6. Clinically relevant serious co-morbid medical conditions including, but not limited to, active infection, recent (less than or equal to six months) myocardial infarction, unstable angina, symptomatic congestive heart failure, uncontrolled hypertension, uncontrolled cardiac arrhythmias, chronic obstructive or chronic restrictive pulmonary disease, active CNS disease uncontrolled by standard of care, known positive status for human immunodeficiency virus (HIV) and/or active hepatitis B or C, cirrhosis, or psychiatric illness/social situations that would limit compliance with study requirements.