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Expected Events in Untreated Patients Over 5 Years a Taiwan Observational Cohort Study and Safety Cohort b Chen CJ et al. EASL 2005, abstract 1256 c Iloeje UH. EASL 2005, abstract 1265 Non-skin Non-HCC cancers a HCC b Cirrhosis c Events / 1000 Patients 15-20

Pregnancies in ETV Clinical Program: Outcome (N = 41) Safety Update Outcome ETV N = 21 LVD N = 16 ETV / LVD N = 2 Placebo N = 2 Elective Termination Spontaneous Abortion 1301 Live Birth3120 Outcome Unknown

Substitutions Selected by ETV Study Patient Population Residues with Novel Emerging Substitutions ETV EC Nucleoside naïve, eAg+ E8G, E8Q, R18K, V23A, N33S, G52R, S57P, A62T, S75P, N76K, S78T, R110G, N118S, R120K, H124Q, L132R, L147P, Y148H, G152E, K154R, K154T, H156Y, R167Q, P170S, F178S, A181T, I187V, K212R, K212T, S219P, T222S, L229S, S230A, G232D, G232S, H234Q, K241E, W243G, S246C, G251E, C256G, P261S, I265S, R274G, K275E, I278M, V278L, I282L, K285N, K285T, I290L, C303Y, I315V, N337I, V341I WT levels nM 027 Nucleoside naïve, eAg- D2N, H9R, R18S, N33T, N71D, S78Y, S78T, D83G, V84M, S117Y, I121S, Q125K, M129T, R153L, A194S, T222S, H234R, R270E, K275N, R280K, W284Stop, R289Q, G292D, F296L, I315L, K318R, A320T, M336I, A342T WT levels 0.8 – 12 nM 014 LVD Refractory L80I, L229W LVD R levels 22 – 45 nM 026 LVD Refractory V27A, I53F, S78T, L80V, K168E, A181T, C188S, V191A, A200V, V224A, D263G, G295S, M309L LVD R levels 2.4 – 31 nM 13-15

ETV Virologic Rebounds: Year Two Study022 eAg pos 027 eAg neg YR 1 Treated YR 2 Treated YR 1 Rebounds 6 (2%) 5 (2%) YR 2 Rebounds 6 (2%) 1 (<1%) Genotypic Resistance* 0 (0%) ETVLVD n = Wk Wk HBV DNA (Copies/mL) 10 3 < Percent of Subjects Study 022 eAg pos Study

Knodell Necroinflammatory Mean Score Naïve eAg+ Naïve eAg- LVD-Ref eAg+ ETV N = 292 LVD N = 269 ETV N = 265 LVD N = 250 ETV N = 110 LVD N = 98 Baseline Week Week 48 change from baseline * -3.2* -2.9 * 0.6 * Analyses were based on patients with baseline Knodell necroinflammatory score ≥ 2 and adequate Week 48 biopsy * p < 0.01 (ETV vs. LVD) Studies 022, 027 and

Sustained Response Through 24 Weeks Off Treatment for Responders at Week 48 – Naïve Patients Studies 022 and 027 Naïve eAg+ Naïve eAg- Percent N = LVD ETV n = 61n = 49 n = 124n =

Histologic Improvement, HBV DNA, and ALT at Week 48 Studies 022, 027 and 026 Naïve eAg+ Naïve eAg- LVD-Ref eAg+ ETV N = 314 LVD N = 314 ETV N = 296 LVD N = 287 ETV N = 124 LVD N = 116 Histologic Improvement, ALT ≤ 1 x ULN and HBV DNA < 400 copies/mL 138 ( 44) 80 ( 25) ( 25)170 ( 57) 112 ( 39) ( 39)16 ( 13) 0 ( 0) Histologic Improvement, ALT ≤ 1 x ULN and HBV DNA < 10 5 copies/mL 169 ( 54) 122 ( 39) ( 39)179 ( 60) 130 ( 45) ( 45)29 ( 23) 1 ( 1) Evaluable Baseline Histology Number of patients (%) 17-1

< >210 Doubling Time (days) Number of Cases Growth Rates of HCC Sheu J-C et al, Gastro 1985;89:259 Median doubling time = 117 days (range )

Start of Therapy Tumor Volume (cc) Months Six cases of HCC Origin Relative to Start of Therapy – Doubling Time 29 d 3E 2L 1L 4E5E 6L

Start of Therapy Months Six cases of HCC Origin Relative to Start of Therapy 6L doubling time 29 d doubling time 117 d