Melanoma Vaccine Ushers in New Hope for Cancer Patients

An experimental vaccine developed by Merck and Moderna could become the first vaccine of its kind used to treat cancer. Scientists hope it won’t be the last.

On Thursday, the drug makers announced that patients with melanoma who received a vaccine tailored to help their immune systems attack their tumors were 42 percent less likely to experience a recurrence of the cancer within two years than those who did not receive the vaccine. The companies have yet to show the treatment can prolong melanoma patients’ overall survival.

The results come at a time of great momentum in the development of cancer vaccines — an idea scientists have tried and failed to realize for decades.

“There have been thousands of papers written on therapeutic cancer vaccines,” said Dr. Steven Rosenberg, chief of the surgery branch at the National Cancer Institute and a pioneer of immunotherapy, the use of the body’s immune system to fight cancer.

Buoyed by recent scientific advances, however, researchers are now testing whether such vaccines could one day be used for a range of cancers, including hard-to-treat ones like pancreatic and brain cancer. Those efforts have been bolstered by investments from drug makers like Moderna as well as hospitals like Memorial Sloan Kettering Cancer Center, which in 2024 established a center dedicated to designing, producing and administering cancer vaccines on site. This year, the federal government also announced a $200 million public-private partnership to advance these vaccines.

There is still reason for skepticism. It’s unclear, for example, whether other cancers will respond to this approach as favorably as melanoma, a cancer that is easier to target with, and particularly responsive to, therapies that harness the immune system.