What medication increases T-cell activation by blocking PD-1 receptors?

Pembrolizumab (Keytruda) is a monoclonal antibody that specifically targets the programmed cell death protein 1 (PD-1) receptor on T-cells. By blocking this receptor, pembrolizumab enhances T-cell activation and promotes an immune response against cancer cells. The PD-1 pathway is a crucial mechanism that tumors use to evade the immune system; by inhibiting this pathway, pembrolizumab allows T-cells to remain active and effectively attack cancer cells.

This mechanism is particularly important in the treatment of various cancers, including melanoma, lung cancer, and other malignancies, where the immune response can be critical in controlling tumor growth and progression. Immunotherapies like pembrolizumab have revolutionized cancer treatment by utilizing the body's own immune system to fight cancer more effectively.

In contrast, the other medications listed do not have a direct action on T-cell activation through PD-1 blockade. Trastuzumab is primarily used to target the HER2 protein in certain breast cancers, Rituximab targets the CD20 antigen on B-cells for the treatment of specific lymphomas, and Bevacizumab is an angiogenesis inhibitor that targets VEGF to inhibit blood vessel growth in tumors. None of these