Melanoma vaccine approval has not happened yet. No regulator has approved intismeran autogene, and its developers have not announced a filing date. On 22 October 2026, Merck and Moderna released detailed phase 3 data. They said they are engaging with regulatory authorities. The full presentation at the ESMO Congress is due on 24 October.
The companies call the product an individualised neoantigen therapy rather than a vaccine. Many outlets use the vaccine label, and this article uses both terms. The answer to the timing question depends on filings that have not yet been announced.
What the INTerpath-001 data show
INTerpath-001 (NCT05933577) is a randomised, double-blind phase 3 trial. It enrolled 1,137 patients with completely resected stage IIB to IV cutaneous melanoma. Patients were randomised 2:1 to intismeran plus pembrolizumab, or placebo plus pembrolizumab. Intismeran was given at 1 mg every three weeks, for up to nine doses.
Merck and Moderna first announced that the trial had met its primary endpoint on 19 August 2026. That announcement gave no hazard ratios. An earlier article on the topline result covers the manufacturing questions it raised.
The comparator arm received pembrolizumab, so the trial measures the added effect of intismeran. The wider INTerpath programme now covers nine phase 2 and phase 3 studies, according to the August release. Indications include melanoma, non-small cell lung cancer, bladder cancer and renal cell carcinoma.
Efficacy
The October release reports a median follow-up of 24.6 months. Recurrence-free survival favoured the combination, with a hazard ratio of 0.58 (95 per cent confidence interval 0.45 to 0.75). Two-year recurrence-free survival was 82.2 per cent, against 70.0 per cent with pembrolizumab alone. Median recurrence-free survival was not reached in either arm.
Distant metastasis-free survival also favoured the combination. The hazard ratio was 0.62 (95 per cent confidence interval 0.45 to 0.85). Overall survival data are immature. The companies report a favourable trend, and the study continues.
The benefit was not immediate. In the first six months, the recurrence-free survival hazard ratio was 0.99 (0.66 to 1.49). A pre-specified analysis after six months gave 0.42 (0.30 to 0.58). Both figures come from the companies’ own release. A peer-reviewed paper has been accepted by the New England Journal of Medicine.
The release also reports a modified intention-to-treat sensitivity analysis. It gave a recurrence-free survival hazard ratio of 0.51 (0.39 to 0.67). The distant metastasis-free survival ratio was 0.55 (0.40 to 0.77). Sensitivity analyses do not replace the primary result, which is the 0.58 figure.
Safety
Treatment-related adverse events occurred in 95.8 per cent of patients on the combination (723 of 755). The figure was 90.0 per cent on pembrolizumab alone (342 of 380). Grade 3 to 5 treatment-related events were 14.2 per cent (107 patients) versus 13.4 per cent (51 patients).
The most common events with the combination were pyrexia (52.2 per cent) and injection site pain (51.0 per cent). Fatigue followed at 38.5 per cent. The companies report no new safety signals.
Melanoma vaccine approval: what have the companies said about filing?
In August, Merck and Moderna said they would engage with regulators on filing submissions. The October release says those discussions are under way. Neither release gives a submission date or a target decision date.
IBTimes UK reported on 20 August that Moderna president Stephen Hoge had given a possible date. He said patients could potentially receive treatment in 2027 if reviews succeed. That is one secondary report of a best case. It is not a company timetable, and no later statement repeats it.
A search on 23 October 2026 found no announced submission to the FDA, the EMA or the MHRA. That is a dated search finding, not proof that no filing exists.
What regulators have already granted
The FDA granted breakthrough therapy designation in February 2023, for adjuvant treatment of high-risk melanoma after complete resection. The EMA awarded PRIME scheme designation in April 2023, for high-risk stage III and IV melanoma after resection.
Both designations relate to development support. Neither is a melanoma vaccine approval, and neither lowers the evidence bar. The earlier phase 2b KEYNOTE-942 trial, published in The Lancet in 2024, supplied the signal behind both.
What could shape the timing of a decision
Several features of the dataset may matter to reviewers. The results come from a pre-planned interim analysis, according to the August release. The October release describes the same readout as the primary pre-specified analysis. Overall survival is immature. The benefit also emerged mainly after about six months.
Whether regulators will want more survival data has not been stated by the companies. A search on 23 October 2026 found no FDA or EMA comment on the point. Early melanoma vaccine approval is therefore plausible but unconfirmed. Timing depends on filing dates and review length.
Investigators have framed the result as significant. BioPharma Dive quoted Hussein Tawbi, a trial investigator at MD Anderson Cancer Center. He said none of the trials he had led had improved on PD-1 inhibitors. It also reported that Janice Mehnert of NYU Langone Health said patients would likely accept the side-effect risk.
Expectations also matter. BioPharma Dive reported that analysts had expected a 40 to 50 per cent reduction in risk. It added that Moderna had called 35 per cent clinically significant. The trial’s 42 per cent reduction sat inside that range.
Shares in Moderna fell after the data, and Merck’s slipped, BioPharma Dive reported. An analyst at RBC Capital Markets called the result the “low end” of expectations. The same analyst wrote that approval seems likely but commercial success is far less certain.
Reviewers will also weigh the safety balance in any melanoma vaccine approval decision. Any-grade adverse events were more frequent with the combination, mainly fever and injection site pain. Grade 3 to 5 events were similar between arms, at 14.2 and 13.4 per cent. How that profile compares with the recurrence benefit will be a matter for each regulator.
Manufacturing is the other open variable. Each treatment is designed and produced for one patient, using that patient’s tumour sample, according to the August release. The releases reviewed on 23 October did not give capacity figures or a price.
Melanoma vaccine approval in the UK: what is known?
UK use would need MHRA authorisation. The MHRA’s International Recognition Procedure lets it rely on reference regulators, including the FDA and EMA. The guidance lists first-in-class new active substances under Recognition B, which runs to a 110-day timetable.
Whether the MHRA would treat intismeran as first-in-class has not been stated. A search of the electronic medicines compendium on 23 October 2026 returned no product for intismeran. A web search the same day found no NICE guidance page for it.
Routine NHS funding would follow a separate assessment. IBTimes UK noted that pricing is unannounced. For now, intismeran remains investigational. According to IBTimes UK, access is limited to clinical studies until approval. The Merck trial page lists no study locations, so UK trial sites are unconfirmed.
What would settle the question
Three events would move the answer. The first is a filing announcement from Merck and Moderna. The second is an FDA acceptance, ideally with a review designation and an action date. The third is a European or UK submission.
The ESMO presentation on 24 October will add detail. So will the New England Journal of Medicine paper, on subgroups and safety. Until a filing is announced, the melanoma vaccine approval date remains unknown. The FDA decisions tracker will list any action date once one is set.
