JUN 08, 2022
An extension of the original OPTIC study was conducted to see if patients with a longer duration of thyroid eye disease (TED) have the same response to teprotumumab as patients with a shorter course of disease, and if re-treatment is safe and effective in nonresponders.
The phase 3 randomized, double-masked, placebo-controlled, 8-week OPTIC study assessed teprotumumab for the treatment of moderate-to-severe active thyroid eye disease (TED). This open-label extension (OPTIC-X) included 51 patients from the original OPTIC study—37 from the placebo group and 14 from the teprotumumab group—who were nonresponders or who had a disease flare. All patients were given teprotumumab for 24 weeks. The primary objective was the rate of proptosis response (reduction ≥2 mm) over the long term; investigators also measured the efficacy of a second course of treatment in patients who were originally randomized to teprotumumab.
Thirty-three of the 37 patients originally given placebo achieved proptosis response (average disease duration: 12 months), and 29 of the 33 had maintained proptosis reduction at the 48-week follow-up visit. In the patients with recurrent disease following the OPTIC trial, 63% achieved proptosis response, along with diplopia improvement and a reduction in the clinical activity score. Adverse effects were mild-to-moderate, with 4 patients reporting auditory issues.
There were a low number of patients in each group, particularly in the subpopulations with recurrent disease or treatment resistance. The temptation is to apply these findings to all patients with TED, especially those with indolent disease, but 12 months was the average disease duration of those patients originally given placebo in the OPTIC trial.
Recurrent disease following teprotumumab therapy does occur with relative frequency, and additional treatment courses could be considered in these patients with similar adverse effects profiles. It is possible that patients with a long-term disease course may benefit from this therapy.