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US-20260125478-A1 - BINDING MOLECULES SPECIFIC FOR FCGAMMA RIIA AND USES THEREOF

US20260125478A1US 20260125478 A1US20260125478 A1US 20260125478A1US-20260125478-A1

Abstract

Effector-deficient anti-CD32a monoclonal antibodies are encompassed, as are method and uses for treating CD32a-mediated diseases and disorders, including, thrombocytopenia, allergy, hemostatic disorders, immune, inflammatory, and autoimmune disorders.

Inventors

  • Katherine Ann Vousden
  • Bo Chen
  • Gary Patrick Sims

Assignees

  • HORIZON THERAPEUTICS IRELAND DAC

Dates

Publication Date
20260507
Application Date
20250825

Claims (20)

  1. 1 . An isolated binding molecule that specifically binds to FcγRIIA, wherein the binding molecule comprises: a. an immunoglobulin variable heavy chain complementarity determining region 2 (VH-CDR2) and an immunoglobulin variable light chain complementarity determining region 1(VL-CDR1) comprising amino acid sequences selected from the group consisting of: (i) SEQ ID NO: 19 and SEQ ID NO: 22; (ii) SEQ ID NO: 19 and SEQ ID NO: 23; (iii) SEQ ID NO: 19 and SEQ ID NO: 24; (iv) SEQ ID NO: 20 and SEQ ID NO: 25; (v) SEQ ID NO: 20 and SEQ ID NO: 23; and (vi) SEQ ID NO: 20 and SEQ ID NO: 26, respectively; b. an immunoglobulin variable heavy chain complementarity determining region 1 (VH-CDR1) comprising SEQ ID NO: 29; c. an immunoglobulin variable heavy chain complementarity determining region 3 (VH-CDR3) comprising SEQ ID NO: 30 or SEQ ID NO: 45; d. an immunoglobulin variable light chain complementarity determining region 2 (VL-CDR2) comprising SEQ ID NO: 31; and e. an immunoglobulin variable light chain complementarity determining region 3 (VL-CDR3) comprising SEQ ID NO: 32.
  2. 2 . The binding molecule of claim 1 , comprising SEQ ID NO: 19 and SEQ ID NO: 22.
  3. 3 . The binding molecule of claim 1 , comprising a heavy chain variable (VH) region and a light chain variable (VL) region, comprising amino acid sequences selected from the group consisting of: (i) SEQ ID NO: 33 and SEQ ID NO: 34, (ii) SEQ ID NO: 35 and SEQ ID NO: 36, (iii) SEQ ID NO: 37 and SEQ ID NO: 38, (iv) SEQ ID NO: 39 and SEQ ID NO: 40, (v) SEQ ID NO: 41 and SEQ ID NO: 42, and (vi) SEQ ID NO: 43 and SEQ ID NO: 44, respectively.
  4. 4 . The binding molecule of claim 3 , comprising a VH region and a VL region, comprising the amino acid sequences of SEQ ID NO: 33 and SEQ ID NO: 34, respectively.
  5. 5 . An isolated binding molecule that competes or cross-competes with the binding molecule of any preceding claim .
  6. 6 . The binding molecule of any preceding claim , which is selected from a murine antibody, a human antibody, a humanized antibody, a chimeric antibody, a monoclonal antibody, a polyclonal antibody, a recombinant antibody, a bi-specific antibody, a multi-specific antibody, and an antigen-binding fragment thereof.
  7. 7 . The binding molecule of any preceding claim , which is selected from an Fv, an Fab, an F(ab′)2, an Fab′, a dsFv fragment, a single chain Fv (scFV), an sc(Fv)2, a disulfide-linked (dsFv), a diabody, a triabody, a tetrabody, a minibody, or a single chain antibody.
  8. 8 . The binding molecule of any preceding claim , comprising an immunoglobulin (Ig) heavy chain constant region.
  9. 9 . The binding molecule of claim 8 , wherein the constant region is a human IgG constant region.
  10. 10 . The binding molecule of claim 9 , wherein the constant region comprises amino acid substitutions at Kabat positions 234, 235, and 331, wherein: a. the amino acid at Kabat position 234 is substituted with Phenylalanine (F), b. the amino acid at Kabat position 235 is substituted with Glutamic acid (E), and c. the amino acid at Kabat position 331 is substituted with Serine(S).
  11. 11 . The binding molecule of claim 9 or 10 , wherein the constant region comprises one or more substitutions of amino acid residues at positions 251-257, 285-290, 308-314, 385-389, and 428-436, relative to a wild-type human IgG constant region, wherein the amino acid position numbering is according to the EU index as set forth in Kabat.
  12. 12 . The binding molecule of claim 11 , wherein the constant region comprises amino acid substitutions at Kabat positions 252, 254, and 256, wherein: a. the amino acid at Kabat position 252 is substituted with Tyrosine (Y), b. the amino acid at Kabat position 254 is substituted with Threonine (T), and c. the amino acid at Kabat position 256 is substituted with Glutamic acid (E).
  13. 13 . The binding molecule of any preceding claim , comprising an immunoglobulin light chain constant region.
  14. 14 . The binding molecule of claim 13 , wherein the light chain constant region is a human kappa constant region.
  15. 15 . The binding molecule of any preceding claim , which specifically binds human FcγRIIA 131R with an affinity characterized by a dissociation constant (K D ) of about 0.15 nM, as measured by a BIAcore assay.
  16. 16 . The binding molecule of any preceding claim , which specifically binds human FcγRIIA 131H with an affinity characterized by a dissociation constant (K D ) of about 0.13 nM, as measured by a BIAcore assay.
  17. 17 . The binding molecule of any preceding claim , which does not specifically bind to FcγRI, FcγRIIB, or FcγRIII.
