Merck & Co. received breakthrough therapy designation from the US Food and Drug Administration for its lambrolizumab drug as a treatment of patients with advanced melanoma. Lambrolizumab is Merck's investigational antibody therapy targeting Programmed Death receptor that is currently being evaluated for the treatment of patients with advanced melanoma and nonsmall cell lung cancer. Lambrolizumab disrupts the action of the immune checkpoint protein PD-1 and inhibits the ability of some cancers to evade the immune system. The designation of an investigational drug as a breakthrough therapy is intended to expedite the development and review of a candidate that is planned for use, alone or in combination, to treat a serious or life-threatening disease or condition when preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints.