The cancer field has witnessed remarkable innovation in recent years, and advances in the development of cancer vaccines are among the most promising.

Cancer vaccines, which have been in development for decades, differ from traditional vaccines that protect against infectious diseases. They train the immune system to target specific cancer-associated antigens, which are proteins unique to cancer cells.

The vaccines are used as a treatment for patients who have already been diagnosed with cancer, and each vaccine is custom-made using neoantigens from the patient’s tumor after it is removed.

“What makes these vaccines so exciting is they are tailored to the specific cancer cells and avoid affecting our healthy cells,” says medical oncologist Alissa Marr, MD. "This leads to a really individualized, personalized approach, and also allows this therapy to be quite tolerable."

Many are now familiar with mRNA vaccines, thanks to COVID-19, but mRNA technology was initially developed to fight cancer. After years of limited success, scientists recently reached a turning point in priming the immune system to find and destroy cancer cells.

In spring 2023, results were released from a melanoma mRNA vaccine trial that combined the vaccines with immunotherapy. The likelihood of melanoma recurrence or melanoma-related death was reduced by 44% compared to immunotherapy alone.

“The results of the melanoma trial really brought this technology to the forefront,” Dr. Marr says. “It was the first time we’ve had reports of a randomized, well-designed clinical trial showing the benefit of this technology.”

While the vaccines have shown minimal side effects, one challenge they present is the time it takes to produce them. Dr. Marr calls the nine to 14 weeks it can take to create a customized vaccine their single downside.

“Because these are so individualized, the production time is longer than anyone would like,” she says.

Additional targets for mRNA vaccines include pancreatic, lung, breast, ovarian and other cancers. Dr. Marr believes, for the time being, the vaccines will continue to be used when a cancer has been removed but has a high risk of recurring.

However, scientists hope to one day use the vaccines to treat metastatic or incurable cancer and prevent cancer in people with high-risk conditions.

“The future is wide open,” Dr. Marr says. “The vaccines are very promising and exciting and provide a lot of hope going forward.”