> 18 years Chronic HCV infection Compensated cirrhosis ** POLARIS-3 study: SOF/VEL/VOX 8 weeks vs SOF/VEL 12 weeks in patients with genotype 3 and cirrhosis Design Randomisation* 1 : 1 Open-label W8 W12 N = 110 SOF/VEL/VOX 400/100/100 mg QD SVR12 > 18 years Chronic HCV infection Genotype 3 Treatment-naïve or IFN-experienced Compensated cirrhosis ** SOF/VEL 400/100 mg QD SVR12 N = 109 ** Metavir F4 or Ishak 5-6 or Fibroscan > 12.5 kPa or Fibrotest  > 0.75 + APRI > 2 * Randomisation on prior treatment-experience (naïve or IFN-experienced) Objective SVR12 (HCV RNA < 15 IU/mL), with 95% CI, by ITT: superiority of SOF/VEL/VOX > 5% to a prespecified rate of 83% (two-sided significance level of 5%, 80% power) POLARIS-3 Jacobson IM. Gastroenterology 2017; 153:113-22

Baseline characteristics and patient disposition POLARIS-3 study: SOF/VEL/VOX 8 weeks vs SOF/VEL 12 weeks in patients with genotype 3 and cirrhosis Baseline characteristics and patient disposition SOF/VEL/VOX 8 weeks N = 110 SOF/VEL 12 weeks N = 109 Age, years, mean 54 55 Female, % 33 8 White, % 91 89 BMI, kg/m2, mean 28 27 HCV RNA, log10 IU/mL, mean 6.0 6.3 IL28B CC, % 37 48 Fibroscan, kPa, mean (range) 23 (13-75) 22 (13-75) Platelets, 103/mm3, mean 140 150 IFN-experienced, % 32 29 Discontinuation, N Adverse event Lack of efficacy 2 1 POLARIS-3 Jacobson IM. Gastroenterology 2017; 153:113-22

SVR12 overall and by prior treatment, % (95% CI) Treatment-experienced POLARIS-3 study: SOF/VEL/VOX 8 weeks vs SOF/VEL 12 weeks in patients with genotype 3 and cirrhosis SVR12 overall and by prior treatment, % (95% CI) SOF/VEL/VOX 8 weeks SOF/VEL 12 weeks % 96 (91-99) * 96 (91-99) 99 100 97 96 91 2 relapses 1 withdrew consent 1 death 80 60 1 on-treatment failure 1 relapse 1 discontinuation for AE 1 lost to follow-up 40 20 N= 110 109 75 77 35 32 Overall Treatment-naive Treatment-experienced * p < 0.001 for superiority compared with prespecified 83% performance goal SVR12 according to baseline RASs (present in 22% and 23% of patients) If absent, SVR12 = 98% vs 97% ; If present, SVR12 = 100% (in both treatment groups) POLARIS-3 Foster GR. AASLD 2016, Abs. 258; Jacobson IM. Gastroenterology 2017; 153:113-22

POLARIS-3 study: SOF/VEL/VOX 8 weeks vs SOF/VEL 12 weeks in patients with genotype 3 and cirrhosis Adverse events SOF/VEL/VOX 8 weeks N = 110 SOF/VEL 12 weeks N = 109 At least one adverse event, % 75 74 Serious adverse events, N (%) Related to study drug 2 (2%) 3 (3%) Grade 3-4 adverse events, N (%) Discontinuation due to adverse event, N (%) 1 (< 1%) Adverse events in > 10% of patients, % Fatigue 25 28 Headache 29 Nausea 21 9 Diarrhea 15 5 Grade 3-4 laboratory abnormalities, % 13 8 Hemoglobin < 10 g/dl 1 ALT > 5 x ULN / AST > 5 x ULN 0 / 1 POLARIS-3 Jacobson IM. Gastroenterology 2017; 153:113-22

POLARIS-3 study: SOF/VEL/VOX 8 weeks vs SOF/VEL 12 weeks in patients with genotype 3 and cirrhosis Summary In patients with HCV genotype 3 infection and cirrhosis, SOF/VEL/VOX for 8 weeks resulted in a 96% SVR12 rate as did SOF/VEL for 12 weeks Baseline NS5A RASs, including Y93H, did not impact treatment outcome for either SOF/VEL/VOX or SOF/VEL No treatment emergent RASs in the SOF/VEL/VOX group In the SOF/VEL group, both virologic failures had Y93H emergence SOF/VEL/VOX and SOF/VEL were safe and well tolerated Mild gastrointestinal adverse events (nausea and diarrhea) were associated with treatment regimens that included VOX There was no evidence of VOX-related hepatotoxicity SOF/VEL/VOX for 8 weeks and SOF/VEL for 12 weeks both provide simple, safe, and effective treatment regimens for patients with HCV genotype 3 and cirrhosis POLARIS-3 Jacobson IM. Gastroenterology 2017; 153:113-22