FDA expert panel unanimously recommends approval for Horizon Therapeutics eye drug
An FDA advisory committee noted with concern a small safety database but unanimously endorsed a Horizon Therapeutics drug for a rare eye autoimmune disease that can blind patients: teprotumumab for thyroid eye disease (TED).
“It was a pretty easy vote,” said Erica Brittain, an NIH biostatistician and one of the 12 panelists on FDA’s Dermatologic and Ophthalmic Drugs Advisory Committee.
After listening to testimony from patients and advocates, the advisers debated the drug’s label and whether there was enough data to properly understand the drug’s adverse effects, but rarely showed the kind of alarm that would lead to a ‘no’ vote. Horizon submitted a Phase III trial showing that the drug could dramatically lower proptosis, or bulging of the eye, by at least 2 mm in 89.2% of patients, but between the Phase III and the Phase II there were less than 90 patients actually treated with a profusion.
“The uncertainty lies in the small patient population and potential risk of side effects,” said Timothy Murray, a panelist and director of Miami Ocular Oncology and Retina. But “this is one of the more remarkable drugs to come out of an unmet need.”
The FDA had raised concerns about how the primary endpoint in Horizon’s Phase III was calculated, but that did not seem to be a major issue for the panel. Like the FDA, they determined the biotech nevertheless showed strong efficacy and spent much of the session debating how a post-approval study should be constructed. Horizon had proposed a registry of 200 patients but some experts wanted 500.
The PDUFA date is set for March 8. The FDA does not have to listen to the recommendations but generally does.
Horizon has projected $750 million in peak sales for the drugs, while analysts have pegged the number closer to $500 million. It would be a significant win for the company and end a long road for an antibody that began life as a Roche-licensed treatment for solid tumors. Horizon purchased it two years ago from Narrow Vision for $145 million upfront two years ago.
The company expects to treat around 15,000 to 20,000 TED patients per year. The autoimmune disease primarily affects women and manifests in midlife and can severely handicap people.
Patient and patient advocates testified before the FDA advisors’ discussion, and the panelists cited their words when explaining their vote. Patients talked about the disease rendering them unable to drive or do daily tasks, while also changing their appearance.
“I welcome the addition of this drug to our armamentarium to treat this horrible, horrible disease,” said John Stamler, a University of Iowa ophthalmologist and panelist. “It may be the only arrow in our quiver.”