The story so far
written Oct 25What is happening
Moderna and Merck are seeking to establish a new standard of care for skin cancer patients after Phase 3 trial data showed their personalized mRNA vaccine reduces the risk of recurrence or death by 42% 12. The vaccine, intismeran (mRNA-4157/V940), was tested in combination with the immunotherapy drug Keytruda against Keytruda alone in patients with resected stage IIB-IV melanoma 14. Results released October 22, 2026, also showed a 38% reduction in the risk of distant metastasis or death 2. Moderna and Merck are currently in discussions with regulatory authorities regarding these results 5. A pre-specified analysis of the INTerpath-001 trial found that patients who completed the full six-month immunization schedule saw the risk of recurrence or death drop by 58% 1. While some analysts noted that the distant metastasis data did not reach the levels seen in earlier Phase 2 studies, oncologists have characterized the findings as a major breakthrough 246.
What to watch
The presentation of detailed Phase 3 results is scheduled for the European Society for Medical Oncology (ESMO) Congress 2026 Presidential Symposium 1. Publication of the full Phase 3 trial results in a peer-reviewed medical journal would provide further validation of the data. The filing of a Biologics License Application with the FDA would mark the start of the formal regulatory review process for the vaccine. An FDA decision to approve or reject the therapy would determine when it becomes available to the public. Moderna and Merck would then be expected to announce a commercial launch date for the treatment. Testing of the vaccine for use in non-small cell lung cancer also continues in separate Phase 3 trials 912.
Read the full brief · how we got here
How we got here
The vaccine is an individualized neoantigen therapy designed to prime a patient's immune system to recognize and attack specific mutations in their own tumor 1014. Earlier Phase 2b trial data showed the combination therapy reduced the risk of recurrence or death by 44% compared to Keytruda alone 1013. Long-term follow-up from that study released in late 2023 indicated the benefit was sustained over three years 11.
References · 11
- 1merck.com — Merck and Moderna Will Present Results From Landmark Phase 3 INTerpath-001 Trial for Intismeran Autogene Plus KEYTRUDA® (pembrolizumab) at ESMO 2026 Presidential Symposium - Merck.com
- 2cnbc.com — Doctors call Moderna, Merck cancer vaccine data a major advancement — despite Wall Street reaction
- 4fiercebiotech.com — ESMO: After leak, Merck and Moderna post phase 3 cancer vaccine data early
- 5cnn.com — Experimental mRNA vaccine cuts risk melanoma returns by 42% | CNN
- 6nytimes.com — Cancer Vaccine Cuts the Risk of Melanoma Recurrence, Merck and Moderna Report - The New York Times
- 9merck.com — Merck and Moderna Initiate Phase 3 Trial Evaluating Adjuvant V940 (mRNA-4157) in Combination with KEYTRUDA® (pembrolizumab) After Neoadjuvant KEYTRUDA and Chemotherapy in Patients With Certain Types o
- 10merck.com — Moderna and Merck Announce mRNA-4157/V940, an Investigational Personalized mRNA Cancer Vaccine, in Combination With KEYTRUDA® (pembrolizumab), Met Primary Efficacy Endpoint in Phase 2b KEYNOTE-942 Tri
- 11clinicaltrialsarena.com — Moderna and MSD share encouraging three-year data from trial of melanoma therapy
- 12appliedclinicaltrialsonline.com — Merck and Moderna Initiate Phase III Study of mRNA-4157 and Keytruda Combination for Non-Small Cell Lung Cancer | Applied Clinical Trials Online
- 13ajmc.com — Merck, Moderna Cancer Vaccine Cuts Melanoma Recurrence Risk by 42% | AJMC
- 14drugdiscoverynews.com — Moderna and Merck say personalized melanoma cancer vaccine worked in late-stage trial | Drug Discovery News
What would close this
0 of 4 metTimeline
1newest firstWhen we started following: Moderna and Merck to present Phase 3 data showing mRNA cancer vaccine reduces melanoma recurrence risk by 42%
Moderna and Merck are scheduled to present detailed Phase 3 results for their individualized neoantigen therapy, intismeran (mRNA-4157/V940), at the European Society for Medical Oncology (ESMO) Congress 2026 1. Data from the INTerpath-001 trial released early on October 22, 2026, following an online leak, show the vaccine combined with Keytruda reduced the risk of recurrence or death by 42% in patients with resected stage IIB-IV melanoma compared to Keytruda alone 148.
The combination also met a secondary endpoint by reducing the risk of distant metastasis or death by 38% 2. A pre-specified sensitivity analysis indicated the risk of recurrence or death dropped by 58% for patients who completed the full six-month immunization regimen 1. While oncologists described the results as a "major breakthrough" and a potential new standard of care, some market analysts noted that distant metastasis data fell short of expectations set by earlier Phase 2 readouts 246.
Moderna and Merck stated they are currently engaging with regulatory authorities, suggesting a forthcoming application for FDA approval 5. The therapy is also undergoing Phase 3 testing for non-small cell lung cancer 912.