The trial was a randomized, double-masked, placebo-controlled, parallel-group, multicenter study aimed at evaluating the efficacy and safety of teprotumumab in patients with thyroid eye disease (TED). Patients were randomized to receive either teprotumumab or placebo over a 24-week period, with the primary outcome being the change in proptosis measurements in the study eye from baseline at Week 24.
Key inclusion criteria required patients to be at least 18 years old with a TED diagnosis of at least 2 years but less than 10 years before screening, and a diagnosis of stable, chronic (inactive) TED. The study excluded patients with previous strabismus surgery, orbital radiation, or orbital decompression in the study eye, among other criteria.
The primary analysis showed a statistically significant decrease in proptosis in the teprotumumab group compared to placebo, with a higher percentage of patients achieving a 2 mm reduction from baseline. Secondary outcomes included improvements in the Graves’ Ophthalmopathy Quality of Life (GO-QOL) questionnaire appearance and visual functioning subscales, and changes in diplopia.
Safety assessments conducted throughout the study revealed no new safety signals, with the most common adverse event being muscle spasms. Other adverse events of special interest included hearing impairment and hyperglycemia, which were managed with medication without leading to study discontinuation.
The study concluded that teprotumumab is effective in reducing proptosis and improving quality of life in patients with TED, with a safety profile consistent with previous studies. The trial's design, including a placebo control arm, provided valuable insights into the natural changes in this long-duration, low CAS population, highlighting the potential of teprotumumab as a treatment option for TED.
