On October 22, 2026 Merck (NYSE: MRK), known as MSD outside of the United States and Canada, and Moderna, Inc. (NASDAQ: MRNA) reported detailed positive recurrence-free survival (RFS) and distant metastasis-free survival (DMFS) results from the Phase 3 INTerpath-001 trial evaluating intismeran autogene (intismeran; V940 or mRNA-4157), a novel investigational mRNA-based individualized neoantigen therapy (INT) being jointly developed by Merck and Moderna, in combination with KEYTRUDA (pembrolizumab), Merck’s anti-PD-1 therapy, as adjuvant treatment for patients with completely resected stage IIB-IV melanoma. These late-breaking results will be presented for the first time during Presidential Symposium I at the European Society for Medical Oncology (ESMO) (Free ESMO Whitepaper) Congress 2026 (Presentation #LBA1), were selected for an official ESMO (Free ESMO Whitepaper) Press Briefing and have been accepted for publication in The New England Journal of Medicine.
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At the primary pre-specified analysis (intention-to-treat), after a median follow-up of 24.6 months, intismeran in combination with KEYTRUDA significantly reduced the risk of recurrence or death by 42% (HR=0.58 [95% CI, 0.45–0.75]; two-sided p<0.001). Intismeran plus KEYTRUDA also significantly reduced the risk of distant metastasis or death by 38% (HR=0.62 [95% CI, 0.45–0.85]; two-sided p=0.002) compared to KEYTRUDA alone. The improvements observed in RFS and DMFS were generally consistent across pre-specified patient subgroups. Overall survival (OS) data are not yet mature, but a favorable trend in OS with intismeran plus KEYTRUDA has been observed. The study remains ongoing to further evaluate OS and other key endpoints. The safety profile of intismeran plus KEYTRUDA was generally consistent with previously reported studies of the combination, and no new safety signals were observed. Based on these data, we are engaging with regulatory authorities.
The efficacy of the intismeran immunization plus KEYTRUDA in the first six months was comparable with KEYTRUDA alone for risk of recurrence or death (HR=0.99 [95% CI, 0.66–1.49]) and risk of distant metastasis or death (HR=1.01 [95% CI, 0.58–1.79]). At six months, following the intismeran immunization regimen, a pre-specified sensitivity analysis of the primary endpoint showed the addition of intismeran plus KEYTRUDA reduced the risk of recurrence or death by 58% (HR=0.42 [95% CI, 0.30–0.58]) and reduced the risk of distant metastasis or death by half (HR=0.50 [95% CI, 0.34–0.73]) compared to KEYTRUDA alone.
In a pre-specified sensitivity analysis of the modified intent-to-treat (mITT) population, which excluded participants who did not receive at least one dose of intismeran or placebo as planned, intismeran plus KEYTRUDA reduced the risk of recurrence or death by 49% (HR=0.51 [95% CI, 0.39–0.67]) and the risk of distant metastasis or death by 45% (HR=0.55 [95% CI, 0.40–0.77]) compared to KEYTRUDA alone.
"The transformative INTerpath-001 results have the potential to make a foundational shift in how we treat patients with earlier-stage melanoma in the adjuvant setting," said Professor Georgina Long, the study’s principal investigator and medical director of Melanoma Institute Australia, Chair of Melanoma Medical Oncology and Translational Research at the University of Sydney. "For decades, cancer treatment has largely been defined by where a tumor originates in the body. The INTerpath-001 findings support a fundamentally new and individualized approach to treating resected melanoma in the adjuvant setting, one that tailors treatment to the unique mutational signature of a patient’s tumor to enhance an anti-tumor immune response. While these results are in patients with completely resected stage IIB-IV melanoma, they provide valuable insights and will help inform our understanding of intismeran as clinical research continues into other tumor types and across settings."
"INTerpath-001 is the first Phase 3 study to demonstrate a clinically meaningful improvement in RFS and DMFS over standard-of-care KEYTRUDA in patients with resected melanoma, setting a new benchmark in the adjuvant setting and representing one of the most significant advances in melanoma treatment since the advent of immunotherapy," said Dr. Dean Y. Li, president, Merck Research Laboratories. "These results, building on the body of evidence from the Phase 2b study, strengthen our confidence in the curative potential of intismeran autogene when given in combination with KEYTRUDA. Importantly, these data suggest that, by intervening earlier, this approach may offer a tangible opportunity to change the trajectory of a patient’s cancer."
"From the beginning, we believed mRNA technology could make it possible to develop cancer treatments uniquely matched to each patient’s tumor. The INTerpath-001 results mark a defining moment for that vision and show what’s possible when we rethink how medicines are made," said Stéphane Bancel, Chief Executive Officer of Moderna. "These results reinforce our conviction that mRNA has the potential to fundamentally change how we treat cancer."
