Moderna and Merck mRNA melanoma vaccine cuts recurrence risk 42% in phase 3 trial
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The gist
Moderna and Merck's mRNA melanoma vaccine cut death or return risk 42% versus immunotherapy alone.
It is a first proof of principle, but longer survival data is pending.
Background
Intismeran is a personalised mRNA cancer vaccine developed jointly by drugmakers Moderna and Merck (MSD). It uses the same mRNA technology as some COVID-19 vaccines but is designed as a treatment, not prevention, for patients whose high-risk melanoma has been surgically removed. Each dose is made by testing a patient's cancer cells for unique features and generating bespoke mRNA instructions. The phase 3 results, presented at the ESMO 2026 cancer congress, are the first such readout for this approach and drew interest because cancer vaccines have a long history of disappointments in advanced disease.
How it unfolded
- Oct 23, 2026First phase 3 results for intismeran with pembrolizumab reported at ESMO 2026: the combination cut risk of death or melanoma return over two years by 42% versus immunotherapy alone, and cut risk of the cancer spreading by 38%.
- Oct 23, 2026Moderna and Merck announce detailed recurrence-free and distant metastasis-free survival results from the INTerpath-001 trial in completely resected stage IIB-IV melanoma (Presentation #LBA1).
- Oct 23, 2026An MSKCC-reported study, originally published in 2024 and updated, describes an off-the-shelf vaccine targeting KRAS mutations in pancreatic and colorectal cancers, published in Nature Medicine.
- Oct 24, 2026ScienceDaily reports research into how pancreatic cancer rewrites its DNA to escape treatment, citing single-cell clonal analysis by Aristotelis Tsirigos of NYU Grossman School of Medicine and Perlmutter Cancer Center.
- Oct 27, 2026HHS announces the OWH-AHRQ Breast Cancer Screening and Diagnostic Follow-up Initiative, with more than 40 health systems expanding evidence-based practices.
Who’s saying what
- Expert
- Dr Catherine Elliott of Cancer Research UK said the COVID-era science is now showing promise in treating cancer and called the melanoma results encouraging.
- Expert
- Prof Pippa Corrie, a consultant medical oncologist who helped run part of the study, called personalisation the next step up and the trial the first proof of principle.
- Expert
- Dr. Robert Vonderheide of Penn Medicine, not involved in the trial, called the results a game changer and a first step toward using cancer vaccines to their full potential.
- Caution
- Independent cancer experts said the results are impressive but longer-term studies are still needed to establish whether the treatment helps most patients live longer on average.
- Bears
- Financial analysts said the results were not quite as strong as an earlier, much smaller trial, and investors sold off stock on Thursday.
Still unverified
Independent experts say whether the treatment really helps most patients live longer on average requires longer-term studies; sources also note that success in melanoma won't necessarily translate to trials for other cancer types.