Z Su, JD Reeves, A Krambrink, E Coakley, M Hughes, C Flexner, T Wilkin, P Skolnik, W Greaves, D Kuritzkes, R Gulick, ACTG 5211 Team Response to Vicriviroc in HIV-Infected Treatment- Experienced Subjects using an Enhanced Version of the Trofile HIV Co-receptor Tropism Assay: Reanalysis of ACTG 5211 Results

Objective To assess whether the enhanced Trofile assay is an improved screening tool compared to the original Trofile assay for the selection of patients who may benefit from CCR5 antagonist therapy.

Sensitivity - X4 Minor Variant Detection Enhanced Trofile detected 0.3% CXCR4-tropic (X4) variants with 100% sensitivity (from assay validation experiments of 288 samples). 0.3 Trinh et al. XVII International HIV Drug Resistance Workshop, Abstract 118, 2008 Original Enhanced

118 subjects enrolled Stratified by: enfuvirtide use, CD4 ≤50 or >50 cells/µL All regimens included mg RTV Gulick et al., JID 2007; 196: ACTG 5211 Study DesignPlacebo VCV 5 mg qd VCV 10 mg qd VCV 15 mg qd (stopped early) STUDY ENTRY DAY 14 WEEK 24 WEEK 48 optimized ART regimenfailing ART regimen STUDY SCREEN SCREENING: R5 tropism by the original Trofile assay

Coreceptor Tropism by the Original and Enhanced Trofile 25/114 Enhanced Trofile reclassified 25 individuals with R5 virus at screen 15/25 were VCV recipients 12/15 had early detection of X4 virus on study (before week 8) by original Trofile Original TrofileEnhanced Trofile ScreenEntryOn studyDM at Screen (n, %) R5DMDM/X47/12, 58% R5 DM/X49/18, 50% R5 9/84, 11%

Change in Viral Load among VCV Recipients at Day 14 by Co-receptor Tropism (Enhanced Trofile) *From a regression model adjusted for baseline log 10 HIV-1 RNA and study stratification factors Change in log 10 HIV-1 RNA DM ScreenR5 Screen R5 Entry R5 Screen DM Entry n15564 Mean Adjusted p value* < Reference

Change in Viral Load among VCV Recipients at Week 24 by Co-receptor Tropism (Enhanced Trofile) *From a regression model adjusted for baseline log 10 HIV-1 RNA and study stratification factors DM Screen R5 Screen R5 Entry R5 Screen DM Entry Change in log 10 HIV-1 RNA n14558 Mean Adjusted p value* Reference

Change in CD4 Counts among VCV Recipients at Week 24 by Co-receptor Tropism (Enhanced Trofile) *From a regression model adjusted for baseline CD4 count and study stratification factors DM Screen R5 Screen R5 Entry R5 Screen DM Entry Change in CD4 Cell Count n Mean Median (Q1, Q3)32 (-1, 68)68 (68, 125)86 (40, 192) Adjusted p value* Reference

Viral Load Reduction in Subjects with R5 Virus at Screen by the original & Enhanced Trofile Assays Placebo Placebo Day 14Week 24 Change in Viral Load (log10 HIV-1 RNA) Original Enhanced

Proportion of VCV Recipients with R5 Virus Achieving Defined HIV-1 RNA Levels at Week 24 ≥ 1.0 log10 <400 <50 Reduction cp/mL cp/mL Trofile (ES)

Summary Screen tropism results from the enhanced Trofile were predictive of early detection of CXCR4-use in ACTG 5211 VCV recipients Greater viral load reduction was observed at Day 14 and Week 24 in subjects with R5 virus at screen and entry compared to DM at screen by the enhanced Trofile There were trends for improved virologic responses at Day 14 and Week 24 in VCV recipients with R5 virus at screen by the enhanced Trofile compared to original analysis according to the original Trofile

Conclusions Enhanced Trofile showed improved ability to predict antiretroviral responses to VCV Enhanced Trofile is an improved screening tool for determining patient eligibility for CCR5 antagonist therapy

Acknowledgements (1) Monogram Biosciences Jackie Reeves Eoin Coakley Dong Han Wei Huang Linda Kiss Jeff Larson Neil Parkin Chris Petropoulos Lan Trinh Jeannette Whitcomb Terri Wrin Monogram Biosciences Clinical Reference Laboratory ACTG 5211 Team Chair: Trip Gulick Co-Chair: Dan Kuritzkes Charles Flexner Statisticians: Zhaohui Su Amy Krambrink Michael Hughes Pharmaceutical Rep: Wayne Greaves Eoin Coakley Immunologist: Paul Skolnik Neurologist: David Clifford

Acknowledgements (2) ACTG 5211 Team (Cont) DAIDS Clincal Rep: Carla Pettinelli Catherine Godfrey Clinical Trials Specialist: Beatrice Kallungal Data Manager: Susan Owens Field Rep: Valery Hughes Team Investigators: Timothy Wilkin Robert Gross Scott Hammer Andrew Zolopa Martin Hirsch DAIDS Pharmacist: Ana Martinez Laboratory Tech: Antoine Simmons Lab Data Coordinator: Mary Dobson Howard Gutzman Community Rep: Jim Smith Participating ACTG sites, ACTG/NIAID/NIH, and patient volunteers