- Serious medical disease, such as severe liver or kidney disease, uncompensated congestive heart failure, myocardial infarction within six months, unstable angina, uncontrolled hypertension, severe pulmonary disease or uncontrolled asthma, demyelinating neurological disease, history of cancer (other than cutaneous basal and squamous cell carcinoma) with less than five years documentation of a disease-free state, insulin-dependent diabetes, recurrent opportunistic infections or other concurrent medical condition that, in the opinion of the investigator, would make the subject unsuitable for the study.