Complex Pattern of Resistance-Associated Substitutions of Hepatitis C Virus after Daclatasvir/Asunaprevir Treatment Failure

Analysis of the susceptibility of refractory hepatitis C virus resistant to nonstructural 5A inhibitors

Resistance-associated substitutions (RASs) of hepatitis C virus (HCV) affect the efficacy of direct-acting antivirals (DAAs). In this study, we aimed to clarify the susceptibility of the coexistence of nonstructural (NS) 5A Q24K/L28M/R30Q (or R30E)/A92K RASs, which were observed in patients with DAAs re-treatment failure and to consider new therapeutic agents. We used a subgenomic replicon system in which HCV genotype 1B strain 1B-4 was electroporated into OR6c cells derived from HuH-7 cells (Wild-type [WT]). We converted WT genes to NS5A Q24K/L28M/R30Q/A92K or Q24/L28K/R30E/A92K. Compared with the WT, the Q24K/L28M/R30Q/A92K RASs was 36,000-fold resistant to daclatasvir, 440,000-fold resistant to ledipasvir, 6300-fold resistant to velpatasvir, 3100-fold resistant to elbasvir, and 1.8-fold resistant to pibrentasvir. Compared with the WT, the Q24K/L28M/R30E/A92K RASs was 640,000-fold resistant to daclatasvir and ledipasvir, 150,000-fold resistant to velpatasvir, 44,000-fold resistant to elbasvir, and 1500-fold resistant to pibrentasvir. The Q24K/L28M/R30E/A92K RASs was 816.3 times more resistant to pibrentasvir than the Q24K/L28M/R30Q/A92K RASs. Furthermore, a combination of pibrentasvir and sofosbuvir showed therapeutic efficacy against these RASs. Combination regimens may eradicate HCV with NS5A Q24K/L28M/R30E/A92K RASs.

Ledipasvir/Sofosbuvir Is Effective for Relapsed Genotype 1b Hepatitis C Virus Patients after Achieving a Sustained Virological Response at Post-treatment Week 12 with Glecaprevir/Pibrentasvir

A patient with genotype 1b chronic hepatitis C virus who had been treated with pegylated interferon and ribavirin (RBV) was treated with glecaprevir/pibrentasvir (GLE/PIB) for 12 weeks. A sustained virological response at post-treatment week 12 (SVR12) was achieved, but relapse occurred approximately 31 weeks after the end of treatment. The patient had a history of allergy to RBV and was treated with ledipasvir/sofosbuvir (LDV/SOF), achieving SVR12 and remaining hepatitis C virus-negative until 24 weeks after the completion of treatment. LDV/SOF can thus be a secondary treatment for GLE/PIB.

Low Incidence of Hepatocellular Carcinoma after Antiviral Therapy in Patients with Chronic Hepatitis C and Hemophilia

Background: Hepatocellular carcinoma (HCC) rarely develops in patients with chronic hepatitis C (CHC) who achieve sustained virological response (SVR). We assessed the incidence of HCC in CHC patients with hemophilia after treatment with pegylated interferon plus ribavirin (PegIFN/RBV) and direct-acting antivirals (DAAs). Methods: Patients (n = 202) were enrolled between March 2007 and July 2019. A total of 139 patients were treated with PegIFN/RBV (genotype 1, n = 98; genotype 2, n = 41). Sixty-three patients were treated with DAAs (genotype 1, n = 44; genotype 2, n = 19). The cumulative incidence rates of HCC were estimated using the Kaplan−Meier method and compared using the log-rank test. Results: For genotype 1, SVR was achieved in 78.6% (77/98) and 90.9% (40/44) of patients in the PegIFN/RBV and DAAs groups, respectively. For genotype 2, SVR was achieved in 95.1% (39/41) and 94.7% (18/19) of patients in the PegIFN/RBV and DAAs groups, respectively. Six HCC cases were identified. The cumulative incidence of HCC was 4.1% at 14 years in PegIFN/RBV and 1.7% at 5 years in DAAs. The 14-year cumulative incidence of HCC was 1.9% in the SVR group and 21.7% in the no-SVR group in the PegIFN/RBV group (p < 0.001). Conclusions: Treatment with PegIFN/RBV led to stable SVR and a low incidence of HCC. Although the follow-up period was short, DAAs led to more stable SVR than PegIFN/RBV and a low incidence of HCC in CHC patients with hemophilia.

Treatment progress and expansion in Japan: From interferon to direct-acting antiviral

Hepatitis C virus (HCV) was first discovered in 1989, and patients infected with HCV were initially treated with interferon (IFN) monotherapy. In the 2000s, pegylated IFN combined with ribavirin was the mainstay of therapy for infected patients, but the sustained virologic response (SVR) rate was less than 50% for patients with HCV genotype 1. To further improve the therapeutic effect, direct-acting antiviral (DAA) was developed, and combination therapy with DAA and IFN has been available since 2011. In addition, IFN-free DAA therapy became available in 2014, and SVR was achieved in more than 95% of patients with chronic hepatitis and compensated cirrhosis. Thus, in just 30 years since the discovery of HCV, we aim to eliminate HCV in almost all patients. However, there are remaining issues to be addressed. Many of the patients who achieved SVR with DAA therapy had advanced liver fibrosis, and it is necessary to verify to what extent DAA therapy improves their prognosis in terms of liver function, hepatocellular carcinoma occurrence, and mortality. Resistance-associated substitutions can cause failure of DAA therapy, and the search for an effective therapy for high-level resistant viruses such as P32 deletion is particularly important. DAA therapy was approved for use in patients with decompensated cirrhosis in Japan in 2019, which is an unmet need so far. It is also important to verify the efficacy and safety in real-world settings. The World Health Organization aims to eliminate HCV by 2030, and Japan must tackle its remaining issues to achieve this goal.

