Preclinical and human pharmacokinetic data suggest that DPC 083 can be administered once daily and provide trough plasma concentrations of free drug that will suppress replication of HIV-1, including strains containing key resistance mutations observed after failure of treatment with currently available NNRTIs. This study will provide an assessment of safety and a preliminary assessment of the efficacy of DPC 083 when administered at a dose of 100 mg once daily in combination with 2 NRTIs, in a population of HIV-1-infected patients who are failing treatment with an NNRTI-containing regimen.