Moderna shares fell after melanoma vaccine results leaked before a planned ESMO presentation.
Why it matters: For investors and biotech professionals, leaked or incomplete clinical data can trigger volatility before full efficacy, safety and valuation information is available. The episode also shows how expectations built on topline results can shape a stock's response to more detailed data.
- Moderna shares closed down 17.6% on October 22 after falling more than 25% intraday.
- The randomized Phase 3 INTerpath-001 trial reported a recurrence-free-survival hazard ratio of about 0.58, representing an approximate 42% relative reduction in the risk of recurrence or death versus Keytruda alone.
- INTerpath-001 enrolled 1,137 patients with completely resected, high-risk stage IIB-IV melanoma.
- Recurrence-free and distant-metastasis-free survival endpoints were met, while overall-survival follow-up remains ongoing.
Detailed results for Moderna's personalized melanoma cancer vaccine appeared early on Oncology Central, a medical news site operated by Informa, ahead of a scheduled October 24 presentation at the European Society for Medical Oncology Congress in Madrid. The material was removed shortly afterward, and the embargo was lifted before Moderna and Merck released the data earlier than planned. CNBC reported the leak and the subsequent selloff.
The trial tested intismeran autogene, also known as V940 or mRNA-4157, with Merck's Keytruda against Keytruda alone. The randomized 2:1 INTerpath-001 study enrolled 1,137 patients with completely resected stage IIB-IV melanoma. The combination produced a recurrence-free-survival hazard ratio of about 0.58, or an approximate 42% relative reduction in the risk of recurrence or death versus Keytruda alone. Merck and Moderna said the study met its recurrence-free-survival primary endpoint and distant-metastasis-free-survival key secondary endpoint.
At the approximately two-year assessment, recurrence-free survival was 82.2% with the combination versus 70% with Keytruda alone. That measure tracks patients who remain free of recurrence or death; it is not an overall-survival result. Overall-survival follow-up remains ongoing, so the trial has not yet established an overall-survival benefit.
The companies had announced positive topline results in August without publishing detailed efficacy figures. Moderna shares closed down 17.6% on October 22, while Merck declined about 1.7%. Reuters reported that Moderna lost approximately $24 billion in market value.
Intismeran autogene uses a patient's tumor mutations to create an individualized mRNA treatment designed to stimulate an immune response against tumor-specific targets. The treatment remains investigational and subject to regulatory review.
By the numbers
- 17.6% - Moderna's closing share-price decline on October 22
- 1,137 - Patients enrolled in the Phase 3 INTerpath-001 trial
- 0.58 - Approximate recurrence-free-survival hazard ratio for the combination versus Keytruda alone
Yes, but: The reported recurrence-free and distant-metastasis-free-survival results do not yet establish an overall-survival benefit, and the treatment remains investigational.
What's next: The companies had scheduled a detailed presentation at the European Society for Medical Oncology Congress in Madrid on October 24. Overall-survival follow-up and regulatory review remain ongoing.