2. No previous treatment with potent combination anti-retroviral therapy (ART), defined as any protease inhibitor (PI)-based or non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen, or even triple nucleoside reverse transcriptase inhibitors (NRTI)-based regimen, consisting of at least three antiretroviral drugs (including a boosted PI with NNRTI combination). Patients with limited use of ART (less than 12 weeks duration) more than 24 weeks before screening will be eligible for study participation.