrations, serum PK parameters (C max , T max , t 1 / 2 , ACU 0-inf , CL, CL / F, V z , V 55 , V z / F), change from baseline in mature factor D plasma concentrations, incidence of anti-drug antibodies in serum, and occurrence of adverse events were measured. Pharmacokinetic results for subjects receiving 13B1-10-1-NA IV (n=30) or SC (n=24) are listed in Table 2.

[0142] [Table 2]

[0143] PK characteristics were observed to be dose-proportional (nonlinear) for both IV and SC administration. A long half-life (geometric mean range 94-406 hours) was observed, and measurable drug concentrations were detected at day 85 in both cohorts receiving IV (3 mg / kg or 5 mg / kg) and SC (3 mg / kg, 5 mg / kg, or 8 mg / kg) administration.

[0144] Pharmacodynamic results are shown in Figure 3. The percent change in mean mature complement factor D (CFD), an important PD marker of AP activity, demonstrated a dose-proportional response with rapid suppression of mature CFD levels. A greater degree of suppression was observed over a longer period in subjects receiving 3 or 5 mg / kg IV compared with subjects receiving placebo. The lower limit of quantitation in this assay was 43.9 ng / mL. Values ​​measured below this threshold were assigned a value of 43.9 ng / mL.

[0145] Antibody 13B1-10-1-NA was well tolerated. Most treatment-emergent adverse events (TEAEs) observed were mild and short in duration. A summary of adverse events (AEs) for subjects receiving 13B1-10-1-NA by IV (40 subjects) or SC (32 subjects) is listed in Table 3.

[0146] [Table 3]

[0147] The overall confirmed ADA positivity rate was 14.8% in subjects receiving antibody 13B1-10-1-NA. There were no instances of hypersensitivity or anaphylaxis. There was no evidence that ADAs affected PK or PD.

[0148] Example 2 Phase 1b study in patients with PNH who have a suboptimal response to ravulizumab A Phase 1b study will be conducted to evaluate safety and tolerability in patients with PNH who have a suboptimal response to ULTOMIRIS treatment, along with PK, PD, and certain efficacy measures. The study is a multicenter, open-label, uncontrolled trial. Patients with PNH who have a hemoglobin level of less than 10.5 g / dL when treated with ULTOMIRIS will be included. A graphical representation of the study design is shown in Figure 4.

[0149] Subjects will be men or women at least 18 years of age with PNH who are receiving stable treatment with ULTOMIRIS administered every 8 weeks by IV infusion and who have a suboptimal response to this treatment (defined as a hemoglobin level less than 10.5 g / dL despite ULTOMIRIS treatment). A maximum of 12 subjects total are expected to be enrolled, with 4-6 patients per treatment cohort.

[0150] Antibody 13B1-10-1-NA will be evaluated as adjunctive therapy with ULTOMIRIS and as monotherapy. For at least 8 weeks prior to the study and during an 8-week lead-in period, subjects will receive ULTOMIRIS alone on a standard schedule of one dose every 8 weeks. After the 8-week lead-in period, subjects will receive three intravenous doses of ULTOMIRIS and three intravenous doses of antibody 13B1-10-1-NA. The ULTOMIRIS and 13B1-10-1-NA doses will be administered on the same day at weeks 0, 8, and 16 of the study. One cohort will receive 3 mg / kg of antibody 13B1-10-1-NA, and another cohort will receive 5 mg / kg of antibody 13B1-10-1-NA. Samples for PK, PD, ADA, and biomarker analysis will be collected before each dose and at specified intervals during the follow-up period. An independent Data and Safety Monitoring Committee (DSMC) will review safety and tolerability data after the first subject in each cohort completes three doses, and after each of the three subjects in each cohort completes three doses. The DSMC will continue to review safety and tolerability data at intervals throughout the study. Subjects who demonstrate an incomplete response at week 24, defined as a partial increase from an individual subject's baseline hemoglobin level, may continue on three additional doses of supportive treatment administered at weeks 24, 32, and 40.

[0151] Subjects who demonstrate an increase in hemoglobin levels from baseline of at least 2.0 g / dL at week 24 will discontinue treatment with ULTOMIRIS and continue 13B1-10-1-NA monotherapy. Administration of 13B1-10-1-NA will continue at 8-week intervals at the dose assigned to the subject's cohort, and response to monotherapy will be assessed at 4-week intervals. Subjects will continue 13B1-10-1-NA monotherapy unless their hemoglobin level falls below the subject's baseline and / or their clinical condition warrants discontinuation. Subjects who continue to demonstrate a sustained clinical response at week 40 will be eligible to continue 13B1-10-1-NA treatment as part of a long-term extension study. Subjects who discontinue 13B1-10-1-NA monotherapy will return to treatment with ULTOMIRIS or other standard of care (SOC). Subjects who experience breakthrough hemolysis will be treated with any approved C5 inhibitor, including ravulizumab or eculizumab, and / or transfusions according to the SOC.

