Merck's lambrolizumab (MK-3475) has been designated by the the FDA as a Breakthrough Therapy for the 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 other tumor types. This designation is intended to expedite the development and review of a candidate that is planned for use 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.