Keytruda, a drug manufactured by Merck & Co., received approval from the U.S. Food and Drug Administration (FDA) for cancer therapy in 2014. The FDA initially approved Keytruda for the treatment of advanced melanoma in patients whose disease had progressed after other treatments. Keytruda is a type of immunotherapy, which helps the body's immune system fight cancer.

The FDA has since expanded Keytruda's approval to include the treatment of several other types of cancer, such as lung, head and neck, classical Hodgkin lymphoma, urothelial carcinoma, and microsatellite instability-high (MSI-H) cancer.

Sources:

1. U.S. Food and Drug Administration. (2021). Keytruda. <https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/keytruda-pembrolizumab-information>.
2. DrugPatentWatch. (2021). Keytruda (pembrolizumab) Patent, BLA, and FDA Approval History. <https://www.drugpatentwatch.com/drugs/keytruda>.