Cancer Vaccine Keeps 69% Melanoma-Free After 5 Years

Nearly 70% of melanoma patients remained cancer-free five years after receiving a personalized mRNA vaccine alongside immunotherapy, according to groundbreaking results from a major clinical trial.

The KEYNOTE-942 trial tested a vaccine tailored to each patient's unique tumor. Researchers at NYU Langone Health found that combining the vaccine with pembrolizumab immunotherapy reduced the risk of melanoma returning or death by 49% compared to immunotherapy alone.

The numbers tell a powerful story. While 68.8% of patients who received both treatments stayed cancer-free after five years, only 49.1% of those receiving standard immunotherapy alone did. The combination also reduced the risk of the cancer spreading to distant parts of the body by 59%.

Overall survival rates were even more encouraging. After five years, 92.2% of patients in the combination group were still alive, compared to 71.3% in the immunotherapy-only group.

The vaccine works by identifying up to 34 unique markers on each patient's tumor cells. Using mRNA technology similar to COVID vaccines, it trains the immune system to recognize and attack those specific cancer cells. The treatment was tested in patients with high-risk Stage III and IV melanoma who had their tumors surgically removed.

"Our study offers strong evidence to melanoma patients that this vaccine therapy can demonstrably reduce their risk of having their cancer return," said Dr. Janice Mehnert, study senior investigator and director of the melanoma medical oncology program at NYU's Perlmutter Cancer Center.

Side effects were manageable, including fatigue, injection-site pain, and chills. These represent the longest follow-up results yet for a personalized mRNA cancer vaccine in melanoma treatment.

The Bright Side

Melanoma accounts for only 1% of skin cancers but causes most skin cancer deaths. About 112,000 new cases are expected in the United States in 2026, with roughly 8,510 deaths projected.

The good news is that death rates have already been dropping rapidly thanks to advances in immunotherapy. This vaccine approach represents the next frontier, offering hope particularly for younger patients. Melanoma remains one of the most common cancers in adults under 40.

A Phase 3 trial is now underway to further test the vaccine as a first-line treatment. Researchers are also exploring whether this personalized approach could work against other types of cancer.

While prevention through sun protection and avoiding tanning beds remains crucial, this breakthrough offers real hope for patients diagnosed with aggressive melanoma. For the first time, doctors can offer a treatment that's literally designed around each patient's unique cancer, giving the immune system precisely what it needs to fight back.