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.