Moderna and Merck report mRNA vaccine improves recurrence-free survival in melanoma Phase 3 trial
A late-stage study of 1,137 melanoma patients showed that a personalized mRNA vaccine combined with Keytruda extended recurrence-free and distant metastasis-free survival, according to Moderna and Merck.
Moderna and Merck said a Phase 3 trial of a personalized mRNA cancer vaccine plus Merck's Keytruda immunotherapy improved outcomes for patients with surgically removed stage IIB-IV melanoma. The double-blind, placebo-controlled study enrolled 1,137 participants who were randomly assigned in a 2-to-1 ratio to receive the vaccine (intismeran, also known as mRNA-4157) with Keytruda or Keytruda alone for about a year. An interim analysis indicated statistically significant extensions in recurrence-free survival (RFS) and distant metastasis-free survival (DMFS) for the combination therapy.
The vaccine is designed to encode up to 34 tumor-specific mutations identified from each patient’s cancer cells, prompting the immune system to target those neoantigens. The companies plan to present detailed data at an upcoming international medical conference. Earlier Phase 2 results had shown a 49% reduction in the risk of recurrence or death and a 59% reduction in the risk of distant metastasis or death.
Georgina Long, who led the trial, said the results represent a "landmark moment" with the potential to establish a new treatment paradigm. Dean Li, president of Merck Research Laboratories, said the findings reinforce the promise of a more personalized approach to cancer treatment. Moderna CEO Stéphane Bancel called the outcome a pivotal moment for cancer research.
External experts described the trial as the first positive Phase III result for an individualized neoantigen therapy and an mRNA-based cancer treatment, noting that further data on benefit magnitude, subgroup effects, quality of life, and overall survival are needed to determine its place in standard melanoma care.