1. A prospective, randomized, Phase III trial of NRTI-, PI-, and NNRTI-sparing regimens for initial treatment of HIV-1 infection – ACTG 5142 Riddler S.A., Haubrich R., DiRienzo G., Peeples L., Powderly W.G., Klingman K.L., Garren K.W., George T., Rooney J.F., Brizz B., Havlir D., Mellors J.W., AIDS Clinical Trials Group 5142 Study Team

2. A5142 Study Design Primary endpoints* Time from randomization to virologic failure (VF) VF: 2 consecutive HIV-1 RNA measurements > 200 c/mL after week 32 Time from randomization to regimen completion VF OR treatment-limiting toxicity or intolerance, as assessed by the site investigator to any regimen component ARV-naïve HIV RNA >2,000 c/mL Any CD4 count 96 weeks Multicenter Randomized Open-label Screening LPV/r SGC 533/133 mg BID + EFV 600 mg QD EFV 600 mg QD + 3TC + d4T XR or TDF or ZDV LPV/r 533/133 mg BID + EFV 600 mg QD LPV/r SGC 400/100 mg BID + 3TC + d4T XR or TDF or ZDV N  250/arm Stratification by:   HIV RNA > 100,000 copies/mL   Hepatitis infection   Selection of d4T, TDF or ZDV * * Multiple between-arm comparisons and interim analyses  Adjusted significance level = 0.016 Riddler SA, Haubrich R et al., XVI IAC, Toronto 2006, #THLB0204

3. A5142 Primary Results 753 subjects NRTI selection (prior to randomization) – ZDV 42% – D4T XR 24% – TDF 34% median follow up 112 weeks median CD4 182 cells/mm 3 median HIV-1 RNA 100,000 copies/mL No differences between arms in baseline characteristics Riddler SA, Haubrich R et al., XVI IAC, Toronto 2006, #THLB0204

4. A5142 Primary Results AnalysisLPV/EFVLPVEFVP No virologic failure at 96 weeks 73%67%76%0.006* Regimen completion at 96 weeks 61%54%60%0.02** % HIV RNA < 50 at 96 weeks83%77%89%0.003* CD4 increase at 96 weeks2682852410.01*** Grade 3/4 laboratory45%33%32%--- Grade 3/4 sign/ symptom20%19%18%--- * LPV vs EFV- other comparisons ns; ** did not meet significance threshold of 0.016; *** EFV vs both LPV arms Riddler SA, Haubrich R et al., XVI IAC, Toronto 2006, #THLB0204

5. Other Key Findings No difference in time to treatment limiting toxicity between groups Preliminary analysis of 124 of 227 subjects with virologic failure (additional samples being analyzed) – Preliminary resistance analyses show a trend toward more NNRTI resistance in the LPV/EFV arm compared with EFV + 2 NRTI. – Resistance mutations in 2 drug classes (M184I/V + K103N) were more common in the EFV + 2 NRTI arm. PI mutations were not found in the LPV + 2 NRTI arm. Riddler SA, Haubrich R et al., XVI IAC, Toronto 2006, #THLB0204