6. Patients with a history of Human Immunodeficiency Virus (HIV) Hepatitis B (HBV) or hepatitis C (HCV) infection. All patients must be screened for HIV, HBV and HCV up to 28 days prior to first dosing using the routine virus laboratorial panel. Patients who are positive for HBs Ag or HBc Ab will be eligible if they are negative for HBV-DNA. Patients who are positive for anti-HCV antibody will be eligible if they are negative for HCV-RNA