News Feature | December 22, 2014

Auspex Pharma Posts Phase 3 Data For HD-Linked Chorea Drug

By Estel Grace Masangkay

Auspex Pharmaceuticals announced positive topline results from the Phase 3 registration study investigating its drug candidate SD-809 for chorea in patients suffering from Huntington's Disease (HD).

SD-809 (deutetrabenazine) is the company's lead product undergoing late-stage trials for the treatment of chorea associated with Huntington's disease. Aside from chorea, the company is also investigating the drug in a Phase 2/3 trial in tardive dyskinesia and a Phase 1B trial in Tourette syndrome.

The pivotal Phase 3 First-HD trial, which completed enrollment in August, met its primary as well as several secondary efficacy endpoints. The drug also demonstrated favorable safety and tolerability profiles. Results show that SD-809 significantly improved both patient and clinical global impressions of change based on a standardized score measuring involuntary movement. Patients who were treated with SD-809 also experienced improved quality of life and lower rates of anxiety and depression.

“For many individuals with Huntington's disease, chorea is a key symptom impacting safety, function, and quality of life. New, safe, and tolerable therapies for chorea treatment are clearly needed to make this disease an increasingly treatable condition. The primary and secondary efficacy results from this study were confirmed by the Huntington Study Group independent analysis. These clear and unequivocal results are clinically meaningful and suggest that SD-809 may play an important role in the treatment of Huntington's disease symptoms,” said Samuel A. Frank, principal investigator for the First-HD trial, and associate professor of neurology, Boston University School of Medicine.

Huntington's disease is a genetic disorder that leads to the death of certain brain cells over time. The disorder is characterized by a wide range of symptoms, including involuntary movements, emotional and behavioral problems, and difficulties with cognitive tasks such as thinking and processing information. Chorea, or involuntary and excess movements, is the most noticeable of the disease's symptoms. It can serve to debilitate patients as well as affect their quality of life. An estimated 90 percent of patients with Huntington's disease experience chorea.

Joseph Jankovic, treating investigator in the trial and professor neurology, Baylor College of Medicine, said, “The data from both the First-HD and ARC-HD studies suggest clear efficacy and an excellent safety and tolerability profile for SD-809... Any drug that suppresses chorea associated with Huntington's disease, with such a low rate of somnolence and depression, as suggested by these findings, would be a welcome addition to the treatment options available for my patients.”

Shares of the biopharmaceutical company jumped about 60 percent following news of the Phase 3 data announcement. Auspex said it will apply for regulatory approval for SD-809 by mid-2015. An approved drug for the indication known as Xenazine will lose market exclusivity in August 2015, opening up a door of opportunity for Auspex to grab a good slice of the market share should it secure approval from the U.S. Food and Drug Administration (FDA)