Pyrrolobenzodiazepine Dimer Antibody–Drug Conjugates: Synthesis and Evaluation of Noncleavable Drug-Linkers
作者:Stephen J. Gregson、Luke A. Masterson、Binqing Wei、Thomas H. Pillow、Susan D. Spencer、Gyoung-Dong Kang、Shang-Fan Yu、Helga Raab、Jeffrey Lau、Guangmin Li、Gail D. Lewis Phillips、Janet Gunzner-Toste、Brian S. Safina、Rachana Ohri、Martine Darwish、Katherine R. Kozak、Josefa dela Cruz-Chuh、Andrew Polson、John A. Flygare、Philip W. Howard
DOI:10.1021/acs.jmedchem.7b00736
日期:2017.12.14
Three rationally designed pyrrolobenzodiazepine (PBD) drug-linkers have been synthesized via intermediate 19 for use in antibody drug conjugates (ADCs). They lack a cleavable trigger in the linker and consist of a maleimide for cysteine antibody conjugation, a hydrophilic spacer, and either an alkyne (6), triazole (7), or piperazine (8) link to the PBD. In vitro IC50 values were 11-48 ng/mL in HER2 3+ SK-BR-3 and KPL-4 (7 inactive) for the anti-HER2 ADCs (HER2 0 MCF7, all inactive) and 0.10-1.73 mu g/mL (7 inactive) in CD22 3+ BJAB and WSU-DLCL2 for anti-CD22 ADCs (CD22 0 Jurkat, all inactive at low doses). In-vivo antitumor efficacy for the anti-HER2 ADCs in Founder 5 was observed with tumor stasis at 0.5-1 mg/kg, 1 mg/kg, and 3-6 mg/kg for 6, 8, and 7, respectively. Tumor stasis at 2 mg/kg was observed for anti-CD22 6 in WSU-DLCL2. In summary, noncleavable PBD-ADCs exhibit potent activity, particularly in HER2 models.