Yervoy, also known as Ipilimumab, is a monoclonal antibody drug that is used to treat certain types of cancer, including melanoma and advanced renal cell carcinoma. It works by targeting and blocking a protein called CTLA-4, which is found on the surface of T cells, a type of immune cell that plays a critical role in the body's immune response [1]. By blocking CTLA-4, Yervoy enhances the activity of T cells, allowing them to recognize and attack cancer cells more effectively [2].

CTLA-4 is a protein that is involved in regulating the immune response. It acts as a brake on T cells, preventing them from becoming overactive and attacking healthy cells in the body. However, in cancer patients, CTLA-4 can also prevent T cells from recognizing and attacking cancer cells. By blocking CTLA-4, Yervoy releases this brake and allows T cells to become more active, which can help them recognize and attack cancer cells [3].

Yervoy is typically administered intravenously, and the treatment can cause side effects, including fatigue, diarrhea, and skin rash. More serious side effects can also occur, including autoimmune reactions that can affect the skin, liver, and other organs [1].

In conclusion, Yervoy works by blocking CTLA-4, a protein that regulates the immune response, to enhance the activity of T cells and help them recognize and attack cancer cells more effectively. However, it can also cause side effects, including autoimmune reactions.

Sources:
[1] https://www.drugpatentwatch.com/p/biologics/tradename/YERVOY
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3011989/
[3] https://www.opdivo.com/about-opdivo/how-opdivo-works-monotherapy