Company is on Track to Announce Topline Data in the Fourth Quarter of 2014

LA JOLLA, CA, USA I August 18, 2014 I Auspex Pharmaceuticals, Inc. (ASPX), a late clinical stage biopharmaceutical company focused on developing and commercializing novel medicines for the treatment of orphan diseases, today announced that it has completed the enrollment of the planned 90 patients in its Phase 3 registration clinical trial (First-HD) of SD-809 for the potential treatment of chorea associated with Huntington’s disease (HD). The company expects to announce the topline data from this study in the fourth quarter of 2014.

“The completion of enrollment of the First-HD trial represents an important milestone for both the company and the SD-809 program,” said David Stamler, M.D., Chief Medical Officer of Auspex. “We are gratified by the interest and support shown by the HD patients, the care givers, the HD advocacy groups and the treating physicians in this trial. We believe that SD-809 has the potential to be an important new treatment for these patients.”

About First-HD

First-HD is a randomized, double-blind, placebo-controlled, parallel-group trial of SD-809 in 90 patients with chorea associated with Huntington’s disease and is designed to evaluate, and generate label information for, the safety, tolerability and efficacy of SD-809 for treating chorea associated with Huntington’s disease. If the primary endpoint of First-HD is met, the Company anticipates submitting a Section 505(b)(2) new drug application, for SD-809 to the U. S. Food and Drug Administration (FDA). In addition, the Company has initiated an open-label clinical trial, which is referred to as ARC-HD that will evaluate long-term safety as well as provide guidance on how to switch patients who are currently on tetrabenazine to SD-809. These studies are being conducted with the Huntington Study Group. More information about clinical trials evaluating SD-809 in First-HD and ARC-HD can be found at www.huntington-study-group.org or by calling 800-487-7671.

About Auspex Pharmaceuticals

Auspex Pharmaceuticals is a late clinical stage biopharmaceutical company focused on the development and commercialization of novel medicines for the treatment of orphan diseases. Auspex’s pipeline includes product candidates to address unmet medical needs in hyperkinetic movement disorders, such as chorea associated with Huntington’s disease, tardive dyskinesia and Tourette syndrome, as well as fibrotic indications, including idiopathic pulmonary fibrosis (IPF) and other orphan conditions. Auspex’s lead product candidate, SD-809 (deutetrabenazine), is in a Phase 3 registration clinical trial for the treatment of chorea (abnormal involuntary movements) associated with Huntington’s disease. Auspex has initiated a Phase 2/3 clinical trial of SD-809 in tardive dyskinesia and a Phase 1b study in Tourette syndrome. Auspex also is evaluating SD-560 (deuterium-containing form of pirfenidone) in a Phase 1 clinical trial. Auspex has employed its deuterium chemistry approach to optimize other compounds in its portfolio that are at various stages of development. For further information, please visit the company’s website www.auspexpharma.com.

SOURCE: Auspex Pharmaceuticals