Personalized mRNA Cancer Vaccines Offer New Hope

Every year, more than 2 million people in the United States are diagnosed with cancer. Many scientists believe a new kind of vaccine could help fight the disease. These vaccines use mRNA technology — the same science behind the COVID-19 shots — to teach the body's immune system to attack cancer cells. Researchers say the early results are exciting, and the treatments could one day help millions of patients.

Two major drug companies, Moderna and Merck, are leading the way. Their treatment combines a powerful medicine that helps the immune system fight disease with a custom-made mRNA cancer vaccine. Studies on the treatment have shown that it can direct the immune system to find and attack specific mutations, or changes, in cancer cells. A mutation is a small change in the DNA of a cell that can cause it to become cancerous.

Dr. Ryan Sullivan is a cancer expert at Mass General Brigham Cancer Institute. He explained that these vaccines are made just for one patient at a time. 'Personalized cancer vaccines are individualized therapies that train a patient's immune system to recognize and kill cancer cells,' he said. He added that the results so far give real hope to people with melanoma, which is a type of skin cancer. Scientists are also working on vaccines for lung, breast, pancreatic, brain, and other cancers.

So how does an mRNA cancer vaccine actually work? Think of it like a 'wanted poster' for your body. The vaccine gives your immune system a picture of the cancer cell so it knows what to look for. Then your immune system hunts down those cancer cells and destroys them, while leaving healthy cells alone. One study found that the vaccine kept melanoma from coming back for five full years.

Researchers have looked closely at three types of cancer in major studies. In patients with melanoma, the vaccine reduced the chance of the cancer coming back or spreading. In pancreatic cancer patients, the vaccine helped create special immune cells called T cells, which are linked to longer periods without cancer. In brain cancer patients, early results showed the vaccine helped wake up the immune system to fight very dangerous tumors.

The results of these trials are very encouraging. In one study, patients with a high risk of melanoma returning were given both the vaccine and immunotherapy. Those patients had less cancer spread and fewer cases of the cancer coming back, compared to patients who did not get the vaccine. Dr. Sullivan said these results give hope not just to melanoma patients but also to the wider field of cancer research.

Scientists have run more than 120 clinical trials for mRNA cancer vaccines since the early 2000s. Researchers are finding better ways to identify targets in tumors so the immune system can recognize and destroy them. They are also looking at combining cancer vaccines with other treatments to make the body's response even stronger. The American Cancer Society says this area of science is moving fast.

There are some challenges ahead, though. Last year, federal funding for mRNA technology was cut by $500 million, which could slow some research. Even with strong results, bringing a new vaccine all the way from the lab to the public can take 10 to 15 years. Still, scientists and doctors remain hopeful that these vaccines could one day change how cancer is treated for millions of people.