Subjects will be randomized in a 2:1 ratio to one of the two treatment groups. The safety of each treatment group will be assessed by evaluating study drug exposure, adverse events, serious adverse events, all deaths, changes in laboratory determinations and vital sign parameters. Progression -Free Survival (PFS) using Response Evaluation Criteria in Solid Tumors (RECIST) (version 1.1) will be assessed as well as Overall Survival (OS) and the Objective Response Rate (ORR). Study visits will be conducted according to the protocol schedule. Study visits will include physical examination, laboratory blood sample collection, and assessment of vital signs, medical history and urinalysis. 12-lead Electrocardiogram (ECG) will be performed at protocol specified visits.