Merck and Moderna's mRNA melanoma vaccine clears the bar at ESMO, but Moderna's stock drops
- Adjuvant intismeran plus Keytruda cut the relative risk of recurrence or death versus Keytruda alone, with a similar cut in distant spread, at about two years' median follow-up.
- Side effects were broadly similar between arms apart from more fever and injection-site pain; discontinuations for adverse events were slightly higher with the vaccine.
- Moderna's shares fell sharply after the early data leak and presentation; Merck's barely moved. Studies in lung, bladder and kidney cancer continue.
💡 Points
The result landed at the low end of what analysts wanted, and the benefit looks smaller than the Phase 2 signal. Approval looks plausible; the harder question is how many more tumor types a personalized, patient-by-patient manufacturing model can serve. The kidney and lung readouts will say whether this is a platform or a one-indication product.
Moderna, Merck shares fall on eagerly anticipated cancer vaccine results ↗