The AIDS Clinical Trials Group Study A5202 is an ongoing phase 3B, randomized, partially blinded study comparing four antiretroviral regimens for the initial treatment of HIV-1 infection. The planned study duration was 96 weeks after enrollment of the last patient. Baseline evaluations included a medical history, physical examination, CD4 cell count, and HIV-1 RNA level. At screening, a genotypic resistance test was required in patients with recent HIV-1 acquisition. Testing for the HLA-B*5701 allele was permitted but not required. Patients were randomly assigned to receive one of four oral once-daily regimens: 600 mg of efavirenz (Sustiva, Bristol-Myers Squibb) or 300 mg of atazanavir (Reyataz, Bristol-Myers Squibb) plus 100 mg of ritonavir (Norvir, Abbott Laboratories) given with either 600 mg of abacavir plus 300 mg of lamivudine (Epzicom, GlaxoSmithKline) or 300 mg of tenofovir DF plus 200 mg of emtricitabine (Truvada, Gilead Sciences). The study was double-blinded with regard to the NRTIs.
Randomization was stratified according to the screening HIV-1 RNA level obtained before study entry (≥100,000 vs. <100,000 copies per milliliter), with the use of a permuted-block design with dynamic balancing according to the main institution. Screening of HIV-1 RNA levels was performed at any laboratory certified under the Clinical Laboratory Improvement Amendments. Study evaluations were completed before entry, at entry, at weeks 4, 8, 16, and 24, and every 12 weeks thereafter for the duration of the study in all patients, regardless of any treatment modification. After screening, the level of HIV-1 RNA was measured (Roche Amplicor Monitor assay, version 1.5) at Johns Hopkins University. At the time of protocol-defined virologic failure, geno-typing for drug resistance was performed at Stanford University; the baseline samples obtained from the patients were genotyped retrospectively.
Abbott Pharmaceuticals, Bristol-Myers Squibb, Gilead Sciences, and GlaxoSmithKline provided the study medications and had input into the protocol development and review of the manuscript. All the authors participated in the trial design, data analysis, and preparation of the manuscript, and all the authors vouch for the completeness and accuracy of the reported data.
Sax P.E., Tierney C., Collier A.C., Fischl M.A., Mollan K., Peeples L., Godfrey C., Jahed N.C., Myers L., Katzenstein D., Farajallah A., Rooney J.F., Ha B., Woodward W.C., Koletar S.L., Johnson V.A., Geiseler P.J, & Daar E.S. (2009). Abacavir–Lamivudine versus Tenofovir–Emtricitabine for Initial HIV-1 Therapy. The New England journal of medicine, 361(23), 2230-2240.