1. Combined PI and NNRTI Resistance Analysis of the Pooled DUET Trial: Towards a Regimen-Based Resistance Interpretation J. M. Schapiro, J. Vingerhoets, S. Nijs, M. Peeters, G. De Smedt, B. Woodfall, MP de Béthune and G. Picchio National Hemophilia Center, Sheba Medical Center Israel, Tibotec, Mechelen, Belgium; Tibotec, Yardley, USA

2. Introduction Resistance determinations are currently performed for each drug component in isolation Resistance interpretation of drug combinations could lead to improved predictions of virologic response The DUET trials included the combination of a potent PI and NNRTI (darunavir and etravirine) This afforded an opportunity to perform analyses on the combined impact of resistance mutations for these two ARV classes on virologic response

3. 24-week primary analysis DUET-1 and DUET-2 differed only in geographical location; pooled analysis was pre-specified Major inclusion criteria – plasma viral load >5,000 HIV-1 RNA copies/mL and stable therapy for ≥8 weeks – ≥1 NNRTI RAMs 2, at screening or in documented historical genotype – ≥3 primary PI RAMs at screening Patients recruited from Thailand, Australia, Europe and the Americas Screening 6 weeks 600 patients target per trial 48-week treatment period with optional 48-week extension *All patients received a background regimen (BR) of DRV/r with optimised NRTIs and optional enfuvirtide TMC125 + BR* Placebo + BR* Follow-up 4 weeks DUET Study Design 2 From extended list of NNRTI RAMs (Tambuyzer L, et al. EHDRW 2007. Abstract 67); DRV/r = darunavir with low-dose ritonavir 48-week analysis

4. Pooled DUET-1 and DUET-2: Week 48 Results 024812162024324048 61% 40% p<0.0001* Responders (%) ± 95% CI 100 90 80 70 60 50 40 30 20 10 0 Time (weeks) Patients with VL <50 copies/mL at Week 48 (ITT-TLOVR) ETR + BR (n=599) Placebo + BR (n=604) * Logistic regression model; ‡ ANCOVA model; VL = viral load; ITT = intention to treat; BR = background regimen TLOVR = time to loss of virologic response; NC=F = noncompleter equals failure; CI = confidence interval; SE = standard error

5. Pooled DUET-1 and DUET-2: Week 48 Results 024812162024324048 61% 40% p<0.0001* Responders (%) ± 95% CI 100 90 80 70 60 50 40 30 20 10 0 Time (weeks) ETR + BR (n=599) Placebo + BR (n=604) * Logistic regression model; ‡ ANCOVA model; VL = viral load; ITT = intention to treat; BR = background regimen TLOVR = time to loss of virologic response; NC=F = noncompleter equals failure; CI = confidence interval; SE = standard error <50 HIV-1 copies at Week 24 Patients with VL <50 copies/mL at Week 48 (ITT-TLOVR)

6. Methods Analyses were performed in the subgroup of patients (n = 406) that excluded patients: – Using enfuvirtide as a new drug – Who discontinued for reasons other than virologic failure Baseline resistance-associated mutations (RAMs) having an effect on the virological response to ETR or DRV have been identified previously Virological response was defined as a confirmed viral load (VL) <50 HIV-1 RNA copies/mL at Week 24 Genotypes and phenotypes were determined by Virco

7. Resistance Associated Mutations ETR: V90I, A98G, L100I, K101E/P, V106I, V179D/F, Y181C/I/V, G190A/S DRV: V11I, V32I, L33F, I47V, I50V, I54L/M, T74P, L76V, I84V, L89V 1 Vingerhoets J, et al. Antivir Ther. 2007;12:S34 2 De Meyer S, et al. EHDRW 2008. Abstract 54

8. Combined effect of ETR and DRV RAMs on virologic response (<50 copies/mL)

9. DRV 912331 0 44381475 1 41241676 2 402420510 3 272311 5 >3 0123 ETR Number of patients per subgroup Combined effect of ETR and DRV RAMs on virologic response (<50 copies/mL)

11. 78 67 82 71 0 10 20 30 40 50 60 70 80 90 100 ETR RAMs 0ETR RAMs 1 ETR RAMs 2ETR RAMs 3 ETR RAMs >3 DRV RAMs >3 DRV RAMs 3 DRV RAMs 2 DRV RAMs 1 DRV RAMs 0

12. Combined effect of ETR and DRV RAMs on virologic response (<50 copies/mL) 78 67 100 82 71 93 73 75 56 0 10 20 30 40 50 60 70 80 90 100 ETR RAMs 0ETR RAMs 1 ETR RAMs 2ETR RAMs 3 ETR RAMs >3 DRV RAMs >3 DRV RAMs 3 DRV RAMs 2 DRV RAMs 1 DRV RAMs 0 78 67

