0567 Tirzepatide for the Treatment of OSA: Rationale and Design of the SURMOUNT-OSA Phase 3 Trial

Introduction Weight reduction is a standard recommended component of OSA treatment in people with obesity or overweight; however, the challenge to achieve and maintain weight reduction has limited its clinical application outside of the benefit established after bariatric surgery. Currently no FDA-approved anti-obesity medication (AOM) has demonstrated clinically meaningful improvement in OSA severity and symptomology. Methods Tirzepatide is a single molecule GIP and GLP-1 receptor agonist. In SURMOUNT-1, a 72-week phase 3 clinical trial in participants with obesity or overweight, tirzepatide 15mg provided average reductions in body weight of 22.5% which occurred with beneficial effects on blood pressure, lipids, and physical functioning. In a linear meta regression model, we estimated that tirzepatide treatment would provide clinically meaningful apnea-hypopnea index decrease compared to placebo-treated participants with obesity and OSA. SURMOUNT-OSA, a placebo controlled 52-week, phase 3 trial, will investigate efficacy and safety of tirzepatide for the treatment of moderate to severe OSA (defined as AHI ≥15) in participants with obesity. SURMOUNT-OSA utilizes an umbrella master protocol and 2 Intervention-Specific Appendices (ISAs): ISA 1 includes participants with no current OSA treatment and ISA 2 includes participants using positive airway pressure therapy. Approximately 412 participants will be randomly assigned to placebo or tirzepatide across the entire master protocol, with approximately 206 participants in each ISA. While participants will receive tirzepatide or placebo based on a 1:1 randomization ratio, all participants will receive background lifestyle intervention for weight reduction. Results The primary endpoint for the individual ISAs is the difference in AHI response measured by polysomnography between tirzepatide and placebo arms at week 52. Secondary endpoints include hypoxic burden, functional outcomes and cardiometabolic biomarkers. The trial is utilizing a unique hierarchical functional outcomes endpoint based on Functional Outcomes of Sleep Questionnaire methodology. The trial employs wearables, such as home sleep testing and accelerometry to capture time to improvement as exploratory outcomes. Conclusion SURMOUNT-OSA aims to explore whether tirzepatide provides clinically meaningful improvement in obesity-related OSA by targeting an underlying etiology. Support (if any) Eli Lilly