The purpose of this study is to demonstrate that virologically controlled HIV-infected individuals can successfully switch from a protease inhibitor (PI)-based regimen to an efavirenz-based regimen while maintaining virologic control, as evaluated by the proportion of subjects who continue to have plasma HIV-1 levels < 50 copies/mL. In addition, a simplified once-daily regimen will improve adherence and quality of life.

Patients randomized to the non Videx enteric coated (ddl EC)+lamivudine (3TC)+efavirenz (EFV) arm would continue their baseline nucleoside reverse transcriptase inhibitors (NRTIs) on study.

Inclusion Criteria:

• Documented HIV infection
• ≥ 18 years of age and weight at least 40kg
• Two plasma HIV RNA levels < 50 copies/mL during the qualification and screening period
• Patients receiving a PI and ≥ 2 NRTIs

Exclusion Criteria:

• Pregnancy or breastfeeding
• Documented virologic failure while on their first PI-based antiretroviral (ARV) regimen
• Active AIDS-defining opportunistic infection or disease
• Proven or suspected acute hepatitis within 30 days prior to study entry