Teprotumumab improves outcomes in thyroid eye disease

Treatment with teprotumumab in patients with active thyroid eye disease confers beneficial effects on proptosis, Clinical Activity Score, diplopia and quality of life, without increasing the incidence of serious adverse events, according to the results of a phase III trial.

A total of 83 patients were randomized to receive teprotumumab (n=41) or placebo (n=42). Treatment was administered as intravenous infusions, with the active drug dosed at 10 mg/kg of body weight for the first infusion and 20 mg/kg for subsequent infusions, once every 3 weeks for 21 weeks. The last trial visit for the present analysis was at week 24.

The primary outcome of a proptosis response (reduction of ≥2 mm) at week 24 occurred with greater frequency in the teprotumumab vs placebo arm (83 percent vs 10 percent; p<0.001), with a number needed to treat of 1.36.

Results for all secondary outcomes were likewise more favourable with the active drug than with placebo: overall response (78 percent vs 7 percent), Clinical Activity Score of 0 or 1 (no or minimal inflammation; 59 percent vs 21 percent), the mean change in proptosis (−2.82 vs −0.54 mm), diplopia response (reduction of ≥1 grade; 68 percent vs 29 percent), and the mean change in Graves’ ophthalmopathy-specific quality-of-life overall score (13.79 vs 4.43 points; p_all≤0.001).

Among patients who underwent orbital imaging, six showed improvements in extraocular muscle, orbital fat volume, or both.

Most adverse events were mild or moderate in severity; two serious events occurred in the teprotumumab group, of which one (an infusion reaction) led to treatment discontinuation.