Randomization to Once-daily Stavudine Extended Release/lamivudine/efavirenz Versus a More Frequent Regimen Improves Adherence While Maintaining Viral Suppression

Background: In antiretroviral (ARV) therapy, pill burden, dosing frequency, and regimen complexity adversely affect adherence. We sought to evaluate the effect of regimen simplification on maintenance of virologic suppression and treatment adherence.

Method: In this 48-week, open-label, randomized study, 320 HIV-1-infected adult patients with a viral load of <50 copies/mL on a twice-daily or more frequent ARV regimen were either switched to a once-daily regimen of efavirenz, extended-release stavudine, and lamivudine (QD arm) or continued on existing therapy (BID+ arm). Medication Event Monitoring System (MEMS) caps, AIDS Clinical Trials Group (ACTG)-validated questionnaire, and pill counts were used to evaluate adherence. Treatment satisfaction and preference were also evaluated.

Results: The QD arm was noninferior to the BID+ arm in the primary efficacy measure (proportion of patients who maintained virologic suppression at Week 48; QD arm, 80.0% vs. BID+ arm, 75.8%). Adherence and treatment satisfaction significantly favored the QD arm, in which 91.0% of patients preferred the simpler regimen. Overall, the majority of adverse events were mild to moderate in severity and resulted in a low rate of treatment discontinuations.

Conclusions: Simplifying twice-daily or more frequent ARV therapy to a once-daily efavirenz-containing regimen in virologically suppressed HIV-1-infected patients maintains virologic suppression while improving adherence and patient satisfaction.