New Drug Breakthroughs at Home and Abroad Usher in a New Landscape for Thyroid Eye Disease Treatment

Thyroid eye disease, a disfiguring autoimmune condition that can bulge the eyes outward, distort vision and in severe cases lead to blindness, is entering a new era of treatment. Two drugs—one from global pharma giant Roche and another from China's Innovent Biologics—are reshaping how the disease is managed, shifting the paradigm from reactive symptom control to early intervention and full-course therapy.

On Oct. 16, Genentech, a subsidiary of Roche, announced that the U.S. Food and Drug Administration approved Enspryng, also known as satralizumab-mwge, for the treatment of adults with thyroid eye disease. The drug, administered via subcutaneous injection, can be self-administered at home by patients or caregivers after proper medical training. A marketing application has also been filed in China, where the Center for Drug Evaluation is currently reviewing the submission.

Satralizumab is a humanized monoclonal antibody that targets the interleukin-6 receptor. It employs what Roche calls Recycling Antibody technology, which allows the drug to continuously bind to the IL-6 receptor, achieving rapid and sustained suppression of inflammatory signaling pathways. The drug is already approved for the treatment of neuromyelitis optica spectrum disorder in approximately 90 countries and regions, including the European Union and the United States.

The TED approval was based on two Phase 3 trials, SatraGO-1 and SatraGO-2, which demonstrated improvements across multiple key efficacy endpoints, including proptosis and diplopia in patients with active thyroid eye disease. Notably, neither trial identified side effects such as hyperglycemia, hearing impairment or menstrual irregularities.

In the SatraGO-2 study, which included Chinese patients, the proptosis response rate at Week 24 reached 53% in the satralizumab group, significantly higher than the 23% observed in the placebo group, achieving statistical significance. The drug also delivered meaningful improvements on secondary endpoints: in SatraGO-2, satralizumab reduced the Clinical Activity Score in 90% of patients with active TED and improved diplopia in 61% of active TED patients.

While international players accelerate their push, Chinese innovative pharmaceutical companies are also making significant strides in the TED treatment space. Innovent Biologics' Xibimin, known generically as tebrotumab N01 injection, has already landed in the Chinese market.

Xibimin is a recombinant monoclonal antibody targeting the insulin-like growth factor 1 receptor, or IGF-1R. IGF-1R is a transmembrane tyrosine kinase receptor that plays roles in development, metabolism and immune regulation, and is overexpressed in orbital fibroblasts, B cells and T cells of thyroid eye disease patients. Xibimin blocks IGF-1 and related ligand-mediated IGF-1R signaling pathway activation, reduces downstream inflammatory factor expression, inhibits orbital fibroblast activation leading to hyaluronic acid and other glycosaminoglycan synthesis, suppresses inflammation, and prevents the differentiation of orbital fibroblasts into adipocytes or myofibroblasts. This comprehensive mechanism alleviates disease activity and improves symptoms including proptosis, diplopia, and ocular congestion and edema.

In March 2025, Xibimin received approval from China's National Medical Products Administration for the treatment of thyroid eye disease. On Jan. 1, 2026, it was formally included in the National Reimbursement Drug List, significantly reducing the financial burden for Chinese patients.

On Oct. 9, Innovent Biologics announced positive topline results from RESTORE-3, a Phase 3 clinical study evaluating Xibimin in patients with inactive thyroid eye disease. The multi-center, randomized, double-blind, placebo-controlled trial met its primary endpoint at Week 24, demonstrating significant efficacy in improving proptosis among patients with inactive TED, with a favorable safety profile.

"As the first approved TED targeted therapy drug in China that has also been successfully included in the National Reimbursement Drug List, Xibimin has benefited numerous TED patients," the company said. "With the positive readout of this Phase 3 clinical study, Xibimin has achieved full disease course coverage—from early control in the active phase to sustained repair in the inactive phase. This further demonstrates Innovent Biologics' firm commitment to serving TED patients and consolidates Xibimin's position in this field."

The continuous breakthroughs in new drug development represent not only pharmaceutical companies' deep cultivation in autoimmune eye diseases, but also a fundamental shift in the TED treatment philosophy: from simple symptomatic management to early intervention and full-course management. As more new drugs enter development, clinicians will have a broader selection of targeted therapies to match individual patient needs.

Drug accessibility remains a key concern for TED patients. Xibimin's inclusion in China's medical insurance system has substantially eased the financial pressure on domestic patients. Should satralizumab gain approval in China, it will further expand treatment options. With accumulating clinical data and broader drug availability, thyroid eye disease patients can look forward to protecting their vision and improving ocular appearance through standardized targeted therapy, enabling them to return to normal life.