Relay Therapeutics (RLAY) 3rd Annual Guggenheim Healthcare Innovation Conference summary

ASH update and regulatory strategy

• ASH update: efficacy and safety data on all 32 dose-randomization patients, up from efficacy data on 20 at ISSVA; earlier volumetric response rate was 60%, with consistency the goal.

• Dose-expansion data will focus on tolerability; most enrolled patients received 400 mg once daily and will have only one scan, with early efficacy assessed at 12 weeks.

• Target profile: low hyperglycemia, diarrhea, rash and dermatitis, while efficacy clears alpelisib’s response bar in the high 20s.

• ASH will include longer-follow-up safety data and a regulatory update on the indication statement and accelerated-approval path.

• Seeking a pooled PROS and lymphatic malformations label based on shared PI3Kα biology; separate labels and trials remain an acceptable precedent, subject to FDA input.

Dose selection and commercial preparation

• Dose selection prioritizes lifelong tolerability and minimizing total grade 3 AEs; safety review will consider severity, timing, duration, management and resolution.

• The 300 mg once-daily dose has shown a 100% response rate in the observed cohort, but the rate is expected to decline with more patients; the goal is to balance efficacy and tolerability.

• Moderate-to-severe patients seeking complex or systemic treatment often reach vascular anomaly centers; dozens of centers in the U.S. and Europe likely capture a large share of today’s known addressable market.

• Shannon Campbell, former U.S. Head of Novartis Oncology, was announced as Head of Commercial last week; commercial sizing is underway, with medical education and patient advocacy work needed in vascular anomalies.

• Pediatric-to-adult care transitions are a recognized continuity challenge for patients aging out of children’s hospitals.

Breast cancer programs and competition

• ReDiscover-2 planning uses a 5.5-month capivasertib median PFS benchmark; prior zovega data showed 11 months in a mixed second- and third-line population, with broader site participation and a pure second-line population expected to offset each other.

• Trial design included conservatism for possible zovega PFS compression and capivasertib overperformance; two phase I single-arm experiences showed 10.5–11 months median PFS versus a 5.5-month capivasertib benchmark.

• Gedatolisib’s weekly IV regimen includes prophylactic steroid mouthwash; management said a PFS above 15 months, potentially closer to 18 months, would pose a difficult commercial challenge, while its reported result was 11 months.

• If phase I/II results are replicated in ReDiscover-2, the expected proposition is similar or slightly better median PFS, markedly better tolerability and oral convenience.

• Frontline trial with Pfizer-supplied atirmociclib remains on track to start early next year; 150 mg zovega with atirmociclib provides ~the same target coverage as 400 mg in the fulvestrant doublet.