An update on direct antiviral agents for the treatment of hepatitis C

Introduction: The development of direct-acting antiviral (DAA) agents for the treatment of hepatitis C virus (HCV) infection has completely transformed the management of this disease. The advantages of using DAA therapies include high efficacy (sustained virological response (SVR) rate >95%) with minimal side effects, good tolerability, easy drug administration (once daily oral dosing), and short duration of treatment (8-12 weeks). This transformative nature of DAA therapy underpins the goal of the World Health Organization to eliminate HCV infection as a public health threat by 2030.Areas covered: This review seeks to address the current status of DAA therapies, including recent developments, current limitations, and future challenges.Expert opinion: The current DAA regimens, with their high effectiveness and safety profiles, have changed patient perception of HCV infection from a disease that requires complex evaluation and long-term monitoring to a disease that can be cured after one visit to the general practitioner. Despite the remarkably high success rate of DAAs, few patients (4-5%) fail to obtain SVR even after treatment. Five years ahead, the landscape of HCV treatment will undoubtedly continue to evolve, and more pan-genotypic treatment options will be available to all patients.

Novel drug resistance-associated substitutions against pibrentasvir emerged in genotype 1b hepatitis C virus-infected human hepatocyte transplanted mice

Combination therapy with glecaprevir and pibrentasvir (PIB) has high efficacy for patients with hepatitis C virus (HCV) infection except among those who experienced NS5A-P32 deletion (del) mutation during prior DAA treatment failure. However, some patients fail to achieve SVR through combination treatment even in the absence of NS5A-P32del. We analyzed emergence of NS5A resistance-associated substitutions (RASs) against PIB using HCV-infected mice. Male human hepatocyte transplanted mice were infected with genotype 1b wild-type HCV. Mice were treated with PIB, resulting in a transient decrease in serum HCV RNA levels but followed by relapse during the treatment. Direct sequence analysis showed emergences of various mutations in the NS5A region, including L31V/P32del, L31F/P32del/Y93H, NS5A-P29del/Y85C, and NS5A-F37Y. PIB was less effective in mice with NS5A-F37Y mutations compared to mice with wild-type HCV. NS5A-F37Y showed 5.4-fold resistance to PIB relative to wild-type based on analysis using HCV subgenomic replicon systems. The present in vivo and in vitro studies identified NS5A-F37Y as a novel RAS against PIB and showed the possibility of emergence of various NS5A RASs including P29del, P32del and F37Y following PIB treatment. These mutations might emerge and lead to failure to respond to DAA therapies including PIB-based regimens in chronic hepatitis C patients.

Real-world safety and effectiveness of ledipasvir/sofosbuvir for the treatment of chronic hepatitis C virus genotype 1 in Japan

As patients with chronic hepatitis C virus (HCV) tend to be older and/or have advanced liver disease in Japan, real-world data are needed to evaluate safe and effective treatment options. The study aim was to assess safety and effectiveness of ledipasvir/sofosbuvir (LDV/SOF) in a real-world cohort of Japanese patients with HCV genotype (GT) 1 infection overall and by patient subgroups: elderly, compensated cirrhotic, advanced fibrotic and those with hepatocellular carcinoma (HCC). A large prospective observational study was conducted, enrolling adult patients treated for HCV GT1 infection with LDV/SOF at clinical sites across Japan. Patients were observed for safety outcomes during and 4 weeks after treatment, and for sustained virologic response at 12-weeks post-treatment (SVR12). Incidence rates (IRs) of adverse drug reactions (ADRs) and serious ADRs (SADRs) and SVR12 rates were assessed overall and by subgroups. ADR and SADR IRs were low (2.26 and 0.17 per 100 person-months, respectively) and did not significantly differ in elderly patients or those with presence of compensated cirrhosis, worsening fibrosis or HCC. SVR12 rates were high overall (98.5%) and across subgroups investigated (≥94%), including patients who were elderly (98.2%), treatment-experienced (97.6%), advanced fibrotic (≥95.8%), had existing NS5A resistance-associated substitutions reported pre-treatment (95.0%), compensated cirrhosis (95.7%), HCC (94.0%) and other chronic liver diseases (96.1%). In this large, real-world observational study of Japanese patients with HCV GT1 infection, LDV/SOF treatment resulted in low incidence of adverse events, with high real-world effectiveness, even among patients with potentially higher risks of adverse safety outcomes and treatment failure.

Efficacy and safety of glecaprevir and pibrentasvir combination therapy in old-aged patients with chronic hepatitis C virus infection

Objective: Combination therapy with glecaprevir and pibrentasvir (G/P) has been shown to provide a sustained virologic response (SVR) rate of >97% in patients with chronic hepatitis C virus (HCV) infection in the first published real-world Japanese data. However, a recently published study showed that the treatment was often discontinued in patients ≥75 years old, resulting in low SVR in intention-to-treat (ITT) analysis. Thus, our aim was to evaluate real-world data for G/P therapy in patients ≥75 years of age, the population density of which is high in “rural” regions.

Patients and Methods: We conducted a multicenter study to assess the efficacy and safety of G/P therapy for chronic HCV infection, in the North Kanto area in Japan.

