Keytruda, a medication produced by Merck & Co., was first approved by the U.S. Food and Drug Administration (FDA) in 2014. The FDA approved Keytruda for the treatment of advanced melanoma in September 2014 [1]. Keytruda is a type of drug known as a programmed death receptor-1 (PD-1) blocking antibody, which helps the body's immune system fight cancer cells [2].

In May 2017, the FDA expanded its approval of Keytruda to include the treatment of adult and pediatric patients with solid tumors that have specific genetic features [3]. This was the first time the FDA had approved a cancer treatment for any solid tumor with a specific genetic feature [3]. This approval was based on data from 149 patients with 12 different types of cancers, all of whom had tumors with a specific genetic feature known as microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) [3].

In summary, the FDA approved Keytruda for the first time in 2014 for the treatment of advanced melanoma, and expanded its approval in 2017 to include the treatment of solid tumors with specific genetic features.

Sources:
[1] <https://www.drugpatentwatch.com/p/biologics/tradename/KEYTRUDA>
[2] <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5679831/>
[3] <https://www.fda.gov/news-events/press-announcements/fda-approves-first-cancer-treatment-any-solid-tumor-specific-genetic-feature>