[0152] Subjects who do not demonstrate a clinical response at 24 weeks, defined as an increase from their baseline hemoglobin level, will be returned to treatment with ULTOMIRIS alone or another SOC therapy.

[0153] Subjects will be monitored over a 16-week follow-up period at the end of the adjuvant treatment phase (weeks 0-24 or 0-40) or at the end of the monotherapy phase for subjects entering monotherapy (duration of monotherapy will depend on clinical response).

[0154] Samples collected during the study will be analyzed for various components, including hemoglobin levels, indicators of hemolysis (including reticulocytes and lactate dehydrogenase), evidence of ADA, serum concentrations of antibody 13B1-10-1-NA, serum concentrations of CFD and other serum / plasma PD parameters, as well as various biomarkers such as C3 opsonization of PNH red blood cells (RBCs), PNH RBC clonal size, systemic MASP-3 levels, C-reactive protein, D-dimer, etc. Subjects will also be monitored for the number of transfusions during the study and quality of life as assessed using the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale.

[0155] Example 3 A Phase 1b study in patients with PNH, including those treated with C5 inhibitors and / or those not receiving C5 inhibitor treatment A Phase 1b study will be conducted to evaluate the safety and tolerability of antibody 13B1-10-1-NA in patients with PNH, along with PK, PD, and certain efficacy measures. This study is a multicenter, open-label, uncontrolled study. Patients with PNH who have shown an inadequate response to eculizumab or ravulizumab treatment or who are not currently receiving or have not previously received complement inhibitor treatment will be included. An inadequate response is defined as a hemoglobin level of less than 10.5 g / dL when treated with eculizumab or ravulizumab.

[0156] Subjects will be males or females at least 18 years of age with PNH who have been receiving stable eculizumab or ravulizumab treatment for at least 6 months at the time of screening and who have had an inadequate response to treatment or are not receiving complement inhibitor treatment at the time of screening. A maximum of approximately 10 subjects total will be enrolled.

[0157] Subjects will receive subcutaneous (SC) administration of antibody 13B1-10-1-NA every 4 weeks for a total of 13 doses. 5 mg / kg of antibody 13B1-10-1-NA will be administered. Subjects who complete the 48-week treatment period may be eligible for a long-term extension study. Subjects who develop breakthrough hemolysis will be treated with ravulizumab or eculizumab and / or transfusion according to SOC. After the treatment period, subjects will be monitored for an 8-week follow-up period.

[0158] Samples for PK, PD, ADA, and biomarker analysis will be collected before each dose and at specified intervals during the follow-up period. Samples will be analyzed for various components, including hemoglobin levels, bilirubin levels, indicators of hemolysis (including reticulocytes and lactate dehydrogenase (LDH)), evidence of ADA, serum concentrations of antibody 13B1-10-1-NA, serum concentrations of CFD and other serum / plasma PD parameters, as well as various biomarkers such as C3 opsonization of PNH red blood cells (RBCs), PNH RBC clonal size, and systemic MASP-3 levels. Subjects will also be monitored for the number of transfusions during the study.

[0159] Interim results showed statistically significant and clinically meaningful improvements in all measured hemolytic markers. The first set of interim results was obtained from eight complement inhibitor-naive adults with PNH treated with antibody 13B1-10-1-NA administered SC at a dose of 5 mg / kg every four weeks, as described above. Interim results for eight subjects up to 85 days after the first dose are shown in Table 4. P values ​​shown are for change from zero using a t-test.

[0160] [Table 4]

[0161] Baseline mean hemoglobin (Hgb) was 6.34 g / dL. By Day 57 (after two doses), all treated subjects achieved an increase in Hgb of 4.0 g / dL or greater. By Day 85 (after three doses), mean Hgb was 12.4 g / dL, a mean change from baseline of 6.27 g / dL (p=0.005). Improvement was rapid, with a significant mean Hgb improvement of 0.88 g / dL (p=0.003) observed at the first time point (Day 8) that continued to increase and remain statistically significant until the last observation time point (Day 85). Mean baseline LDH was 2067, more than eight times the upper limit of normal. A statistically significant improvement in LDH was observed at the first measurement point, Day 8, with further substantial reductions observed thereafter throughout the study.

