Vaccines to prevent and treat breast cancer are in development right now. But how would they work? And when might they be available? For the latest, we spoke with Cesar Augusto Santa-Maria, an oncologist at Johns Hopkins Medicine, and Pavani Chalasani, division director at the GW Cancer Center. Several vaccines are being researched for different types of breast cancer. There are three kinds of breast cancer—hormone-receptor-positive, HER2-positive, and triple-negative—and most vaccine research is currently being done with HER2-positive and triple-negative, the two that are less common but more aggressive, and likelier to produce an immune response. Dozens of clinical trials have been completed, and dozens more are happening across the country right now. The “vaccines” are not vaccines in the way we’re used to understanding them­—at least not yet. Typically, we think of vaccines, such as those for infectious diseases, as tools for prevention, but vaccines can also be therapeutic—teaching the body to recognize and fight active disease. One trial that Johns Hopkins oncologist Cesar Augusto Santa-Maria is currently involved in is a therapeutic-vaccine study for patients with metastatic, or Stage IV, triple-­negative breast cancer. “It’s a really cool trial using a personalized vaccine approach,” he says. “We sequence [each individual patient’s] tumor . . . and develop a vaccine based on that.” Because that can take months, Santa-­Maria explains, patients are treated with chemotherapy to make sure the disease doesn’t progress, then given the vaccine along with immunotherapy and lighter chemotherapy. “It’s using a vaccine in a treatment setting versus a preventative setting.” As development continues, the goal is to have vaccines that can also prevent recurrence and, ultimately, prevent breast cancer entirely. We’re still several years away from having a breast-cancer vaccine that’s FDA-approved. Dr. Pavani Chalasani of the GW Cancer Center says that, optimistically, it could be five to ten years, but Santa-Maria cautions that there’s no way to predict without full trial results. In the meantime, researchers working on the vaccine trials are learning a lot. “Our understanding of how vaccines work and the different types of vaccines there are has developed more in the last few years,” says Santa-­Maria. For example, he explains, “with the Covid pandemic, we understood a little better how to use messenger RNA vaccines.” Santa-Maria says combining vaccines with other immunotherapy agents has changed the way researchers think about treatment: “How do we pair a vaccine with something to make it potentially work better?” Ultimately, says Chalasani, the goal is both to prevent breast cancer from occurring and to have a cure for it—regardless of the stage. But that will take time: “These trials, we are looking at long-term follow-­ups, long-term safety. We are looking at curing or changing the standard of care, so there’s a lot of due diligence and safety and oversight.” Other promising treatments are being developed, too. “We’re really looking at developing better, more effective, more targeted, less toxic therapies,” says Santa-Maria, for a disease that for years has been treated with traditional systemic chemotherapy and radiation.“These days,” says Chalasani, “the cool thing is what we call antibody drug conjugates.” Essentially, she explains, doctors put chemotherapy on something called a “linker,” which is attached to an antibody. The antibody then travels to a “target” cancer cell, where the linker is digested and the chemotherapy is released. Researchers are currently trying to find and identify targets for different types of cancers—for example, Chalasani says, triple-negative breast cancer has a target called TROP2, which can be attacked with this approach: “These [antibody drug conjugates] are currently approved and there are newer and more potent ones. They also come with some side effects, but they’re getting improved on.” Chalasani explains that further research and clinical trials are looking into harnessing the immune system to assist with treatments they already have. “There’s a lot going on in the immunotherapies and cellular-therapy field,” she says. “Trying to understand our immune system is a huge area [of growth] right now. I’m optimistic we’ll be able to do more there.” This article appears in the October 2024 issue of Washingtonian.The post Breast Cancer Vaccines? 4 Things You Need to Know. first appeared on Washingtonian.