A randomized study of antiretroviral management based on plasma genotypic antiretroviral resistance testing in patients failing therapy

Abstract
To determine the short-term effects of using genotypic antiretroviral resistance testing (GART) with expert advice in the management of patients failing on a protease inhibitor and two nucleoside reverse transcriptase inhibitors. Prospective randomized controlled trial. Multicenter community-based clinical trials network. One-hundred and fifty-three HIV-infected adults with a threefold or greater rise in plasma HIV-1 RNA on at least 16 weeks of combination antiretroviral therapy. Randomization was either to a GART group, where genotype interpretation and suggested regimens were provided to clinicians, or to a no-GART group, where treatment choices were made without such input. Plasma HIV-1 RNA levels and CD4 cell counts were measured at 4, 8, and 12 weeks following randomization. The primary endpoint was change in HIV-1 RNA levels from baseline to the average of the 4 and 8 week levels. The average baseline CD4 cell count was 230 × 106 cells/l and the median HIV-1 RNA was 28 085 copies/ml. At entry, 82 patients were failing on regimens containing indinavir, 51 on nelfinavir, 11 on ritonavir, and nine on saquinavir. HIV-1 RNA, averaged at 4 and 8 weeks, decreased by 1.19 log10 for the 78 GART patients and -0.61 log10 for the 75 no-GART patients (treatment difference: −0.53 log, 95% confidence interval, −0.77 to −0.29;P = 0.00001). Overall, the best virologic responses occurred in patients who received three or more drugs to which their HIV-1 appeared to be susceptible. In patients failing triple drug therapy, GART with expert advice was superior to no-GART as measured by short-term viral load responses.