Comparison Atazanavir/Ritonavir (ATV/r) vs Nevirapine (NVP) Twice a Day (Bid) on Truvada Backbone

Inclusion criteria:

1. Signed informed consent in accordance with Good Clinical Practice (GCP) and local regulatory requirements prior to trial participation

2. HIV-1- infected males or females greater than or equal to 18 years of age with documented positive serology Enzyme-linked Immuno Sorbert Assay (ELISA) confirmed by Western blot

3. No prior nucleoside reverse transcriptase inhibitor (NRTI) or non-nucleoside reverse transcriptase inhibitor (NNRTI) use of more than 10 days AND

4. No prior use of other classes of antiretrovirals (ARVs) of more than 2 weeks duration

5. Males with CD4+ count less than 400 cells/mm cubed or females with CD4+ count less than 250 cells/mm cubed

6. NVP and ATV/r susceptibility on screening HIV-1 genotypic resistance assay

7. Adequate renal function defined as a calculated creatinine clearance greater than or equal to50 ml/min according to the Cockcroft-Gault formula

8. Karnofsky score greater than or equal to 70 (see Appendix 10.7)

9. Acceptable medical history, as assessed by the investigator

Exclusion criteria:

1. History of active drug or alcohol abuse within 2 years prior to study entry (at the investigators discretion)

2. Hepatic cirrhosis with stage Child-Pugh B or C hepatic impairment

3. Female patients of child-bearing potential who:

have a positive serum pregnancy test at screening, are breast feeding, are planning to become pregnant, are not willing to use a barrier method of contraception, or are not willing to use methods of contraception other than ethinyl estradiol containing oral contraceptives

4. Laboratory parameters greater than Division of Aids (National Institute of Health, USA) (DAIDS) grade 2 (triglycerides greater than DAIDS grade 3, total cholesterol no restrictions, see Appendix 10.1)

5. Active hepatitis B or C disease, defined as HBsAg-positive or Hepatitis C Virus (HCV) RNA positive with alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ALT/AST greater than2.5x Upper Limit of Normal (ULN) (greater than DAIDS grade 1)

6. Known hypersensitivity to any ingredients in nevirapine or atazanavir

7. Patients who are receiving concomitant treatments which are not permitted, as listed in Appendix 10.6

8. Use of other investigational medications within 30 days before study entry or during the trial

9. Use of immunomodulatory drugs within 30 days before study entry or during the trial (e.g., interferon, cyclosporin, hydroxyurea, interleukin 2, chronic treatment with prednisone)

10. Patients with Progressive Multifocal Leukoencephalopathy (PML), visceral Kaposi's Sarcoma (KS), and/or any lymphoma

11. Any AIDS defining illness that is unresolved, symptomatic or not stable on treatment for at least 12 weeks at the screening visit

12. Patients who are receiving systemic chemotherapy