Results: Of the 308 patients enrolled, 294 (95.5%) completed the treatment according to the protocol. In ITT and per-protocol analyses, the overall SVR12 rate was 97.1% and 99.7%, respectively. The old-aged patients group consisted of 59 participants, 56 of whom (94.9%) completed the scheduled protocol. Although old-aged patients tended to have non-SVR factors such as liver cirrhosis, history of HCC, and prior DAA therapies, the SVR12 rates in old-aged patients were 98.3% and 100% in the ITT and PP analyses, respectively. Of 308 patients enrolled, adverse events were observed in 74 patients (24.0%), with grade ≥3 events in 8 patients (2.6%). There was no significant difference in any grade and grade ≥3 adverse events between the old-aged group and the rest of the study participants. Only one patient discontinued the treatment because of adverse events.

Conclusion: G/P therapy is effective and safe for old-aged patients.

Features of resistance-associated substitutions after failure of multiple direct-acting antiviral regimens for hepatitis C

BACKGROUND & AIMS

We aimed to clarify the features of resistance-associated substitutions (RASs) after failure of multiple interferon (IFN)-free regimens in HCV genotype 1b infections.

METHODS

A total of 1,193 patients with HCV for whom direct-acting antiviral (DAA) treatment had failed were enrolled from 67 institutions in Japan. The RASs in non-structural protein (NS)3, NS5A, and NS5B were determined by population sequencing.

RESULTS

Failure of 1, 2, and 3 regimens was observed in 1,101; 80; and 12 patients, respectively. Among patients with failure of 1 regimen, Y56H and D168V in NS3 were more frequently detected after failure of paritaprevir, whereas D168E was more frequently detected after failure of regimens including asunaprevir. R30H and L31-RAS in NS5A were frequently detected after failure of regimens including daclatasvir. The prevalence of Y93-RAS was high irrespective of the regimen. S282T RAS in NS5B was detected in 3.9% of ledipasvir/sofosbuvir failures. The prevalence of D168-RAS increased significantly according to the number of failed regimens (p <0.01), which was similar to that seen with L31-RAS and Y93-RAS. The prevalence of patients with RASs in either NS3 or NS5A, or in both, increased significantly with increasing numbers of failed regimens. The P32del, which is unique to patients for whom DAA had failed, was linked to the absence of Y93H, the presence of L31F, and previous exposure to IFN plus protease inhibitor regimens.

CONCLUSIONS

Failure of multiple DAA regimens can lead to the generation of multiple RASs in the NS3 and NS5A regions of the HCV 1b genome. These mutations contribute to viral resistance to multiple treatment regimens and, therefore, should be considered during decision making for treatment of chronic HCV.

LAY SUMMARY

Resistance-associated substitutions (RAS) in the genome of the hepatitis C virus are 1 of the major causes for failed treatment. We investigated RASs after failure of various treatments for chronic hepatitis C, and found that more complicated RASs accumulated in the viral genome with successive failed treatments. The highly resistant P32del RAS at NS5A region was uniquely found in patients for whom DAA treatments had failed, and was linked to the presence and absence of specific RASs.

Viral and host factors are associated with retreatment failure in hepatitis C patients receiving all-oral direct antiviral therapy

AIM

Direct-acting antiviral (DAA) therapy for hepatitis C virus is associated with high sustained virologic response rates. However, patients for whom DAA therapy fails acquire resistance-associated substitutions (RASs). We therefore evaluated the efficacy of DAA retreatment and factors associated with retreatment failure.

METHODS

Non-structural 5A RASs were investigated at the start of DAA therapy and at treatment failure in 64 patients with hepatitis C virus genotype 1b for whom DAA combination therapy had failed. A total of 59 patients were introduced to DAA retreatment. The factors associated with retreatment failure were investigated.

RESULTS

A total of 20 of 43 (46.5%) daclatasvir + asunaprevir-treated patients with virologic failure had no RASs at baseline, and three (15%) acquired P32 deletion RASs. Four of seven sofosbuvir/ledipasvir-treated patients with virologic failure had more than two RASs of NS5A at baseline. The sustained virologic response rates on retreatment were as follows: sofosbuvir/ledipasvir, 81.8%; with elbasvir + grazoprevir, 0%; and glecaprevir/pibrentasvir, 87.5%. Patients for whom sofosbuvir/ledipasvir or elbasvir + grazoprevir failed achieved sustained virologic response with glecaprevir/pibrentasvir. Two of three patients for whom glecaprevir/pibrentasvir retreatment failed had Q24/L28/R30 and A92K RASs; the other had P32 deletion RAS at baseline. Interestingly, 10 of 11 patients with retreatment failure had the interleukin (IL)-28B single-nucleotide polymorphism (SNP) minor allele. A multivariate analysis showed that the IL28B SNP minor allele (P = 0.005, odds ratio 28.291) was an independent risk factor for retreatment failure.

CONCLUSIONS

In addition to viral factors (e.g. Q24, L28, R30, and A92 or P32 deletion RASs), host factors (e.g. IL28B SNP) are associated with DAA retreatment failure.

Durability of Sustained Virologic Response and Improvement of Fibrosis Markers after Daclatasvir and Asunaprevir Treatment in Genotype 1b Hepatitis C Virus-Infected Patients: a Real Life and Multicenter Study

BACKGROUND

The long-term data with direct acting antiviral agents were rare. This study investigated the durability of a sustained virologic response (SVR) and the improvement of fibrosis after daclatasvir and asunaprevir (DCV/ASV) treatment in genotype 1b (GT1b) hepatitis C virus (HCV)-infected patients.

METHODS

A total of 288 HCV GT1b patients without baseline non-structural 5A (NS5A) resistance-associated substitution (RAS) treated with DCV/ASV were enrolled. Virologic response was measured at 12 weeks and 1 year after treatment completion. In cirrhotic patients, liver function, aspartate transaminase to platelet ratio index (APRI), FIB-4 index, fibrosis index (FI), and liver stiffness measurement (LSM) at baseline and 1 year after treatment completion were evaluated.

