Acceleron discontinues dalantercept after Phase II miss

Acceleron Pharma Inc. (NASDAQ:XLRN) discontinued development of dalantercept (ACE-041) after reporting top-line data from 119 evaluable patients with advanced renal cell carcinoma (RCC) in the double-blind part 2 of the Phase II DART trial showing that the product plus Inlyta axitinib missed the primary endpoint of improving median progression-free survival (PFS) vs. placebo plus Inlyta (6.8 vs. 5.6 months, HR=1.11, 2-sided 95% CI: 0.71, 1.73, 1-sided p=0.67). Dalantercept plus Inlyta also missed the secondary endpoint of improving median PFS in patients who received ≥2 prior systemic therapies vs. placebo plus Inlyta (8.1 vs. 7 months, HR=0.78, 2-sided 95% CI: 0.33, 1.87, 1-sided p=0.29). Additionally, dalantercept plus Inlyta led to an objective response rate (ORR) of 19% vs. 25% for placebo plus Inlyta (p=0.43).

The U.S. trial enrolled patients who progressed following treatment with a VEGF receptor tyrosine kinase inhibitor to receive placebo or subcutaneous dalantercept every 3 weeks plus Inlyta. The trial's primary endpoints are safety (part 1) and PFS (part 2). Secondary endpoints include overall survival (OS), time to tumor progression, ORR, duration of response, disease control rate (DCR) and biomarkers. Acceleron has previously reported data from the dose-escalation part 1 of the trial (see BioCentury, May 26, 2014 & March 16, 2015)...