• The immunologic effects from baseline at the 48th and 144th week [ Time Frame: 144 weeks ] [ Designated as safety issue: Yes ]
• Reasons of treatment failure by 144th week [ Time Frame: 144 weeks ] [ Designated as safety issue: Yes ]
• Adverse events and their rate of incidence by 144th week [ Time Frame: 144 weeks ] [ Designated as safety issue: Yes ]

• The immunologic effects from baseline at the 48th and 144th week [ Time Frame: 144 weeks ]
• Reasons of treatment failure by 144th week [ Time Frame: 144 weeks ]
• Adverse events and their rate of incidence by 144th week [ Time Frame: 144 weeks ]

A non-inferiority randomized control trial in treatment naïve HIV patients to compare virologic effect of two backbone regimens with Epzicom (lamivudine and abacavir) and Truvada (emtricitabine and tenofovir). Both arms are treated with fixed combination of ritonavir boosted atazanavir as key drugs.

In treatment naïve HIV-1-infected patients, once daily combination antiretroviral therapy containing ritonavir boosted atazanavir combined with Epzicom will offer non inferior antiretroviral efficacy compared to ritonavir boosted atazanavir combined with Truvada. This non inferiority hypothesis is studied by a randomized, open label, multicenter trial over 48 weeks as the primary endpoint and long term safety of both arms are followed for 144 weeks.

The primary endpoint is the antiretroviral effect over 48 weeks.

The secondary endpoints are;

1. The immunologic effects from baseline at the 48th and 144th week
2. Reasons of treatment failure by 144th week
3. Adverse events and their rate of incidence by 144th week
4. Serum concentration of tenofovir in selected patients
5. Serum concentration of atazanavir in selected patients
6. Renal complication in tenofovir arm

• Drug: lamivudine, abacavir , ritonavir, atazanavir
• Drug: emtricitabine, tenofovir, ritonavir, atazanavir

• Active Comparator: Patients are treated with Epzicom (lamivudine 300mg and abacavir 600mg) combined with ritonavir 100mg boosted atazanavir 300mg
• Active Comparator: Patients are treated with Truvada (emtricitabine 200mg and tenofovir 300mg) combined with ritonavir 100mg boosted atazanavir 300mg

Inclusion Criteria:

• Clinical diagnosis of HIV infection,
• Antiretroviral initiation is recommended by current clinical guidelines,
• Treatment naïve,
• Age over 20 years old Japanese,
• Able to obtain written informed consent

Exclusion Criteria:

• Current malabsorption condition,
• Prior use of lamivudine for hepatitis B treatment,
• Positive serology of Hepatitis B surface antigen,

• Patients who have following abnormal laboratory results within 6 weeks prior enrollment;

  1. alanine aminotransferase is more than 2.5 times higher of upper normal limit
  2. estimated glomerular filtration rate is less than 60ml/min by Cockcroft-Gault equation
  3. serum phosphate level is less than 2.0mg/dl
• Patients with hemophilia, diabetes mellitus which require pharmacological treatment, congestive heart failure, cardiomyopathy or other serious medical condition
• Patients in pregnancy or breat feeding
• Patients who are taking medications contraindicated combine use of study medicine
• Patients whose primary care physicians consider inadequate to be enroll the study