  18. 18 . The binding molecule of any preceding claim , which is conjugated to an agent selected from the group consisting of an antimicrobial agent, a therapeutic agent, a prodrug, a peptide, a protein, an enzyme, a lipid, a biological response modifier, a pharmaceutical agent, a lymphokine, a heterologous antibody or fragment thereof, a detectable label, a polyethylene glycol (PEG), a toxin, and a combination of two or more of any said agents.
  19. 19 . A composition comprising the binding molecule of any preceding claim and a carrier.
  20. 20 . The composition of claim 19 , which is a diagnostic reagent.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a Continuation of U.S. patent application Ser. No. 18/350,267, filed Jul. 11, 2023, which is a continuation of Ser. No. 17/684,018, filed Mar. 1, 2022, U.S. Pat. No. 11,746,153, which is a Continuation of U.S. patent application Ser. No. 16/097,573, filed Oct. 29, 2018, U.S. Pat. No. 11,306,145, which is the U.S. National Stage of International Patent Application No. PCT/EP2017/060188, filed Apr. 28, 2017, which claims the benefit of priority to U.S. Provisional Application No. 62/349,804, filed Jun. 14, 2016 and U.S. Provisional Application No. 62/329,627, filed Apr. 29, 2016, the contents of which are incorporated herein by reference in their entireties. DESCRIPTION OF THE TEXT FILE SUBMITTED ELECTRONICALLY The contents of the electronic sequence listing (10733-US07-CNT Sequence Listing.xml; Size: 57,741 bytes; and Date of Creation: Aug. 22, 2025) are herein incorporated by reference in its entirety. BACKGROUND FcγRs are a family of cell surface receptors that bind to the Fc portion of antibodies of the immunoglobulin G (IgG) subclasses. Human Fc gamma receptors (FcγRs) differ in function, binding affinity, and in their cellular distribution1. In humans, there are five FcγRs: the high-affinity receptor FcγRI (CD64), which can bind monomeric IgG; and the low-affinity receptors FcγRIIA (CD32A), FcγRIIB (CD32B), FcγRIIIA (CD16A), and FcγRIIIB (CD16B), which bind weakly to monomeric IgG, but avidly to immune complexes of IgG. FcγRI, FcγRIIA, FcγRIIIA, and FcγRIIIB are considered to have activating properties, whereas FcγRIIB is predominately inhibitory. FcγRIIA and FcγRIIB are the most closely related receptors. The extracellular regions of these receptors, which are responsible for interactions with IgG, share greater than 90% sequence identity2. Sequence differences in the intracellular signaling regions of FcγRIIA and FcγRIIB mediate the alternative cellular responses. FcγRs mediate several cellular processes, including antigen or pathogen uptake, degranulation, antigen presentation, and antibody-dependent cellular cytotoxicity (ADCC). In addition, FcγRs can interact with other receptors to influence the production of specific cytokines. Failure of the immune system to appropriately limit the reactivity of FcγRs can play a role in the development of inflammatory, immune-mediated, or autoimmune diseases or disorders3. Systemic lupus erythematosus (SLE) is a heterogeneous autoantibody driven immune-complex mediated autoimmune disease. A hallmark of SLE patients is the presence of autoantibodies directed against nuclear antigens, including dsDNA, ssDNA, and nucleic acid associated proteins (e.g., RNP, histones, Smith, Ro). Disease manifestations in the skin, lung, and kidney are associated with deposition of immune complexes4. Immune-complex-mediated activation of FcγRIIA has been implicated to play a role in the pathogenesis of SLE5. Approximately 60% of SLE patients have a type I interferon (IFN) gene signature which is most prevalent in patients with severe disease activity. Importantly, immune complexes containing DNA and RNA induce plasmacytoid dendritic cells to produce type I IFNα in an FcγRIIA-dependent manner5,6,7. Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) refers to a heterogeneous group of inflammatory diseases of blood vessels with multisystem manifestations8. AAV comprises granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), necrotizing crescentic glomerulonephritis (NCGN), and eosinophilic granulomatosis (EGPA). A hallmark of AAV patients is the presence of autoantibodies directly against neutrophil cytoplasmic antigens. The target antigens of ANCA include myeloperoxidase (MPO), proteinase 3 (PR3), lactoferrin, and others. GPA is primarily associated with antibodies to PR3, whereas MPA and EGPA are both associated with antibodies to MPO. ANCAs not only serve as a diagnostic marker, but they also play a direct pathogenic role in the disease. ANCAs can induce the direct activation of neutrophils via FcγRIIA, which can drive vascular injury9. Moreover, ANCAs may also trigger FcγRIIA-dependent induction of neutrophil extracellular traps (NETs), cytokines, and chemokines, which may contribute to inflammation and the autoimmune response10. Therefore, FcγRIIA appears to play a central role in the development and pathology of AAV. Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by the production of auto-reactive antibodies directed against platelet antigens. Autoantibodies coating the surface of platelets promote their clearance by phagocytic macrophages of the reticuloendothelial system. The repertoire and cellular expression of FcγRs differ between mouse and human, and although FcγRII is the most broadly expressed FcγR in humans, it is absent in mice. Using mice, transgenic for human FcγRIIA and deficient for the murine activating FcγRs, it was demonstrated that pa