49% Lower risk: Vaccine combo slashes melanoma recurrence after surgery

A personalized cancer vaccine combined with immunotherapy cut the risk of skin cancer recurrence and death by 49%, a new phase 2b trial shows. The benefit held steady five years after patients had their tumors surgically removed.

Researchers at NYU Langone’s Perlmutter Cancer Center led the study. They tested a vaccine called intismeran alongside pembrolizumab, the immunotherapy drug sold as Keytruda. Intismeran is made from each patient’s own tumor, training the immune system to target cancer cells specifically.

The KEYNOTE-942 trial randomly assigned 107 melanoma patients to receive the vaccine + pembrolizumab after surgery. Results were compared with 50 patients who got pembrolizumab alone, the current standard of care.

After five years of follow-up, 68.8% of patients on the combination therapy remained cancer-free, vs 49.1% of those on pembrolizumab only. The combo also reduced risk of distant metastasis — cancer spreading to other parts of the body — by 59%.

Overall survival was higher too. 92.2% of patients on vaccine + immunotherapy were alive from any cause after five years, compared with 71.3% on immunotherapy alone.

Results were presented June 1 at the 2026 American Society of Clinical Oncology annual meeting in Chicago and published simultaneously in the Journal of Clinical Oncology.

“Our study offers strong evidence to melanoma patients that intismeran vaccine therapy, when used in combination with immunotherapy, can demonstrably reduce their risk of having their cancer return and improve clinical outcomes,” said senior investigator Janice Mehnert, MD, professor in the Department of Medicine at NYU Grossman School of Medicine.

The trial suggests personalized vaccines could become a new tool to keep melanoma from coming back after surgery.