Dr. Galsky on Ipilimumab in Bladder Cancer

Matthew D. Galsky, MD, assistant professor of medicine, Department of Medicine, Division of Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, director, Genitourinary Medical Oncology, Tisch Cancer Institute at Mount Sinai Medical Center, explains the mechanism of action of ipilimumab in bladder cancer.

Ipilimumab is an antibody that blocks the immune checkpoint CTLA-4, Galsky says. In order for the immune cell to recognize an antigen, an antigen-presenting cell must present the antigen to a T cell. Glasky says this interaction leads to an immune response only when certain co-stimulatory molecules need to be engaged as well. However, if there is an interaction between CTLA-4 and the co-stimulatory molecules, there is an inactivation of T cells. Galsky says this is one of the ways that tumors evade the immune system.

Ipilimumab blocks the CTLA-4 interaction so that the T cells can become activated.