8-K: Relay Therapeutics Reports Promising Zovegalisib Data in Vascular Anomalies

Relay Therapeutics announced initial Phase 2 ReInspire trial data for zovegalisib in vascular anomalies, showing a 60% volumetric response rate and strong patient-reported outcomes, with a favorable safety profile for chronic use.

Summary

• Relay Therapeutics presented initial clinical data from the Phase 2 ReInspire trial of zovegalisib for PIK3CA-driven vascular anomalies.
• The data, from 32 adult and adolescent patients (ages 12+), showed a 60% volumetric response rate (VRR) in 20 response-evaluable patients at the first MRI assessment (12 weeks).
• Responses were observed across different PIK3CA mutation types and in patients previously treated with sirolimus and/or alpelisib.
• 95% of patients experienced lesion reduction, and four responding patients showed confirmed response with deepening reductions at 24 weeks.
• Investigator- and patient-reported outcomes at week 12 indicated clinical improvement in 89% and 79% of patients, respectively, with 71% of pain symptoms improving.
• The safety profile was generally as expected, consistent with mutant-selective PI3K inhibition, with no patients discontinuing treatment due to adverse events.
• Dose reductions were seen in 23% of patients treated at 100mg and 300mg BID, with median dose intensity greater than 99%.
• The 400mg BID dose was deprioritized due to a less optimal safety profile for this patient population.

Sentiment

Score: 8

Explanation: StockSavvy.ai views this as a highly positive update, with strong efficacy signals and a favorable safety profile in a difficult-to-treat rare disease, supporting the company's precision medicine approach.

Positives

• A 60% volumetric response rate (VRR) was observed in response-evaluable patients, with responses seen across various PIK3CA mutations and in previously treated patients.
• Nearly all patients (95%) experienced lesion reduction, and responses deepened over time.
• Significant clinical improvement was reported by investigators (89%) and patients (79%) at week 12.
• The safety profile supports potential for chronic dosing, with no treatment discontinuations due to adverse events.
• Low rates of Grade 3+ treatment-related adverse events (TRAEs) were observed (9% among patients at 100mg and 300mg BID).
• Key adverse events like rash, stomatitis, Grade 3 hyperglycemia, and diarrhea were notably absent or low-grade.
• Expansion cohorts at 400mg QD and 300mg BID have been opened for adults and adolescents.
• The drug is being evaluated for potential accelerated approval based on this dataset.

Negatives

• The 400mg BID dose showed a safety profile that was not optimal for this patient population and is deprioritized.
• While 60% of patients showed a volumetric response, 40% did not achieve the 20% reduction threshold at 12 weeks.
• The 100mg BID dose had a lower volumetric response rate (29% initially, 43% after an unconfirmed response conversion).
• A significant portion of patients (72%) had prior treatment with sirolimus and/or alpelisib, which could influence response interpretation.

Risks

• The preliminary or interim results of clinical trials may not be predictive of future or final results.
• Interim and early clinical data may change as more patient data become available and are subject to audit and verification procedures.
• The company's ability to successfully demonstrate the safety and efficacy of its drug candidates is subject to inherent risks.
• Interactions with regulatory authorities and the timing of regulatory updates or approvals carry inherent uncertainties.
• The impact of global economic uncertainty, geopolitical instability, and public health epidemics could affect clinical trial timelines and results.

Future Outlook

The company is continuing to execute the ReInspire trial, enrolling expansion cohorts for adults and adolescents, and initiating dose escalation for pediatrics. Frontline Phase 3 readiness activities for zovegalisib plus atirmociclib plus aromatase inhibitor are planned to initiate in early 2027. The company anticipates further disclosures in 2026, including Phase 3 enrollment updates and data/regulatory updates by year-end.

Management Comments

• "These data demonstrate, for the first time, the promise of PI3K mutant-selective inhibition for patients with vascular anomalies."
• "The combination of robust volumetric responses, symptomatic improvement, and a safety profile that supports chronic dosing underscores the potential of zovegalisib to meaningfully change the treatment paradigm for this underserved population."
• "These early results strengthen our conviction in zovegalisib's differentiated profile and its potential ability to deliver lasting benefit for patients and families affected by vascular anomalies."

Industry Context

StockSavvy.ai notes that Relay Therapeutics' announcement positions zovegalisib as a potentially differentiated therapy in the rare disease space of PIK3CA-driven vascular anomalies, leveraging its mutant-selective PI3K inhibition. This aligns with the broader industry trend towards precision medicine targeting specific genetic drivers of disease.

Comparison to Industry Standards

• In 2L Breast Cancer, zovegalisib + fulvestrant (400mg BID, Phase 3 dose) showed a median Progression-Free Survival (mPFS) of 11.1-11.2 months in kinase/non-kinase subgroups, compared to capivasertib + fulvestrant's 5.5 months mPFS in a similar setting (CAPItello-291 trial).
• For 1L Breast Cancer, the proposed zovegalisib + atirmociclib + aromatase inhibitor triplet showed a 44% Objective Response Rate (ORR) and 50-90% Grade 3+ adverse events (AEs), compared to standard of care (CDK4/6 + ET) with 40% ORR and 14-32% Grade 3+ AEs.
• In vascular anomalies, the 60% overall volumetric response rate (VRR) across doses for zovegalisib compares favorably to alpelisib's reported VRR of 17-27% at week 12/16 in similar patient populations (EPIK-P1/P2 trials).
• The Grade 3+ TRAE rate for zovegalisib (9% at 100mg/300mg BID) is significantly lower than alpelisib's reported rates (e.g., 73% for Grade 3+ hyperglycemia in EPIK-B5).

Stakeholder Impact

• Shareholders: Positive data may increase confidence in the company's pipeline and future prospects, potentially impacting stock valuation.
• Patients: The results offer hope for a new, potentially more effective and tolerable treatment option for vascular anomalies.
• Healthcare Providers: The data provide evidence for a novel therapeutic approach in a patient population with limited treatment options.
• Competitors: The promising results may spur further research and development in PI3K inhibition for vascular anomalies and other indications.

Next Steps

• Continue enrollment in expansion cohorts for adults and adolescents (ages 12 and up) in the ReInspire trial.
• Continue enrollment of the Part 1 dose escalation cohort for pediatrics (ages 6-11).
• Implement the fit-for-purpose patient-reported outcome (PRO) tool into the ReInspire trial.
• Continue execution of the Phase 3 ReDiscover-2 trial of zovegalisib + fulvestrant in breast cancer.
• Continue frontline Phase 3 readiness activities for zovegalisib + atirmociclib + aromatase inhibitor, with trial initiation intended for early 2027.
• Provide Phase 3 enrollment updates by year-end 2026.
• Provide data and regulatory updates by year-end 2026.
• Provide Phase 1/2 data in 1H 2027.

Key Dates

Recommendation

The initial clinical data for zovegalisib in vascular anomalies demonstrate a compelling combination of efficacy and safety, exceeding benchmarks set by existing therapies like alpelisib. The observed volumetric response rates and significant patient-reported outcome improvements, coupled with a favorable tolerability profile that supports chronic dosing, suggest a strong potential for this drug to become a best-in-class therapy. This, combined with the ongoing progress in breast cancer trials, presents a robust growth opportunity for Relay Therapeutics, justifying a strong buy recommendation.

Keywords

zovegalisib, vascular anomalies, PIK3CA, Relay Therapeutics, clinical trial, Phase 2, PROS, lymphatic malformation