Tepezza First Drug Approved to Treat Thyroid Eye Disease

January 21, 2020 – The U.S. FDA has approved TepezzaTM (teprotumumab-trbw), manufactured by Horizon Therapeutics, to treat thyroid eye disease (TED). It is the first and only FDA-approved therapy for this indication.

Thyroid eye disease is a rare autoimmune condition that causes inflammation of the muscles and fatty tissues behind the eye. It is a serious, progressive disease that can cause diplopia (double vision), proptosis (bulging of the eyes), strabismus (misalignment of the eyes), blurred vision, pain, and facial disfigurement. In severe cases, the optic nerve may be compromised, leading to vision loss. Proptosis can be so severe that the eyelids are unable to close completely over the eye, creating the potential for damage to the cornea.

In clinical studies, 82.9% of patients treated with Tepezza had meaningful improvement in proptosis without deterioration of the other eye at 24 weeks of treatment compared to 9.5% of patients who received a placebo. More than half (67.9%) of patients who received Tepezza experienced a change from baseline of at least one grade in diplopia compared to 28.6% of patients receiving placebo, with 53% of patients who received Tepezza experiencing complete resolution of diplopia compared with 25% of patients in the placebo group.

Recommended initial dosing is 10mg/kg of body weight for the first treatment, followed by 20mg/kg every three weeks for seven additional infusions. Tepezza is administered via intravenous (IV) infusion over the course of 60 to 90 minutes.

Horizon has launched Tepezza at a wholesale acquisition cost (WAC) of $14,900 per vial.