Drug pipeline
Subcutaneous teprotumumab shows benefit in thyroid eye disease trial
Clinical Takeaway: In a phase 3 trial, subcutaneous teprotumumab administered every two weeks significantly reduced proptosis in adults with active thyroid eye disease (TED), with efficacy comparable to the intravenous formulation and a similar overall safety profile.
Teprotumumab (Tepezza) is a monoclonal antibody targeting the insulin‑like growth factor‑1 receptor (IGF‑1R), a pathway implicated in TED. The IV formulation is approved for TED; the SC formulation evaluated in this study remains investigational.
Amgen reported positive topline results from a randomized, double-masked, placebo-controlled phase 3 study evaluating SC teprotumumab delivered via on-body injector in adults with moderate-to-severe active TED. The 24‑week trial met its primary endpoint, showing a proptosis response in 76.7% of treated patients compared with 19.6% with placebo (P<0.0001).
Mean reduction in proptosis, a key secondary endpoint, was −3.17 mm with SC treatment vs. −0.80 mm with placebo at week 24 (P<0.0001). Additional secondary endpoints—including overall responder rate, improvements in Clinical Activity Score, diplopia outcomes, and appearance-related quality-of-life measures—also favored teprotumumab, while changes in visual functioning didn't reach statistical significance.
Safety profile was generally consistent with prior IV studies. Mild-to-moderate injection site reactions were reported, without treatment discontinuations attributed to administration.
Jay Bradner, MD, executive vice president of research and development at Amgen, said the phase 3 findings reinforce the established efficacy of teprotumumab in thyroid eye disease and show that subcutaneous administration can achieve outcomes comparable to intravenous dosing.
Full study results are expected to be presented at a future medical meeting.
Source: Amgen. [Press release]. April 6, 2026. Amgen announces positive topline phase 3 results for subcutaneous Tepezza in adults living with moderate-to-severe active thyroid eye disease