[0162] 13B1-10-1-NA was observed to be safe and well tolerated, and treated subjects did not require or receive blood transfusions after treatment began.

[0163] Two interim result sets were obtained from 10 complement inhibitor-naive adults with PNH treated with antibody 13B1-10-1-NA administered SC at a dose of 5 mg / kg every 4 weeks, as described above. Interim results for these 10 subjects up to 141 days after the first dose are shown in Figures 5–11. Patients were adults with a flow cytometry-confirmed diagnosis of PNH (clone size >10%), complement inhibitor treatment-naive, and had a starting hemoglobin level of <10.5 g / kL and a starting LDH level >1.5 times the upper limit of normal. At the time of this interim data collection, 10 patients had received ≥1 dose of antibody 13B1-10-1-NA, 8 patients had received ≥2 doses, 4 patients had received ≥3 doses, and 3 patients had received ≥5 doses. Seven of the 10 patients had received RBC transfusions within the 12 months prior to the first dose. None of these 10 patients required transfusions during the study.

[0164] Figure 5 shows the mean hemoglobin levels in 10 patients over time, through 141 days after the first dose. The number of patients contributing data for each time point is indicated below the x-axis. Horizontal lines indicate the lower limit of normal for men (LLN(M)) and women (LLN(F)), as indicated. After the first dose, mean hemoglobin levels increased by 3.3 g / dL from baseline, p=0.001. After five doses, mean hemoglobin levels increased by 8.7 g / dL from baseline, p=0.018.

[0165] Figure 6 shows the hemoglobin levels over time in each of the 10 patients after the first dose. The horizontal lines indicate the lower limit of normal for men (LLN(M)) and women (LLN(F)), as indicated. Male patients are represented by squares and female patients are represented by circles. All 10 patients had a hemoglobin increase of 2 g / dL or more, and 8 of the 10 patients had a hemoglobin increase of 12 g / kL or more. Two patients who had a smaller hemoglobin increase (Patient 6 and Patient 7) also had myelodysplastic syndrome (MDS).

[0166] Figure 7 shows the mean LDH levels over time in 10 patients, up to 141 days after the first dose. The number of patients contributing data for each time point is shown below the x-axis. Horizontal lines indicate the upper limit of normal (ULN) and 1.5 x upper limit of normal (ULN 1.5 x), as indicated. After the first dose, mean LDH levels decreased by 1548 U / L from baseline, p=0.001. After five doses, mean LDH levels decreased by 1916 U / L from baseline, p=0.003.

[0167] Figure 8 shows LDL levels over time in each of the 10 patients after the first dose. Horizontal lines indicate the upper limit of normal (ULN) and 1.5x the upper limit of normal (ULN 1.5x), as indicated. Three patients had increased LDH at or near the end of the dosing period, but hemoglobin levels did not decrease in any of these patients. This information will help inform future dosing levels and dosing frequency.

[0168] Figure 9 shows absolute reticulocyte counts over time in 10 patients through day 141 after the first dose. The number of patients contributing data for each time point is shown below the x-axis. Horizontal lines indicate the upper limit of normal (ULN) and lower limit of normal (LLN), as indicated. After the first dose, the mean absolute reticulocyte count increased from baseline by 130 x 10 9 / L (p=0.001). After 5 doses, the mean absolute reticulocyte count decreased from baseline by 106 × 10 9 / L (p=0.015). The mean reticulocyte count was 90-133 × 10 from baseline at all time points. 9 / L reduced.

[0169] Figure 10 shows the absolute reticulocyte counts over time in each of the 10 patients after the first dose. Horizontal lines indicate the upper limit of normal (ULN) and lower limit of normal (LLN), as indicated.

[0170] Figure 11 shows the mean GPI-deficient (glycosylphosphatidylinositol-deficient) RBC clone size over time in seven patients through day 85 after the first dose. The number of patients contributing data for each time point is shown below the x-axis. After two doses, the mean RBC clone size increased by 38.4% from baseline (p=0.077).

[0171] These data demonstrate that antibody 13B1-10-1-NA resulted in normalization of hemoglobin levels in 8 of 10 patients receiving monthly SC administration without clinical breakthrough hemolysis. Antibody 13B1-10-1-NA also resulted in normalization of LDH in 7 of 10 patients, normalization of reticulocyte counts in 9 of 10 patients, and transfusion independence in all 10 patients.

[0172] Based on these data, as well as pharmacokinetic data in both healthy volunteers and PNH patients, it is predicted that once every three months may be an effective dosing frequency for antibody 13B1-10-1-NA when administered either SC or IV.

