Melanoma Neoantigen Vaccines: EVX-01 Peptide and V940 mRNA Evidence
EVX-01 is an investigational personalized peptide vaccine studied with anti-PD-1 therapy in melanoma. A separate randomized study tested the mRNA product V940. Their populations, designs, and results cannot be combined into one peptide-vaccine efficacy claim.
Correction, September 29, 2026: The original version combined results from different vaccine platforms and described a nonexistent randomized peptide-vaccine result. The trial with 157 randomized participants and 18-month recurrence-free survival estimates of 79% and 62% tested V940 (mRNA-4157), an mRNA-based individualized therapy, not EVX-01 or a synthetic-peptide vaccine. Its findings cannot establish EVX-01 efficacy.
Personalized neoantigen therapies use a tumor’s mutations to select patient-specific immune targets. EVX-01 packages selected peptides with an adjuvant; V940 (mRNA-4157) uses mRNA to encode selected neoantigens. Both have been studied alongside pembrolizumab, but the products and trials answer different questions.
What the EVX-01 studies show
The peer-reviewed EVX-01 dose-escalation study enrolled 12 people with metastatic melanoma receiving anti-PD-1 therapy. Its primary endpoint was safety and tolerability. Investigators detected EVX-01-specific CD4+ and/or CD8+ T-cell responses in all 12 participants and observed objective tumor responses in 8 of 12 during the combination treatment Mørk et al., 2024. This was a small, open-label study without an anti-PD-1-only comparison group. The observed tumor responses cannot show how much, if any, benefit EVX-01 added.
A separate, single-arm Phase 2 study in checkpoint-inhibitor-naive unresectable or metastatic melanoma enrolled 17 participants, according to its official registration. A 2025 company release and AACR 2026 sponsor poster reported objective responses in 12 of 16 response-evaluable participants after pembrolizumab and EVX-01. The trial began with a pembrolizumab run-in, had no randomized pembrolizumab-only arm, and the company said its registered response-conversion primary endpoint was not formally analyzed after lower enrollment. These sponsor-reported results are not a controlled estimate of EVX-01’s added clinical benefit; the registry had no posted results when checked on September 29, 2026.
What the V940 study shows
The separate KEYNOTE-942 randomized Phase 2b study assigned 157 people with completely resected high-risk melanoma to V940 plus pembrolizumab (107) or pembrolizumab alone (50). At the reported follow-up, 18-month recurrence-free survival estimates were 79% versus 62%; the recurrence-or-death hazard-ratio point estimate was 0.561, with a 95% confidence interval of 0.309–1.017 and two-sided p=0.053. This is an mRNA-product result in a post-surgery population. It is neither an EVX-01 result nor evidence that the peptide-vaccine approach as a class produces that effect.
What remains open
The EVX-01 clinical studies show that vaccine-specific immune responses can be measured in treated participants. Whether adding EVX-01 improves survival, recurrence, or tumor response over checkpoint treatment alone remains unresolved by these single-arm data. The randomized V940 trial provides a different, product-specific comparison in a different melanoma setting. Future controlled studies and independently reported outcomes are needed to assess each approach’s clinical effect.
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Disclaimer: This article is for educational purposes only and does not constitute medical advice. The information presented is based on current research but should not be used for diagnosis, treatment, or prevention of any disease. Always consult a qualified healthcare provider before making health decisions.