Thyroid eye disease (TED) remains a serious, progressive, and debilitating autoimmune condition. Some patients can experience disfigurement, and clinical outcomes are typically poor. Until now, treatment options have been limited to steroids and surgery. The emergence of a new drug, teprotumumab, could fill an unmet need for patients with TED, according to Raymond S. Douglas, MD, PhD. He spoke about the newly available treatment during the “TED Talks” session (Ocu03V) at Oculofacial Plastic Surgery Subspecialty Day.
How does it work? Teprotumumab is a human monoclonal antibody that inhibits insulin-like growth factor receptor (IGF-1R). The drug works by halting IGF-1R and all downstream activation, thus reducing inflammation and reversing retro-orbital tissue expansion.
Trial data show promise. Data from a randomized, double-masked, placebo-controlled trial showed a “profound” reduction in proptosis by 24 weeks. The drug, which is administered once every three weeks for a total of eight infusions, led to a mean reduction in proptosis of 3.14 mm; minimal changes (0.37 mm) were observed in the placebo group. In addition, teprotumumab provided significant improvements in diplopia as well as reductions in orbital fat and inferior rectus muscle size.
Treatment durability. Among the patients who were followed through week 72, a majority maintained their response—indicating that benefits were maintained for nearly a year after treatment cessation. A small number of patients relapsed, but they improved again with additional infusions.
Side effect profile. The majority of adverse events appeared to be mild to moderate. The most common reactions included muscle spasm, nausea, hair loss, and diarrhea. There were no events that led to treatment discontinuation. During the panel discussion, Dr. Douglas noted that hydration therapy and a Myers’ cocktail with teprotumumab infusions could be helpful in limiting muscle spasms.
How does it compare to surgical interventions? This remains to be determined, said Dr. Douglas. Thus far, evidence suggests that teprotumumab offers a reduction in proptosis comparable to that obtained with decompression techniques.
Dr. Douglas concluded by reiterating that teprotumumab remains the only FDA approved therapy for TED to date. With careful patient selection, it represents a viable addition to the thyroid eye disease armamentarium. —Keng Jin Lee, PhD
Watch Oculofacial Plastic Surgery Subspecialty Day. If you are registered for AAO 2020 Virtual, you have access to the archived presentations on the virtual meeting platform until Feb. 15, 2021. Log in to the virtual meeting platform: Next, from the Lobby screen, select “Sessions” from the top navigation; click “Agenda” from the drop-down menu; and click on the “Friday” tab.
Financial disclosures. Dr. Douglas: Horizon Therapeutics: C; Immunovant: C.
Disclosure key. C = Consultant/Advisor; E = Employee; L = Speakers bureau; O = Equity owner; P = Patents/Royalty; S = Grant support.
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