Switching Undetectables to Selzentry

The objective of the study is to determine if regimen tolerability/toxicity can be maintained or improved while maintaining virologic suppression following a switch to once-daily Selzentry®. The study duration is 48 weeks. Patients must have an HIV-1 RNA \<100 copies/mL for ≥3 months on their first HIV treatment regimen. Prior regimen modifications for reasons other than virologic failure are acceptable if any previously achieved virologic suppression has been maintained. A Trofile® DNA will be used to document exclusive CCR5 tropism. Patients with history of dual/mixed or CXCR4-tropic HIV-1 are excluded from participation. Patients with prior exposure to Selzentry® are also excluded. Patients that qualify for participation will discontinue the PI, NNRTI, or Integrase inhibitor portion of their regimen and begin Selzentry® 600mg QD. Patients will continue the two (2) NRTIs from the previous treatment regimen. The primary endpoints is: the percentage of HIV positive patients with undetectable viral load (HIV-1 RNA \<100 copies/mL) at Week 24. Secondary endpoints are: the safety and tolerability of once-daily Selzentry® through Weeks 24 and 48(as measured by clinical and laboratory adverse events and regimen satisfaction questionnaire), the percentage of HIV positive patients with undetectable viral load (HIV-1 RNA \< 100 copies/mL) at Week 48, the change from baseline in CD4+ T-cell counts at Weeks 24 and 48, the change from baseline in inflammatory markers (C-reactive protein) at Weeks 24 and 48, and assessment of resistance-associated mutations or viral tropism changes from baseline, if any, emerging at virologic failure.