Relay Therapeutics Releases zovegalisib Clinical Data, 60% of Patients Show Significant Improvement

Relay Therapeutics announced initial clinical data from the Phase 2 ReInspire trial of zovegalisib in vascular anomalies signaling the advantage of PI3Kalpha mutant-selective inhibition. Vascular anomalies are a group of rare disorders characterized by abnormal development of blood vessels, lymphatic vessels and surrounding tissues. As of April 15, in the Part 1 dose randomization portion of the study for adults and adolescents ages 12 and up, 60% of patients achieved a volumetric response at the earliest time point - 12 weeks - and nearly all patients experienced symptomatic improvement at 12 weeks while maintaining a safety and tolerability profile showing the potential for chronic use. The data are being presented at the International Society for the Study of Vascular Anomalies Congress 2026 in Philadelphia. The data showed "promising" initial efficacy data with 60% volumetric response rate across doses and 29% at the lowest tested dose of 100mg twice daily with all patients ongoing. Interim investigator- and patient-reported outcomes show 89% and 79% of patients achieved clinical improvement at week 12, respectively, and support the potential of zovegalisib to drive clinically meaningful benefit for patients. Evaluation across a wide dose range confirms potential therapeutic window, with interim safety profile supportive of chronic dosing and no patients discontinuing treatment due to adverse events. Expansion cohorts for adults and adolescents have been opened at 400mg once daily and 300mg BID. Pediatric dose-finding is ongoing.