Meta-analysis Shows Limited Benefit of Drug Resistance Testing in Treatment-experienced Patients

This study aimed to estimate the effectiveness of resistance assessments based on viral sequencing (genotypic antiretroviral resistance testing, GART), phenotypic antiretroviral resistance testing (PART) or virtual PART (vPART) in the management of treatment-experienced HIV-1-infected patients.

The study results derived from a meta-analysis of randomized controlled trials comparing treatments aided by GART, PART and vPART, and controls.

The meta-analysis synthesized data on the proportion of patients with undetectable plasma viral load, the decrease in viral load, and the increase in CD4 cell count at 3 and 6 months after randomization.

Results

Ten trials were analyzed (total 2258 participants). Compared with controls, at 3 and 6 months GART increased the proportion of patients with viral load below detection by 11%, and 10%, respectively. The difference in viral load change was 0.27 log10 copies/ml and 0.21 log10 copies/ml, respectively.

However, no improvement was observed in the CD4 cell count at either time point: the difference in CD4 cell count -5.7 x 106 cells/l  and 1.2 x 106 cells/l, respectively, at 3 and 6 months.

For PART, there was no clear evidence for any benefit versus no testing (three trials). vPART conferred a small benefit in indirect comparisons versus no testing.

Conclusion

The authors conclude, “Evidence for benefit of antiretroviral resistance testing is sparse and limited to small short-term improvements of virologic response, mostly with GART and less with vPART.”

“Current guidelines widely recommending the use of antiretroviral resistance testing in clinical practice are not commensurate with the available evidence.”

11/24/04

Reference
E T Panidou and others. Limited benefit of antiretroviral resistance testing in treatment-experienced patients: a meta-analysis. AIDS 18(16): 2153-2161, November 5, 2004.