Teva Pharmaceutical Industries has announced that its NDA for SD-809 (deutetrabenazine) has been accepted by the FDA for the treatment of chorea associated with Huntington’s disease (HD), a rare and fatal neurodegenerative disorder caused by the progressive breakdown of nerve cells in the brain that affects about five to seven people per 100,000 in Western countries, according to the World Health Organization.

The NDA filing is based on positive results from two phase III studies, FIRST-HD and ARC-HD. In the placebo-controlled, randomized FIRST-HD study, SD-809 reduced chorea in patients with HD. Positive top-line data from the phase III, open-label ARC-HD study demonstrated that patients were able to safely convert from tetrabenazine, currently the only approved HD treatment, to SD-809 overnight with continued control of chorea.

SD-809 was granted Orphan Drug designation for HD by the FDA in November 2014 and became part of Teva’s CNS portfolio with the acquisition of Auspex Pharmaceuticals in May 2015.

The FDA designates orphan status to drugs and biologics that are intended for the treatment of rare diseases affecting fewer than 200,000 people in the U.S.