Moderna-Merck melanoma vaccine cuts recurrence risk by 42 percent in phase 3 trial

Moderna and Merck announced positive phase 3 results for their personalized melanoma vaccine, intismeran autogene, also known as V940 or mRNA-4157. The INTerpath-001 trial studied 1,137 high-risk patients after surgical removal of cancerous tumors.

The two-drug combination reduced the risk of melanoma returning or causing death by 42 percent compared with Keytruda alone. It also cut the risk of distant metastasis or death by 38 percent.

“proof of principle that personalized cancer vaccines work”

After a median follow-up of 24.6 months, 82.2 percent of patients receiving the vaccine plus Keytruda remained alive and recurrence-free after two years, compared with 70 percent in the placebo-plus-Keytruda group. Distant metastasis-free rates were 88.5 percent versus 80.2 percent.

The vaccine is custom-made for each patient using genetic material from the removed tumor and can encode up to 34 neoantigens. Patients also received Merck’s Keytruda immunotherapy during the trial.

Companies have begun discussions with regulators, and results have been accepted for publication in The New England Journal of Medicine. Overall survival data are not yet mature, and the companies describe only a favorable trend.

Moderna shares fell 17.4 percent on October 22, close to the stock’s worst trading day in its history, while Merck dropped 1.8 percent. The decline followed a leak of trial results hours before presentation at the ESMO cancer conference in Madrid.