STARTVerso1: A randomized trial of faldaprevir plus pegylated interferon/ribavirin for chronic HCV genotype-1 infection.

BACKGROUND & AIMS: The efficacy and tolerability of faldaprevir, a potent hepatitis C virus (HCV) NS3/4A protease inhibitor, plus peginterferon (PegIFN) and ribavirin (RBV) was assessed in a double-blind, placebo-controlled phase 3 study of treatment-naïve patients with HCV genotype-1 infection. METHODS: Patients were randomly assigned (1:2:2) to PegIFN/RBV plus: placebo (arm 1, n = 132) for 24 weeks; faldaprevir (120 mg, once daily) for 12 or 24 weeks (arm 2, n = 259); or faldaprevir (240 mg, once daily) for 12 weeks (arm 3, n = 261). In arms 2 and 3, patients with early treatment success (HCV-RNA <25 IU/ml at week 4 and undetectable at week 8) stopped all treatment at week 24. Other patients received PegIFN/RBV until week 48 unless they met futility criteria. The primary endpoint was sustained virologic response 12 weeks post-treatment (SVR12). RESULTS: SVR12 was achieved by 52%, 79%, and 80% of patients in arms 1, 2, and 3, respectively (estimated difference for arms 2 and 3 vs. arm 1: 27%, 95% confidence interval 17%-36%; and 29%, 95% confidence interval, 19%-38%, respectively; p < 0.0001 for both). Early treatment success was achieved by 87% (arm 2) and 89% (arm 3) of patients, of whom 86% and 89% achieved SVR12. Adverse event rates were similar among groups; few adverse events led to discontinuation of all regimen components. CONCLUSIONS: Faldaprevir plus PegIFN/RBV significantly increased SVR12, compared with PegIFN/RBV, in treatment-naïve patients with HCV genotype-1 infection. No differences were seen in responses of patients given faldaprevir once daily at 120 or 240 mg.

Restoration of HCV-specific CD8+ T cell function by interferon-free therapy.

BACKGROUND & AIMS: Chronic hepatitis C virus (HCV) infection is characterised by a failure of virus-specific CD8+ T cells that is mainly caused by viral escape and T cell exhaustion. Constant antigen stimulation has been suggested to contribute to HCV-specific CD8+ T cell exhaustion. However, IFN-based therapies failed to recover HCV-specific CD8+ T cell function suggesting that the damage to CD8+ T cells may be permanent even after antigen removal. It was therefore the objective of this study to analyse the impact of inhibition of ongoing viral replication by IFN-free therapy with direct acting antivirals (DAA) on the phenotype and function of HCV-specific CD8+ T cells. METHODS: Virus-specific CD8+ T cells obtained from a patient cohort of 51 previously untreated chronically infected patients undergoing IFN-free therapy with a combination of faldaprevir (a protease inhibitor) and deleobuvir (a non-nucleoside polymerase inhibitor) with or without ribavirin were analysed ex vivo and after in vitro expansion at baseline, wk4, wk 12, and after treatment. RESULTS: Our results show the rapid restoration of proliferative HCV-specific CD8+ T cells in the majority of patients with SVR12 within 4 weeks of therapy suggesting that IFN-free therapy mediated antigen removal may restore CD8+ T cell function. CONCLUSIONS: This study indicates a specific restoration of proliferative HCV-specific CD8+ T cells under IFN-free therapy. This is in contrast to PegIFN-based therapies that have been shown not to restore T cell function during and after chronic infection.

Faldaprevir combined with pegylated interferon alfa-2a and ribavirin in treatment-naïve patients with chronic genotype 1 HCV: SILEN-C1 trial.

UNLABELLED: Faldaprevir (BI 201335) is a potent, hepatitis C virus (HCV) NS3/4A protease inhibitor with pharmacokinetic properties supportive of once-daily (QD) dosing. Four hundred and twenty-nine HCV genotype (GT)-1 treatment-naïve patients without cirrhosis were randomized 1:1:2:2 to receive 24 weeks of pegylated interferon alfa-2a and ribavirin (PegIFN/RBV) in combination with placebo, faldaprevir 120 mg QD with 3 days of PegIFN/RBV lead-in (LI), 240 mg QD with LI, or 240 mg QD without LI, followed by an additional 24 weeks of PegIFN/RBV. Patients in the 240 mg QD groups achieving maintained rapid virologic response (mRVR; viral load [VL] <25 IU/mL at week 4 and undetectable at weeks 8-20) were rerandomized to cease all treatment at week 24 or continue receiving PegIFN/RBV up to week 48. VL was measured by Roche TaqMan. Sustained virologic response (SVR) rates were 56%, 72%, 72%, and 84% in the placebo, faldaprevir 120 mg QD/LI, 240 mg QD/LI, and 240 mg QD groups. Ninety-two percent of mRVR patients treated with faldaprevir 240 mg QD achieved SVR, irrespective of PegIFN/RBV treatment duration. Eighty-two percent of GT-1a patients who received faldaprevir 240 mg QD achieved SVR versus 47% with placebo. Mild gastrointestinal disorders, jaundice resulting from isolated unconjugated hyperbilirubinemia, and rash or photosensitivity were more common in the active groups than with placebo. Discontinuations resulting from adverse events occurred in 4%, 11%, and 5% of patients treated with 120 mg QD/LI, 240 mg QD/LI, and 240 mg QD of faldaprevir versus 1% with placebo. CONCLUSION: Faldaprevir QD with PegIFN/RBV achieved consistently high SVR rates with acceptable tolerability and safety at all dose levels. The 120 and 240 mg QD doses are currently undergoing phase 3 evaluation. (HEPATOLOGY 2013;57:2143-2154).