[0173] Example 4 Phase 1b study in patients with C3G and idiopathic ICGN A Phase 1b study will be conducted to evaluate the safety and tolerability of antibody 13B1-10-1-NA in patients with C3 glomerulopathy (C3G) and idiopathic immune complex-mediated glomerulonephritis (ICGN), along with PK, PD, and certain efficacy measures. This is a multicenter, open-label, uncontrolled study. Patients with C3G or idiopathic ICGN with a biopsy-confirmed diagnosis within 36 months of screening will be enrolled.

[0174] Subjects will be males or females, at least 18 years of age, with C3G or idiopathic ICGN who have been receiving stable treatment with angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) for at least 90 days at the time of screening. Up to approximately 10 patients with C3G and up to approximately 10 patients with ICGN will be enrolled.

[0175] Subjects will receive subcutaneous (SC) administration of antibody 13B1-10-1-NA every 4 weeks for a total of 13 doses. 5mg / kg of antibody 13B1-10-1-NA will be administered. Subjects who complete the 48-week treatment period may be eligible for a long-term extension study. After the treatment period, subjects will be monitored for an 8-week follow-up period.

[0176] Samples for PK, PD, ADA, and biomarker analysis will be collected before each dose and at specified intervals during the follow-up period. Samples will be analyzed for various components, including proteinuria levels, creatinine, evidence of ADA, serum concentrations of antibody 13B1-10-1-NA, serum concentrations of CFD, and other serum / plasma PD parameters. Subjects may elect to participate in a renal biopsy at 24 weeks, which will be used to identify changes from baseline in renal histopathology.

[0177] VIII. Other Aspects All publications and patent applications and patents mentioned herein are hereby incorporated by reference.

[0178] While certain embodiments of the invention have been illustrated and described, it will be understood 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 herein should not be unduly limited to such specific embodiments. Indeed, various modifications of the described specific embodiments 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.

