Checkpoint Inhibitor Therapy

Checkpoint inhibitor therapy is a form of cancer immunotherapy that targets immune checkpoints, the key regulators of the immune system that, when stimulated, can dampen the body's response to an immunologic threat. Some cancers protect themselves from immune attack by activating these inhibitory checkpoints, and checkpoint inhibitor drugs work by blocking that activation, restoring the immune system's ability to recognize and attack the tumor. The first anti-cancer drug to target an immune checkpoint was ipilimumab, a CTLA-4 blocker approved in the United States in 2011, and currently approved checkpoint inhibitors target the molecules CTLA-4, PD-1 and related pathways.