FDA Approves First Treatment for Rare Thyroid Eye Disease

The U.S. Food and Drug Administration has approved Horizon Therapeutics’ Tepezza, the first approved therapeutic for the treatment of thyroid eye disease.

Thyroid eye disease (TED) is a serious, progressive and vision-threatening rare autoimmune disease that is associated with eye bulging, double vision, blurred vision, pain, inflammation, and facial disfigurement. TED is caused by autoantibodies activating an IGF-1R-mediated signaling complex on cells within the retro-orbital space, leading to a cascade of negative effects, which may cause long-term, irreversible damage, including blindness in some cases. Historically, patients have had to live with TED until the inflammation subsides, after which they are often left with permanent and vision-impairing consequences.

Tepezza is a fully human monoclonal antibody and a targeted inhibitor of the insulin-like growth factor-1 receptor (IGF-1R) that is administered to patients once every three weeks for a total of eight infusions.

“The FDA approval of Tepezzanis momentous for the TED community and has the potential to change the treatment paradigm for TED – providing new hope for people who are living with this horrible, vision-threatening disease,” said Raymond Douglas, director of the Orbital and Thyroid Eye Disease Program, Cedars-Sinai Medical Center and co-principal investigator of the Tepezza phase 3 confirmatory clinical trial. “Today’s news brings forward a medicine for patients that targets the underlying biology of the disease and has been shown to significantly improve eye bulging and double vision, which are the most debilitating aspects of the disease.”

Tepezza was approved based on the results of two studies consisting of a total of 170 patients with active thyroid eye disease who were randomized to either receive Tepezza or a placebo. Of the patients who were administered Tepezza, 71 percent in Study 1 and 83 percent in Study 2 demonstrated a greater than 2 millimeter reduction in proptosis (eye protrusion) as compared to 20 percent and 10 percent of subjects who received placebo, respectively.

The most common adverse reactions observed in patients treated with Tepezza are muscle spasm, nausea, alopecia (hair loss), diarrhea, fatigue, hyperglycemia (high blood sugar), hearing loss, dry skin, altered sense of taste, and headache.

The FDA approval came ahead of its Prescription Drug User Fee Act goal date of March 8, 2020, and had previously granted the application Priority Review, in addition to Fast Track, Breakthrough Therapy, and Orphan Drug designations.

“Tepezza is a much-needed breakthrough for a community of people who have historically had to struggle in pain as their symptoms progress – risking permanent damage to their eyes and making it extremely difficult to go about their daily lives,” said Jeff Todd, president and CEO, Prevent Blindness. “This approval is meaningful to our organization because we are committed to helping patients with vision impairment and those who are at significant risk.”

Horizon will conduct a post-marketing study to evaluate safety in a larger patient population. The drug is expected to be available in the United States in the coming weeks.

Photo: Jeff Todd, president and CEO of Prevent Blindness

Author: Rare Daily Staff