- Antiretroviral treatment-naïve or -experienced study candidates must be able to add two new NRTIs as part of their new therapy in this protocol, or have genotypic evidence of sensitivity to two NRTIs (the NRTIs must be used in combinations recommended in the Guidelines for the Use of Antiretroviral Agents in Pediatric and Adolescent HIV Infection). More information about this criterion can be found in the protocol.