When did merck co first receive approval for keytruda?

When did Merck first get approval to sell Keytruda (pembrolizumab)?

Merck first received approval for Keytruda (pembrolizumab) in the United States in September 2014. [1]

What approval was it for at the time?

The first U.S. approval for Keytruda was granted for unresectable or metastatic melanoma that had progressed after treatment with ipilimumab (Yervoy) and, if it was a BRAF V600 mutation–positive tumor, after a BRAF inhibitor. [1]

Source

[1] https://www.drugpatentwatch.com/p/Keytruda