Which mechanism does Nivolumab utilize as a checkpoint inhibitor?

Nivolumab functions as a checkpoint inhibitor by targeting the PD-1 (programmed cell death protein 1) receptor on T cells. By blocking PD-1, Nivolumab prevents its interaction with PD-L1 and PD-L2, which are ligands that can negatively regulate T cell activation and proliferation. In cancers, this PD-1 pathway is often exploited by tumor cells to evade immune detection and destruction.

By inhibiting PD-1, Nivolumab enhances the immune response against cancer cells, allowing T cells to remain active and increase their ability to attack tumors. This mechanism of action is pivotal in improving the body's immune response in patients with various types of cancers, thereby leading to better clinical outcomes. Understanding this mechanism is essential for grasping how immunotherapy can be employed effectively in cancer treatment.