Relay Therapeutics (RLAY) Guggenheim Securities Inaugural Healthcare Innovation Conference summary

Key clinical data and development plans

• RLY-2608 demonstrated a 33% response rate and median PFS of 9.2 months in heavily pretreated, HR+/HER2- metastatic breast cancer, with only one grade 3 hyperglycemia event among 64 patients.

• Plans are underway for a randomized phase III trial in second-line breast cancer, comparing RLY-2608 to capivasertib, with expectations of favorable outcomes due to superior tolerability and efficacy.

• Triplet dose exploration with ribociclib is ongoing, focusing on safety and identifying a biologically active, combinable dose, with early data expected later this year.

• A clinical trial supply agreement with Pfizer will enable a triplet study with atirmociclib, aiming to initiate dosing by year-end.

• Expansion into first-line studies is being considered, with future trial designs influenced by evolving standards in CDK4/6 inhibitor use.

Competitive landscape and differentiation

• RLY-2608’s mutant selectivity offers a significant safety advantage over non-selective PI3K inhibitors, which often require stringent patient selection due to high rates of grade 3 hyperglycemia.

• Inavolisib and gedatolisib face challenges with non-selectivity and administration route, while RLY-2608’s oral formulation and safety profile position it favorably for chronic use.

• The company aims to be the first mutant-selective PI3K inhibitor to market, leveraging recent fundraising and a dedicated team to accelerate pivotal trials.

Pipeline updates and new indications

• RLY-2608 is advancing into vascular malformations, targeting a patient pool of 170,000 in the U.S., with 25%-40% estimated to seek systemic therapy; initial clinical trials will focus on PROS and lymphatic malformations.

• The proof-of-concept study will leverage oncology dosing experience, aiming to characterize safety and efficacy using volumetric CT and patient-reported outcomes.

• The FGFR2 inhibitor RLY-4008 is nearing pivotal trial completion in cholangiocarcinoma, with plans for NDA filing and potential global out-licensing.

• Fabry disease program targets both amenable and non-amenable mutations with a non-inhibitory chaperone, aiming for broader efficacy than Galafold and potential combination with ERT.

• An NRAS-selective inhibitor is in preclinical development, addressing a 28,000-patient market in the U.S. with a focus on improved tolerability and efficacy.