[0179] Thus, for clarity of disclosure, numbered paragraphs describing specific embodiments are provided below, which should not be construed as limiting the scope of the claims. 1. A method for treating a human subject suffering from paroxysmal nocturnal hemoglobinuria (PNH), comprising administering to the subject an amount of a MASP-3 inhibitory agent sufficient to inhibit alternative pathway complement activation. 2. The method of paragraph 1, wherein said subject exhibits a suboptimal response to treatment with a C5 inhibitor. 3. The method of paragraph 2, wherein the C5 inhibitor is eculizumab, ravulizumab, or a biosimilar of either eculizumab or ravulizumab. 4. The method of paragraph 2, wherein the subject exhibits a hemoglobin level of less than 10.5 g / dL in response to C5 inhibitor treatment. 5. Any of the methods of paragraphs 1 to 4, wherein the MASP-3 inhibitory agent is an anti-MASP-3 antibody or an antigen-binding fragment thereof. 6. The method of paragraph 5, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4 or 11, and an HCDR3 having the sequence shown as SEQ ID NO:5, and a light chain variable region comprising an LCDR1 having the sequence shown as SEQ ID NO:6 or 14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. 7. The method of paragraph 6, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:6, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. 8. The method of paragraph 7, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:1 and a VL having the sequence shown as SEQ ID NO:2. 9. The method of paragraph 7, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a VH having the sequence shown as SEQ ID NO:12 and a VL having the sequence shown as SEQ ID NO:10. 10. The method of paragraph 6, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:11, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:6, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. 11. The method of paragraph 10, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:9 and a VL having the sequence shown as SEQ ID NO:10. 12. The method of paragraph 6, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:11, and an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. 13. The method of paragraph 12, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a VH having the sequence shown as SEQ ID NO:9 and a VL having the sequence shown as SEQ ID NO:13. 14. The method of paragraph 6, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. 15. The method of paragraph 14, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:12 and a VL having the sequence shown as SEQ ID NO:13. 16. The method of paragraph 15, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a light chain having the sequence shown as SEQ ID NO:15 and a heavy chain having the sequence shown as SEQ ID NO:16. 17. The method of any one of paragraphs 1 to 16, wherein the MASP-3 inhibitory agent is administered subcutaneously or intravenously. 18. Any one of the methods of paragraphs 1 to 17, wherein the MASP-3 inhibitory agent is administered at intervals of 4 to 16 weeks. 19. The method of paragraph 18, wherein the MASP-3 inhibitory agent is administered at intervals of 6 to 12 weeks. 20. The method of paragraph 18, wherein the MASP-3 inhibitory agent is administered at 4-week intervals. 21. The method of paragraph 18, wherein the MASP-3 inhibitory agent is administered at 8-week intervals. 22. The method of paragraph 18, wherein the MASP-3 inhibitory agent is administered at 12-week intervals. 23. Any one of the methods of paragraphs 1 to 22, wherein the MASP-3 inhibitory agent is administered at a dosage of 0.1 mg / kg to 50 mg / kg. 24. The method of paragraph 23, wherein the MASP-3 inhibitory agent is administered at a dosage of 1 mg / kg to 25 mg / kg. 25. The method of paragraph 23, wherein the MASP-3 inhibitory agent is administered at a dosage of 1.0 mg / kg to 15.0 mg / kg. 26. The method of paragraph 23, wherein the MASP-3 inhibitory agent is administered at a dosage of about 1.0 mg / kg. 27. The method of paragraph 23, wherein the MASP-3 inhibitory agent is administered at a dosage of about 3.0 mg / kg. 28. The method of paragraph 23, wherein the MASP-3 inhibitory agent is administered at a dosage of about 5.0 mg / kg. 29. The method of paragraph 23, wherein the MASP-3 inhibitory agent is administered at a dosage of about 7.0 mg / kg. 30. The method of paragraph 23, wherein the MASP-3 inhibitory agent is administered at a dosage of about 10 mg / kg. 31. The method of paragraph 23, wherein the MASP-3 inhibitory agent is administered at a dosage of about 12 mg / kg. 32. The method of paragraph 23, wherein the MASP-3 inhibitory agent is administered at a dosage of about 15 mg / kg. 33. The method of paragraph 23, wherein the MASP-3 inhibitory agent is administered at a dosage of about 17 mg / kg. 34. The method of paragraph 23, wherein the MASP-3 inhibitory agent is administered at a dosage of about 20 mg / kg. 35. Any one of the methods of paragraphs 23 to 34, wherein a pharmaceutical composition comprising a MASP-3 inhibitory antibody or its antigen-binding fragment in an aqueous solution is administered to the subject. 36. The method of paragraph 35, wherein the pharmaceutical composition comprises a MASP-3 inhibitory antibody or its antigen-binding fragment in an aqueous solution comprising a buffer system having a pH of 6.0±5%, 20±5% mM histidine, 100±5% mg / mL sucrose, and 0.035±5% polysorbate 80 (w / w). 37. The method of paragraph 36, wherein the MASP-3 inhibitory antibody or its antigen-binding fragment is contained in the pharmaceutical composition at a concentration of 110 mg / mL ± 5%. 38. Any one of the methods of paragraphs 1-37, wherein the subject receives both a MASP-3 inhibitory agent and a second complement inhibitor. 39. The method of paragraph 38, wherein the second complement inhibitor is a C5 inhibitor. 40. The method of paragraph 39, wherein the C5 inhibitor is eculizumab, ravulizumab, or a biosimilar of either eculizumab or ravulizumab. 