13. Combined effect of ETR and DRV RAMs on virologic response (<50 copies/mL)

14. 78 50 45 60 30 0 10 20 30 40 50 60 70 80 90 100 ETR RAMs 0ETR RAMs 1 ETR RAMs 2ETR RAMs 3 ETR RAMs >3 DRV RAMs >3 DRV RAMs 3 DRV RAMs 2 DRV RAMs 1 DRV RAMs 0

15. Combined effect of ETR and DRV RAMs on virologic response (<50 copies/mL) 78 50 45 60 30 63 35 27 0 0 10 20 30 40 50 60 70 80 90 100 ETR RAMs 0ETR RAMs 1 ETR RAMs 2ETR RAMs 3 ETR RAMs >3 DRV RAMs >3 DRV RAMs 3 DRV RAMs 2 DRV RAMs 1 DRV RAMs 0

16. Combined effect of ETR and DRV RAMs on virologic response (<50 copies/mL) 0/1 (0.0%) 1/1 (100%) 7 1/2 (50.0%)0/2 (0.0%) 1/1 (100%) 6 0/4 (0.0%)1/3 (33.3%)0/4 (0.0%)4/11 (36.4%)4/7 (57.1%) 5 1/6 (16.7%)3/5 (60.0%)4/10 (40.0%)11/18 (61.1%) 4 0/2 (0.0%)3/8 (37.5%)3/5 (60.0%)9/20 (45.0%)12/24 (50.0%)31/40 (77.5%) 3 0/3 (0.0%)1/3 (33.3%)2/7 (28.6%)9/16 (56.3%)18/24 (75.0%)30/41 (73.2%) 2 1/2 (50.0%)1/3 (33.3%)4/7 (57.1%)13/14 (92.9%)27/38 (71.1%)36/44 (81.8%) 1 0/1 (0.0%) 2/3 (66.7%)3/3 (100%)8/12 (66.7%)7/9 (77.8%) 0 543210 DRV RAMs ETR RAMs > 61% 40-61% < 40% Virologic response:

17. Combined effect of ETR and DRV RAMs on virologic response (<50 copies/mL) DRV RAMs ETR RAMs 0123>3 0 77.8% (7/9)66.7% (8/12)100% (3/3)66.7% (2/3)0.0% (0/1) 1 81.8% (36/44)71.1% (27/38)92.9% (13/14)57.1% (4/7)40.0% (2/5) 2 73.2% (30/41)75.0% (18/24)56.3% (9/16)28.6% (2/7)16.7% (1/6) 3 77.5% (31/40)50.0% (12/24)45.0% (9/20)60.0% (3/5)30.0% (3/10) >3 63.0% (17/27)34.8% (8/23)27.3% (3/11) 0.0% (0/5) > 61%< 40% Virologic response: 40-61%

18. In vitro susceptibility to DRV in subgroups by DRV and ETR RAMs ETR RAMs DRV RAMs012345 0 0.71.01.21.3 0.6 1 2.4 1.91.42.81.6 2 4.74.16.45.34.512.7 3 10.19.79.05.115.612.2 4 32.723.434.553.4 5 74.624.273.3122.080.6 6 68.0362.0302.092.0 7 655.0 909.0 FC  10 FC 10 - 40 FC > 40 Median DRV FC:

19. In vitro susceptibility to ETR in subgroups by DRV and ETR RAMs ETR RAMs DRV RAMs012345 0 0.51.80.613.4 5.3 1 1.13.22.16.613.314.9 2 0.82.91.94.942.44.1 3 1.03.93.45.14.45.7 4 0.71.91.42.6 5 0.83.33.02.010.7 6 0.20.95.611.0 7 0.7 26.2 FC  3 FC 3 - 13 FC > 13 Median ETR FC:

20. Results - Summary Virological response rates declined with increasing numbers of combined baseline DRV and ETR RAMs: – 0 total RAMs: 77.8% – >7 total RAMs: 14.3% For patients with 0 or 1 RAM to each of the drugs (4 subgroups): – median DRV FC: 0.7 – 2.4 – median ETR FC: 0.5 – 3.2 – response rates: 66.7% to 81.8% For patients with 2 or less RAMs to each drug (9 subgroups): – median DRV FC: 0.7 – 6.4 – median ETR FC: 0.5 – 3.2 – response rates: 56.3% to 100.0%

21. Conclusions In this highly treatment experienced population, patients with 1 or less mutations to each drug had virological responses similar to those seen in trials of drug naïve patients. Responses below 50% required at least 3 mutations to either drug DRV continued to contribute to responses ≥50% even in the presence of 3 mutations Resistance to a drug regimen appears to be a function of the combined genetic barrier to resistance (GBR) of the different drug components Resistance interpretations considering drug combinations may be more clinically relevant than those addressing only each drug individually

22. Acknowledgements The patients and DUET investigators The study center staff Tibotec clinical trial staff, clinical virology, and biometrics Virco