Keytruda, a medication developed by Merck & Co., received its first approval from the U.S. Food and Drug Administration (FDA) for cancer therapy in September 2014 [1]. This approval was specifically for the treatment of advanced melanoma in patients whose disease progressed after other treatments [1]. Since then, Keytruda has received additional FDA approvals for various types of cancers, including lung, head and neck, classical Hodgkin lymphoma, microsatellite instability-high (MSI-H) cancer, and colorectal cancer [1].

Keytruda, also known as pembrolizumab, is a type of drug called a programmed death receptor-1 (PD-1) blocking antibody [1]. PD-1 is a protein on the surface of T cells, which are a type of white blood cell that is important in the body's immune response [1]. PD-1 helps keep the immune system from attacking normal cells in the body [1]. Keytruda works by blocking PD-1, which helps the immune system recognize and attack cancer cells [1].

It is important to note that while Keytruda has been approved for use in certain types of cancer, it may not be appropriate for all patients [1]. The decision to use Keytruda should be made by a healthcare professional based on the individual patient's circumstances [1].

Sources:
[1] DrugPatentWatch.com. (n.d.). Keytruda. Retrieved from <https://www.drugpatentwatch.com/drugs/keytruda>.