BMS-986158, a Small Molecule Inhibitor of the Bromodomain and Extraterminal Domain Proteins, in Patients with Selected Advanced Solid Tumors: Results from a Phase 1/2a Trial
John Hilton, Mihaela Cristea, Sophie Postel‐Vinay, Capucine Baldini, Mark Voskoboynik, William J. Edenfield, Geoffrey I. Shapiro, Michael L. Cheng, Jacqueline Vuky, Bradley R. Corr, Sharmila Das, Abraham Apfel, Ke Xu, Martin Kozicki, Keziban Ünsal-Kaçmaz, Amy Hammell, Guan Wang, Palanikumar Ravindran, Georgia Kollia, Oriana Esposito, Shodeinde Coker, Jennifer R. Diamond
Abstract
This phase 1/2a, open-label study (NCT02419417) evaluated the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics of BMS-986158, a selective bromodomain and extraterminal domain (BET) inhibitor. Dose escalation was performed with 3 BMS-986158 dosing schedules: A (5 days on, 2 days off; range, 0.75-4.5 mg), B (14 days on, 7 days off; 2.0-3.0 mg), and C (7 days on, 14 days off; 2.0-4.5 mg). Eighty-three patients were enrolled and received ≥1 BMS-986158 dose. Diarrhea (43%) and thrombocytopenia (39%) were the most common treatment-related adverse events (TRAEs). A lower incidence of TRAEs was found with schedules A (72%) and C (72%) vs. B (100%). Stable disease was achieved in 12 (26.1%), 3 (37.5%), and 9 (31.0%) patients on schedules A, B, and C, respectively. Two patients on schedule A with a 4.5-mg starting dose (ovarian cancer, n = 1; nuclear protein in testis [NUT] carcinoma, n = 1) experienced a partial response. BMS-986158 demonstrated rapid-to-moderate absorption (median time to maximum observed plasma concentration, 1-4 h). As expected with an epigenetic modifier, expression changes in select BET-regulated genes occurred with BMS-986158 treatment. Schedule A dosing (5 days on, 2 days off) yielded tolerable safety, preliminary antitumor activity, and a dose-proportional PK profile.