Symptomatic congestive heart failure of New York heart Association Class III or IV Unstable angina pectoris, myocardial infarction within 6 months of start of study drug, Serious uncontrolled cardiac arrhythmia or any other clinically significant cardiac disease Severely impaired lung function Uncontrolled diabetes as defined by fasting serum glucose >1.5 x ULN Active (acute or chronic) or uncontrolled severe infections Liver disease such as cirrhosis, chronic active hepatitis or chronic persistent hepatitis A known history of HIV seropositivity.