41. A method for treating a human subject suffering from complement factor 3 glomerulopathy (C3G) or idiopathic immune complex-mediated glomerulonephritis (ICGN), comprising administering to the subject an amount of a MASP-3 inhibitory agent sufficient to inhibit alternative pathway complement activation. 42. The method of paragraph 41, wherein the MASP-3 inhibitory agent is an anti-MASP-3 antibody or an antigen-binding fragment thereof. 43. The method of paragraph 42, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4 or 11, and an HCDR3 having the sequence shown as SEQ ID NO:5, and a light chain variable region comprising an LCDR1 having the sequence shown as SEQ ID NO:6 or 14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. 44. The method of paragraph 41, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:6, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. 45. The method of paragraph 44, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a VH having the sequence shown as SEQ ID NO:1 and a VL having the sequence shown as SEQ ID NO:2. 46. ​​The method of paragraph 44, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a VH having the sequence shown as SEQ ID NO:12 and a VL having the sequence shown as SEQ ID NO:10. 47. The method of paragraph 41, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:11, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:6, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. 48. The method of paragraph 47, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a VH having the sequence shown as SEQ ID NO:9 and a VL having the sequence shown as SEQ ID NO:10. 49. The method of paragraph 41, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:11, and an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. 50. The method of paragraph 49, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a VH having the sequence shown as SEQ ID NO:9 and a VL having the sequence shown as SEQ ID NO:13. 51. The method of paragraph 41, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. 52. The method of paragraph 51, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a VH having the sequence shown as SEQ ID NO:12 and a VL having the sequence shown as SEQ ID NO:13. 53. The method of paragraph 52, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a light chain having the sequence shown as SEQ ID NO:15 and a heavy chain having the sequence shown as SEQ ID NO:16. 54. The method of any one of paragraphs 41 to 53, wherein the MASP-3 inhibitory agent is administered subcutaneously or intravenously. 55. Any one of the methods of paragraphs 41 to 54, wherein the MASP-3 inhibitory agent is administered at intervals of 4 to 16 weeks. 56. The method of paragraph 55, wherein the MASP-3 inhibitory agent is administered at intervals of 6 to 12 weeks. 57. The method of paragraph 55, wherein the MASP-3 inhibitory agent is administered at 4-week intervals. 58. The method of paragraph 55, wherein the MASP-3 inhibitory agent is administered at 8-week intervals. 59. The method of paragraph 55, wherein the MASP-3 inhibitory agent is administered at 12-week intervals. 60. Any one of the methods of paragraphs 41 to 59, wherein the MASP-3 inhibitory agent is administered at a dosage of 0.1 mg / kg to 50 mg / kg. 61. The method of paragraph 60, wherein the MASP-3 inhibitory agent is administered at a dosage of 1 mg / kg to 25 mg / kg. 62. The method of paragraph 61, wherein the MASP-3 inhibitory agent is administered at a dosage of 1.0 mg / kg to 15.0 mg / kg. 63. The method of paragraph 61, wherein the MASP-3 inhibitory agent is administered at a dosage of about 1.0 mg / kg. 64. The method of paragraph 61, wherein the MASP-3 inhibitory agent is administered at a dosage of about 3.0 mg / kg. 65. The method of paragraph 61, wherein the MASP-3 inhibitory agent is administered at a dosage of about 5.0 mg / kg. 66. The method of paragraph 61, wherein the MASP-3 inhibitory agent is administered at a dosage of about 7.0 mg / kg. 67. The method of paragraph 61, wherein the MASP-3 inhibitory agent is administered at a dosage of about 10 mg / kg. 68. The method of paragraph 61, wherein the MASP-3 inhibitory agent is administered at a dosage of about 12 mg / kg. 69. The method of paragraph 61, wherein the MASP-3 inhibitory agent is administered at a dosage of about 15 mg / kg. 70. The method of paragraph 61, wherein the MASP-3 inhibitory agent is administered at a dosage of about 17 mg / kg. 71. The method of paragraph 61, wherein the MASP-3 inhibitory agent is administered at a dosage of about 20 mg / kg. 72. Any one of the methods of paragraphs 41 to 71, wherein a pharmaceutical composition comprising a MASP-3 inhibitory antibody or its antigen-binding fragment in an aqueous solution is administered to the subject. 73. The method of paragraph 72, wherein the pharmaceutical composition comprises a MASP-3 inhibitory antibody or its antigen-binding fragment in an aqueous solution comprising a buffer system having a pH of 6.0±5%, 20±5% mM histidine, 100±5% mg / mL sucrose, and 0.035±5% polysorbate 80 (w / w). 74. The method of paragraph 73, wherein the MASP-3 inhibitory antibody or its antigen-binding fragment is contained in the pharmaceutical composition at a concentration of 110 mg / mL ± 5%. 75. Use of a MASP-3 inhibitory agent in the treatment of PNH, C3G, or idiopathic ICGN, wherein the MASP-3 inhibitory agent is an anti-MASP-3 antibody or an antigen-binding fragment thereof. 76. Use of paragraph 75, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4 or 11, and an HCDR3 having the sequence shown as SEQ ID NO:5, and a light chain variable region comprising an LCDR1 having the sequence shown as SEQ ID NO:6 or 14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8. 77. Use of a MASP-3 inhibitory agent in the manufacture of a medicament for treating PNH, C3G, or idiopathic ICGN, wherein the MASP-3 inhibitory agent is an anti-MASP-3 antibody or an antigen-binding fragment thereof. 78. Use of paragraph 77, wherein the anti-MASP-3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4 or 11, and an HCDR3 having the sequence shown as SEQ ID NO:5, and a light chain variable region comprising an LCDR1 having the sequence shown as SEQ ID NO:6 or 14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:8.

