Myeloma cells display a promising target for immunotherapy called B-cell maturation antigen (BCMA), which is found in 60 to 70 percent of multiple myeloma patients. So a new potentially successful bispecific antibody therapy might, for example, have one arm that binds to myeloma cells via BCMA and another that binds to T-cells, one of the immune system’s top cancer assassins. While typical antibodies that bind to just one target also recruit immune cells, they generally do not specifically bring in T-cells. A bispecific antibody with this ability is expected to have greater cancer-killing effects than conventional antibodies.
BCMA is also used in another immunotherapy approach for myeloma called chimeric antigen receptor T-cells (CAR T) therapy. In this strategy, a patient’s T-cells are extracted, engineered in the lab to recognize and bind to BCMA, and then placed back into the patient. The goal is for CAR T-cells to home in on and destroy myeloma cells.
CAR T-cells and bispecific antibodies as single agents may offer new hope to patients with myeloma, but they also may provide the opportunity for new combinations with other novel targeted therapies under investigation. Ultimately, the aim with both tactics, alone or in combination, is to cure myeloma, a goal that seems more and more possible with every scientific advance.