Comparison of once-daily versus twice-daily combination antiretroviral therapy in treatment-naive patients: results of AIDS clinical trials group (ACTG) A5073, a 48-week randomized controlled trial

Clin Infect Dis. 2010 Apr 1;50(7):1041-52. doi: 10.1086/651118.


Background: Dosing frequency is an important determinant of regimen effectiveness. Methods. To compare efficacy of once-daily (QD) versus twice-daily (BID) antiretroviral therapy, we randomized human immunodeficiency virus (HIV)-positive, treatment-naive patients to lopinavir-ritonavir (LPV/r) administered at a dosage of 400 mg of lopinavir and 100 mg of ritonavir BID (n = 160) or 800 mg of lopinavir and 200 mg of ritonavir QD (n = 161), plus either emtricitabine 200 mg QD and extended-release stavudine at a dosage of 100 mg QD or tenofovir at a dosage of 300 mg QD. Randomization was stratified by screening HIV RNA level <100,000 copies/mL versus > or = 100,000 copies/mL. The primary efficacy end point was sustained virologic response (SVR; defined as reaching and maintaining an HIV RNA level <200 copies/mL) through week 48.

Results: Subjects were 78% male, 33% Hispanic, and 34% black. A total of 82% of subjects completed the study, and 71% continued to receive the initially assigned dosage schedule. The probability of SVR did not differ significantly for the BID versus QD comparison, with an absolute proportional difference of 0.03 (95% confidence interval [CI], -0.07 to 0.12). The comparison depended on the screening RNA stratum (P=.038); in the higher RNA stratum, the probability of SVR was significantly better in the BID arm than in the QD arm: 0.89 (95% CI, 0.79-0.94) versus 0.76 (95% CI, 0.64-0.84), a difference of 0.13 (95% CI, 0.01-0.25). Lopinavir trough plasma concentrations were higher with BID dosing. Adherence to prescribed doses of LPV/r was 90.6% in the QD arm versus 79.9% in the BID arm (P<.001). Conclusions. Although subjects assigned to QD regimens had better adherence, overall treatment outcomes were similar in the QD and BID arms. Subjects with HIV RNA levels > or =100,000 copies/mL had better SVR with BID regimens at 48 weeks, which suggests a possible advantage in this setting for more frequent dosing. Clinical trial registration. registration number: NCT00036452.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Retroviral Agents / administration & dosage*
  • Drug Administration Schedule
  • Drug Therapy, Combination
  • Female
  • HIV Infections / drug therapy*
  • HIV Infections / virology
  • HIV* / genetics
  • Humans
  • Lopinavir
  • Male
  • Proportional Hazards Models
  • Pyrimidinones / administration & dosage*
  • RNA, Viral / analysis
  • Ritonavir / administration & dosage*
  • Treatment Outcome
  • Viral Load


  • Anti-Retroviral Agents
  • Pyrimidinones
  • RNA, Viral
  • Lopinavir
  • Ritonavir

Associated data


Grant support