Moderna and Merck’s personalized mRNA cancer vaccine intismeran autogene met key endpoints in a large melanoma trial, but investors reacted sharply after detailed results triggered a “sell-the-news” move. The companies’ combination approach with Merck’s Keytruda reduced the risk of relapse or death by 42%, aligning with Wall Street expectations. A detailed STAT+ report stated the therapy reduced disease recurrence and extended the time patients lived without their cancer returning, using trial endpoints consistent with prior expectations for the landmark study. However, at least one analyst characterized the market response as driven by valuation sensitivity rather than failure of the trial’s prespecified goals. A separate report also highlighted data-leak timing: results were released after being disclosed earlier the same day, adding friction to the rollout of the final Phase 3 materials. Together, the reports underscore both the clinical signal and the market’s immediate scrutiny of incremental benefit. For the sector, the readout keeps pressure on other personalized neoantigen strategies to show durable recurrence control while managing expectations for combination regimens and end-to-end manufacturing realities.