Horizon Pharma's Topline Phase 3 ACTIMMUNE Results Didn't Meet Primary, Secondary Endpoint

Horizon Pharma PLC HZNP, a biopharmaceutical company that focuses on unmet medical needs, announced Thursday topline results from a Phase 3 study called STEADFAST.

The trial evaluated Horizon's ACTIMMUNE therapy for the treatment of of Friedreich's ataxia, a rare inherited disease that causes nervous system damage and movement problems.

Horizon said the trial failed to reach its primary endpoint of demonstrating a statistically significant change from baseline in the modified Friedreich's Ataxia Rating Scale (FARS‐mNeuro) at 26 weeks versus treatment with placebo.

Shares of Horizon were halted ahead of the announcement. Once trading resumed at around 7:30 a.m. ET, the stock plummeted more than 22 percent.

FARS‐mNeuro is an exam-based rating scale that measures disease progression based on functional parameters such as speech, ability to swallow, upper and lower limb coordination, gait and posture.

"FARA's mission is to drive research to develop therapies that will treat and cure Friedreich's ataxia and we remain passionately committed to that mission so that one day soon patients and caregivers impacted by this devastating disease will have effective treatment options," said Ronald J. Bartek, co-founder and founding president, FARA. "We want to extend our sincere appreciation to all of the patients, patient families and investigators who were a part of this study as well as Horizon for collaborating with us so impressively on this important research."

Horizon also noted the announcement has no impact on its 2016 net sales or adjusted EBITDA guidance. The company still believes it's "well-positioned" for growth in 2017 and beyond given its already existing portfolio of medicines.

Wall Street analysts may take a fresh look at the company in the coming days and weeks to reevaluate their position. Most recently, analysts at Citi resumed coverage of the stock with a Buy rating based on the thesis that the company "succeeded in increasing its diversification away from its primary care franchise."