Moderna and Merck Cancer Vaccine Hits Phase 3 Primary Goal in Melanoma Trial, Sending Moderna Stock Up More Than 100%

Moderna and Merck announced Wednesday that their personalized mRNA cancer vaccine, intismeran autogene, met both the primary endpoint of recurrence-free survival and the key secondary endpoint of distant metastasis-free survival in the Phase 3 INTerpath-001 trial involving patients with completely resected Stage IIB-IV melanoma. The combination regimen, which pairs intismeran with Merck's blockbuster immunotherapy Keytruda, significantly extended the time patients went without their melanoma returning compared with Keytruda alone. It marks the first-ever positive Phase 3 result for an individualized neoantigen therapy, a class of treatments designed for each patient based on the unique mutation profile of their tumor.

The companies said they plan to present full data at an upcoming international medical meeting and will engage with regulators on filing submissions for the combination. Moderna shares surged more than 100 percent on the news, at one point trading near $142 and on pace for the stock's best single day ever from a prior close around $62.96. Merck shares also rose, with some reports citing a gain of roughly 7 percent.

The Nasdaq biotech index pushed to a record as broader vaccine-related stocks, including BioNTech, also climbed. Analysts said the interim results were broadly positive but noted the market would be watching for full data at the upcoming medical conference before drawing firm conclusions on the path to regulatory approval.