Tepezza (teprotumumab-trbw) is an insulin-like growth factor-1 receptor inhibitor.
Tepezza is specifically indicated for the treatment of thyroid eye disease.
Tepezza is supplied as a solution for intravenous injection administration. The recommended dose is an intravenous infusion of 10 mg/kg for the initial dose followed by an intravenous infusion of 20 mg/kg every three weeks for 7 additional infusions.
The FDA approval of Tepezza was based on results from a Phase 2 clinical study, as well as the Phase 3 confirmatory clinical study, OPTIC.
The phase 2 study, the results of which were published in The New England Journal of Medicine in May of 2017, was multicenter, double-masked, randomized, placebo-controlled trial to determine the efficacy and safety of teprotumumab in patients with active, moderate-to-severe ophthalmopathy. A total of 88 patients were randomly assigned to receive placebo or active drug administered intravenously once every 3 weeks for a total of eight infusions. The primary end point was the response in the study eye. This response was defined as a reduction of 2 points or more in the Clinical Activity Score (scores range from 0 to 7, with a score of ≥3 indicating active thyroid-associated ophthalmopathy) and a reduction of 2 mm or more in proptosis at week 24. In the intention-to-treat population, 29 of 42 patients who received teprotumumab (69%), as compared with 9 of 45 patients who received placebo (20%), had a response at week 24.
The phase 3 OPTIC study was a randomized, double-masked, placebo-controlled, parallel-group, multicenter study enrolled 83 subjects with moderate-to-severe active TED. Significantly more patients treated with Tepezza (82.9%) had a meaningful improvement in proptosis (≥ 2 mm) as compared with placebo patients (9.5%) without deterioration in the fellow eye at Week 24.
In a related analysis of the Phase 2 and Phase 3 clinical studies, there were more patients with complete resolution of diplopia among those treated with Tepezza (53%) compared with those treated with placebo (25%). The majority of adverse events related to Tepezza included muscle spasm, nausea, alopecia, diarrhea, fatigue, hyperglycemia, hearing impairment, dry skin, dysgeusia and headache.
Adverse effects associated with the use of Tepezza may include, but are not limited to, the following:
Teprotumumab-trbw’s mechanism of action in patients with Thyroid Eye Disease has not been fully characterized. Teprotumumab-trbw binds to IGF-1R and blocks its activation and signaling.
For additional information regarding Tepezza or thyroid eye disease, please visit the Tepezza web page.