Study Reports Lower Melanoma Recurrence With Vaccine-Drug Combination
A personalized cancer vaccine used with an established immunotherapy drug reduced the risk of melanoma recurrence or death by 49 percent in a phase 2b clinical trial, according to results presented at the 2026 American Society of Clinical Oncology meeting and published in the Journal of Clinical Oncology.
The study, led by researchers at NYU Langone Health’s Perlmutter Cancer Center, tested intismeran, an mRNA-based personalized vaccine, alongside pembrolizumab, sold as Keytruda. Pembrolizumab is already a standard treatment for melanoma after surgery.
Researchers followed 157 patients whose melanoma tumors had been surgically removed. Of those, 107 received the vaccine-drug combination, while 50 received pembrolizumab alone. After five years, 68.8 percent of patients in the combination group remained cancer free, compared with 49.1 percent in the pembrolizumab-only group.
The study also reported a 59 percent reduction in the risk of distant metastasis, meaning the spread of cancer to other parts of the body. Overall survival was 92.2 percent in the combination group and 71.3 percent among patients receiving only pembrolizumab.
Intismeran is designed using genetic information from each patient’s tumor. Researchers identify abnormal proteins, known as neoantigens, and use mRNA technology to train the immune system’s T cells to recognize and attack cancer cells carrying those markers.
Side effects were described as manageable and included fatigue, chills, and pain at injection sites. Seven patients in each treatment group died during follow-up, most from cancer.
The trial enrolled patients in the United States and Australia between 2019 and 2021. A larger phase 3 trial is now underway to evaluate the vaccine and pembrolizumab as a first-line treatment for melanoma. Researchers are also studying whether similar approaches may help prevent recurrence in lung and other cancers.
The study was funded by Moderna, which makes intismeran, and Merck, which makes pembrolizumab.