RESULTS

SVR12 was obtained in 278 patients (96.5%). Six patients who checked NS5A RAS after treatment failure were RAS positive. Only one patient showed no durability of SVR. In cirrhotic patients who achieved SVR12 (n = 59), the changes of albumin (3.8 [2.2-4.7] to 4.3 [2.4-4.9] g/dL; P < 0.001), platelet count (99 [40-329] to 118 [40-399] × 10³/mm³; P < 0.001), APRI (1.8 [0.1-14.8] to 0.6 [0.1-4.8]; P < 0.001), FIB-4 index (5.45 [0.6-32.8] to 3.3 [0.4-12.2]; P < 0.001), FI (5.5 [0.6-32.8] to 3.3 [0.4-12.2]; P < 0.001), and LSM (17.2 [5.3-48.0] to 11.2 [3.7-28.1] kPa; P = 0.001) between baseline and 1 year after treatment completion were observed.

CONCLUSION

DCV/ASV treatment for HCV GT1b infected patients without RAS achieved high SVR rates and showed durable SVR. Cirrhotic patients who achieved SVR12 showed the improvement of liver function and fibrosis markers.

Real-world efficacy of elbasvir and grazoprevir for hepatitis C virus (genotype 1): A nationwide, multicenter study by the Japanese Red Cross Hospital Liver Study Group

AIM

The present study aimed to determine the real-world efficacy and safety of the non-structural protein (NS)5A inhibitor elbasvir (EBR) combined with the NS3/4A protease inhibitor grazoprevir (GZR) in patients with hepatitis C virus (HCV) genotype 1 (GT1) infection.

METHODS

This study retrospectively evaluated the rate of sustained virologic response at 12 weeks post-treatment (SVR12) and the safety of EBR/GZR treatment in 159 men and 194 women with a median age of 72 years, and it assessed factors associated with the SVR12 rate. The attending physicians were responsible for selecting candidate patients for EBR/GZR in this retrospective study.

RESULTS

Treatment outcomes for EBR/GZR were good in direct-acting antiviral (DAA)-naïve patients, of whom 99.4% achieved SVR. Of 353 patients, 10 (2.9%) had treatment failure. Of these patients, eight previously underwent DAA therapy, and the remaining two had NS5A-L31/Y93 double mutation. The SVR rate was 50% (8/16 patients) in patients who previously underwent DAA therapy, and 18.2% (2/11 patients) in patients with NS5A-L31/Y93 double mutation. On multivariate logistic regression analysis, NS5A-Y31/Y93 double mutation (odds ratio 356.3; 95% confidence interval, 23.91-16 940; P < 0.0001) was identified as an independent predictor of treatment failure. No serious adverse events were observed with EBR/GZR therapy.

CONCLUSIONS

The SVR rate of EBR/GZR would have been 100% in patients without either a history of DAA therapy or double mutation. This combination of drugs could be safely given and is, thus, considered a highly useful first-line treatment for DAA-naïve patients with HCV.

Worldwide prevalence of baseline resistance-associated polymorphisms and resistance mutations in HCV against current direct-acting antivirals

BACKGROUND

HCV infections can now be completely cured, thanks to the currently marketed direct-acting antivirals (DAAs). It is known that HCV patients carry viral populations with baseline polymorphisms and/or mutations that make them resistant against some of these DAAs, which can negatively impact the patient's treatment outcome. Using complete HCV coding sequences isolated from 1,306 treatment-naive patients of genotypes (GTs) 1, 2, 3, 4 and 6 from around the globe, we studied the prevalence of baseline resistance-associated polymorphisms (RAPs) and resistance mutations (RMs) against DAAs that are currently on the market or in clinical trials.

METHODS

The HCV genome sequences used in this study were retrieved from the NCBI database. RAPs and RMs, with reference to HCV GT1a, were identified using the HCV Geno2pheno web server.

RESULTS

Nearly 50% of the total amino acid positions (including NS3 protease, NS5A and NS5B) studied are baseline polymorphisms that differentiated one GT from the rest. A proportion of these baseline polymorphisms and baseline non-polymorphic RMs could confer a significant increase in resistance against DAAs.

CONCLUSIONS

In this study, we show the presence and prevalence of RAPs and RMs in DAA treatment-naive patients against currently used DAAs or DAAs in clinical trials. Our study suggests that RAPs and RMs profiling of HCV patients should be performed before the start of the therapy. Our results should be relevant especially in low- and middle-income countries, where the patients have a large variation of GTs and subtypes, and where the generic HCV treatment is now increasingly available.

Real-world virological efficacy and safety of daclatasvir/asunaprevir/beclabuvir in patients with chronic hepatitis C virus genotype 1 infection in Japan

BACKGROUND

The virological efficacy and safety of the direct-acting antiviral (DAA) regimen consisting of daclatasvir, asunaprevir, and beclabuvir (DCV/ASV/BCV) for patients chronically infected with hepatitis C virus (HCV) genotype 1 have not been previously evaluated in Japanese real-world settings.

METHODS

In a Japanese nationwide multicenter study, the rate of sustained virologic response (SVR) and safety were analyzed in 91 patients who started the DCV/ASV/BCV regimen between November 2016 and July 2017. SVR rates were compared based on baseline patient characteristics.

RESULTS

More than 60% of patients had a history of failure to achieve SVR with interferon (IFN)-free DAA therapy. Overall, 50 of 91 patients (54.9%) achieved SVR. Multivariate analysis identified a history of failure with IFN-free DAA therapy and pretreatment HCV RNA levels as factors significantly associated with treatment failure. Whereas the SVR rate in patients without a history of IFN-free DAA therapy was 91.7% (33 of 36 patients), it was only 30.9% (17 of 55 patients) among patients with a history of IFN-free DAA therapy. The rate of discontinuation due to an adverse event was 4.4%.

