# US 11,078,274 B2 · Siglec neutralizing antibodies > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,078,274 B2 - Document ID: US11078274B2 - Status: Granted - Kind: B2 - Application number: 16/082,959 - Filed: 2017-03-07 - Published: 2019-03-21 - Granted: 2021-08-03 - Earliest claimed: 2016-03-08 - Assignees: Innate Pharma - Applicants: Innate Pharma - Inventors: Stephanie Cornen; Benjamin Rossi; Nicolai Wagtmann - Web page: https://patentgrep.com/patent/US11078274B2 ## CPC - C07K 16/2803: {against the immunoglobulin superfamily} - A61K 47/6801: {Drug-antibody or immunoglobulin conjugates defined by the pharmacologically or therapeutically active agent} - A61P 35/00: Antineoplastic agents - C12N 5/12: Fused cells, e.g. hybridomas - G01N 33/5758: {involving compounds serving as markers for tumours, cancers or neoplasias, e.g. cellular determinants, receptors, heat shock/stress proteins, A-protein, oligosaccharides or metabolites} - C07K 2317/33: Crossreactivity, e.g. for species or epitope, or lack of said crossreactivity - C07K 2317/34: Identification of a linear epitope shorter than 20 amino acid residues or of a conformational epitope defined by amino acid residues - C07K 2317/55: Fab or Fab' - C07K 2317/70: characterized by effect upon binding to a cell or to an antigen - C07K 2317/76: Antagonist effect on antigen, e.g. neutralization or inhibition of binding - C07K 2317/92: Affinity (KD), association rate (Ka), dissociation rate (Kd) or EC50 value - C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00) - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) - A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS - C12N: MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA (microbiological testing media C12Q1/00) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract This invention relates to agents that bind human Siglecs having inhibitory activity in immune cells, and that neutralize the inhibitory activity of such Siglec. Such agents can be used for the treatment of cancers or infectious disease. ## Claims ### Claim 1 An isolated antibody that binds a human Siglec-9 polypeptide and is capable of neutralizing the inhibitory activity of a Siglec-9 polypeptide expressed by a human NK cell, wherein the antibody is selected from the group consisting of: (a) an antibody comprising (i) a heavy chain variable region comprising CDR 1, 2 and 3 of the heavy chain variable region of SEQ ID NO: 15 and (ii) a light chain variable region comprising CDR 1, 2 and 3 of the light chain variable region of SEQ ID NO: 16; (b) an antibody comprising (i) a heavy chain variable region comprising CDR 1, 2 and 3 of the heavy chain variable region of SEQ ID NO: 17 and (ii) a light chain variable region comprising CDR 1, 2 and 3 of the light chain variable region of SEQ ID NO: 18; (c) an antibody comprising (i) a heavy chain variable region comprising CDR 1, 2 and 3 of the heavy chain variable region of SEQ ID NO: 19 and (ii) a light chain variable region comprising CDR 1, 2 and 3 of the light chain variable region of SEQ ID NO: 20; (d) an antibody comprising (i) a heavy chain variable region comprising CDR 1, 2 and 3 of the heavy chain variable region of SEQ ID NO: 21 and (ii) a light chain variable region comprising CDR 1, 2 and 3 of the light chain variable region of SEQ ID NO: 22; (e) an antibody comprising (i) a heavy chain variable region comprising CDR 1, 2 and 3 of the heavy chain variable region of SEQ ID NO: 23 and (ii) a light chain variable region comprising CDR 1, 2 and 3 of the light chain variable region of SEQ ID NO: 24; and (f) an antibody comprising (i) a heavy chain variable region comprising CDR 1, 2 and 3 of the heavy chain variable region of SEQ ID NO: 25 and (ii) a light chain variable region comprising CDR 1, 2 and 3 of the light chain variable region of SEQ ID NO: 26. ### Claim 2 (depends on 1) The antibody of claim 1, wherein the antibody enhances and/or restores the cytotoxicity of NK cells in a standard 4-hour in vitro 51Cr release cytotoxicity assay in which NK cells that express Siglec-9 are purified from human donors and incubated with target cells that express a sialic acid ligand of Siglec-9. ### Claim 3 (depends on 1) The antibody of claim 1, wherein the antibody is capable of