Reduced doses of antiretroviral (ARV) drugs may lower toxicity while preserving efficacy. We aimed to evaluate the efficacy of reduced doses of both tenofovir disoproxil fumarate (TDF) and efavirenz for the treatment of HIV-1 infection. In this open-label, non-inferiority trial, HIV-1-infected antiretroviral-naive adults were randomly assigned to receive either a lower dose anti-retroviral regimen comprised of TDF (200 mg), efavirenz (400 mg), and standard dose lamivudine (300 mg) or the standard dose regimen. The primary endpoint was the proportion of participants with HIV-1 RNA≤ 50 copies/mL at week 48 using a non-inferiority margin of -10%. At week 48, 79 of 92 (85.9%) participants in the lower dose regimen group and 78 of 92 (84.8%) in the standard dose regimen group achieved HIV-1 RNA≤ 50 copies/mL (treatment difference 1.1%, 95% CI -9.1 to 11.3) in the intention-to-treat analysis. Drug-related adverse events occurred more frequently in the participants receiving the standard dose regimen compared with the lower dose one (63.0% vs 80.4%). Changes in estimated glomerular filtration rate and bone mineral density were comparable between the two groups. The non-inferior efficacy and better safety profile of the lower dose ARV regimen support its use as alternative initial therapy for HIV-1 infected patients.
Keywords: HIV; efavirenz; low dose; non-inferiority; tenofovir disoproxil fumarate.