6. Severe or unstable medical condition, such as congestive heart failure (New York Heart Association [NYHA] Class III or IV), ischemic heart disease, uncontrolled hypertension, uncontrolled diabetes mellitus, psychiatric condition, as well as an uncontrolled cardiac arrhythmia requiring medication (≥ Grade 2, according to NCI CTCAE v4.03), myocardial infarction within 6 months prior to starting study treatment, or any other significant or unstable concurrent medical illness that in the opinion of the Investigator would preclude protocol therapy