FDA Approves Biologic Teprotumumab, First Drug for Thyroid Eye Disease

The FDA Tuesday approved teprotumumab, to be sold as Tepezza, the first drug for the treatment of adults with thyroid eye disease. The FDA granted the approval of Tepezza, a biologic, to Horizon Therapeutics Ireland DAC; it is a targeted inhibitor of the insulin-like growth factor-1 receptor that is administered to patients once every 3 weeks for a total of 8 infusions.

Thyroid eye disease is a rare condition where the muscles and fatty tissues behind the eye become inflamed, causing the eyes to be pushed forward and bulge outwards (proptosis).

A spokesperson for the company said teprotumumab will cost $14,900 per vial, with full treatment over 6 months approximately 23 vials, and that the wholesale acquisition cost for that amount is $343,000, with an annual net realized price of $200,000.

The FDA granted this application Priority Review, in addition to Fast Track and Breakthrough Therapy designations. It also received an Orphan Drug designation.

Teprotumumab was approved based on the results of 2 studies of 170 patients with active thyroid eye disease who were randomized to either receive the drug or a placebo. Of the patients who were administered teprotumumab, 71% in study 1 and 83% in study 2 demonstrated a greater than 2 millimeter reduction in proptosis compared with 20% and 10% of subjects, respectively, who received placebo, according to the FDA.

“Today’s approval marks an important milestone for the treatment of thyroid eye disease. Currently, there are very limited treatment options for this potentially debilitating disease. This treatment has the potential to alter the course of the disease, potentially sparing patients from needing multiple invasive surgeries by providing an alternative, nonsurgical treatment option,” Wiley Chambers, MD, deputy director of the Division of Transplant and Ophthalmology Products in the FDA’s Center for Drug Evaluation and Research, said in a statement. “Additionally, thyroid eye disease is a rare disease that impacts a small percentage of the population, and for a variety of reasons, treatments for rare diseases are often unavailable. This approval represents important progress in the approval of effective treatments for rare diseases, such as thyroid eye disease.”

Thyroid eye disease can cause eye pain, double vision, light sensitivity or difficulty closing the eye. More women than men are affected. The most common adverse reactions are muscle spasm, nausea, alopecia, diarrhea, fatigue, hyperglycemia, hearing loss, dry skin, dysgeusia (altered sense of taste), and headache.