Patients with certain types of lymphoma (B cell) and leukemia have access to several effective therapies. But when these standard treatments stop working for them, patients may benefit from treatment with chimeric antigen receptor (CAR) T-cell therapy, an innovative approach to immunotherapy.
“The basic idea of CAR T immunotherapy is to train the patient’s immune system to find cancer cells and eliminate them,” said Nirav Shah, MD, hematologist/oncologist, Medical College of Wisconsin researcher and faculty member.
The first step is to remove a sample of T cells from the patient’s blood. T cells are the body’s mechanism for eliminating abnormal cells, so they are the natural enemy of cancer. The patient’s T cells are then genetically altered to express chimeric antigen receptors — special structures that recognize a specific protein on the surface of an individual’s cancer cells.
“The modified cells are called CAR T cells,” Dr. Shah said. “After the CAR T cells multiply, they are reinfused into the patient’s body, where they seek out and destroy cancer.”
Recently, Dr. Shah led a team of researchers at MCW who developed a unique CAR T cell that targets not one but two B-cell proteins. Dual-targeting could make this cell more effective at locating and destroying cancer. The new therapy is available only through a Froedtert & MCW clinical trial. Late in 2017, the first patient was treated successfully in this trial for mantle cell lymphoma.
Patients throughout the Froedtert & MCW Cancer Network have access to two CAR T options at Froedtert & MCW Froedtert Hospital. These options and others are approved by the Food and Drug Administration for clinical trials for lymphoma and myeloma. Axicabtagene ciloleucel (Yescarta®) is a CAR T-cell therapy for patients with aggressive B-cell lymphomas. Tisagenlecleucel (KYMRIAH®) is another CAR T-cell option approved for adults with aggressive B-cell lymphomas and for pediatric and young adult patients with acute lymphoblastic leukemia.
According to Walter Longo, MD, hematologist/oncologist, MCW researcher and faculty member, while CAR T-cell therapy, like other immune-based treatment, is not without potential side effects, patients are carefully managed and autoimmune reactions are addressed immediately. “Our team is trained to care for patients receiving CAR T-cell therapy,” Dr. Longo said. “For the right patient, the benefits outweigh the risks. The development of CAR T-cell therapy has led to a significant number of patients achieving lasting remission.”
Parameswaran Hari, MD, hematologist/oncologist, MCW researcher and faculty member, calls immunotherapy the most “organic” way to treat cancer.
“Many people don’t get cancer because their innate immune systems take care of abnormal cells before they become cancerous,” Dr. Hari said. “Right now, we are in the first wave of development of CAR T-cell immunotherapy, similar to where antibiotics were in the 1940s.”
Today, CAR T-cell research is focused on blood cancers like lymphoma and myeloma. But Dr. Hari believes immunotherapy will eventually expand to solid tumor malignancies such as breast and prostate cancer. He also expects it to become a first-line option for many diseases, rather than treatment used if standard options are unsuccessful.
“In the future, many patients may not need chemotherapy,” Dr. Hari said. “They might be treated with immune cell therapy right off the bat.”