The U.S. Food and Drug Administration approved Horizon Therapeutics PLC's medication for an autoimmune eye disorder.
Dublin-based Horizon's Tepezza, or teprotumumab-trbw, is now approved for treating thyroid eye disease. The drug is expected to be available in the U.S. in the coming weeks.
Thyroid eye disease is common in people with hyperthyroidism or Graves' disease. Patients experience bulging and misalignment of the eyes, blurred or double vision and sometimes blindness.
The regulator's approval comes over a month before the expected decision date of March 8 and follows a recommendation by an FDA panel that unanimously voted in favor of the drug. The agency previously granted Tepezza the priority review, orphan drug, fast-track and breakthrough therapy designations aiming to speed up the regulatory process.
The FDA's approval is supported by data from a phase 2 study, as well as a phase 3 study, dubbed Optic. Results from the trial showed that Tepezza reduced bulging of the eye in 82.9% of patients compared to 9.5% of patients on placebo. The drug also maintained its effectiveness in patients for about a year after the treatment.
Tepezza is a monoclonal antibody, meaning it is derived from identical immune cells to target a specific antigen. It targets the insulin-like growth factor 1 receptor that is overexpressed in thyroid eye disease, causing inflammation and tissue expansion behind the eyes.
Horizon plans a post-marketing study to evaluate Tepezza's safety in a larger population. Additionally, Horizon is eligible for milestone payments in lieu of the drug's approval. It expects to receive $105 million during the first half of 2020.