Dr. Joseph Baar is doubling down in an attempt to develop a breast cancer vaccine. While previous attempts have failed because cancer cells have developed ways to evade regular immune cells, the University Hospitals Seidman Cancer Center doctor is the first to study a combined immunotherapy and chemotherapy approach for breast cancer. Baar’s vaccine for select metastatic breast cancer patients helps generate disease-fighting T cells that target the tumor blood supply in an attempt to shrink the tumor. Here are a few things to know about Baar’s study, which is currently enrolling patients.
Therapy Session: The vaccine targets the source of the tumor growth, since targeting the tumor itself previously had little success. “Essentially what we are trying to do with the vaccine is to train the immune system not to attack cancer cells themselves, but rather the blood vessels that feed the cancer cells,” says Baar, a breast cancer medical oncologist. “They die because they’re eventually starved of their blood supply.”
Match Game: The vaccine is only a fit for women with metastatic breast cancer and the approximately 40 to 50 percent of women with the HLA-A2 protein. Researchers use the patient’s blood to make the vaccine, and the patient is given six doses of a milder form of chemotherapy to get rid of suppressor cells that blunt the immune response. “[We’re] getting rid of these suppressor cells that have in the past prevented these vaccines from working,” he says.
Immunity Idol: After the chemotherapy has already cleared the body of the suppressor cells that dampen immunity, Baar’s team injects the patient with the vaccine twice, one week apart to activate a stronger immune response. “We’re getting more and more evidence that the immune system is important in controlling cancer,” says Baar. “It’s a novel approach to try to control breast cancer.”
