Site-specific conjugation of a cytotoxic drug to an antibody improves the therapeutic index

• Published in: Nature biotechnology Vol. 26; no. 8; pp. 925 - 932
• Main Authors: Junutula, Jagath R, Mallet, William, Raab, Helga, Clark, Suzanna, Bhakta, Sunil, Leipold, Douglas D, Weir, Sylvia, Chen, Yvonne, Simpson, Michelle, Tsai, Siao Ping, Dennis, Mark S, Lu, Yanmei, Meng, Y Gloria, Ng, Carl, Yang, Jihong, Lee, Chien C, Duenas, Eileen, Gorrell, Jeffrey, Katta, Viswanatham, Kim, Amy, McDorman, Kevin, Flagella, Kelly, Venook, Rayna, Ross, Sarajane, Spencer, Susan D, Lee Wong, Wai, Lowman, Henry B, Vandlen, Richard, Sliwkowski, Mark X, Scheller, Richard H, Polakis, Paul
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.08.2008; Nature Publishing Group
• Subjects: Agriculture; Animals; Antibodies, Monoclonal - genetics; Antibodies, Monoclonal - pharmacology; Antibodies, Neoplasm - genetics; Antibodies, Neoplasm - pharmacology; Antibody Specificity; Antibody-drug conjugates; Antineoplastic Agents - pharmacology; Antineoplastic drugs. Cytokines; Binding Sites; Bioinformatics; Biological and medical sciences; Biomedical and Life Sciences; Biomedical Engineering/Biotechnology; Biomedical research; Biomedicine; Biotechnology; CA-125 Antigen - immunology; Cell Line, Tumor; Chemistry, Pharmaceutical - methods; Cysteine - genetics; Cytotoxins - pharmacology; Female; Fundamental and applied biological sciences. Psychology; Health. Pharmaceutical industry; Humans; Immunotoxins - pharmacokinetics; Industrial applications and implications. Economical aspects; Life Sciences; Macaca fascicularis; Membrane Proteins - immunology; Mice; Mutagenesis, Site-Directed; Oligopeptides - pharmacology; Ovarian cancer; Ovarian Neoplasms - drug therapy; Ovarian Neoplasms - immunology; Production of active biomolecules; Rats; Rats, Sprague-Dawley; Sulfhydryl Compounds - pharmacology; Toxicology; Tumors; Antineoplastic agent; Drug; Cysteine; Thiol; Rat; Antibody; Toxicity; Rodentia; Site directed mutagenesis; Site specificity; Vertebrata; Phage display; Mammalia; Mouse; Conjugation; Conjugated compound
• ISSN: 1087-0156; 1546-1696
• DOI: 10.1038/nbt.1480

Systemic toxicity associated with heterogeneity in the stoichiometries and sites of drug attachment is a major hurdle to developing antibody-drug conjugates (ADCs) for cancer therapy. Junutula et al . engineer cysteine residues in constant domains to produce near-homogenous ADCs that are better tolerated than conventional ADCs, without any loss of antitumor activity. Antibody-drug conjugates enhance the antitumor effects of antibodies and reduce adverse systemic effects of potent cytotoxic drugs. However, conventional drug conjugation strategies yield heterogenous conjugates with relatively narrow therapeutic index (maximum tolerated dose/curative dose). Using leads from our previously described phage display–based method to predict suitable conjugation sites, we engineered cysteine substitutions at positions on light and heavy chains that provide reactive thiol groups and do not perturb immunoglobulin folding and assembly, or alter antigen binding. When conjugated to monomethyl auristatin E, an antibody against the ovarian cancer antigen MUC16 is as efficacious as a conventional conjugate in mouse xenograft models. Moreover, it is tolerated at higher doses in rats and cynomolgus monkeys than the same conjugate prepared by conventional approaches. The favorable in vivo properties of the near-homogenous composition of this conjugate suggest that our strategy offers a general approach to retaining the antitumor efficacy of antibody-drug conjugates, while minimizing their systemic toxicity.