Immunotherapy refers to treatments that use the body’s own immune system to combat diseases. While no immunotherapy drugs are currently approved for breast cancer, clinical trials at Dana-Farber and elsewhere are exploring the effectiveness of these drugs — and whether they could work in combination with other cancer therapies.
“I think we’re going to make a lot of progress over the next five years,” Ian E. Krop, MD, PhD, Chief of Breast Medical Oncology in the Susan F. Smith Center for Women’s Cancers at Dana-Farber, said in a recent Facebook Live chat. “My colleagues and I, who are leading clinical trials on immunotherapy for breast cancer, are very hopeful that these therapies are going to improve the way we treat breast cancer.”
The immune system can help protect against cancer, but cancer has evolved an array of escape mechanisms. Immune checkpoint inhibitors are drugs, often made of antibodies, that overcome one of cancer’s main defenses against an immune system attack, and unleash an immune system attack on cancer cells. These drugs have been approved for treatment in certain patients with melanoma, non-small cell lung cancer, and other cancers — but not yet for breast cancer. Still, researchers are optimistic about the future of immunotherapy in treating breast cancer, particularly in combination with other cancer therapies.
Right now, using immunotherapies alone in breast cancer – particularly checkpoint inhibitors – show benefits only in a small minority of breast cancer patients, so it appears that the immune system needs to be stimulated even further or needs help in recognizing breast cancer cells, Krop said. He noted that clinical trials at Dana-Farber are currently exploring the effectiveness of combination therapy — with chemotherapy, plus a checkpoint inhibitor — in patients with early stage, pre-operative breast cancer, as well as patients with metastatic breast cancer. Another trial is exploring the combination of radiation and a checkpoint inhibitor.
Researchers are also continuing to investigate why some patients respond to immunotherapy, and others don’t. It appears that the more recognizable the cancer cells are to the immune system, the more effective the treatment will be. Clinical trial data also show that if a cancer is filled with immune cells, it is more likely to be vulnerable to a checkpoint inhibitor, according to Krop – who still emphasized that researchers need to do more studies.
“Over the next five years, we’re going to find better ways to use the current generation of immunotherapies ,” Krop said. “And we’ll start looking at the new immunotherapies in the pipeline – either by themselves, or in combination with therapies we already have.”
Learn more by viewing a recording of Krop’s Facebook Live below: