Virological response to HIV-1 nucleoside/nucleotide reverse transcriptase inhibitors-based, tenofovir DF-including regimens in the ANRS Aquitaine Cohort

Background: HIV-1 nucleoside/fide reverse transcriptase inhibitors (NRTI)-only based, comprising tenofovir DF(TDF) have been shown to lead to high rates of virological failures (VF), mainly in patients on first-fine combination therapy. We wished to investigate the virological response to these regimens in a large cohort of antiretroviral (ARV)-treated patients. Methods: Patients followed-up in the Aquitaine Cohort in 2001-2003 and who had received NRTI-based, TDF-including regimens for at least 3 months were included. The VF was defined as: (i) a decrease in plasma HIV-1 RNA < 0.5 loglocopies/ml between M0 and M3; or (ii) a plasma HIV-1 RNA > 50 copies/ml at M3 in patients with plasma HIV-1 RNA < 50 copies/ml at M0. The baseline RT genotype was determined in a subgroup of patients. Results: Within 121 patients (95% ARV-experienced) who received either lamivudine (3TC)/didanosine (DDI)TDF (n = 48). or abacavir (ABC)/3TC/TDF (n = 14), or 3TC/zidovudine (ZDV)/TDF (n = 27), or 3TC/ZDV/ABC/TDF (n = 20), or DDI/ABC/TDF (n = 12), the ABC/3TC/TDF and DDI/ABC/TDF combinations were associated with the highest frequencies of VF. In contrast the use of ZDV was related to a better virological response. The baseline RT genotype was also predictive of the virological outcome. Conclusion: NRTI-based, TDF-including therapies can lead to high rates of VF both in ARV-naive and in ARV-experienced patients. Our data strongly suggest the interest of associating ZDV and TDF in these regimens. (c) 2006 Elsevier B.V. All rights reserved.