Relay Therapeutics announces positive interim data for RLY-2608 emphasizing clinically meaningful progression free survival

Relay Therapeutics, Inc., a clinical-stage precision medicine company, shared promising interim data for RLY-2608, the first investigational allosteric, pan-mutant, and isoform-selective PI3Ka inhibitor. The data indicated that despite prior extensive treatments, patients with PI3Ka-mutated, HR+, HER2- advanced or metastatic breast cancer who were treated with RLY-2608 600mg BID plus fulvestrant showed clinically meaningful progression-free survival (PFS).

RLY-2608 is being studied in the ongoing ReDiscover trial, evaluating its safety, tolerability, pharmacokinetics, and preliminary antitumor activity. As of August 12, 2024, 118 patients were enrolled, with 64 patients receiving the recommended phase 2 dose (RP2D) of 600mg BID. The interim results demonstrated a median PFS of 9.2 months for all mutations and 10.3 months for kinase mutations, with a clinical benefit rate of 57%. The treatment was well-tolerated, showing mostly low-grade treatment-related adverse events (TRAEs).

Relay Therapeutics plans to initiate several expansion cohorts and trials in 2024 and 2025.