Merck and Moderna's mRNA melanoma vaccine shows 42% risk reduction in Phase 3 trial, easing analyst concerns

At the European Society of Medical Oncology meeting, Merck and Moderna presented data from their Phase 3 INTerpath-001 trial of a personalized mRNA vaccine combined with Keytruda in resected melanoma.

The trial enrolled 1,137 patients with stage 2b to 4 melanoma and reported a 42% reduction in the risk of recurrence or death, corresponding to a hazard ratio of 0.58.

The results were leaked online before the official presentation, triggering a sharp sell-off in both companies' shares as some analysts noted the hazard ratio barely met their preferred threshold.

After reviewing the full data at the conference, analysts have softened their stance, describing the efficacy as acceptable and expressing renewed optimism about the vaccine's potential.