Horizon's stock price soared after the release of the results of its Phase 3 trial of its TED drug teprotumumab, rocketing more than 27% to $27.76.
Nearly 83% of TED patients given teprotumumab had a "meaningful improvement in in proptosis, or bulging of the eye," the main cause of morbidity in the disease, the Dublin-based pharmaceutical company reported.
That was compared to 9.5% of patients given a placebo.
Horizon said it will submit an application for a biologics license mid-year to the U.S. Food and Drug Administration for its proposed treatment of the thyroid eye disease. The company plans to submit detailed data later this year to a peer-reviewed journal and to a medical conference as well.
If successful in winning FDA approval, Horizon's new drug would be the first on the market to treat TED, a rare eye disease that affects as many as 20,000 people each year in the U.S., the company said.
A "progressive, debilitating autoimmune disease," TED can cause eye bulging, misalignment of the eyes, double vision and, in some cases, blindness, according to Horizon.
Currently, the disease must run its course over a three-year period before patients can be operated on surgically, the only way now to treat TED.
"The dramatic results of the teprotumumab Phase 3 confirmatory trial ... form a highly convincing body of clinical evidence supporting teprotumumab for the treatment of active thyroid eye disease," said Timothy Walbert, chairman, president and CEO of Horizon, in a press release. "This is a key milestone as we evolve into a research-focused company."