Pembrolizumab is a humanized antibody used in cancer immunotherapy.
Sold by Merck under the trade name Keytruda, pembrolizumab is an anti–PD-1 antibody (PD-1 is the programmed cell death 1 receptor) first approved in 2014 by the U.S. Food and Drug Administration to treat patients with advanced melanoma that has not responded to standard therapies.Wikipedia
In 2015, the FDA approved pembrolizumab for the treatment of metastatic non-small cell lung cancer (NSCLC) in patients whose tumors express PD-L1 and who have failed treatment with other chemotherapeutic agents. Pembrolizumab was priced at $150,000 per year when it launched.Wikipedia
As of early 2016, several Phase I and/or II trials utilizing pembrolizumab to treat advanced cancers were underway. According to Merck, the pembrolizumab clinical development program includes more than 30 tumor types in more than 270 clinical trials, including more than 100 trials combining it with other cancer treatments.news article
One of the ongoing Phase II trials reported at a 2015 conference that an overall response rate of 60% was observed in patients with mismatch repair–deficient cancers.ASCO abstract