Prospective Trials of Drug Resistance Testing

Prospective Trials of Drug Resistance Testing

VIRA3001

The VIRA3001 study tested the clinical utility of phenotypic resistance testing in selecting a salvage regimen (22). In this study, patients failing their first PI-containing regimen were randomized to phenotyping (using the Antivirogram assay) or standard of care. Two-hundred twenty-one patients were enrolled. Patients in the phenotyping arm had a significantly greater reduction in plasma HIV-1 RNA level by week 16, as compared to patients in the standard of care arm.

Using an intention-to-treat analysis in which missing patients were considered as failures, the proportion of patients achieving the primary endpoint (HIV-1 RNA 400 copies/mL) was not significantly different in the two arms. However, this difference was significant in a secondary analysis limited to actually observed values (59% vs 42%; P=0.033). Similar increases in CD4 cell counts were observed in both arms. Of note, very few patients entering this trial had prior NNRTI experience. Overall, patients in the phenotyping arm received significantly more new drugs to which the virus was sensitive than was true for the control arm.

4/15/01

Contents

Drug Resistance Testing in HIV-1 Infection

Diagnosing HIV Infection

Virus Load Testing

Immunologocal Testing

Therapeutic Drug Level Monitoring

Glossary of Terms

References

Tables