# US 11,896,675 B2 · Site-specific antibody conjugation and antibody-drug conjugate as specific embodiment thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,896,675 B2 - Document ID: US11896675B2 - Status: Granted - Kind: B2 - Application number: 18/154,998 - Filed: 2023-01-16 - Published: 2023-08-10 - Granted: 2024-02-13 - Earliest claimed: 2019-03-08 - Assignees: Abtis Co., Ltd. - Applicants: AbTis Co., Ltd. - Inventors: Sang Jeon Chung; Ju Hwan Kim; Young Geun Lee; Tae Jin Lee; Jin Woo Seo - Web page: https://patentgrep.com/patent/US11896675B2 ## CPC - C07D 498/18: Bridged systems - A61K 47/68031: {the drug being an auristatin} - A61K 47/68033: {the drug being a maytansine} - A61K 47/68037: {the drug being a camptothecin [CPT] or derivatives} - A61K 47/6811: {the drug being a protein or peptide, e.g. transferrin or bleomycin} - A61K 47/6855: {the tumour determinant being from breast cancer cell} - A61K 47/6889: {Conjugates wherein the antibody being the modifying agent and wherein the linker, binder or spacer confers particular properties to the conjugates, e.g. peptidic enzyme-labile linkers or acid-labile linkers, providing for an acid-labile immuno conjugate wherein the drug may be released from its antibody conjugated part in an acidic, e.g. tumoural or environment} - A61P 35/00: Antineoplastic agents - C07D 207/46: with hetero atoms directly attached to the ring nitrogen atom - C07K 7/08: having 12 to 20 amino acids (gastrins C07K14/595; somatostatins C07K14/655; melanotropins C07K14/68) - C07K 16/32: against translation products of oncogenes - C07K 2317/24: containing regions, domains or residues from different species, e.g. chimeric, humanized or veneered - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) - 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 - 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) ## Abstract The present invention relates to technology capable of labeling a certain site of an antibody with a certain number of chemical functional groups or cargo moieties. The present invention may provide an antibody product having high uniformity. The present invention may provide an antibody product whose antibody functions are not degraded. That is, the present invention may provide an antibody product whose antibody binding affinity and half-life are not degraded. The present invention is of great significance as being the first technology allowing site-specific labeling of an antibody without any complicated processes. ## Claims ### Claim 1 A modified antibody or its fragment comprising bio-orthogonal click chemistry functional group, wherein the modified antibody comprises one or more modified heavy chain, wherein each of the modified heavy chain comprises a modified lysine residue at 248 position of heavy chain amino acid sequence, wherein the 248 position is determined by an EU numbering system, and wherein the modified lysine residue comprises a bio-orthogonal click chemistry functional group at terminal end, and wherein the modified lysine residue does not comprise a terminal bio-reactive functional group selected from terminal hydroxy group, terminal carboxyl group, terminal thiol group, terminal amino group, and terminal aldehyde group. ### Claim 2 (depends on 1) The modified antibody of claim 1, wherein the modified lysine residue has following structure: wherein H1 is a group having the bio-orthogonal click chemistry functional group, and wherein D1 is bond, or is selected from C1-4 alkylene, C2-4 alkenylene, C2-4 alkynylene and C3-8 cycloalkylene. ### Claim 3 (depends on 2) The modified antibody of claim 2, wherein D1 is bond, or is selected from unsubstituted C1-4 alkylene, unsubstituted C2-4 alkenylene, unsubstituted C2-4 alkynylene and unsubstituted C3-8 cycloalkylene. ### Claim 4 (depends on 1) The modified antibody of claim 1, wherein the modified heavy chain comprises an amino acid sequence having a structure of formula 8-2: G-P—S-V-F-L-F—P-P-K-P—(K)′-D-T-L-M-I (SEQ ID NO: 21), [formula 8-2] wherein K′ is the modified lysine residue. ### Claim 5 (depends on 2) The modified antibody of claim 2, wherein D1 comprises one or more heteroatoms. ### Claim 6 (depends on 2) The modified antibody of claim 2, wherein D1 is —[CH2]a—O—[CH2]b—, wherein each of a and b is independently selected from 0 to 4, and each of a and b is integer, and wherein sum of a and b is 0 or more and 4 or less. ### Claim 7 (depends on 2) The modified antibody of claim 2, wherein D1 is —CH2CH2OCH2— or —CH2OCH2—. ### Claim 8 (depends on 1) The modified antibody of claim 1, wherein the modified antibody comprises two modified heavy chains. ### Claim 9 (depends on 1) The modified antibody of claim 1, wherein the bio-orthogonal click chemistry functional group is a group capable of participating in a click chemistry reaction selected from Huisgen 1,3-dipolar cycloaddition and Diels-Alder reaction. ### Claim 10 (depends on 1) The modified antibody of claim 1, wherein the bio-orthogonal click chemistry functional group is selected from azide group, tetrazine group, dibenzocyclooctyne group, and norbornene group. ### Claim 11 (depends on 1) The modified antibody of claim 1, wherein the modified lysine residue has following structure: ### Claim 12 (depends on 3) The modified antibody of claim 3, wherein the bio-orthogonal click chemistry group is a group capable of participating in a click chemistry reaction selected from Huisgen 1,3-dipolar cycloaddition and Diels-Alder reaction. ### Claim 13 (depends on 3) The modified antibody of claim 3, wherein the bio-orthogonal click chemistry functional group is selected from the group consisting of an azide group, a tetrazine group, a dibenzocyclooctyne group, and a norbornene group.