Moderna-Merck mRNA cancer vaccine shows landmark interim success in melanoma trial

An interim analysis of a Phase 3 trial of an individualized mRNA cancer vaccine from Moderna and Merck showed the treatment met its primary goals. The vaccine, given together with Merck's immunotherapy Keytruda, delayed disease recurrence and halted tumor spread in patients who had surgery for melanoma.

Independent data monitors reported statistically significant and clinically meaningful improvements compared with Keytruda alone, allowing the trial to be declared a success at the pre‑planned interim check. Detailed efficacy data were not released but are expected at an upcoming medical conference.

The announcement sent Moderna's share price soaring, more than doubling on the news. Analysts described the result as a landmark moment and projected substantial future sales for the melanoma indication. The companies also plan to evaluate the vaccine in other cancers, including lung, kidney and bladder.