San Francisco, California, U.S., and Suzhou, China, October 8, 2026

Innovent Biologics has announced positive Phase 3 results for SYCUME® (teprotumumab N01 injection, IBI311) in patients with inactive thyroid eye disease (TED). The company reported that its RESTORE-3 clinical trial met its primary endpoint at Week 24, demonstrating a statistically significant improvement in proptosis, or abnormal forward protrusion of the eyes, compared with placebo. In the study, 60.4% of participants receiving SYCUME achieved a proptosis response, compared with 23.5% of those receiving placebo. The multicenter, randomized, double-blind, placebo-controlled trial enrolled 116 Chinese participants with inactive TED. These findings extend the clinical evaluation of SYCUME into the inactive phase of the disease, when inflammation may have subsided but persistent eye protrusion and related physical changes can remain. Innovent stated that the treatment demonstrated a favorable safety profile, with most treatment-emergent adverse events reported as mild to moderate and no new safety signals identified.

RESTORE-3 Trial Meets Its Primary Endpoint

The Phase 3 RESTORE-3 study was designed to evaluate the efficacy and safety of IBI311 in Chinese participants with inactive thyroid eye disease. A total of 116 eligible participants were randomized in an approximate 2:1 ratio to receive either SYCUME or placebo. The primary endpoint was the proptosis response rate in the study eye at Week 24, while the key secondary endpoint measured the change in proptosis from baseline at the same time point. The primary endpoint results showed a response rate of 60.4% with SYCUME versus 23.5% with placebo, representing a difference of 36.9 percentage points. The result was statistically significant, with a reported p-value of 0.0003. For the key secondary endpoint, the least-squares mean change in proptosis from baseline was −1.88 mm with SYCUME, compared with −0.88 mm with placebo, a treatment difference of −1.00 mm. The findings indicate that SYCUME reduced eye protrusion more effectively than placebo in the study population. Innovent said the results provide additional clinical evidence for the use of its anti-IGF-1R antibody in inactive TED. However, the company noted that study follow-up remains ongoing and that complete results are expected to be presented at future scientific conferences or published in peer-reviewed journals.

SYCUME Targets IGF-1R in Thyroid Eye Disease

SYCUME is a recombinant antibody targeting the insulin-like growth factor 1 receptor (IGF-1R), a pathway implicated in the biological processes associated with thyroid eye disease. TED is an autoimmune condition affecting tissues around the eyes and is commonly associated with Graves’ disease. It can cause eye protrusion, swelling, discomfort, double vision and, in severe cases, vision-threatening complications. The disease generally progresses through active and inactive phases. During the active phase, inflammation is prominent, while the inactive phase may be characterized by persistent structural changes even after acute inflammation has diminished. Patients with inactive TED can continue to experience proptosis and changes in appearance that affect daily life and quality of life. Innovent stated that patients with inactive TED account for approximately two-thirds of the overall TED population. Historically, treatment options for persistent proptosis during the inactive phase have been limited, and some patients may undergo surgical intervention. The RESTORE-3 results suggest that IGF-1R-targeted treatment may offer a potential nonsurgical option for this patient group, subject to further clinical evaluation and applicable regulatory decisions.

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Innovent Advances SYCUME’s Role in TED Care

SYCUME has previously received approval in China for thyroid eye disease and was included in China’s National Reimbursement Drug List effective January 1, 2026, according to Innovent. The company describes it as the first IGF-1R antibody approved in China and the second approved worldwide for TED. The positive RESTORE-3 results represent a further milestone in Innovent’s effort to evaluate SYCUME across different stages of thyroid eye disease. While the product is already approved in China for TED, the newly announced findings concern its performance in the specific population with inactive disease. The Phase 3 results alone do not establish that the inactive-disease indication has received separate regulatory approval. The findings may support further discussions among clinicians, researchers and regulators about treatment options for patients with persistent symptoms after the active inflammatory phase. Additional follow-up and full clinical data will be important to assess the durability of the response, longer-term safety and potential place of SYCUME in clinical practice. Innovent continues to develop medicines for major diseases, including oncology, autoimmune disorders and ophthalmology. The RESTORE-3 outcome adds clinical evidence for its antibody-based approach to TED, while highlighting the continuing need for effective treatments for patients living with chronic eye changes.

Source: Innovent Biologics press release