What is "dexpramipexole"

n. An experimental drug being investigated for the treatment of amyotrophic lateral sclerosis.

Dexpramipexole (KNS-760704) is a drug that was investigated by Knopp Biosciences and Biogen Idec for the treatment of amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease. The drug failed to show efficacy in terms of function or survival in a Phase III study of patients with ALS.

In September 2009, dexpramipexole received Fast Track designation for ALS from the U.S. Food and Drug Administration (FDA). It has received Orphan Drug designation by both the FDA and the European Medicines Agency. Dexpramipexole is a low molecular weight, water-soluble, orally bioavailable, renally excreted compound with linear pharmacokinetics, and has been shown to be well tolerated in human subject testing.

KNS-760704 is the enantiomer of pramipexole, and has been shown to improve mitochondrial function and to confer significant cellular protection in neurons under stress. KNS-760704 was originally identified as a candidate therapy for ALS by James Bennett, M.D., Ph.D., then of the University of Virginia.

A 2010 Phase II clinical trial involving 102 patients showed a slowing of ALS disease progression.

In January 2013, Biogen Idec announced that it was discontinuing its development of dexpramipexole in ALS due to lack of efficacy in a Phase III study.