Used in the treatment of certain types of cancer, particularly classical Hodgkin lymphoma and non-small cell lung cancer. It works by enhancing the body's immune response against cancer cells by blocking the PD-1 receptor, which cancer cells often exploit to evade detection. This allows T-cells to recognize and destroy tumor cells more effectively. Administered intravenously, it is part of immunotherapy regimens, especially in patients who have relapsed or are refractory to standard treatments. Ongoing studies explore its use in other solid tumors and combination therapies with chemotherapy or other immune checkpoint inhibitors.