Faldaprevir combined with peginterferon alfa-2a and ribavirin in chronic hepatitis C virus genotype-1 patients with prior nonresponse: SILEN-C2 trial.

UNLABELLED: Faldaprevir (BI 201335) is a potent, hepatitis C virus (HCV) NS3/4A protease inhibitor. In all, 290 noncirrhotic HCV genotype (GT)-1 patients with prior null (<1 log10 viral load [VL] drop at any time on treatment) or partial response (≥1 log10 VL drop but never undetectable on treatment) were randomized 2:1:1 to receive 48 weeks of peginterferon alfa-2a and ribavirin (PegIFN/RBV) in combination with faldaprevir 240 mg once daily (QD) with 3 days PegIFN/RBV lead-in (LI), 240 mg QD without LI, or 240 mg twice daily (BID) with LI. Patients in the 240 mg QD/LI group achieving maintained rapid virologic response (mRVR; VL <25 IU/mL [Roche TaqMan] at week 4 and undetectable at weeks 8 to 20) were rerandomized to cease all treatment at week 24 or continue PegIFN/RBV up to week 48. Sustained virologic response (SVR) rates were 32%, 50%, and 42% in prior partial responders, and 21%, 35%, and 29% in prior null responders in the faldaprevir 240 mg QD/LI, 240 mg QD, and 240 mg BID/LI groups, respectively. In the 240 mg QD/LI group, a significantly higher proportion of mRVR patients rerandomized to 48 weeks' treatment achieved SVR compared with those assigned to 24 weeks treatment (72% versus 43%; P = 0.035). Rates of gastrointestinal disorders, jaundice, dry skin, and photosensitivity were increased at 240 mg BID compared with the 240 mg QD dose. Faldaprevir discontinuations owing to adverse events occurred in 6%, 4%, and 23% of patients in the 240 mg QD/LI, 240 mg QD, and 240 mg BID/LI groups, respectively. CONCLUSION: Faldaprevir 240 mg QD with PegIFN/RBV was safe and tolerable and produced substantial SVR rates in prior null and partial responders. The 240 mg QD dose is currently undergoing phase 3 evaluation.

Rapid and strong antiviral activity of the non-nucleosidic NS5B polymerase inhibitor BI 207127 in combination with peginterferon alfa 2a and ribavirin.

BACKGROUND & AIMS: BI 207127 is a potent non-nucleoside hepatitis C virus (HCV) NS5B polymerase inhibitor in vitro. METHODS: In this double-blind, placebo-controlled study, 57 HCV genotype (GT)-1 patients (n=27 treatment-naïve [TN]; n=30 treatment-experienced [TE]) with compensated liver disease were randomised for 28-day treatment with 400, 600, or 800 mg BI 207127 three times daily (TID) or placebo (only TN) in combination with peginterferon alfa 2a and ribavirin (PegIFN/RBV). Plasma HCV RNA was measured by Roche COBAS TaqMan assay. RESULTS: HCV RNA decreased in a dose-dependent manner with little difference between 600 mg (TN 5.6 log(10), TE 4.2 log(10)) and 800 mg (TN 5.4 log(10), TE 4.5 log(10)). Rapid virological response (RVR; HCV RNA <15 IU/ml) at day 28 occurred in 11/19 TN and 4/30 TE patients treated with BI 207127. GT-1b patients had stronger reductions in HCV RNA than GT-1a (RVR: TN 64% vs. 43%; TE 33% vs. 5%). There were no breakthroughs (HCV RNA rebound >1 log(10) from nadir) in the TN groups, whereas 3/30 TE patients experienced breakthrough due to P495-mutations. Gastrointestinal adverse events (AEs) and rash were the major AEs and most frequent at higher doses. One and four patients discontinued due to AEs in the 600 and 800 mg groups, respectively. Overall, tolerability was good and better at 600 mg than 800 mg. CONCLUSIONS: BI 207127 in combination with PegIFN/RBV demonstrated strong antiviral activity with a favourable safety and tolerability profile. The best benefit/risk ratio was observed at 600 mg.

