Plasma samples were obtained at every visit for safety laboratory and VL analyses. VL was routinely measured using the Roche Cobas TaqMan assay, which was subsequently shown to perform differently from the Roche Cobas Amplicor Ultrasensitive HIV-1 test (Roche Diagnostics, Risch, Switzerland). Data suggested that, at a low VL (< 48 copies/mL), the TaqMan assay may report detectable VL results at a higher frequency than the Amplicor test [15]. As the trial design was based on the test performance of the Amplicor test, plasma samples with TaqMan results ≥48 copies/mL and ≤200

copies/mL after randomization to week 24 inclusive were assayed using the Amplicor Ultrasensitive assay, in order to provide an Amplicor-based endpoint result. If the Amplicor Ultrasensitive assay detected virus (VL ≥ 50 copies/mL), buy Navitoclax the samples obtained before and after the index sample were also tested using the Amplicor Ultrasensitive assay. The VL recorded for the patient was the result using the Amplicor assay, whenever it was performed. For visits PF-02341066 purchase where the Amplicor assay was not performed, the result from the TaqMan assay was recorded. The primary study

endpoint was the proportion of patients with continued virological response (< 50 copies/mL) at week 24, using the combined Amplicor–TaqMan results. Patients were classed as having treatment failure at the first occurrence of any one of the following: two consecutive VLs of ≥50 copies/mL at least 2 weeks apart; missing VL measurement at week 24; change in background antiretroviral (ARV) therapy other than because of adverse events (AEs); death; loss to follow-up; or study discontinuation. Secondary efficacy endpoints included the proportion of patients with a continued virological response using a lower limit of quantification (LLOQ) of <400 copies/mL (as

measured by Cobas Amplicor and Cobas TaqMan assay), and time to loss of virological response. Analyses were also performed where only the TaqMan data were used to define VL. Treatment adherence monitoring of study medication (tablet count and duration of medication intake) was performed using an adherence worksheet where tablet Oxalosuccinic acid counts and treatment interruptions were documented. Adherence was calculated as the actual number of pills taken divided by the number of pills that should have been taken. AEs, serious AEs (SAEs) including AIDS-defining events, Division of Acquired Immunodeficiency Syndrome (DAIDS) grade 3 or 4 AEs, laboratory abnormalities and change in baseline laboratory values to week 24 were recorded. When rashes that were possibly related to NVP or hepatic AEs occurred, specific rash and hepatic electronic case report forms were completed. Patients were assessed for changes in haematology, liver enzymes, bilirubin, coagulation parameters, renal function, glucose, amylase and lipase, and triglycerides.