Of the five anti-HIV drug classes, four were recommended as first-line regimens for patients who have never received anti-HIV treatment before (treatment naive): nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), Integrase Inhibitors (INIs) and protease inhibitors (PIs). The U.S. Department of Health and Human Services (HHS) guidelines recommend that treatment-naive HIV infected patients be treated with a triple drug regimen that includes 2 NRTIs + 1 NNRTI, 2 NRTIs + INI, or 2 NRTIs + 1 PI as their initial treatment regimen.
According to data, an efavirenz (EFV)-containing regimen (2 NRTIs + 1 NNRTI, with EFVas the NNRTI) requires fewer pills for the patient, has mild and few side effects, and is more effective in reducing viral load than other regimens, making it the preferred choice for most patients. However, for some patients, an EFV-containing regimen is not feasible due to side effects, acquired NNRTI-resistant HIV virus, or other undesirable effects. For these patients, it is necessary to find alternative regimens with comparable safety and efficacy. This study examined how well different combinations of anti-HIV drugs work, including safety and drug tolerability for various combinations.
This was a phase III, prospective, randomized study. Participants was randomly assigned to one of three different groups (treatment arms)-A, B, or C -each representing a different drug combination regimen, none of which contained an NNRTI.
Arm A: Atazanavir (ATV) + Ritonavir (RTV) + Emtricitabine/tenofovir disoproxil fumarate (FTC/TDF)
Arm B: Raltegravir (RAL) + FTC/TDF
Arm C: Darunavir (DRV) + RTV + FTC/TDF
The duration of this study was between 96 and 192 weeks, depending on when the participant enrolled. There were a total of 1,809 participants, approximately 600 per treatment arm. Screening and pre-entry evaluations must occur prior to the participant starting any study medication, treatments, or interventions. Participants were randomly assigned to their treatment groups at the entry visit and must begin treatment within 72 hours of randomization. Participants was told which group they were in and what medications they were administered. The study drugs were distributed at entry. All drugs were provided by the study with the exception of RTV, which would have to be obtained through the participant's primary care physician (Group A or C). If a participant was unable to tolerate any of the study medications during the course of the study then their doctor could switch them to another regimen.
During the study, participants was asked to return to the clinic at Weeks 4, 8, 16, 24, 36, and 48 and then every 16 weeks until the end of the study. They were also contacted by telephone during Week 2 to check on their status. Visits were last about 1 hour. At most visits, participants had a physical exam and answered questions about any medications they were taken. Additionally, participants completed questionnaires addressing their smoking and alcohol habits, had blood drawn, and were asked to give urine samples. At some visits, participants had to come to the clinic without having eaten for 8 hours. If the participant was female and able to become pregnant, a pregnancy test might be given at any visit if pregnancy was suspected.
Some participants of A5257 were asked to participate in an optional metabolic substudy A5260s. This substudy took place at only some study sites and continued last up to 144 weeks, including time on A5257. The primary focus of this substudy was to examine carotid artery intima-media thickness (CIMT) as it relates to both RTV- and RAL-containing regimens. Randomization, stratification, treatment assignments, and study visits were as per A5257.
