Intismeran Autogene (mRNA-4157) Plus Pembrolizumab: Landscape

Intismeran autogene (also called mRNA-4157 or V940) is an individualized cancer therapy from Moderna and Merck, given together with pembrolizumab (Keytruda). On October 24, 2026, the first Phase 3 results were presented at the ESMO Congress in Madrid. They matter because the companies describe this as the first positive Phase 3 readout for an individualized neoantigen therapy.

Mechanism at a glance

Each patient’s tumor is sequenced and compared with healthy tissue. Intismeran is then manufactured as messenger RNA encoding up to 34 tumor-specific mutations (“neoantigens”), to teach the immune system to recognize that patient’s cancer. It is injected, and pembrolizumab, a PD-1 inhibitor, is given alongside it. More than 99% of patients in the combination arm had a vaccine successfully manufactured, and the median time to the first dose was 64 days (as reported by OncLive from the presentation).

Why it matters

INTerpath-001 (NCT05933577) enrolled 1,137 patients with completely resected stage IIB to IV melanoma, randomized 2:1 to intismeran plus pembrolizumab or placebo plus pembrolizumab. The primary endpoint was recurrence-free survival (RFS). The trial was announced as positive by press release on August 19, 2026, without numbers.

What was actually reported at ESMO. Georgina Long of Melanoma Institute Australia presented the data (abstract LBA1, Presidential Symposium I). Median follow-up was 24.6 months. The results, as reported by Merck and Moderna:

• RFS hazard ratio 0.58 (95% CI 0.45 to 0.75), a 42% lower risk of recurrence or death. Two-year RFS was 82.2% vs 70.0%.
• Distant metastasis-free survival HR 0.62. Overall survival HR 0.77 (95% CI 0.45 to 1.31, P = .33), which is immature and did not cross the significance boundary.
• In the first six months the curves did not separate (RFS HR 0.99); after six months the HR was 0.42, a prespecified analysis.
• Grade 3 to 5 treatment-related events: 14.2% vs 13.4%. Treatment discontinuation was 16.6% vs 9.5%, and 8 fatal adverse events (1.1%) occurred in the combination arm versus none in the control arm; none were attributed to intismeran.

Peer-reviewed or not? At the time of the presentation these were conference and company figures. The companies say the results were accepted by The New England Journal of Medicine, and OncLive reports publication is slated for November 11, 2026, which has not happened as of November 4. The data were also released two days early on October 22 after a leak that STAT reported, and ESMO said it is investigating.

Competitive pressure points

• Autogene cevumeran (BioNTech and Genentech): an individualized mRNA vaccine. Its adjuvant pancreatic cancer Phase 2 trial (IMcode003, NCT05968326) finished enrollment in August 2026, per BioNTech’s November 3 report. BioNTech also said early termination began in its Phase 2 trial in ctDNA-positive colorectal cancer.
• Anchored to pembrolizumab: the regimen is built on Keytruda, so success would extend the pembrolizumab franchise into earlier-stage use. See our pembrolizumab landscape.
• Other adjuvant melanoma options: the benchmark is pembrolizumab alone, as the control arm shows. The 42% reduction is smaller than the 49% reported in the earlier Phase 2b KEYNOTE-942 study, though the trials are not directly comparable (EMJ).
• Cost and logistics: one analyst quoted by BioPharma Dive noted that per-patient manufacturing is likely costlier than standard biologics.

What to watch

• The NEJM paper and any regulatory filing. The companies say they plan to engage with regulators; no filing had been announced as of November 4.
• Overall survival, which is still immature.
• Whether the benefit repeats in lung cancer, where the program has Phase 3 trials.
• Moderna’s third-quarter update on November 6.

Recent developments

Updated November 4, 2026. Items are drawn from company announcements, regulators and trade press; links go to the sources.

• Oct 24, 2026: Long presented INTerpath-001 results at ESMO (RFS HR 0.58; OS HR 0.77, not significant). (OncLive)
• Oct 22, 2026: Merck and Moderna released full results two days early after the data surfaced; Moderna shares closed 17.3% lower that day, after rising more than fivefold earlier in the year. (EMJ) The companies’ release is here: (Merck)
• Aug 19, 2026: Topline announcement that INTerpath-001 met its RFS and distant metastasis-free survival endpoints, with no efficacy numbers given. (Merck)

Other INTerpath trials

• INTerpath-002: Phase 3, adjuvant NSCLC (NCT06077760, 868 patients planned). Not recruiting; ongoing.
• INTerpath-009: Phase 3, adjuvant NSCLC after incomplete response to neoadjuvant therapy (NCT06623422).
• INTerpath-014: Phase 3, high-risk stage I NSCLC, including subcutaneous pembrolizumab (NCT07513376).
• INTerpath-012: Phase 2, first-line advanced melanoma. INTerpath-007 (cutaneous squamous cell carcinoma) was terminated for business reasons. Renal and bladder Phase 2 trials are also under way (ClinicalTrials.gov).

Upcoming catalysts

• Nov 6, 2026: Moderna third-quarter results and company update.
• Nov 11, 2026: planned NEJM publication of INTerpath-001 (per OncLive).
• Late 2026 or 2027: possible mid-stage kidney and bladder results (BioPharma Dive).

Bottom line

INTerpath-001 is a real Phase 3 win on RFS, but a moderate one with immature survival data, a delayed onset of benefit and a more modest effect than the earlier Phase 2b. Next come the full paper, regulators, and the lung cancer trials.

For how conference readouts feed competitor tracking, see ASCO, ESMO and ASH competitive intelligence.

Want this kind of analysis for the cancer areas you compete in? Request information and we will share sample deliverables.

This article is for informational and competitive-intelligence purposes only and is not medical advice. Approvals, labels and trial results change; verify details against current prescribing information and primary sources.