7th Conference on Retroviruses and Opportunistic Infections
 


Phenotypic Resistance Testing Significantly Improves Response to Therapy (Tx): A Randomized Trial (VIRA 3001)

C. COHEN*, S. HUNT, M. SENSION, C. FARTHING, M. CONANT, S. JACOBSON, J. NADLER, W. VERBIEST1, K. HERTOGS1, M. AMES2, A. RINEHART2, and N. GRAHAM2*. 1Virco, Belgium; 2Glaxo Wellcome, NC

Objective: Open-label, randomized comparison of phenotypic resistance testing (Antivirogram(tm); AVG) guided Tx switch vs. standard of care (SOC) in subjects failing first PI-containing HAART regimen.
Design: 271 subjects with >2 NRTIs and 1 PI prior Tx and plasma viral load (VL) > 2,000 copies/mL were randomized to Tx based on AVG results vs. SOC and followed for 16 wks. Outcomes include VL change from baseline (BL) by ITT (observed and LOCF), and percent < 400 copies/mL.
Results: Preliminary analysis of first 127 subjects shows mean BL CD4 cell counts of 339 and 345 for the AVG and SOC arms, respectively. At BL, 38%, 32%, and 13% of subjects were resistant to >2, 1, and 0 drugs, respectively.

At wk 16, 62% and 33% of subjects in AVG and SOC arms, respectively, had VL < 400 copies/mL. CD4 cell count increases were not different between arms.
Conclusions: Preliminary analysis shows that AVG results significantly improve virologic outcome when used by physicians to guide Tx choices for subjects failing their first PI-containing regimen.

Key Words: antiretroviral therapy, antiretroviral therapy response, phenotypic resistance

 

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