FDA approves first use of novel immune system drug for cancer

This new class of drugs unleashes the body's immune system to fight tumors. This seems to solve a century-old mystery of how cancerous cells manage to evade the body's immune system. The drug which Merck will sell under the name of Keytruda was approved by patients with advanced melanoma who have exhausted other therapies. 

http://www.nytimes.com/2014/09/05/business/merck-wins-approval-of-novel-immune-system-drug-for-cancer.html?emc=eta1