Claims

1. A method for treating a human subject suffering from paroxysmal nocturnal hemoglobinuria (PNH), comprising administering to the subject an amount of a MASP-3 inhibitory agent sufficient to inhibit alternative pathway complement activation.

2. The method of claim 1, wherein the subject exhibits a suboptimal response to treatment with a C5 inhibitor.

3. 3. The method of claim 2, wherein the C5 inhibitor is eculizumab, ravulizumab, or a biosimilar of either eculizumab or ravulizumab.

4. 3. The method of claim 2, wherein the subject exhibits a hemoglobin level of less than 10.5 g / dL in response to C5 inhibitor treatment.

5. The method of any one of claims 1 to 4, wherein the MASP-3 inhibitory agent is an anti-MASP-3 antibody or an antigen-binding fragment thereof.

6. The method of claim 5, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a heavy chain variable region comprising an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4 or 11, and an HCDR3 having the sequence shown as SEQ ID NO:5, and a light chain variable region comprising an LCDR1 having the sequence shown as SEQ ID NO:6 or 14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

7. The method of claim 6, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:6, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

8. The method of claim 7, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:1 and a VL having the sequence shown as SEQ ID NO:

2.

9. The method of claim 7, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:12 and a VL having the sequence shown as SEQ ID NO:

10.

10. The method of claim 6, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:11, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:6, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

11. The method of claim 10, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:9 and a VL having the sequence shown as SEQ ID NO:

10.

12. The method of claim 6, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:11, and an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

13. The method of claim 12, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:9 and a VL having the sequence shown as SEQ ID NO:

13.

14. The method of claim 6, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

15. The method of claim 14, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:12 and a VL having the sequence shown as SEQ ID NO:

13.

16. The method of claim 15, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a light chain having the sequence shown as SEQ ID NO:15 and a heavy chain having the sequence shown as SEQ ID NO:

16.

17. The method of any one of claims 1 to 16, wherein the MASP-3 inhibitory agent is administered subcutaneously or intravenously.

18. The method of any one of claims 1 to 17, wherein the MASP-3 inhibitory agent is administered at intervals of 4 to 16 weeks.

19. The method of claim 18, wherein the MASP-3 inhibitory agent is administered at intervals of 6 to 12 weeks.

20. The method of claim 18, wherein the MASP-3 inhibitory agent is administered at intervals of 4 weeks.

21. The method of claim 18, wherein the MASP-3 inhibitory agent is administered at intervals of 8 weeks.

22. The method of any one of claims 1 to 21, wherein the MASP-3 inhibitory agent is administered at a dosage of 1 mg / kg to 25 mg / kg.

23. The method of claim 22, wherein the MASP-3 inhibitory agent is administered at a dosage of 1 mg / kg to 15.0 mg / kg.

24. The method of claim 22, wherein the MASP-3 inhibitory agent is administered at a dosage of approximately 3.0 mg / kg.

25. The method of claim 22, wherein the MASP-3 inhibitory agent is administered at a dosage of approximately 5.0 mg / kg.

26. The method of claim 22, wherein the MASP-3 inhibitory agent is administered at a dosage of approximately 7.0 mg / kg.

27. The method of claim 22, wherein the MASP-3 inhibitory agent is administered at a dosage of approximately 10.0 mg / kg.

28. The method of any one of claims 1 to 27, wherein the subject receives both a MASP-3 inhibitory agent and a second complement inhibitor.

29. 29. The method of claim 28, wherein the second complement inhibitor is a C5 inhibitor.

30. 30. The method of claim 29, wherein the C5 inhibitor is eculizumab, ravulizumab, or a biosimilar of either eculizumab or ravulizumab.

31. A method for treating a human subject suffering from complement factor 3 glomerulopathy (C3G) or idiopathic immune complex-mediated glomerulonephritis (ICGN), comprising administering to the subject an amount of a MASP-3 inhibitory agent sufficient to inhibit alternative pathway complement activation.

32. The method of claim 31, wherein the MASP-3 inhibitory agent is an anti-MASP-3 antibody or an antigen-binding fragment thereof.

33. The method of claim 32, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a heavy chain variable region comprising an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4 or 11, and an HCDR3 having the sequence shown as SEQ ID NO:5, and a light chain variable region comprising an LCDR1 having the sequence shown as SEQ ID NO:6 or 14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

34. The method of claim 33, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:6, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

35. The method of claim 34, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:1 and a VL having the sequence shown as SEQ ID NO:

2.

36. The method of claim 34, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:12 and a VL having the sequence shown as SEQ ID NO:

10.

37. The method of claim 33, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:11, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:6, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

38. The method of claim 37, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:9 and a VL having the sequence shown as SEQ ID NO:

10.

39. The method of claim 33, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:11, and an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

40. The method of claim 39, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:9 and a VL having the sequence shown as SEQ ID NO:

13.

41. The method of claim 33, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4, an HCDR3 having the sequence shown as SEQ ID NO:5, an LCDR1 having the sequence shown as SEQ ID NO:14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

42. The method of claim 41, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a VH having the sequence shown as SEQ ID NO:12 and a VL having the sequence shown as SEQ ID NO:

13.

43. The method of claim 42, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a light chain having the sequence shown as SEQ ID NO:15 and a heavy chain having the sequence shown as SEQ ID NO:

16.

