Used in the treatment of various cancers, particularly non-small cell lung cancer and melanoma, by enhancing the body's immune response against tumor cells. It works by blocking the PD-1 receptor on T-cells, preventing cancer cells from evading immune detection. This antibody helps restore T-cell activation and proliferation, leading to improved tumor cell killing. It is administered intravenously and is often used when other treatments have failed or in combination with other immunotherapies. Clinical trials continue to explore its effectiveness in additional cancer types and settings.