1. Rational design, biophysical and biological characterization of site-specific antibody-tubulysin conjugates with improved stability, efficacy and pharmacokinetics
- Author
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Robert E. Hollingsworth, Adeela Kamal, Haihong Zhong, Ryan Fleming, Nazzareno Dimasi, Herren Wu, Mary Jane Hinrichs, Xiang-Qing Yu, Pamela Thompson, Robert M. Woods, Patrick Strout, Song Cho, Cui Chen, Molly Reed, Rakesh Dixit, Binyam Bezabeh, Fengying Huang, Jay Harper, Xizhe Gao, Shenlan Mao, and Changshou Gao
- Subjects
0301 basic medicine ,Immunoconjugates ,Cell Survival ,Mice, Nude ,Pharmaceutical Science ,Antineoplastic Agents ,Receptors, Fc ,03 medical and health sciences ,0302 clinical medicine ,Pharmacokinetics ,In vivo ,Cell Line, Tumor ,Animals ,Humans ,Cysteine ,Molecular Targeted Therapy ,Chromatography, High Pressure Liquid ,Protein Stability ,Chemistry ,Rational design ,Antibodies, Monoclonal ,Small molecule ,In vitro ,body regions ,030104 developmental biology ,Biochemistry ,Drug Design ,030220 oncology & carcinogenesis ,Female ,Ex vivo ,Conjugate - Abstract
Antibody-drug conjugates (ADCs) are among the most promising empowered biologics for cancer treatment. ADCs are commonly prepared by chemical conjugation of small molecule cytotoxic anti-cancer drugs to antibodies through either lysine side chains or cysteine thiols generated by the reduction of interchain disulfide bonds. Both methods yield heterogeneous conjugates with complex biophysical properties and suboptimal serum stability, efficacy, and pharmacokinetics. To limit the complexity of cysteine-based ADCs, we have engineered and characterized in vitro and in vivo antibody cysteine variants that allow precise control of both site of conjugation and drug load per antibody molecule. We demonstrate that the chemically-defined cysteine-engineered antibody-tubulysin conjugates have improved ex vivo and in vivo stability, efficacy, and pharmacokinetics when compared to conventional cysteine-based ADCs with similar drug-to-antibody ratios. In addition, to limit the non-target FcγRs mediated uptake of the ADCs by cells of the innate immune system, which may result in off-target toxicities, the ADCs have been engineered to lack Fc-receptor binding. The strategies described herein are broadly applicable to any full-length IgG or Fc-based ADC and have been incorporated into an ADC that is in phase I clinical development.
- Published
- 2016