FDA Greenlights Tepezza as First Treatment for Thyroid Eye Disease

By Rajaneesh K. Gopinath, Ph.D.

Yesterday, Dublin based Horizon Therapeutics received the early FDA authorization of its human monoclonal antibody, Tepezza (teprotumumab-trbw). With this, the drug became the first and only approved treatment for a rare autoimmune disease.

The Disease

Thyroid Eye Disease (TED) is a debilitating autoimmune disorder in which autoantibodies trigger an abnormal reaction against the muscles and fatty tissues surrounding the eyes causing reddening and swelling. Progressive TED causes further trouble with symptoms like eye bulging (proptosis), double vision (diplopia) and misalignment of the eyes (strabismus) eventually leading to the loss of vision. The inflammation of the orbit (socket) is caused by the activation of insulin-like growth factor-1 receptor (IGF-1R)-mediated signaling complex. In some patients, the immune reaction also affects the thyroid gland thereby causing Grave’s disease.

The Treatment

Until now, treatments included steroids, eye surgeries and attachment of prisms in spectacles. Tepezza is the first experimental human monoclonal antibody to be developed for this condition. It is an inhibitor of IGF-1R that is administered to patients once every three weeks for a total of eight infusions. The FDA had previously granted Priority Review for this application. The drug also garnered Orphan Drug and Breakthrough Therapy designations. Last December, the FDA’s Dermatologic and Ophthalmic Drugs Advisory Committee voted 12-0 in favor of its approval.

The Clinical Data

The approval of Tepezza is based is based on positive data from two key studies that enrolled a total of 170 patients. The Phase 3 OPTIC study found that 82.9% of patients treated with the drug had a significant improvement in proptosis (≥ 2 mm) as compared to placebo only (9.5%). Secondary endpoints were also met with 67.9% of patients receiving Tepezza showing statistically significant improvement in diplopia as compared to 28.6% of patients receiving placebo. A related analysis of the data found that more patients in the drug arm showing a complete resolution of diplopia (53%) as compared to placebo (25%). The company would still conduct a large-scale study to determine its safety.

“Today is a great day for people living with Thyroid Eye Disease, a rare, vision-threatening disease that previously had no FDA-approved treatment options,” said Timothy Walbert, chairman, president, and CEO of Horizon. “The TED community has gone far too long without an FDA-approved therapy, and we are grateful to the people living with TED and physicians who partnered with us on the clinical development program that led to today’s approval of Tepezza. This also marks the early approval of Horizon’s first Biologics License Application – a key step in our evolution to an innovation-focused biopharma company, developing new medicines for debilitating diseases with few or no treatment options.”

References

1. https://ir.horizontherapeutics.com/news-releases/news-release-details/fda-approves-tepezzatm-teprotumumab-trbw-treatment-thyroid-eye
2. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-thyroid-eye-disease
3. https://ir.horizontherapeutics.com/news-releases/news-release-details/fda-advisory-committee-votes-unanimously-support-use

Author

Rajaneesh K. Gopinath