Atazanavir plus ritonavir or efavirenz as part of a 3-drug regimen for initial treatment of HIV-1

Ann Intern Med. 2011 Apr 5;154(7):445-56. doi: 10.7326/0003-4819-154-7-201104050-00316. Epub 2011 Feb 14.

Abstract

Background: Limited data compare once-daily options for initial therapy for HIV-1.

Objective: To compare time to virologic failure; first grade-3 or -4 sign, symptom, or laboratory abnormality (safety); and change or discontinuation of regimen (tolerability) for atazanavir plus ritonavir with efavirenz-containing initial therapy for HIV-1.

Design: A randomized equivalence trial accrued from September 2005 to November 2007, with median follow-up of 138 weeks. Regimens were assigned by using a central computer, stratified by screening HIV-1 RNA level less than 100 000 copies/mL or 100 000 copies/mL or greater; blinding was known only to the site pharmacist. (ClinicalTrials.gov registration number: NCT00118898)

Setting: 59 AIDS Clinical Trials Group sites in the United States and Puerto Rico.

Patients: Antiretroviral-naive patients.

Intervention: Open-label atazanavir plus ritonavir or efavirenz, each given with with placebo-controlled abacavir-lamivudine or tenofovir disoproxil fumarate (DF)-emtricitabine.

Measurements: Primary outcomes were time to virologic failure, safety, and tolerability events. Secondary end points included proportion of patients with HIV-1 RNA level less than 50 copies/mL, emergence of drug resistance, changes in CD4 cell counts, calculated creatinine clearance, and lipid levels.

Results: 463 eligible patients were randomly assigned to receive atazanavir plus ritonavir and 465 were assigned to receive efavirenz, both with abacavir-lamivudine; 322 (70%) and 324 (70%), respectively, completed follow-up. The respective numbers of participants in each group who received tenofovir DF-emtricitabine were 465 and 464; 342 (74%) and 343 (74%) completed follow-up. Primary efficacy was similar in the group that received atazanavir plus ritonavir and and the group that received efavirenz and did not differ according to whether abacavir-lamivudine or tenofovir DF-emtricitabine was also given. Hazard ratios for time to virologic failure were 1.13 (95% CI, 0.82 to 1.56) and 1.01 (CI, 0.70 to 1.46), respectively, although CIs did not meet prespecified criteria for equivalence. The time to safety (P = 0.048) and tolerability (P < 0.001) events was longer in persons given atazanavir plus ritonavir than in those given efavirenz with abacavir-lamivudine but not with tenofovir DF-emtricitabine.

Limitations: Neither HLA-B*5701 nor resistance testing was the standard of care when A5202 enrolled patients. The third drugs, atazanavir plus ritonavir and efavirenz, were open-label; the nucleoside reverse transcriptase inhibitors were prematurely unblinded in the high viral load stratum; and 32% of patients modified or discontinued treatment with their third drug.

Conclusion: Atazanavir plus ritonavir and efavirenz have similar antiviral activity when used with abacavir-lamivudine or tenofovir DF-emtricitabine.

Primary funding source: National Institutes of Health.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Alkynes
  • Atazanavir Sulfate
  • Benzoxazines / adverse effects
  • Benzoxazines / therapeutic use*
  • CD4 Lymphocyte Count
  • Cyclopropanes
  • Drug Resistance, Viral
  • Drug Therapy, Combination
  • Female
  • HIV Infections / drug therapy*
  • HIV Infections / immunology
  • HIV Infections / virology
  • HIV Protease Inhibitors / adverse effects
  • HIV Protease Inhibitors / therapeutic use*
  • HIV-1* / drug effects
  • Humans
  • Male
  • Medication Adherence
  • Middle Aged
  • Oligopeptides / adverse effects
  • Oligopeptides / therapeutic use*
  • Pyridines / adverse effects
  • Pyridines / therapeutic use*
  • Ritonavir / adverse effects
  • Ritonavir / therapeutic use*
  • Viral Load
  • Young Adult

Substances

  • Alkynes
  • Benzoxazines
  • Cyclopropanes
  • HIV Protease Inhibitors
  • Oligopeptides
  • Pyridines
  • Atazanavir Sulfate
  • efavirenz
  • Ritonavir

Associated data

  • ClinicalTrials.gov/NCT00118898

Grant support