Treatment Options for Protease Inhibitor-exposed Children

The investigators hypothesize that switching to a regimen based on efavirenz will be as effective and safe as remaining on a regimen based on Lopinavir/ritonavir for HIV-infected children. The investigators propose an unblinded randomized clinical trial to evaluate a simplification, protease-inhibitor (PI)-sparing treatment strategy among nevirapine (NVP)-exposed HIV-infected children treated initially with lopinavir/ritonavir (LPV/r). HIV-infected children aged 3-5 years, who have a history of exposure to NVP as part of prevention of mother-to-child HIV transmission (PMTCT), initiated LPV/r-based therapy in the first 36 months of life or who were enrolled on the control arm of Neverest 2 and who are virally suppressed with a viral load \ 1000 copies/ml) on the EFV-based regimen will reinitiate the LPV/r regimen. The primary objective is to test whether the durability of viral suppression is equivalent when children are switched to EFV-based therapy. The primary study endpoint is failure to have HIV RNA \1000 copies/ml. Secondary aims include comparison of immune preservation, toxicities, selection of resistance mutations, and adherence across the two arms. Antiretroviral drug concentrations and adherence will be investigated as possible explanations for the success and/or failure of this simplification regimen. The overall goal of the study is to contribute to the evidence base to allow expans