What's Happening?
Sling Therapeutics, Inc., a clinical-stage biopharmaceutical company, has announced that the first patients have been dosed in its global Phase 3 ORBIT pivotal trial. This trial is evaluating linsitinib, an oral small molecule inhibitor of the insulin-like
growth factor-1 receptor (IGF-1R), for the treatment of moderate to severe active Thyroid Eye Disease (TED) in adults. The ORBIT trial is a global, randomized, double-masked, placebo-controlled study designed to assess the efficacy and safety of linsitinib. TED is a serious, progressive, and vision-threatening rare autoimmune disease affecting over 200,000 people in the U.S., often occurring in individuals with Graves’ disease and hyperthyroidism. The disease is characterized by fibrous tissue growth behind the eyes, leading to symptoms like pain, eye bulging (proptosis), and potential vision loss. Linsitinib is the first and only oral IGF-1R inhibitor in Phase 3 development, aiming to provide a convenient oral treatment option for TED patients.
Why It's Important?
This Phase 3 trial is significant because it could introduce a new, more accessible treatment option for Thyroid Eye Disease, a condition that currently relies heavily on invasive orbital surgery or lengthy intravenous infusions. The current standard of care for TED often involves treatments with potential adverse events such as hearing loss, hyperglycemia, or menstrual cycle changes, and requires patients to travel to infusion centers. An effective oral therapy like linsitinib could address these barriers, potentially expanding access to treatment and improving the quality of life for patients. Ryan Zeidan, Ph.D., President and Chief Executive Officer of Sling Therapeutics, highlighted that linsitinib has already shown potential for clinically meaningful improvements in proptosis with a differentiated safety profile, offering a less burdensome alternative to existing biologic options. The development of an oral treatment could reduce the treatment burden on patients, physicians, and the healthcare system.
What's Next?
The ORBIT trial is expected to enroll approximately 130 participants, who will be randomized to receive either oral linsitinib 150 mg or a placebo twice daily for 24 weeks. The primary endpoint of the study is the proportion of proptosis responders at Week 24, defined as a reduction of at least 2 mm in proptosis in the study eye without worsening in the fellow eye. Secondary endpoints include changes in mean proptosis, overall responder rate, Clinical Activity Score (CAS), and the Graves' Ophthalmopathy Quality of Life (GO-QoL) questionnaire. Following the 24-week double-masked treatment period, patients will have the option to enroll in a 24-week open-label extension. The results of this trial will be crucial in determining the future availability of linsitinib as a treatment for TED, potentially offering a new paradigm in managing this debilitating condition.
Beyond the Headlines
The introduction of an oral treatment for Thyroid Eye Disease could represent a broader shift in the management of autoimmune diseases, moving towards more patient-friendly and less invasive therapeutic options. The convenience of an oral medication, compared to infusions, could significantly impact patient adherence and overall treatment outcomes, especially for those in rural areas or with limited access to specialized medical centers. Furthermore, the focus on IGF-1R inhibition highlights a targeted approach to addressing the underlying pathology of TED, which could pave the way for similar precision medicine strategies in other autoimmune conditions. The potential for a more favorable safety profile, as suggested by Sling Therapeutics, could also reduce the long-term health risks associated with current treatments, thereby improving the overall well-being of TED patients.
