To compare the effectiveness (efficacy, safety & tolerability) of a Single Tablet Regimen of efavirenz/emtricitabine/tenofovir DF to subjects continuing on unmodified HAART as measured by the proportion of patients who maintain viral load (HIV-1 RNA) <200 copies/mL at Week 48.

Inclusion Criteria:

• HIV-1 positive patients who have maintained an HIV-1 viral load <200 copies/mL, for at least 3 months.

• Patients must be on their first HAART or have documented viral suppression on a PI-based regimen at the time of any prior change in therapy.

• HAART must consist of either:

  1. A PI (with or without ritonavir) + at least 2 NRTIs or
  2. An NNRTI + at least 2 NRTIs.

• Negative serum pregnancy test.

Exclusion Criteria:

• Patients who have taken any NNRTI prior to their current therapy.
• Patients who have taken a NRTI-only therapy for greater than 7 days prior to their current therapy.
• Patients who are currently taking EFV+FTC+TDF.
• Patients who have a creatinine clearance of <60 mL/min by Cockcroft-Gault estimation.
• Patients who have experienced virologic failure with any previous ARV therapy.
• Patients who have documented resistance to any of the study agents at any time in the past.