Lamivudine and Indinavir/Ritonavir Maintenance Therapy in Highly Pretreated HIV-Infected Patients (Vista Anrs 109)

Abstract

Objective

In patients with extensive HIV resistance, one option is to delay salvage therapy until new drugs become available. We hypothesized that this delay period could be based on a simplified treatment, which would reduce drug toxicity, stabilize resistance, and prevent resurgence of wild-type virus.

Methods

A prospective 24-week treatment simplification study in HIV-1-infected patients having failed several lines of antiretroviral therapy, with CD4⁺ T-cell counts ≥100 cells/ml, plasma HIV RNA (viral load [VL]) ≥4 log₁₀ copies/ml and a resistance genotype predicting less than two active drugs. Treatment associated ritonavir-boosted low-dose indinavir (200 mg twice daily) and lamivudine (150 mg twice daily). The primary endpoint was a decrease in CD4⁺ T-cell counts ≥25% or increase in VL ≥0.7 log copies/ml relative to baseline.

Results;

Twenty-six patients were included. Baseline median VL was 4.5 log₁₀ copies/ml and median CD4⁺ T-cell count was 290 cells/ml. During the study, 10/26 patients (38%, 95% confidence interval=20.2–59.4) reached the primary endpoint. No patient had an AIDS-defining event. At week 24, the median change in plasma VL was +0.2 log₁₀ copies/ml (interquartile range (IQR): 0–0.5; P=0.003). The median change in CD4⁺ T-cell counts was -49 cells/ml (IQR: -14 to -93, P<0.001), with a median decline slope of 10 cells/ml/month, which was not different from that measured under full highly active antiretroviral therapy during the 6 months preceding inclusion. There were no significant changes in HIV-1 protease and reverse transcriptase genotypes during the study.

Conclusions

In patients with advanced resistance, treatment simplification prevented resurgence of wild-type HIV, reduced drug burden, but failed to stabilize progression of the immune deficiency.