ABSTRACT: Objectives: We report the 12 month follow-up of patients participating in the Viradapt study.
Methods: 108 patients failing therapy (HIV RNA > 10000 copies/ml, therapy with nucleoside analogues > 6 months, with protease inhibitor > 3 months) were randomized in two arms: standard of care in the control arm and treatment according to the resistance mutations in protease and reverse transcriptase genes in the study arm.
Results: The two arms were comparable in terms of risk factor, age, sex, previous treatment, CD4 cell count and log10 HIV-1 RNA at baseline. At week 24, analysis showed a statistically significant difference in the drop in viral load combined at 3 and 6 months (P=0.015, Anova repeat measures) in favour of the genotypic group. After 6 months, a reduction of 1.15 log10 copies RNA versus 0.67 log10 was seen in the genotypic arm compared to the control arm, with 32.3% versus 14% of the patients below 200 copies/ml (P=0.048), respectively. Patients in the control arm were then offered open label genotype treatment. In the constant genotypic treatment arm the mean drop in HIV RNA was -1.15±0.18 log10 copies/ml and -1.1±0.2 log copies/ml at month 9 and 12, respectively. Sixty-nine percent (30/43) of patients from the control arm received genotype treatment. In the switched to genotypic treatment group, the mean drop in HIV-1 RNA was -0.85±0.22 log10 copies/ml and -0.89±0.20 log10 copies/ml at month 9 and 12, respectively. The percentage of patients with HIV-1 RNA below the detection level (200 copies/ml) rose from 14% at month 6 to 25.7% at month 12 in patient receiving open label genotype. This percentage remained stable at 31.3% and 28.4%, at month 9 and 12, respectively in the study arm.
Conclusion: The benefit of using genotype to guide antiretroviral therapy persists at month 12. Patients in the control group still benefit from the genotypic analysis when receiving open labeled genotype treatment after 6 months of standard of care treatment.
