Through the development of immunotherapy, scientists are learning how to boost the body’s own immune system to identify and attack cancer cells. Currently, immunotherapy is showing successful results in about 15-20 percent of cancer patients, and researchers believe more life-saving breakthroughs are on the horizon.
“With advances in molecular and cellular biology, we’ve started developing antibodies, which are proteins that bind other proteins,” says medical oncologist Dr. Keith Wells. “The antibodies can be directed at proteins that are on the surface of cancer cells, and they can target those cells, allowing the body to eliminate them. Right now, there are hundreds of antibodies that are being used and studied in cancer treatment.”
There are two main types of immunotherapy: checkpoint inhibitors and cell therapy.
Checkpoint inhibitors block normal proteins on cancer cells, or the proteins on the T-cells that respond to them. Several checkpoint inhibitors are FDA approved to treat melanoma, Hodgkin lymphoma, as well as lung, liver, kidney and bladder cancers. Additional drugs and drug combinations are currently being studied in clinical trials.
One of the newest areas of immunotherapy is called adoptive cell transfer (ACT), which uses a patients’ own immune cells to treat their cancer.
There are several types of ACT, including CAR T-cell therapy. Doctors remove immune-boosting T-cells from a patient, engineer them to fight cancer cells and infuse them back into a patient’s body. In 2017, the FDA approved two types of CAR T-cell immunotherapy for treatment of adults with advanced lymphomas and children with acute lymphoblastic leukemia.
Side effects of immunotherapy vs. traditional treatment
Traditional cancer treatments, like chemotherapy, often damage healthy tissue along with the cancer cells and cause fatigue, nausea and other side effects. Immunotherapy is more targeted and better at sparing normal tissue. However, side effects, while usually less severe, may occur.
Since checkpoint inhibitors prevent over-activation of the immune system, they can also affect healthy cells and normal tissues and cause autoimmune disorders. Since these side effects are different from those associated with chemotherapy and tumor-targeting drugs, it’s important for patients to understand the potential risk and work with their oncologist to manage any side effects that occur.
To help educate patients, the National Comprehensive Cancer Network (NCCN) and the American Society of Clinical Oncology recently issued new guidelines on understanding and managing immunotherapy-related side effects.
Changing the treatment landscape
With the development of immunotherapy, researchers believe they have just begun to scratch the surface of what many believe is possible in cancer treatment.
Dr. Wells says the ultimate goal is to develop an arsenal of effective therapies, so that oncologists can turn a patient’s potentially life-threatening cancer diagnosis into a manageable illness.
“With the development of immunotherapy, people with many blood cancers and even some solid tumors are living years and years with their disease. We want to see more of that.”