By Gary Simmons, DO, MSHA
As CAR T-cell therapy continues to evolve as a novel treatment for various types of cancers, an awareness of both its promise and potential toxicities is important for physicians of all specialties.
Formally known as chimeric antigen receptor T cell therapy, this treatment uses laboratory-engineered T cells to target specific proteins on cancer cells. The process requires removing T cells from a patient’s blood, reprogramming them and infusing them back into the body to bind to cancer cells and kill them without damaging healthy cells.
Currently, CAR T-cell therapy is FDA-approved for diffuse large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, multiple myeloma, and B-cell acute lymphoblastic leukemia (ALL) for adults and children.
One remarkable aspect of this form of immunotherapy is that when successful, it can lead to long-lasting remissions, even in patients with very advanced disease. In most of the cancers cited above, the complete response rate for indicated patients is 40 to 50 percent with T-cell infusions, compared to less than 10 percent without them.
Additionally, clinical trials are ongoing to judge CAR T’s efficacy in treating multiple solid malignancies, including neuroblastoma and other brain cancers, ovarian and breast cancer. Several of those trials should be available to local patients in the fall.
While not enough data has yet been collected to predict benefits, early results have been promising. Therefore, the expansion of CAR T-cell therapy and products seems certain to occur in the near future, nationally and at more practices in Hampton Roads.
Furthermore, CAR T-cell therapy is moving up the treatment algorithm for liquid tumors. In many cases, medical oncologists now offer it earlier in a patient’s treatment course, no longer considering it a last resort after chemotherapy and radiation have failed.
All that said, CAR T-cell therapy can put patients at higher risk for serious short and long-term health issues. Therefore, physicians outside oncology practices will be tasked with diagnosing and treating complications in patients seen on hospital rounds or in office settings.
Producing an anti-cancer immune reaction can trigger a systemic inflammatory response, most commonly cytokine release syndrome (CRS). The severity and length of CRS can vary widely, with side effects ranging from mild flu-like symptoms to multiorgan failure.
Adverse cardiovascular events may include sinus tachycardia, hypotension, arrhythmias and reduced ejection fractions. Neurologic symptoms such as confusion, tremors, speech problems, seizures and even coma also can occur in CAR T-cell patients, as can bacterial, viral and fungal infections linked to immunosuppression.
Although researchers are working to remodel the CAR T-cell process to reduce such complications, providers should be prepared to recognize them and collaborate with a patient’s oncology team as needed.
Together, we can give patients the greatest chance of a return to health as we embrace this innovative approach to fighting cancer.
Dr. Simmons is a specialist in Medical Oncology, Hematology, and Transplant and Cellular Therapy with Virginia Oncology Associates, based at the Brock Cancer Center in Norfolk. virginiacancer.com