CONCLUSIONS

Many patients treated with the DCV/ASV/BCV regimen have a history of a failure to achieve SVR with previous IFN-free DAA therapy. SVR rate was not as high as that in pre-approval clinical trial of this regimen in IFN-free DAA-naïve patients. In addition, most patients with a history of failure with IFN-free DAA therapy, particularly the DCV/ASV regimen, showed resistance to this regimen.

Efficacy of glecaprevir and pibrentasvir treatment for genotype 1b hepatitis C virus drug resistance-associated variants in humanized mice

Combination therapy with glecaprevir (GLE) and pibrentasvir (PIB) has high efficacy for pan-genotypic hepatitis C virus (HCV)-infected patients. However, the efficacy for patients who acquired potent NS5A inhibitor resistance-associated variants (RAVs) as a result of failure to respond to previous direct-acting antiviral (DAA) therapies is unclear. We investigated the efficacy of GLE/PIB treatment for genotype 1b HCV strains containing RAVs using subgenomic replicon systems and human hepatocyte transplanted mice. Mice were injected with serum samples obtained from a DAA-naïve patient or daclatasvir plus asunaprevir (DCV/ASV) treatment failures including NS5A-L31M/Y93H, -P58S/A92K or -P32 deletion (P32del) RAVs, then treated with GLE/PIB. HCV was eliminated by GLE/PIB treatment in mice with wild-type and NS5A-L31M/Y93H but relapsed in mice with NS5A-P58S/A92K, followed by emergence of additional NS5A mutations after cessation of the treatment. In NS5A-P32del-infected mice, serum HCV RNA remained positive during the GLE/PIB treatment. NS5A-P58S/A92K showed 1.5-fold resistance to PIB relative to wild-type based on analysis using HCV subgenomic replicon systems. When mice were administered various proportions of HCV wild-type and P32del strains and treated with GLE/PIB, serum HCV RNA remained positive in mice with high frequencies of P32del. In these mice, the P32del was undetectable by deep sequencing before GLE/PIB treatment, but P32del strains relapsed after cessation of the GLE/PIB treatment. GLE/PIB is effective for wild-type and NS5A-L31M/Y93H HCV strains, but the effect seems to be low for P58S/A92K and NS5A-P32del RAVs. Although NS5A-P32del was not detected, the mutation may be present at low frequency in DCV/ASV treatment failures.

Glecaprevir and pibrentasvir for Japanese patients with chronic hepatitis C genotype 1 or 2 infection: Results from a multicenter, real-world cohort study

AIM

Glecaprevir (GLE) and pibrentasvir (PIB) are new direct-acting antiviral agents (DAAs) with pangenotypic inhibitors that respectively target the hepatitis C virus (HCV) NS3/4 protease and NS5A. The aim of this study was to evaluate the effectiveness and safety of combining GLE and PIB for patients with HCV genotype (GT) 1 or 2 infection in the clinical setting, including patients DAA-experienced or on hemodialysis.

METHODS

This multicenter, real-world, retrospective, cohort study consisted of 314 Japanese patients who were treated with GLE (300 mg) and PIB (120 mg) for a fixed 8- or 12-week duration. We evaluated the sustained virologic response rate 12 weeks after the end of treatment (SVR12) and adverse events.

RESULTS

Among the treated patients, 122 had GT1 and 192 GT2 infection. The overall SVR12 rates in the per-protocol populations were 99.2% (119/120) for GT1 and 98.9% (183/185) for GT2. High SVR12 rates were observed in almost all subgroups, including cirrhosis, receiving hemodialysis, or previous all-oral DAA groups treated with asunaprevir and daclatasvir (GT1b), ledipasvir/sofosbuvir (GT1), or sofosbuvir and ribavirin (GT2). Virological relapse occurred in only 1.0% (3/305) of the patients who completed treatment. The most common adverse events were pruritus and fatigue (>5% of patients). Serious adverse events were rare and discontinuation due to an adverse event was required for 1.6% of the patients.

CONCLUSIONS

In this real-world cohort study, treatment with GLE/PIB achieved high SVR12 rates with a low rate of serious adverse events among patients with HCV GT1 or 2 infection.

NS5A-P32 deletion as a factor involved in virologic failure in patients receiving glecaprevir and pibrentasvir

BACKGROUND

This study sought to clarify the factors involved in virologic failure in patients with HCV receiving retreatment with glecaprevir/pibrentasvir (GLE/PIB) in real-world practice.

METHODS

Forty-two patients who had previously received direct-acting antivirals (DAAs) therapies consisting of 35, 3, 3, and 1 patient(s) with genotype (GT)-1b, GT-2a, GT-2b, and GT-3b HCV, respectively, received GLE/PIB for 12 weeks. Resistance-associated substitutions (RASs) at baseline were evaluated, and the dynamics of NS5A-RASs were assessed by deep sequencing in patients showing virologic failure.

RESULTS

Baseline NS5A-RASs were found in all the patients with GT-1b HCV including 16 patients with NS3-RASs. In contrast, both NS5A-RASs and NS3-RASs were absent in 3 and 2 patients with GT-2a and GT-2b HCV, respectively. Virologic failure occurred in 3 patients with GT-1b HCV with NS5A-P32del, while a sustained virologic response (SVR) was achieved in the remaining 39 patients including those with GT-1b HCV carrying NS5A-L31V + Y93H and NS5A-A92K. Virologic failure even occurred in a patient in whom the NS5A-P32del HCV strains had become undetectable by direct sequencing, and the percentage of such strains relative to the total HCV strains was 10%, as determined by deep sequencing. In the other patient with GT-1b HCV with NS5A-P32del, NS3-A156A/V/S were found at 4 weeks after GLE/PIB therapy, but had disappeared at 11 weeks, as determined by direct sequencing.

