Nivolumab is a medication used in cancer treatment, specifically as an immunotherapy. It works by blocking a protein called PD-1 on the surface of immune cells, which helps the immune system recognize and attack cancer cells more effectively. Nivolumab is commonly used for various types of cancer, including melanoma, lung cancer, and kidney cancer. This drug is administered through an intravenous infusion, typically in a healthcare setting. Patients may receive Nivolumab alone or in combination with other treatments, such as ipilimumab, to enhance its effectiveness. Side effects can include fatigue, rash, and immune-related reactions, which require monitoring by healthcare professionals.