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14th International AIDS ConferenceBarcelona, Spain — July 7-12, 2002 |
Int Conf AIDS. 2002 Jul 7-12;14:Abstract No. ThOrB1389
BACKGROUND: Previous short-term studies have shown the benefit of HIV resistance testing for antiretroviral(ARV) management. The impact of resistance testing on long-term clinical outcome has not been assessed. We studied the long-term efficacy of either genotype or phenotype to guide therapy changes in a large cohort of HIV-1 infected US Department of Defense beneficiaries.
METHODS: 450 HIV-1-infected subjects on 3 or more ARV drugs, including at least one NNRTI or PI, were enrolled in a long-term study to assess the efficacy of resistance testing. Subjects were randomized to genotype (G), Phenotype (P) and viral burden (VB) arms. Resistance results were available in the G and P arms at time of virologic failure(VF). VF was defined as either a rise in plasma viral load (VL) to > 3 logs in a subject with previously undetectable viral load, or a failure to suppress VL to < 3 logs by 16 weeks. Study endpoint was reached when a subject had persistent VF despite a change in therapy. Subjects remained on study if therapy changes resulted in resolution of VF. The primary analysis was the difference in time to endpoint between the arms.
RESULTS: There were no differences in age, CD4 count, viral burden, number of previous antiretroviral drugs, or number of previous NNRTI between study arms at baseline. At baseline, there were 299, 69, and 82 subjects in CDC stages A, B, and C respectively. Median time of follow-up was 525 days. Median times to endpoint were 478 days, 521 days and 574 days for the VB, P, and G arms, respectively. A Kaplan-Meyer analysis of time to endpoint stratifying by study arm and CDC stage revealed a delayed time to study endpoint for the G and P arms compared with the VB arm (Log rank p=.00035) at 600 days of follow-up. There was no difference between G and P arms.
CONCLUSIONS: When employed as part of routine clinical HIV care, resistance testing appears to delay the time to virologic failure compared with empiric selection of drug regimens.
Presenting author: S A Wegner
1 US Military HIV Research Program, 1600 East Gude Drive, Rockville, MD, 20850, United States
2 US Military HIV Research Program, 1600 East Gude Drive, Rockville, MD, 20850, United States
3 US Military HIV Research Program, 1600 East Gude Drive, Rockville, MD, 20850, United States
4 US Military HIV Research Program, 1600 East Gude Drive, Rockville, MD, 20850, United States
5 US Military HIV Research Program, 1600 East Gude Drive, Rockville, MD, 20850, United States
6 US Military HIV Research Program, 1600 East Gude Drive, Rockville, MD, 20850, United States
7 US Military HIV Research Program, 1600 East Gude Drive, Rockville, MD, 20850, United States
8 US Military HIV Research Program, 1600 East Gude Drive, Rockville, MD, 20850, United States
9 Henry M. Jackson Foundation, Rockville, MD, United States
020711
ThOrB1389
Copyright © 2002 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.
