Key Takeaways

• The first patients have been dosed in the global phase 3 ORBIT clinical trial of linsitinib, an oral small molecule inhibitor of the insulin-like growth factor-1 receptor for the treatment of adults with moderate to severe active thyroid eye disease
• The primary endpoint is the proportion of patients who experience a reduction of at least 2 mm in proptosis in the study eye without corresponding worsening in the fellow eye.
• Following the 24-week treatment period, patients will be eligible to enroll in a 24-week open-label extension study.

Sling Therapeutics announced the first patients have been dosed in the global phase 3 ORBIT pivotal trial (NCT07753603), a randomized, double-masked, placebo-controlled study evaluating the efficacy and safety of linsitinib, an oral small molecule inhibitor of the insulin-like growth factor-1 receptor, in adults with moderate to severe active thyroid eye disease (TED).¹

The ORBIT trial is expected to enroll approximately 130 patients, randomized 1:1 to receive oral linsitinib 150 mg or placebo twice daily for 24 weeks. The primary endpoint is the proportion of patients who experience a reduction of at least 2 mm in proptosis in the study eye without corresponding worsening in the fellow eye. Secondary endpoints include mean change from baseline in proptosis, overall responder rate, Clinical Activity Score, and the Graves' Ophthalmopathy Quality of Life questionnaire. Following the 24-week treatment period, patients will be eligible to enroll in a 24-week open-label extension.¹

The ORBIT trial is actively enrolling as of the date of the press release.¹ “TED is a serious ocular autoimmune disease that can progress rapidly, cause permanent damage and, in severe cases, threaten vision. Early treatment is critical, yet many patients remain untreated due to limitations of currently available therapies, including concerns about long-term hearing loss and the burden of traveling to infusion centers,” said Raymond Douglas, MD, PhD, board-certified aesthetic and reconstructive oculoplastic surgeon, in a press release.¹ “An effective oral therapy such as linsitinib could help address these barriers and meaningfully expand access to treatment. With the proptosis responses and favorable safety profile observed with linsitinib to date, I look forward to seeing its potential further evaluated in the ORBIT trial.”

1. Sling Therapeutics announces first patients dosed in global phase 3 ORBIT pivotal trial of linsitinib for thyroid eye disease [press release]. September 16, 2026. Accessed September 17, 2026. Sling Therapeutics. www.businesswire.com/news/home/20260916871832/en/Sling-Therapeutics-Announces-First-Patients-Dosed-in-Global-Phase-3-ORBIT-Pivotal-Trial-of-Linsitinib-for-Thyroid-Eye-Disease