Nivolumab is a type of immunotherapy that is used in the treatment of various types of cancer. It belongs to a class of drugs known as immune checkpoint inhibitors, which work by blocking a protein called PD-1 on immune cells, allowing the immune system to better recognize and attack cancer cells. Nivolumab has been approved for the treatment of several types of cancer, including melanoma, non-small cell lung cancer, kidney cancer, and Hodgkin lymphoma. Research on nivolumab continues to explore its effectiveness in different types of cancer and in combination with other treatments.