In the phase 3 RESTORE-3 trial of 116 Chinese participants, the anti-IGF-1R antibody produced a 60.4% proptosis response rate vs 23.5% with placebo at week 24.
Teprotumumab N01 injection (SYCUME, IBI311; Innovent Biologics) met the primary end point of the phase 3 RESTORE-3 trial in inactive thyroid eye disease, according to a company announcement.¹ At week 24, 60.4% of participants receiving the anti-IGF-1R antibody achieved a proptosis response in the study eye vs 23.5% with placebo (P = .0003).¹ The multicenter, randomized, double-blind, placebo-controlled study enrolled 116 Chinese participants with inactive disease.
China's National Medical Products Administration
RESTORE-3 was a randomized, double-blind, placebo-controlled study conducted at multiple centers in China.¹ Investigators randomized 116 participants with inactive thyroid eye disease at roughly a 2:1 ratio to SYCUME or placebo. Mean disease duration was 4.3 years.
Mean baseline proptosis in the study eye was 22.16 mm, and about 74.1% of participants had a baseline Clinical Activity Score (CAS) of 0 or 1. The primary end point was the proptosis response rate in the study eye at week 24. SYCUME met the primary end point. The response rate was 60.4% with SYCUME vs 23.5% with placebo, a difference of 36.9 percentage points (P = .0003).¹ Follow-up in the trial is ongoing, and Innovent said full data will be presented at future conferences or published in peer-reviewed journals.
The key secondary end point was the change from baseline in study-eye proptosis at week 24. The least squares mean change was −1.88 mm with SYCUME vs −0.88 mm with placebo, a difference of −1.00 mm (P <.0001).¹
Results in the non-study eyes followed the same direction. The response rate was 46.0% with SYCUME vs 19.8% with placebo (P = .0071), and the least squares mean change in proptosis was −1.77 mm vs −0.91 mm (P <.0001).¹
Innovent reported good safety and tolerability. Most treatment-emergent adverse events were mild to moderate, and the company identified no new safety signals.¹ The company described the response rate and proptosis reduction as generally consistent with data for Tepezza (teprotumumab) in inactive disease, while noting the comparison is indirect and baseline proptosis was lower in RESTORE-3.¹
Lead principal investigator Zhongyan Shan, MD, of First Hospital of China Medical University, said in a news release that the therapy yields "robust and clinically meaningful reductions in proptosis" in chronic, inactive disease.¹ Lei Qian, MD, PhD, chief research and development officer of the General Biomedicine Pipeline at Innovent, said the results allow SYCUME to cover the disease course from early acute control to chronic-phase tissue remodeling.¹
"This milestone underscores Innovent's steadfast commitment to serving TED patients while reinforcing SYCUME's leading position in this therapeutic space. We will work closely with medical experts to rapidly translate these clinical findings into standard clinical practice, benefiting a broader patient population and elevating the overall standard of TED diagnosis and care in China," Qian said.