44. The method of any one of claims 31 to 43, wherein the MASP-3 inhibitory agent is administered subcutaneously or intravenously.

45. The method of any one of claims 31 to 44, wherein the MASP-3 inhibitory agent is administered at intervals of 4 to 16 weeks.

46. The method of claim 45, wherein the MASP-3 inhibitory agent is administered at intervals of 6 to 12 weeks.

47. The method of claim 45, wherein the MASP-3 inhibitory agent is administered at intervals of 4 weeks.

48. The method of claim 45, wherein the MASP-3 inhibitory agent is administered at intervals of 8 weeks.

49. The method of any one of claims 31 to 48, wherein the MASP-3 inhibitory agent is administered at a dosage of 0.1 mg / kg to 50 mg / kg.

50. The method of claim 49, wherein the MASP-3 inhibitory agent is administered at a dosage of 1 mg / kg to 25.0 mg / kg.

51. The method of claim 49, wherein the MASP-3 inhibitory agent is administered at a dosage of 1.0 mg / kg to 15.0 mg / kg.

52. The method of claim 49, wherein the MASP-3 inhibitory agent is administered at a dosage of approximately 1.0 mg / kg.

53. The method of claim 49, wherein the MASP-3 inhibitory agent is administered at a dosage of approximately 3.0 mg / kg.

54. The method of claim 49, wherein the MASP-3 inhibitory agent is administered at a dosage of approximately 5.0 mg / kg.

55. The method of claim 49, wherein the MASP-3 inhibitory agent is administered at a dosage of approximately 7.0 mg / kg.

56. The method of claim 49, wherein the MASP-3 inhibitory agent is administered at a dosage of approximately 10 mg / kg.

57. The method of any one of claims 1 to 56, wherein a pharmaceutical composition comprising a MASP-3 inhibitory antibody or its antigen-binding fragment in an aqueous solution is administered to the subject.

58. The method of claim 57, wherein the pharmaceutical composition comprises a MASP-3 inhibitory antibody or its antigen-binding fragment in an aqueous solution comprising a buffer system having a pH of 6.0±5%, 20±5% mM histidine, 100±5% mg / mL sucrose, and 0.035±5% polysorbate 80 (w / w).

59. The method of claim 57, wherein the MASP-3 inhibitory antibody or its antigen-binding fragment is contained in the pharmaceutical composition at a concentration of 110 mg / mL ± 5%.

60. The use of a MASP-3 inhibitory agent in the treatment of PNH, C3G, or idiopathic ICGN, wherein the MASP-3 inhibitory agent is an anti-MASP-3 antibody or its antigen-binding fragment.

61. The use described in claim 60, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a heavy chain variable region comprising an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4 or 11, and an HCDR3 having the sequence shown as SEQ ID NO:5, and a light chain variable region comprising an LCDR1 having the sequence shown as SEQ ID NO:6 or 14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

62. The use of claim 60 or 61, wherein the MASP-3 inhibitory agent is provided as a pharmaceutical composition comprising a MASP-3 inhibitory antibody or its antigen-binding fragment at a concentration of 110 mg / ml ± 5% in an aqueous solution comprising a buffer system having a pH of 6.0 ± 5%, 20 ± 5% mM histidine, 100 ± 5% mg / mL sucrose, and 0.035 ± 5% polysorbate 80 (w / w).

63. Use of a MASP-3 inhibitory agent in the manufacture of a medicine for treating PNH, C3G, or idiopathic ICGN, wherein the MASP-3 inhibitory agent is an anti-MASP-3 antibody or its antigen-binding fragment.

64. The use described in claim 63, wherein the anti-MASP-3 antibody or its antigen-binding fragment comprises a heavy chain variable region comprising an HCDR1 having the sequence shown as SEQ ID NO:3, an HCDR2 having the sequence shown as SEQ ID NO:4 or 11, and an HCDR3 having the sequence shown as SEQ ID NO:5, and a light chain variable region comprising an LCDR1 having the sequence shown as SEQ ID NO:6 or 14, an LCDR2 having the sequence shown as SEQ ID NO:7, and an LCDR3 having the sequence shown as SEQ ID NO:

8.

65. The use of claim 63 or 64, wherein the MASP-3 inhibitory agent is provided as a pharmaceutical composition comprising a MASP-3 inhibitory antibody or its antigen-binding fragment at a concentration of 110 mg / ml ± 5% in an aqueous solution comprising a buffer system having a pH of 6.0 ± 5%, 20 ± 5% mM histidine, 100 ± 5% mg / mL sucrose, and 0.035 ± 5% polysorbate 80 (w / w).

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