Potency, safety, and pharmacokinetics of the NS3/4A protease inhibitor BI201335 in patients with chronic HCV genotype-1 infection.

BACKGROUND & AIMS: BI201335 is a highly specific and potent HCV protease inhibitor. This multiple rising dose trial evaluated antiviral activity and safety in chronic HCV genotype-1 patients. METHODS: Thirty-four treatment-naïve patients were randomized to monotherapy with placebo or BI201335 at 20-240 mg once-daily for 14 days, followed by combination with pegylated interferon alfa/ribavirin (PegIFN/RBV) through Day 28. Nineteen treatment-experienced patients received 48-240 mg BI201335 once-daily with PegIFN/RBV for 28 days. HCV-RNA was measured with Roche COBAS TaqMan. RESULTS: In treatment-naïve patients, median maximal viral load (VL) reductions during 14-day monotherapy were -3.0, -3.6, -3.7, and -4.2 log(10) for the 20, 48, 120, and 240 mg groups. VL breakthroughs (≥1 log(10) from nadir) were seen in most patients on monotherapy and were caused by NS3/4A variants (R155K, D168V) conferring in vitro resistance to BI201335. Adding PegIFN/RBV at Days 15-28 led to continuous viral load reductions in most patients. In treatment-experienced patients, treatment with BI201335 and PegIFN/RBV achieved VL<25 IU/ml at Day 28 in 3/6, 4/7, and 5/6 patients in the 48, 120, and 240 mg dose groups. VL breakthroughs were observed during triple combination in only 3/19 patients. BI201335 was generally well tolerated. Mild rash or photosensitivity was detected in four patients. Mild unconjugated hyperbilirubinemia was the only dose-dependent laboratory abnormality of BI201335. BI201335 elimination half-life supports once-daily dosing. CONCLUSIONS: BI201335 combined with PegIFN/RBV was well tolerated and induced strong antiviral responses. These results support further development of BI201335 in HCV genotype-1 patients.

Faldaprevir (BI 201335), deleobuvir (BI 207127) and ribavirin oral therapy for treatment-naive HCV genotype 1: SOUND-C1 final results.

BACKGROUND: Faldaprevir (BI 201335) and deleobuvir (BI 207127) are direct-acting antiviral agents under development for the treatment of chronic HCV infection. This article describes the final results of the Phase Ib SOUND-C1 study that evaluated the interferon-free oral combination of faldaprevir, deleobuvir and ribavirin in 32 treatment-naive patients infected with HCV genotype 1. METHODS: Patients were randomized to receive deleobuvir 400 mg (n=15) or 600 mg (n=17) three times daily plus faldaprevir 120 mg once daily and weight-based ribavirin for 4 weeks. Interferon-free therapy was followed by response-guided faldaprevir plus pegylated interferon-α2a/ribavirin to week 24 or 48. RESULTS: At week 4, 73% (11/15) and 100% (17/17) of patients in the deleobuvir 400 mg and 600 mg groups achieved HCV RNA<25 IU/ml, respectively. During interferon-free treatment, virological breakthrough was reported in one patient and re-increase of HCV RNA in one patient. Both patients were successfully treated with interferon-containing therapy. The rate of sustained virological response 24 weeks after completion of treatment was 73% (11/15) in the deleobuvir 400 mg group and 94% (16/17) in the 600 mg group. During faldaprevir plus pegylated interferon-α2a/ribavirin treatment, the most common adverse events were pruritus (38% of patients), rash (31%) and asthenia (31%); these were severe in approximately 3% of patients. CONCLUSIONS: Potent antiviral activity and favourable safety of the treatment regimen were demonstrated. Furthermore, the results suggest that patients with breakthrough at week 4 may be rescued with an interferon-containing regimen. Clinical trials.gov number NCT01132313.

Development and validation of a high-throughput screening assay for the hepatitis C virus p7 viroporin.

The HCV p7 protein is not involved in viral RNA replication but is essential for production of infectious virus. Based on its putative ion channel activity, p7 belongs to a family of viral proteins known as viroporins that oligomerize after insertion into a lipid membrane. To screen for compounds capable of interfering with p7 channel function, a low-throughput liposome-based fluorescent dye permeability assay was modified and converted to a robust high-throughput screening assay. Escherichia coli expressing recombinant p7 were grown in high-density fed-batch fermentation followed by a detergent-free purification using a combination of affinity and reversed-phase chromatography. The phospholipid composition of the liposomes was optimized for both p7 recognition and long-term stability. A counterscreen was developed using the melittin channel-forming peptide to eliminate nonspecific screening hits. The p7 liposome-based assay displayed robust statistics (Z' > 0.75), and sensitivity to inhibition was confirmed using known inhibitors.