Moderna Falls as Leaked Melanoma Trial Data Miss Investor Hurdle
Moderna shares dropped 17.6% after leaked Phase 3 results for its personalized melanoma vaccine showed a 42% reduction in recurrence or death risk when combined with Keytruda, missing some investors’ expectations. A prespecified analysis found no difference during the first six months but a 58% risk reduction afterward, while overall survival data remain immature. The selloff erased roughly $17 billion in market value, yet the stock still traded above the mean analyst target.
Moderna’s Phase 3 melanoma vaccine trial enrolled 1,137 patients and paired intismeran with Keytruda. The primary result showed a 42% lower risk of recurrence or death versus Keytruda alone, corresponding to a hazard ratio of 0.58. At two years, 82% of combination patients remained recurrence-free, compared with 70% on Keytruda alone.
A preplanned sensitivity check found no gap during the first six months, followed by a 58% lower risk later. In patients who actually received their assigned treatment, a modified intention-to-treat review showed a 49% reduction. Mature overall-survival results are not yet available. Moderna shed roughly $17 billion in market value, while Merck, its equal profit-sharing partner, declined 1.76%.
The readout may affect melanoma patients and their families by shaping expectations for a personalized vaccine that could reduce recurrence after surgery, though overall survival evidence is still pending. Investors, including pension funds and individual shareholders, may feel wealth effects from sharp moves in Moderna and Merck. Health systems and payers could later weigh cost and access if regulators approve the therapy, but the data do not yet settle its broader clinical or economic value.