# Moderna and Merck melanoma vaccine clinical trials

> Live situation record from CLSTR: https://clstr.news/situations/20260821-moderna-and-merck-melanoma-vaccine-clinical-trials
> Updated: 2026-08-21T00:17:57.000Z. Sources: 307. Developments: 2.

Moderna and Merck have reported positive Phase 3 clinical trial results for intismeran autogene, an experimental personalized mRNA cancer vaccine. The therapy is designed to target the unique mutational fingerprint of an individual patient’s tumor and is administered alongside Merck’s immunotherapy, Keytruda.

The INTerpath-001 trial, which included 1,137 patients with high-risk or advanced melanoma (stages IIB through IV) following surgical resection, met its primary endpoint. The combination therapy demonstrated a statistically significant improvement in recurrence-free survival and a reduced risk of cancer metastasis compared to Keytruda alone.

While the findings represent a milestone in personalized oncology, the companies noted that the study is ongoing to evaluate long-term overall survival. Research is also expanding to include trials for non-small cell lung, bladder, kidney, pancreatic, and stomach cancers.

## Claims

- A personalized mRNA vaccine combined with Keytruda significantly increased the time patients remained cancer-free compared to Keytruda alone. (corroborated by 3 sources)
- The combination therapy reduced the risk of melanoma spreading to other organs. (corroborated by 3 sources)
- The Phase 3 clinical trial involved over 1,000 patients with high-risk stage two, three, or four melanoma. (corroborated by 3 sources)
- The vaccine, named intismeran autogene, is custom-built for each patient based on the unique genetic mutations found in their tumor. (corroborated by 2 sources)
- Trials are underway for the vaccine against non-small cell lung cancer, bladder cancer, kidney cancer, pancreatic cancer, and stomach cancer. (single source)

## Timeline

### 2026-08-21: Merck and Moderna cancer vaccine shows promise in melanoma trials

A Phase 3 trial for a personalized mRNA vaccine by Merck and Moderna has shown significant success in preventing the return and spread of high-risk melanoma when used with immunotherapy.

5 sources. https://clstr.news/cluster/merck-and-moderna-cancer-vaccine-shows-promise-in-melanoma-trials

### 2026-08-19: Moderna and Merck report positive Phase 3 results for personalized mRNA melanoma vaccine

Moderna and Merck reported positive Phase 3 trial results for Intismeran, a personalized mRNA cancer vaccine that significantly improves recurrence-free survival in high-risk melanoma patients when combinededla

303 sources. https://clstr.news/cluster/moderna-and-merck-report-successful-phase-3-trial-for-mrna-skin-cancer-vaccine

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Cite as: Moderna and Merck melanoma vaccine clinical trials. CLSTR, https://clstr.news/situations/20260821-moderna-and-merck-melanoma-vaccine-clinical-trials