Ipilimumab is primarily used in the treatment of advanced melanoma, a type of skin cancer. It works by enhancing the immune system's ability to attack cancer cells. This drug is often administered in cases where the cancer has spread or cannot be surgically removed. It may also be used in combination with other therapies, such as nivolumab, to improve treatment outcomes. Additionally, ipilimumab is being investigated for its potential in treating other types of cancers, including lung cancer and renal cell carcinoma. Its application is closely monitored due to potential immune-related side effects, which require careful management by healthcare professionals.