CONCLUSIONS

GLE/PIB was effective for patients with HCV who failed to achieve an SVR after prior DAA therapies except in those with GT-1b HCV carrying NS5A-P32del even when such strains became undetectable by direct sequencing.

Resistance analysis of genotype 3 hepatitis C virus indicates subtypes inherently resistant to nonstructural protein 5A inhibitors

Hepatitis C virus (HCV) genotype (gt) 3 is highly prevalent globally, with non-gt3a subtypes common in Southeast Asia. Resistance-associated substitutions (RASs) have been shown to play a role in treatment failure. However, the role of RASs in gt3 is not well understood. We report the prevalence of RASs in a cohort of direct-acting antiviral treatment-naive, gt3-infected patients, including those with rarer subtypes, and evaluate the effect of these RASs on direct-acting antivirals in vitro. Baseline samples from 496 gt3 patients enrolled in the BOSON clinical trial were analyzed by next-generation sequencing after probe-based enrichment for HCV. Whole viral genomes were analyzed for the presence of RASs to approved direct-acting antivirals. The resistance phenotype of RASs in combination with daclatasvir, velpatasvir, pibrentasvir, elbasvir, and sofosbuvir was measured using the S52 ΔN gt3a replicon model. The nonstructural protein 5A A30K and Y93H substitutions were the most common at 8.9% (n = 44) and 12.3% (n = 61), respectively, and showed a 10-fold and 11-fold increase in 50% effect concentration for daclatasvir compared to the unmodified replicon. Paired RASs (A30K + L31M and A30K + Y93H) were identified in 18 patients (9 of each pair); these combinations were shown to be highly resistant to daclatasvir, velpatasvir, elbasvir, and pibrentasvir. The A30K + L31M combination was found in all gt3b and gt3g samples. Conclusion: Our study reveals high frequencies of RASs to nonstructural protein 5A inhibitors in gt3 HCV; the paired A30K + L31M substitutions occur in all patients with gt3b and gt3g virus, and in vitro analysis suggests that these subtypes may be inherently resistant to all approved nonstructural protein 5A inhibitors for gt3 HCV. (Hepatology 2018).

Impact of novel NS5A resistance-associated substitutions of hepatitis C virus detected in treatment-experienced patients

Resistance-associated substitutions (RASs) of hepatitis C virus (HCV) in the NS5A region impair the efficacy of NS5A inhibitors. In this study, we evaluated the characteristics of the novel RASs observed in treatment-failure patients, A92K and a deletion at P32 (P32del), and the susceptibility of viruses with these RASs to various anti-HCV reagents by using JFH-1 based recombinant HCV with NS5A from a genotype 1b Con1 strain (JFH1/5ACon1). We introduced A92K or P32del solely or in combination with Q24K, L28M, R30Q or L31F into the NS5A of JFH1/5ACon1. Viruses harboring R30Q/A92K showed high extracellular core antigens and infectivity titers, whereas the other viruses with RASs showed low replication levels and infectivity titers. All the viruses with A92K or P32del were markedly resistant to ledipasvir, velpatasvir and elbasvir. Interestingly, viruses with R30Q/A92K were more susceptible to grazoprevir than viruses without RAS. All the viruses had a similar susceptibility to ribavirin and sofosbuvir. In conclusion, combination RASs R30Q/A92K enhanced virus production whereas other RASs impaired virus replication. Both A92K and P32del conferred severe resistance even to second generation NS5A inhibitors. However, these viruses were susceptible to grazoprevir, ribavirin and sofosbuvir. Thus, combination regimens with these reagents may eradicate viruses harboring A92K or P32del.

Real-world efficacy of glecaprevir plus pibrentasvir for chronic hepatitis C patient with previous direct-acting antiviral therapy failures

BACKGROUND

Combination therapy with glecaprevir (GLE) and pibrentasvir (PIB) has high efficacy for pan-genotypic hepatitis C virus (HCV)-infected patients. However, the efficacy of the therapy for failures to prior direct-acting antiviral (DAA) regimens in real-world practice is not well known.

METHODS

Thirty patients infected with HCV genotype 1b, 2a, 2b, or 3a who failed to respond during prior DAA therapies were treated with GLE/PIB for 12 weeks. HCV NS3 and NS5A drug resistance-associated variants (RAVs) were determined by direct sequencing.

RESULTS

Twenty-eight out of 30 patients (93.3%) achieved SVR12 by GLE/PIB treatment. SVR12 rates were similar between patients with and without advanced liver fibrosis (94.7% and 91.0%, respectively). All 9 patients with genotype 2a, 2b, or 3a HCV infection achieved SVR12. However, two genotype 1b HCV-infected patients who failed previous daclatasvir plus asunaprevir treatment experienced HCV relapse after the end of GLE/PIB treatment. Direct sequence analysis showed the presence of NS3-D168E plus NS5A-L31I/P58S/Y93H RAVs in one patient and NS5A-L31F/P32del RAVs in another patient before GLE/PIB treatment. In the former patient, NS3-D168E plus NS5A-L31I/P58S/Y93H RAVs persisted, and additional NS5A-L28M/V75A variants emerged after HCV relapse.

CONCLUSIONS

GLE/PIB treatment for HCV-infected patients who did not respond to prior DAA treatments was highly effective regardless of liver fibrosis stage. However, some genotype 1b HCV-infected patients, especially those with NS5A-P32del, may have low susceptibility to the treatment.

