Relay Therapeutics Shares Jump 15% after 60% Response Rate in Phase 2 Trial
RLAY•Relay Therapeutics reported Phase 2 ReInspire data showing a 60% 12-week volumetric response and 89% clinical improvement in 20 evaluable PIK3CA-driven vascular anomalies patients, with no discontinuations. At 100mg twice daily, 29% responded and expansion arms at 400mg once daily and 300mg twice daily are now open.
1. Trial Design and Enrollment
Relay launched the Phase 2 ReInspire study enrolling 32 adult and adolescent patients with PIK3CA-driven vascular anomalies, randomizing them across three dose cohorts; 20 patients were evaluable for efficacy as of the April 15, 2026 cutoff.
2. Efficacy and Safety Results
At 12 weeks, 60% of evaluable patients achieved at least a 20% volumetric lesion reduction and 89% investigator-reported clinical improvement, with all patients remaining on therapy and zero discontinuations due to adverse events.
3. Dose Management and Expansion
Among 22 patients on 100mg and 300mg twice daily, 23% required dose reductions while median dose intensity exceeded 99%; expansion cohorts at 400mg once daily and 300mg twice daily are now open and pediatric dose-finding continues.
4. Oncology Pipeline Progress
The company is advancing zovegalisib into a Phase 3 trial combining it with fulvestrant in PIK3CA-mutated, CDK4/6 pre-treated, HR+/HER2- advanced breast cancer, leveraging the drug’s favorable safety profile.
