Biogen Idec Inc. reported top-line results of EMPOWER, a Phase 3 trial investigating dexpramipexole in people with amyotrophic lateral sclerosis (ALS). The trial did not meet its primary endpoint, a joint rank analysis of function and survival, and no efficacy was seen in the individual components of function or survival. The trial also failed to show efficacy in its key secondary endpoints.

Additional analyses of multiple subpopulations failed to demonstrate any efficacy among these groups. Based on these results, Biogen Idec will discontinue development of dexpramipexole in ALS. EMPOWER was a randomized, double-blind, placebo-controlled Phase 3 trial which enrolled 943 people with ALS at 81 sites in 11 countries.

Patients were randomized on a one-to-one basis to receive either dexpramipexole or placebo. The primary endpoint was a joint rank analysis of function and survival, known as the Combined Assessment of Function and Survival (CAFS). In addition to CAFS, the trial individually evaluated functional decline, survival and respiratory decline, among other measures.