1. AI444040 Study  Design SOF 1W then DCV + SOF 23W DVC + SOF Randomisation* 1 : 1 : 1 Open-label AI444040 Study: DCV + SOF + RBV for genotypes 1, 2 and 3 W12W24 18-70 years Chronic HCV infection Genotype 1, 2, 3 HCV RNA ≥ 100,000 IU/ml No cirrhosis (Fibrotest ≤ 0.72 and APRI ≤ 2) No HBV or HIV co-infection Sulkowski MS. NEJM 2014;370:211-21 DCV + SOF + RBV Protocol amendment 123 additional patients Genotype 1 Randomisation 1 : 1 Open-label N = 15 N = 14 N = 15 SOF 1W then DCV + SOF 23W DVC + SOF DCV + SOF + RBV N = 16 N = 14 Genotype 1 naïve Genotypes 2, 3 naïve DCV + SOF DCV + SOF + RBV DVC + SOF DCV + SOF + RBV Treatment naïve Treatment experienced Failure to prior PI-based therapy N = 41 N = 20 N = 21 N = 41

2. Drug regimenN Genotype N Female % Fibrosis score HCV RNA, log 10 IU/ml, mean IL28B CC SOF 1W + DCV + SOF 23W16 2, N = 9 3, N = 7 31% F0-F1 : 6 F4 : 3 6.550% DCV + SOF + RBV 24W14 2, N = 8 3, N = 6 57% F0-F1 : 6 F4 : 1 6.836% DCV + SOF 24W14 2, N = 9 3, N = 5 64% F0-F1 : 6 F4 : 2 6.650% SOF 1W + DCV + SOF 23W15 1a, N = 11 1b, N = 4 53% F0-F1 : 4 F4 : 3 6.527% DCV + SOF 24W14 1a, N = 10 1b, N = 4 36% F0-F1 : 6 F4 : 1 6.657% DCV + SOF + RBV 24W15 1a, N = 11 1b, N = 4 53% F0-F1 : 6 F4 : 2 6.727% Baseline characteristics and dosing of medication  DCV : 60 mg qd  SOF : 400 mg qd  RBV (bid dosing) : weight based in genotype 1 : 1000 mg/day if < 75 kg or 1200 mg/day if ≥ 75 kg ; 800 mg/day in genotype 2 or 3 ; dose reduction to 600 mg/day if hemoglobin decreased < 10g/dL AI444040 Study Sulkowski MS. NEJM 2014;370:211-21 AI444040 Study: DCV + SOF + RBV for genotypes 1, 2 and 3

3. Drug regimenN Genotype N Female % Fibrosis score HCV RNA, log 10 IU/ml, mean IL28B CC DCV + SOF 12W41 1a, N = 34 1b, N = 7 51% F0-F1 : 15 F4 : 6 6.222% DCV + SOF + RBV 12W41 1a, N = 33 1b, N = 8 49% F0-F1 : 13 F4 : 5 6.437% DCV + SOF 24W21 1a, N = 16 1b, N = 5 38% F0-F1 : 2 F4 : 3 6.35% DCV + SOF + RBV 24W20 1a, N = 17 1b, N = 3 40% F0-F1 : 3 F4 : 6 6.30 Baseline characteristics (second cohort) and Objective  Primary efficacy endpoint : SVR 12 (HCV RNA < 25 IU/ml) by mITT analysis  Secondary endpoints : SVR 4 SVR 24 Safety : adverse events, discontinuation for adverse events, grade 3-4 laboratory abnormalities AI444040 Study Sulkowski MS. NEJM 2014;370:211-21 AI444040 Study: DCV + SOF + RBV for genotypes 1, 2 and 3

4. HCV RNA < 25 IU/ml Drug regimenGenotypeNSVR 12 SVR 24 SOF 1W + DCV + SOF 23W2 + 3Naïve1688% DCV + SOF 24W2 + 3Naïve1493%100% DCV + SOF + RBV 24W2 + 3Naïve1486%93% SOF 1W + DCV + SOF 23W1a + 1bNaïve15100%93% DCV + SOF 24W1a + 1bNaïve14100% DCV + SOF + RBV 24W1a + 1bNaïve15100% DCV + SOF 12W1a + 1bNaïve41100%95% DCV + SOF + RBV 12W1a + 1bNaïve4195%93% DCV + SOF 24W1a + 1b Failure on prior PI therapy 21100%- DCV + SOF + RBV 24W1a + 1b Failure on prior PI therapy 2095%- HCV RNA < 25 IU/ml  All patients had HCV RNA < 25 IU/ml at end of treatment, except 1 in group B (DCV + SOF 24W) AI444040 Study Sulkowski MS. NEJM 2014;370:211-21 AI444040 Study: DCV + SOF + RBV for genotypes 1, 2 and 3

5.  Virologic relapse post-treatment : 1 patient with genotype 3 who did not received RBV –NS5A A30K polymorphism (DCV resistance) at baseline and failure  Resistance testing (sequencing) –NS5A polymorphisms associated with loss of susceptibility to DCV in vitro detected at baseline in 32 patients : 8% in genotype 1, 61% in genotype 2, 28% in genotype 3 –Most frequent mutations : Q30H (genotype 1a), L31M (genotype 1b and 2), Y93H (genotype 3) –Except the patient with relapse, all other patients with preexisting DCV resistant variants had a SVR –No mutation (S282T) to SOF at baseline or in the patient with breakthrough AI444040 Study Sulkowski MS. NEJM 2014;370:211-21 AI444040 Study: DCV + SOF + RBV for genotypes 1, 2 and 3

6.  Adverse events –Most common : fatigue, headache, nausea (≥ 25% in any group) –Grade 3-4 adverse events : 7 (3.3%) –Discontinuation of treatment for adverse events : 2 (both achieved SVR) DCV-SOF 24W : 1 cerebrovascular accident DCV-SOF + RBV 24W : 1 fibromyalgia exacerbation –Serious adverse events : 10 (4.7%) –Most common grade 3-4 laboratory abnormalities : low phosphorus and elevation of glucose levels –Hemoglobin level more reduced in groups with RBV Reduction of RBV dose in 5 patients because of anemia AI444040 Study Sulkowski MS. NEJM 2014;370:211-21 AI444040 Study: DCV + SOF + RBV for genotypes 1, 2 and 3

7.  Summary –DCV + SOF was assessed in untreated patients and patients in whom previous treatment with telaprevir or boceprevir had failed – Most patients had a SVR, including 98% of patients with genotype 1 infection, regardless of viral subtype or failure of prior treatment with PI, and 91% of naïve patients infected with genotype 2 or 3 – The most common adverse event was fatigue, which was reported in approximately one third of patients –Virologic breakthrough and relapse were rare and were not observed in any of the patients infected with HCV genotype 1 or 2, despite preexisting DCV-resistant variants in 14% –In genotype 3, 1 relapse in a patient with baseline DCV-resistant variant –No additional benefit of RBV addition but greater decrease in hemoglobin AI444040 Study Sulkowski MS. NEJM 2014;370:211-21 AI444040 Study: DCV + SOF + RBV for genotypes 1, 2 and 3