Host innate recognition triggers key immune responses for viral elimination. The sensing mechanism of hepatitis B virus (HBV), a DNA virus, and the subsequent downstream signaling events remain to be fully clarified. Here we found that type III but not type I interferons are predominantly induced in human primary hepatocytes in response to HBV infection, through retinoic acid-inducible gene-I (RIG-I)-mediated sensing of the 5'-ε region of HBV pregenomic RNA. In addition, RIG-I could also counteract the interaction of HBV polymerase (P protein) with the 5'-ε region in an RNA-binding dependent manner, which consistently suppressed viral replication. Liposome-mediated delivery and vector-based expression of this ε region-derived RNA in liver abolished the HBV replication in human hepatocyte-chimeric mice. These findings identify an innate-recognition mechanism by which RIG-I dually functions as an HBV sensor activating innate signaling and to counteract viral polymerase in human hepatocytes.

BackgroundOnce-daily, orally administered, co-formulated glecaprevir (NS3/4A protease inhibitor) and pibrentasvir (NS5A inhibitor) (G/P) demonstrated pangenotypic activity and high sustained virologic response (SVR) rates in studies outside Japan. Here we report safety and efficacy in a subset of Japanese patients with chronic HCV infection who received G/P 300/120 mg in a phase 3, open-label, multicenter study (CERTAIN-1).MethodsThis analysis focuses on three difficult-to-treat subgroups: HCV GT1/2-infected patients who failed to achieve SVR after treatment with a direct acting antiviral (DAA)-containing regimen; GT1/2-infected patients with severe renal impairment (estimated glomerular filtration rate < 30 mL/min/1.73 m2); and GT3-infected patients. Patients in the renal impairment and GT3 cohorts were treatment-naive or interferon treatment-experienced. Noncirrhotic GT1/2-infected, DAA-naïve patients in the renal impairment cohort received G/P for 8 weeks; all other patients were treated for 12 weeks. Primary outcome was SVR (HCV RNA < 15 IU/mL) 12 weeks post-treatment (SVR12).ResultsThe study enrolled 33 GT1/2-infected patients who failed previous DAA treatment (four with cirrhosis); 12 GT1/2-infected patients with severe renal impairment (two with cirrhosis); and 12 GT3-infected patients (two with cirrhosis). SVR12 was achieved by 31/33 (93.9%), 12/12 (100%), and 10/12 (83.3%) patients, respectively. One serious adverse event (fluid overload, not related to G/P) occurred in a patient on chronic intermittent hemodialysis.ConclusionsG/P achieved high SVR12 rates and was well tolerated in three difficult-to-treat patient subgroups with limited treatment options in Japan (DAA-experienced patients, patients with severe renal impairment, and GT3-infected patients). These results support the potential suitability of this regimen for these special populations in Japan.Electronic supplementary materialThe online version of this article (doi:10.1007/s00535-017-1396-0) contains supplementary material, which is available to authorized users.

BackgroundThe once-daily, all oral, RBV-free, pangenotypic direct-acting anti-viral regimen consisting of co-formulated NS3/4A protease inhibitor glecaprevir and NS5A inhibitor pibrentasvir (G/P), demonstrated high rates of sustained virologic response (SVR) in phase 2 and 3 studies outside Japan.MethodsCERTAIN-1 is a phase 3, open-label, multicenter study assessing the safety and efficacy of G/P (300/120 mg) once daily in Japanese patients with chronic HCV GT1 infection. Patients without cirrhosis received 8 weeks of G/P or 12 weeks of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r, 25/150/100 mg); patients with cirrhosis received G/P for 12 weeks. The primary efficacy endpoint was non-inferiority of G/P compared to OBV/PTV/r by assessing SVR at post-treatment week 12 (SVR12) among non-cirrhotic patients without the NS5A Y93H polymorphism.ResultsSVR12 was achieved by 128/129 (99.2%; one patient lost to follow-up) non-cirrhotic patients in the 8-week G/P Arm (including 23/23 patients with the NS5A Y93H polymorphism) and 52/52 (100%) patients in the 12-week OBV/PTV/r Arm. No patients from the G/P Arm prematurely discontinued the study drug or experienced a treatment-emergent serious adverse event (TESAE). Three patients from the OBV/PTV/r Arm experienced five TESAEs and one of these patients discontinued the study drug due to TESAEs. All 38 (100%) patients with compensated cirrhosis achieved SVR12; in this group, no TESAEs were reported and one patient discontinued treatment due to an AE.ConclusionsCERTAIN-1 study results demonstrate high efficacy and favorable tolerability of G/P in GT1-infected Japanese patients including those with the NS5A Y93H polymorphism, with no virologic failures observed.Electronic supplementary materialThe online version of this article (doi:10.1007/s00535-017-1391-5) contains supplementary material, which is available to authorized users.

Glecaprevir (nonstructural protein 3/4A protease inhibitor) and pibrentasvir (nonstructural protein 5A inhibitor) (G/P), a coformulated once‐daily, all oral, ribavirin (RBV)‐free, direct‐acting antiviral regimen, was evaluated for safety and efficacy in hepatitis C virus genotype 2 (GT2)–infected Japanese patients, including those with compensated cirrhosis. CERTAIN‐2 is a phase 3, open‐label, multicenter study assessing the safety and efficacy of G/P (300/120 mg) once daily in treatment‐naive and interferon ± RBV treatment–experienced Japanese patients without cirrhosis but with GT2 infection. Patients were randomized 2:1 to receive 8 weeks of G/P (arm A) or 12 weeks of sofosbuvir (400 mg once daily) + RBV (600‐1000 mg weight‐based, twice daily) (arm B). The primary endpoint was noninferiority of G/P compared to sofosbuvir + RBV by assessing sustained virologic response at posttreatment week 12 (SVR12) among patients in the intent‐to‐treat population. SVR12 was also assessed in treatment‐naive and interferon ± RBV treatment‐experienced patients with GT2 infection and compensated cirrhosis who received G/P for 12 weeks in the CERTAIN‐1 study. A total of 136 patients were enrolled in CERTAIN‐2. SVR12 was achieved by 88/90 (97.8%) patients in arm A and 43/46 (93.5%) patients in arm B. No patient in arm A experienced virologic failure, while 2 did in arm B. The primary endpoint was achieved. In CERTAIN‐1, 100% (18/18) of GT2‐infected patients with compensated cirrhosis achieved SVR12. Treatment‐emergent serious adverse events were experienced by 2 patients without cirrhosis in each arm and no patient with cirrhosis. Conclusion: The results demonstrate high efficacy and favorable tolerability of G/P in GT2‐infected Japanese patients. (Hepatology 2018;67:505‐513).

In patients with chronic hepatitis C; combined interferon and cyclosporin A treatment was more effective than interferon monotherapy. The benefit was mostly achieved in patients with a high viral load and HCV genotype 1.