• Virologic failure, defined as 2 consecutive viral load measurements of 200 copies/ml or greater, at or before Week 30 (24 weeks on ATV/RTV alone)
  

• Grade 3 and 4 laboratory abnormalities and signs and symptoms
  
• time to treatment discontinuation because of toxicity or intolerance
  
• virologic failure at or before Week 54
  
• viral load determined by modified ultrasensitive RT-PCR assay
  
• minor PI variants at virologic failure
  
• total cholesterol, high-density lipoprotein (HDL) cholesterol, calculated low-density lipoprotein (LDL) cholesterol, and triglycerides
  
• CD4 cell count and percentages at Weeks 30 and 54
  
• self-reported adherence scores
  
• plasma drug levels characterized by Cmin and AUC
  
• detectable viral load in the genital compartment at Week 30
  

The expense, difficulty, and long-term adverse events associated with sustained adherence to combination antiretroviral therapy emphasize the need for simpler, alternative treatment strategies for HIV infection. Studies have shown that single protease inhibitor (PI) maintenance therapy may provide sufficient virologic suppression while reducing the risk of nucleoside reverse transcriptase inhibitor (NRTI)-associated metabolic complications. However, it is not known whether ritonavir-boosted atazanavir (ATV/RTV) maintenance therapy would be effective in controlling HIV replication in the genital compartments and whether viral load testing by blood collection would be effective in detecting elevated levels of HIV in the genital compartments. This study will determine whether simplified maintenance therapy with ATV/RTV after 48-week virologic suppression will increase the likelihood of virologic failure.

This study will last 54 weeks. Participants will undergo an electrocardiogram (EKG) at screening. At study start, participants will switch from their current PIs to ATV/RTV and stay on their current NRTIs until Week 6, when they will discontinue their NRTIs and remain on a maintenance regimen of ATV/RTV alone for the duration of the study. Study visits will take place at Weeks 3 and 6, then every 4 weeks until Week 30, then every 8 weeks until the end of the study at Week 54. Medication assessment, physical exam, and blood work will occur at each study visit. At Week 30, viral load will be measured in the genital secretions of both male and female study participants.