Relay Therapeutics, Inc. 8-K

What Happened

• On March 16, 2026, Relay Therapeutics (RLAY) announced and furnished a press release reporting data from its Phase 1/2 ReDiscover trial of zovegalisib (RLY-2608) combined with fulvestrant at the recommended Phase 3 dose of 400 mg twice daily (BID) taken with food (fed). The data cut-off date was January 13, 2026.
• As of the cut-off, 60 patients had received the 400 mg BID fed regimen; the efficacy population (patients without PTEN or AKT co-mutations) included 57 patients who had all previously received a CDK4/6 inhibitor and at least one prior endocrine therapy in the advanced setting.
• Key efficacy and safety findings: median follow-up 12.0 months; median progression-free survival (PFS) 11.1 months (95% CI: 7.3–13.0); confirmed objective response rate (ORR) 43% (15/35) in patients with measurable disease and 52% (11/21) in second-line-only patients. Safety was generally well tolerated with mostly low-grade, manageable treatment-related adverse events (TRAEs); few discontinuations (4 patients) and no Grade 4–5 hyperglycemia.

Key Details

• Recommended Phase 3 dose: 400 mg BID taken with food (fed).
• Patients treated at this dose: 60 total; efficacy-evaluable (no PTEN/AKT co-mutation): 57.
• Efficacy: median PFS 11.1 months (95% CI 7.3–13.0); ORR 43% (15/35) overall measurable disease; ORR 52% (11/21) in second-line patients.
• Pharmacokinetics: 400 mg BID fed achieved exposures comparable to previously tested 600 mg BID fasted, with mean concentrations near IC90 and nearly all patients above IC80 across dosing interval.

Why It Matters

• The filing confirms selection of a Phase 3 dose (400 mg BID fed) supported by clinical activity and pharmacokinetics, which is a key development milestone ahead of pivotal testing and potential regulatory interactions.
• Reported efficacy (median PFS ~11 months and meaningful ORR in a population previously treated with CDK4/6 inhibitors) and an acceptable safety profile may strengthen the program’s clinical case, but these are interim Phase 1/2 results and Relay notes typical forward‑looking risks.
• Investors should watch for upcoming Phase 3 trial initiation details, regulatory guidance, and additional data updates that will better define commercial and clinical potential.