Key Takeaways
Relay Therapeutics Inc. reported its experimental drug zovegalisib shrank lesions in 60% of patients with rare vascular disorders, a pivotal data release that validates its precision-medicine platform and challenges existing treatments for the genetic condition.
"These data demonstrate, for the first time, the promise of PI3Kα mutant-selective inhibition for patients with vascular anomalies,” Don Bergstrom, President of R&D at Relay Therapeutics, said in a statement, highlighting the drug's potential to change the treatment paradigm.
The initial Phase 2 data from 20 evaluable patients in the ReInspire study showed a 60% volumetric response rate at 12 weeks, with 95% of all patients experiencing some lesion reduction. Crucially, no patients discontinued treatment due to side effects. Common toxicities like severe rash and mouth sores associated with non-selective PI3Kα inhibitors were not observed.
The positive results position zovegalisib as a potentially best-in-class therapy for an estimated 170,000 U.S. patients with PIK3CA-driven anomalies, a market with few effective options. Success in this rare disease could also de-risk the drug's larger commercial opportunity in a separate, ongoing Phase 3 trial for PIK3CA-mutated breast cancer.
Zovegalisib is designed as a mutant-selective inhibitor of PI3Kα, the kinase driving abnormal tissue growth in these disorders. This contrasts with existing treatments like sirolimus or Novartis AG's Vijoice (alpelisib), which are less selective and inhibit the wild-type (healthy) version of PI3Kα, leading to a higher burden of side effects that can limit their long-term use.
The trial data supports this differentiated profile, showing that zovegalisib was effective even in a heavily pre-treated population; 72% of enrolled patients had previously received sirolimus and/or alpelisib. Furthermore, 89% of investigators and 79% of patients reported overall clinical improvement at 12 weeks. Relay is now enrolling patients in expansion cohorts to further refine the optimal chronic dose.
This article is for informational purposes only and does not constitute investment advice.
