Merck said the drug received breakthrough status as a treatment for advanced melanoma. Merck recently started a mid-stage clinical trial of lambrolizumab and said it is also studying the drug as a treatment for other types of cancer. The company said the drug is designed to use the immune system to fight cancer.
The FDA created the breakthrough therapy program in 2012 as a way to speed up the approval process for drugs that could be significant improvements in the treatment of serious or life-threatening diseases from what's currently on the market.
Shares of Merck lost 50 cents to $48.13 in afternoon trading.