neutralizing the inhibitory activity of a Siglec-9 polypeptide expressed by a human moDC bearing at its surface Siglec-9 polypeptides that are engaged in cis-interactions with sialic acids. ### Claim 4 (depends on 1) The antibody of claim 1, wherein the antibody lacks the ability to bind to the CD16 human Fcγ receptor. ### Claim 5 (depends on 1) The antibody of claim 1, wherein the antibody lacks the ability to bind to human CD16A, CD16B, CD32A, CD32B and CD64. ### Claim 6 (depends on 1) The antibody of claim 1, wherein the antibody substantially blocks the interaction between a human Siglec-9 polypeptide and a sialic acid ligand thereof. ### Claim 7 (depends on 6) The antibody of claim 6, wherein the antibody (a) substantially blocks the interaction between a human Siglec-9 polypeptide and a Neu5Aca2-3Galb1-4GlcNAcb and (b) substantially blocks the interaction between a human Siglec-9 polypeptide and a 6′-Sialyllactose. ### Claim 8 (depends on 1) The antibody of claim 1, wherein the antibody binds to a Siglec-9 polypeptide comprising the amino acid sequence of SEQ ID NO: 2 and to a Siglec-9 polypeptide comprising the amino acid sequence of SEQ ID NO: 160. ### Claim 9 (depends on 1) The antibody of claim 1, wherein the antibody causes an increase cytotoxicity and/or in a marker associated with cytotoxicity in a Siglec-expressing NK cell purified from a human donor, when the NK cell is brought into contact with a target human cell bearing a ligand of the Siglec on the target cell surface. ### Claim 10 (depends on 1) The antibody of claim 1, wherein the antibody is characterized by reduced binding to: a Siglec-9 polypeptide having a mutation at residue N78, P79, A80, R81, A82 and/or V83; a mutation at residue N77, D96, H98 and/or T99 and/or a mutation at residue W84, E85, E86 and/or R88; a Siglec-9 polypeptide having a mutation at residue S47, H48, G49, W50, I51, Y52, P53 and/or G54; a Siglec-9 polypeptide having a mutation at residue P55, H58, E122, G124, S125 and/or K127 a Siglec-9 polypeptide having a mutation at residue K131 and/or H132; and/or a Siglec-9 polypeptide having a mutation at residue R63, A66, N67, T68, D69, Q70 and/or D71; compared to binding to a wild-type Siglec-9 polypeptide of SEQ ID NO: 2, wherein amino acid residues are indicated with reference to the Siglec-9 polypeptide of SEQ ID NO: 2. ### Claim 11 (depends on 1) The antibody of claim 1, wherein the antibody is an antibody having an Fc domain that is modified to reduce binding between the Fc domain and an Fcγ receptor. ### Claim 12 (depends on 1) The antibody of claim 1, wherein said antibody is an antibody fragment. ### Claim 13 (depends on 1) The antibody of claim 1, wherein said antibody is conjugated or covalently bound to a detectable moiety. ### Claim 14 (depends on 12) An isolated Siglec binding protein comprising an antibody fragment of claim 12. ### Claim 15 (depends on 1) A pharmaceutical composition comprising an antibody according to claim 1, and a pharmaceutically acceptable carrier. ### Claim 16 (depends on 1) A kit comprising the antibody of claim 1 and a labelled secondary anti-IgG antibody that specifically recognizes said antibody. ### Claim 17 (depends on 1) A nucleic acid encoding a heavy and/or light chain of an antibody of claim 1. ### Claim 18 (depends on 1) A hybridoma or recombinant host cell producing the antibody of claim 1. ### Claim 19 (depends on 1) A method for the treatment of a cancer in a patient in need thereof, the method comprising administering to said patient an effective amount of an antibody of claim 1. ### Claim 20 (depends on 19) The method of claim 19, wherein said cancer is characterized by expression of ST3GAL1 and/or ST3GAL6 enzymes. ### Claim 21 (depends on 1) A method for modulating CD56dim NK cells and/or CD56bright NK cells and/or CD8+ T cells in a subject having a cancer, the method comprising administering to said subject an effective amount of an antibody of claim 1. ### Claim 22 (depends on 1) The isolated antibody of claim 1, wherein said antibody is an antibody fragment selected from a Fab, a Fab′, a Fab′-SH, a F(ab′)2, a Fv, a scFv, a diabody, or a single-chain antibody fragment. ### Claim 23 (depends on 22) The isolated antibody of claim 22, wherein said antibody fragment is a scFv.