Dexpramipexole was originally identified as a candidate therapy for amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease by James Bennett, M.D., Ph.D., then of the University of Virginia.
The drug was initially investigated in ALS by Knopp Biosciences and Biogen Idec. A 2010 Phase II clinical trial showed a slowing of ALS disease progression and mortality benefits. In January 2013, Biogen Idec discontinued its development of dexpramipexole in ALS due to lack of efficacy in the Phase III study.
As a result of observing eosinophil lowering in the ALS trials, Knopp pivoted dexpramipexole clinical development to eosinophil associated diseases. In subsequent clinical trials, dexpramipexole significantly reduced eosinophil counts and glucocorticoid requirements in patients with hypereosinophilic syndrome and significantly reduced blood and tissue eosinophil counts in patients with chronic rhinosinusitis with nasal polyps.