Late relapse of hepatitis C virus in patients with sustained virological response after daclatasvir and asunaprevir therapy

The optimal term of follow-up for patients who achieve sustained virological responses (SVR) is an important topic because of the widespread use of direct-acting antivirals (DAA), which achieve a high SVR rate. Investigations of long-term follow-up among patients with SVR after interferon (IFN) therapy have reported that approximately 80%-100% of patients maintained SVR. However, the long-term durability of SVR to DAA treatment is unknown. The aim of this study was to evaluate the incidence of late relapse in patients who achieved SVR with daclatasvir (DCV) and asunaprevir (ASV). Four hundred and thirteen patients infected with hepatitis C virus (HCV) genotype 1b who completed ASV and DCV treatment and achieved SVR were selected. Patients who were persistently negative for serum HCV RNA at 24 weeks after withdrawal of DCV and ASV were considered to have SVR24. Mean follow-up period was 21.5 months (range, 4.8-30.3 months) after SVR24. Four patients redeveloped HCV RNA in serum at 6, 12, 12 and 26 months, respectively, after achieving SVR24. Results of molecular analysis by phylogenetic tree of HCV nonstructural protein 3 and 5A regions from late relapse indicated that the same strain was present at pretreatment and late relapse. In conclusion, late relapse by the original HCV strain was confirmed by direct sequencing in 4 of 413 patients with SVR to ASV and DCV. Although a few patients may develop late relapse, SVR achieved with all oral DAA therapy is as durable as that with IFN therapy.

Real-world efficacy and safety of ledipasvir and sofosbuvir in patients with hepatitis C virus genotype 1 infection: a nationwide multicenter study by the Japanese Red Cross Liver Study Group

BACKGROUND

We aimed to describe the real-world efficacy and safety of combination therapy with ledipasvir and sofosbuvir (LDV/SOF) for chronic hepatitis C virus (HCV) genotype 1 (GT1) infection.

METHODS

This retrospective analysis of a prospective, nationwide, multicenter registry included GT1-infected patients treated with LDV/SOF for 12 weeks. We assessed the rate of sustained virological response at 12 weeks post-treatment (SVR12), incidence of adverse events, and serum markers of hepatocellular carcinoma (HCC).

RESULTS

Among the 1461 patients included (mean age, 69 years; 29.5% aged > 75 years; cirrhosis, 23.8%; history of treatment for HCC, 10.9%), the overall SVR12 rate was 98.4% (1438/1461). Factors associated with treatment failure were cirrhosis (odds ratio, 4.19; p = 0.014) and resistance-associated substitutions (RASs) in NS5A at baseline (odds ratio, 7.78; p = 0.0004). The SVR12 rate in patients with cirrhosis and NS5A RASs was 93.0% compared to 100% in patients without cirrhosis or NS5A RASs. In patients with SVR, the levels of alpha-fetoprotein (AFP), AFP-L3, and Mac-2 binding protein glycosylation isomer (M2BPGi) decreased from baseline to end of treatment (from 13.4 ± 37.6 to 6.0 ± 10.6 ng/mL, p < 0.0001; from 2.2 ± 4.9 to 1.5 ± 6.3%, p < 0.005; and from 3.6 ± 3.7 to 2.0 ± 3.5 cut-off index, p < 0.0001; respectively). Adverse events were rare and not associated with age. No decrease in estimated glomerular filtration rate was observed in patients with baseline chronic kidney disease stage 3.

CONCLUSIONS

LDV/SOF therapy is highly effective and safe in elderly Japanese patients with HCV GT1, even in the presence of cirrhosis or NS5A RASs. Patients with SVR may have a lower risk of HCC.

Real-world safety and efficacy of sofosbuvir and ledipasvir for elderly patients

Background and Aim

In September 2015, sofosbuvir and ledipasvir were approved for clinical use in Japan for patients infected with genotype 1 hepatitis C virus. We conducted a postmarketing prospective cohort study to elucidate the safety and efficacy of this therapy in a real-world setting.

Methods

We treated 509 patients using standard doses of sofosbuvir and ledipasvir for 12 weeks. As sustained virological response (SVR) in 2 patients could not be evaluated, 507 patients were finally analyzed. Patients with daclatasvir plus asunaprevir failure were excluded.

Results

Four patients (0.8%) discontinued treatment due to adverse events. SVR rates for the overall cohort, patients <65 years old, ≥65 and <75 years old, and ≥75 years old were 98% (495/507), 98% (161/163), 96% (179/186), and 98% (155/158), respectively. SVR rates among cirrhotic patients, patients with moderate chronic kidney disease (CKD), patients with a history of hepatocellular carcinoma (HCC) treatment, patients with protease inhibitor (PI) triple therapy failure, and patients with resistance-associated substitutions (RASs) to nonstructural protein 5A (NS5A) were 97% (228/235), 98% (117/119), 95% (95/100), 94% (46/49), and 92% (44/48), respectively. In the comparison of factors between patients with and without SVR, high body weight, discontinuation of therapy, and NS5A RASs were significantly associated with non-SVR.

Conclusions

In this real-world setting, sofosbuvir and ledipasvir were a safe treatment even in patients ≥75 years old. When patients without pre-existing NS5A RASs and daclatasvir plus asunaprevir failure are selected, extremely high SVR rates can be achieved irrespective of age.

Efficacy of ledipasvir/sofosbuvir with or without ribavirin for 12 weeks in genotype 1b HCV patients previously treated with a nonstructural protein 5A inhibitor-containing regimen

AIM

The therapeutic benefit of adding ribavirin (RBV) to 12 weeks of ledipasvir/sofosbuvir (LDV/SOF) for patients who experienced failure of a previous nonstructural protein (NS) 5A inhibitor-containing regimen is unclear.

