The safety and efficacy of tenofovir DF in combination with lamivudine and efavirenz through 6 years in antiretroviral-naïve HIV-1-infected patients.

Background: Study 903 is a phase 3 trial with a completed 144-week, double-blind phase comparing tenofovir DF (TDF) to stavudine (d4T) in combination with lamivudine (3TC) and efavirenz (EFV) and an ongoing additional 336-week open-label extension phase.

Method: Patients in Brazil, Argentina, and the Dominican Republic who completed the 144-week double-blind phase on TDF were eligible to roll over to the extension phase (weeks 144-480). Results from an interim week 288 analysis are presented.

Results: Eighty-six patients (62% male, 70% white) initially randomized to the TDF arm continued treatment with TDF. At the end of the 144-week, double-blind phase, 85 of the 86 had HIV-1 RNA <400 copies/mL, of whom 84% maintained virologic suppression through week 288. CD4 counts continued to improve with a mean increase of 135 cells/mm(3) from entry into the open-label extension to week 288. No patient discontinued due to renal adverse events. Small changes in bone mineral density at the lumbar spine and hip were seen in the first 48 weeks but were nonprogressive through 288 weeks. Mean limb fat increased from 8.0 kg at week 96 to 8.8 kg at week 288.

Conclusion: Through 288 weeks, once-daily TDF+3TC+EFV demonstrated sustained antiretroviral activity with continued immunologic recovery. TDF treatment was not associated with renal adverse events or limb fat loss in antiretroviral-naïve patients.