- Target Disease Exceptions 1. Patients with untreated, symptomatic CNS metastases are excluded. Participants are eligible if CNS metastases are adequately treated and participants are neurologically returned to baseline (except for residual signs or symptoms related to the CNS treatment) for at least 2 weeks prior to treatment assignment. In addition, participants must be either off corticosteroids, or on a stable or decreasing dose of <=10 mg daily prednisone (or equivalent) for at least 2 weeks prior to treatment. 2. Patients with carcinomatous meningitis are excluded. - Physical and Laboratory Test Findings 1. Known history of testing positive for human immunodeficiency virus (HIV) or known acquired immunodeficiency syndrome (AIDS). 2. Any positive test for hepatitis B virus or hepatitis C virus indicating acute or chronic infection. - Allergies and Adverse Drug Reactions a) History of severe hypersensitivity reactions to other monoclonal antibodies - Medical History and Concurrent Diseases 1. Patients with active, known or suspected autoimmune disease. 2. Patients with a condition requiring systemic treatment with either corticosteroids (> 10 mg daily prednisone equivalent) or other immunosuppressive medications within 14 days of the first dose of study drug administration. Inhaled or topical steroids and adrenal replacement steroid doses > 10 mg daily prednisone or equivalent are permitted in the absence of active autoimmune disease. 3. Other active malignancy requiring concurrent intervention. 4. Patients with previous malignancies (except non-melanoma skin cancers, and the following in situ cancers: bladder, gastric, colon, endometrial, cervical/dysplasia, melanoma or breast) are excluded unless a complete remission was achieved at least 2 years prior to study entry AND no additional therapy is required during the study period. 5. Any serious or uncontrolled medical disorder or active infection that, in the opinion of the investigator, may increase the risk associated with study participation, study drug administration, or would impair the ability of the patient to receive protocol therapy. 6. All toxicities attributed to prior anti-cancer therapy other than alopecia and fatigue not resolved to Grade 1 (NCI CTCAE version 4.03) or baseline before administration of study drug. 7. Patients who have not recovered from the effects of major surgery or significant traumatic injury at least 14 days before the first dose of study treatment. 8. Known alcohol or drug abuse. 9. Patients who have received prior therapy with anti-PD-1, anti-PD-L1, anti-PD-L2, anti- CD137, or anti-CTLA-4 antibody (including ipilimumab or any other antibody or drug specifically targeting T-cell co-stimulation or checkpoint pathways) or who have previously taken part in a randomised Bristol Myers Squibb (BMS) clinical trial for nivolumab or ipilimumab including study CA209-743 (CheckMate 172) or in the CCTG trial of pembrolizumab (IND.227).