1. SOF/VEL 400/100 mg qd N = 106 W12 > 18 years Chronic HCV infection Genotype 1-6 Naïve or pre-treatment with IFN-based regimen Compensated cirrhosis allowed* Stable ART ≥ 8 weeks, CD4 ≥ 100/mm 3, HIV RNA ≤ 50 c/ml No HBV or HIV co-infection Open-label SVR 12 * Metavir F4 or Ishak 5-6 or Fibroscan > 12.5 kPa or Fibrotest > 0.75 and APRI > 2 ASTRAL-5  Design  Objective –SVR 12 (HCV RNA < 15 IU/ml), with 95% CI, by ITT ASTRAL-5 study: SOF/VEL in HIV coinfection Wyles D, EASL 2016, Abs. PS104, J Hepatol 2016;64:S188

2. Baseline characteristics ASTRAL-5 ASTRAL-5 study: SOF/VEL in HIV coinfection Wyles D, EASL 2016, Abs. PS104, J Hepatol 2016;64:S188 SOF/VEL N = 106 Mean age, years54 Female, %14 Race: Black, %45 Mean BMI, kg/m²27 Genotype: 1a / 1b / 2 / 3 / 4 (%)62 / 11 / 10 / 11 / 5 Mean HCV RNA, log 10 IU/ml6.3 IL28B CC, %23 Cirrhosis, %18 HCV treatment naïve, (%)71 Mean CD4 count, cells/µl598 NRTI backbone: TDF-based / ABC-based, %86 / 14 PI (DRV, LPV or ATV) / NNRTI (RPV) / II (RAL or EVG)47 / 12 / 34 Other (> 1 of the above classes)7

3. SVR 12 overall, by genotype and by cirrhosis or prior treatment, %  No impact of baseline NS5A RAVs: all 12 patients with baseline RAVS (cutoff 15%) achieved SVR 12 ASTRAL-5 ASTRAL-5 study: SOF/VEL in HIV coinfection Wyles D, EASL 2016, Abs. PS104, J Hepatol 2016;64:S188 0 20 40 60 80 100 95 104 Total 65 95 1a 12 92 1b 11 100 2 12 3 85 100 No Genotype 4 4 92 2 relapse 1 lost to follow-up 1 lost to follow-up 1 withdrew consent % 94 100 97 93 Cirrhosis Yes Treatment-naïve No 1 relapse 1 lost to follow-up 1 withdrew consent 1 relapse 2 relapses 1 lost to follow-up 1 withdrew consent N= 19 2975

4. Adverse events, % No HIV rebound ASTRAL-5 ASTRAL-5 study: SOF/VEL in HIV coinfection Wyles D, EASL 2016, Abs. PS104, J Hepatol 2016;64:S188 N = 106 Any adverse event71 Grade 3-4 AE8 Serious AE 2 (acute radial nerve palsy, toe infection/sepsis) Discontinuation due to adverse event2 Death0 Grade 3 or 4 laboratory abnormality18 Most common adverse events, % Fatigue25 Headache13 Arthralgia8 Upper respiratory tract infection8 Diarrhea8 Insomnia7 Nausea7

5.  Summary –SOF/VEL for 12 weeks resulted in overall 95% SVR 12 in HIV coinfected patients 100% SVR 12 in patients with cirrhosis 97% SVR 12 in patients with prior failure to HCV therapy –Presence of baseline RAVs did not impact efficacy –Treatment was safe and well tolerated, including with TDF-based boosted regimens ASTRAL-5 ASTRAL-5 study: SOF/VEL in HIV coinfection Wyles D, EASL 2016, Abs. PS104, J Hepatol 2016;64:S188