title: Generation of therapeutic immunoconjugates via Residue-Specific Conjugation Technology (RESPECT) utilizing a native cysteine in the light chain framework of Oryctolagus cuniculus.
abstract: The conjugation of toxins, dyes, peptides, or proteins to monoclonal antibodies is often performed via free thiol groups generated by either partial reduction methods or engineering free cysteine residues into the antibody sequence. Antibodies from the rabbit Oryctolagus cuniculus have an additional intrachain disulfide bond, whereby the light chain variable kappa domain is bridged to the constant kappa region between cysteine residues at positions 80 and 171, respectively. Chimerization of rabbit antibodies with human constant domains allows for the generation of a free thiol group at the light chain position 80 (C80) that can be used for site-specific conjugation. An efficient process for the purification and simultaneous removal of cysteinylation at the C80 site was developed. The unpaired C80 was shown to be efficiently conjugated using several different maleimido-based ligands. REsidue SPEcific Conjugation Technology (RESPECT) antibody-drug conjugates prepared using rabbit-human chimeric anti-human mesothelin rabbit antibodies and maleimido-PEG2-auristatin conjugated to C80 were shown to be highly potent and specific in vitro and effective in vivo in reduction of tumor growth in a highly aggressive mesothelin-expressing xenograft tumor model.
authors.affiliation: a Morphotek Inc. , Exton , PA , USA.
authors.forename: Earl F
authors.initials: EF
authors.lastname: Albone
authors.affiliation: a Morphotek Inc. , Exton , PA , USA.
authors.forename: Jared L
authors.initials: JL
authors.lastname: Spidel
authors.affiliation: a Morphotek Inc. , Exton , PA , USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Cheng
authors.affiliation: a Morphotek Inc. , Exton , PA , USA.
authors.forename: Young Chul
authors.initials: YC
authors.lastname: Park
authors.affiliation: a Morphotek Inc. , Exton , PA , USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Jacob
authors.affiliation: a Morphotek Inc. , Exton , PA , USA.
authors.forename: Andrew Z
authors.initials: AZ
authors.lastname: Milinichik
authors.affiliation: a Morphotek Inc. , Exton , PA , USA.
authors.forename: Ben
authors.initials: B
authors.lastname: Vaessen
authors.affiliation: a Morphotek Inc. , Exton , PA , USA.
authors.forename: Janet
authors.initials: J
authors.lastname: Butler
authors.affiliation: a Morphotek Inc. , Exton , PA , USA.
authors.forename: J Bradford
authors.initials: JB
authors.lastname: Kline
authors.affiliation: a Morphotek Inc. , Exton , PA , USA.
authors.forename: Luigi
authors.initials: L
authors.lastname: Grasso
mesh_terms: D062365:Aminobenzoates / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology* / Q000627:therapeutic use; D003545:Cysteine / Q000737:chemistry / Q000276:immunology; D006801:Humans; D018796:Immunoconjugates / Q000276:immunology* / Q000627:therapeutic use; D000090204:Mesothelin; D051379:Mice; D009369:Neoplasms / Q000188:drug therapy* / Q000276:immunology; D009842:Oligopeptides / Q000276:immunology; D011817:Rabbits; D000068878:Trastuzumab / Q000276:immunology; D023041:Xenograft Model Antitumor Assays
chemical_list: D062365:Aminobenzoates; D000911:Antibodies, Monoclonal; D018796:Immunoconjugates; C000715528:Msln protein, mouse; D009842:Oligopeptides; C543533:auristatin; D000090204:Mesothelin; D003545:Cysteine; D000068878:Trastuzumab
keywords: ADC; auristatin; bispecific; chimeric; disulfide; immunoconjugate; mesothelin; site-specific