Merck and Moderna are advancing the robust INTerpath clinical development program evaluating the safety and efficacy of intismeran in combination with KEYTRUDA and other anti-cancer therapies, and as a monotherapy. The INTerpath program currently consists of nine total Phase 2 and Phase 3 clinical trials across multiple tumor types and stages of disease, including three ongoing Phase 3 trials in non-small cell lung cancer (NSCLC). Additional clinical studies include the Phase 2b KEYNOTE-942/mRNA-4157-P201 trial in adjuvant melanoma and a Phase 1 study exploring adjuvant pancreatic ductal adenocarcinoma (Abstract #3151P), perioperative gastric carcinoma and perioperative NSCLC.
The results from INTerpath-001 build on previously reported Phase 2b results for intismeran in combination with KEYTRUDA from the KEYNOTE-942/mRNA-4157-P201 trial, including the five-year follow-up data presented at the 2026 ASCO (Free ASCO Whitepaper) Annual Meeting.
Study design and additional data from INTerpath-001
INTerpath-001 is a randomized, double-blind, placebo- and active-comparator-controlled global Phase 3 trial (ClinicalTrials.gov, NCT05933577) evaluating the safety and efficacy of intismeran in combination with KEYTRUDA compared to KEYTRUDA alone in patients with high-risk (stage IIB-IV) resected cutaneous melanoma. The trial enrolled 1,137 patients who, following complete surgical resection, were randomized 2:1 to receive intismeran (1 mg every three weeks for up to nine doses) and KEYTRUDA (400 mg every six weeks up to nine cycles [for approximately one year]) compared to placebo plus KEYTRUDA for approximately one year until disease recurrence or unacceptable toxicity, or for a total treatment duration of up to approximately 56 weeks, whichever was sooner.
The primary endpoint is RFS, defined as the time from randomization to any disease recurrence (local, locoregional, regional or distant) as assessed by the investigator, or death due to any cause. Key secondary endpoints include DMFS, OS, safety, tolerability and quality of life.
In the ITT population, the two-year RFS rate was 82.2% (95% CI, 79.3%–84.8%) for intismeran plus KEYTRUDA compared to 70.0% (95% CI, 65.0%–74.5%) for KEYTRUDA alone. Median RFS was not reached (NR) (95% CI, not estimable [NE]–NE) for either arm. Additionally, the two-year DMFS rate was 88.5% (95% CI, 86.0%–90.6%) for intismeran plus KEYTRUDA compared to 80.2% (95% CI, 75.6%–84.0%) for KEYTRUDA alone. Median DMFS was NR (95% CI, NE–NE) for either arm.
Treatment-related adverse events (TRAEs) occurred in 95.8% (723 of 755 patients) receiving intismeran plus KEYTRUDA and 90.0% (342 of 380 patients) receiving KEYTRUDA alone. Grade 3–5 TRAEs occurred in 14.2% (n=107) versus 13.4% (n=51) of patients, respectively. The most common adverse events in the intismeran plus KEYTRUDA arm were pyrexia (52.2%), injection site pain (51.0%) and fatigue (38.5%).
About intismeran autogene
Intismeran autogene (intismeran; V940 or mRNA-4157) is a novel, potential first-in-class investigational messenger RNA (mRNA)-based individualized neoantigen therapy (INT) jointly developed by Merck and Moderna. Intismeran is designed and produced using a patient’s tumor sample to identify the unique mutational signature of their cancer and generate an anti-tumor immune response. Information derived from the patient’s tumor and normal DNA is used to create an individualized treatment design, or "blueprint," informed by selected neoantigens unique to that patient’s cancer. Each therapy consists of a synthetic mRNA coding for up to 34 neoantigens. Upon administration, the RNA-encoded neoantigen sequences are translated in the body and presented to the immune system, a key step in generating specific T-cell responses against cancer cells. Individualized neoantigen therapies are designed to train and activate an anti-tumor immune response based on the unique mutational signature of a patient’s tumor.
About melanoma
Melanoma, one of the deadliest forms of skin cancer, is characterized by the uncontrolled growth of pigment-producing cells. The rates of melanoma have been rising over the past few decades, with more than 338,000 new cases diagnosed worldwide in 2024. In the U.S., skin cancer is one of the most common types of cancer diagnosed, and melanoma accounts for a large majority of skin cancer deaths. It is estimated there will be about 112,000 new cases of melanoma diagnosed and over 8,500 deaths resulting from the disease in the U.S. in 2026 alone. Despite advances in treatment, patients with resected melanoma remain at risk of disease recurrence, which most often occurs within the first two years following surgery. Disease recurrence can be metastatic as well as localized, with more than half of patients who experience recurrence developing one or more distant metastases. Distant metastases can spread to critical organs, including the lung, liver and brain, and are associated with substantially worse outcomes, underscoring the continued need for treatment approaches that can help reduce the risk of recurrence and the risk of local and distant metastasis.
(Press release, Merck & Co, OCT 22, 2026, View Source [SID1234673672])