METHODS

A total of 29 genotype 1b HCV patients who had failed prior daclatasvir (DCV) plus asunaprevir (ASV) treatment were retreated for 12 weeks of LDV/SOF, with or without RBV. Antiviral efficacy and predictive factors associating with a sustained virological response at 24 weeks (SVR24) were evaluated retrospectively.

RESULTS

SVR24 was achieved in 67% (10/15) of patients who received LDV/SOF with, and 64% (9/14) without, RBV. The SVR24 rates were 80% in patients with, and 58% without, mild fibrosis (FIB-4 < 3.25). The SVR24 rate was lower with unfavorable IL28B rs8099917 SNP genotypes; specifically, the TT, TG and GG had SVR24 rates of 78%, 50% and 40%. The SVR24 rate was lower with a poor response to prior DCV plus ASV, where relapse, viral breakthrough and no response had SVR24 rates 71%, 58% and 0%. The SVR24 rate was lower with the number of NS5A resistance-associated substitutions (RAS), where 2, 3, 4 and 5 RAS had SVR24 rates of 78%, 67%, 50% and 0%. A patient with an NS5A-P32 deletion, which shows resistance to next-generation NS5A inhibitors, was retreated with LDV/SOF with RBV and achieved SVR24.

CONCLUSIONS

The addition of RBV to 12 weeks of LDV/SOF has little therapeutic benefit when retreating patients in whom a prior NS5A inhibitor-containing regimen had failed.

Efficacy of daclatasvir plus asunaprevir in patients with hepatitis C virus infection undergoing and not undergoing hemodialysis

AIM

To evaluate the virologic responses and clinical course of daclatasvir plus asunaprevir treatment in non-hemodialysis (non-HD) and hemodialysis (HD) patients infected with genotype 1 hepatitis C virus (HCV).

METHODS

A total of 1113 non-HD patients and 67 HD patients were assessed. To evaluate pretreatment factors contributing to sustained virological response at 12 weeks (SVR12), univariate and multivariate analyses were carried out. To adjust for differences in patient background, propensity score matching was undertaken.

RESULTS

The overall SVR12 rates were 91.6% in non-HD patients and 95.5% in HD patients. Compared with non-HD patients, HD patients were younger, were more likely to be male, were less likely to have received interferon-based pretreatment, had a lower viral load, and had lower levels of alanine transaminase, hemoglobin, and α-fetoprotein. Multivariate analysis revealed that viral load, α-fetoprotein, L31 substitution negative, and Y93 substitution negative were independent predictive factors for SVR12 in non-HD patients. The proportion of patients with undetectable HCV-RNA during the initial 4 weeks was significantly higher in HD patients than in non-HD patients. The SVR12 rate was clearly higher in HD patients than in non-HD patients, although the difference was not statistically significant. After propensity score matching to adjust for viral load, α-fetoprotein, L31 substitution, and Y93 substitution, these trends disappeared.

CONCLUSIONS

For treatment of HCV genotype 1 infection, daclatasvir plus asunaprevir is useful not only in non-HD patients but also in HD patients. Viral load, α-fetoprotein levels, L31 substitution, and Y93 substitution influence treatment course and outcome.

Sofosbuvir-velpatasvir plus ribavirin in Japanese patients with genotype 1 or 2 hepatitis C who failed direct-acting antivirals

BACKGROUND/PURPOSE

In Japan, there is a growing population of patients with chronic hepatitis C virus (HCV) infection who failed a direct-acting antiviral (DAA)-based regimen. In this Phase 3 study, we evaluated sofosbuvir-velpatasvir plus ribavirin in Japanese patients with genotype 1 or 2 HCV infection who previously received DAAs.

METHODS

Patients were randomized 1:1 to receive sofosbuvir-velpatasvir plus ribavirin for 12 or 24 weeks. Randomization was stratified by HCV genotype and presence of cirrhosis. The primary endpoint was sustained virologic response 12-week post-treatment (SVR12).

RESULTS

Of 117 participants, 81% had HCV genotype 1 infection, 33% had cirrhosis, and 95% had NS5A resistance-associated substitutions (RAS) at baseline. Overall, SVR12 rates were 97% (58/60; 95% CI 88-100%) with 24 weeks of treatment and 82% (47/57; 95% CI 70-91%) with 12 weeks. For HCV genotype 1 and 2 infected patients, the SVR12 rates with 24 weeks of treatment were 98% and 92%, respectively. In both treatment groups, SVR12 rates in HCV genotype 1 patients were statistically superior to a historical control rate of 50% (p < 0.001). For patients with NS5A RASs at baseline, 85% (46/54) in the 12-week group and 96% (54/56) in the 24-week group achieved SVR12. The most common adverse events were upper respiratory tract viral infection, anemia, and headache. Three (2.6%) patients discontinued treatment because of adverse events.

CONCLUSION

Sofosbuvir-velpatasvir plus ribavirin was highly effective and well tolerated in Japanese patients who previously failed a DAA-based regimen. Baseline NS5A RASs did not affect treatment outcomes.

Deferred treatment with sofosbuvir-velpatasvir-voxilaprevir for patients with chronic hepatitis C virus who were previously treated with an NS5A inhibitor: an open-label substudy of POLARIS-1

BACKGROUND

Direct-acting antiviral regimens containing NS5A inhibitors are highly effective treatments for chronic hepatitis C virus (HCV) infection, but are not always successful. In the POLARIS-1 phase 3 study, sofosbuvir-velpatasvir-voxilaprevir for 12 weeks was highly effective in the treatment of chronic HCV infection in patients previously treated with a direct-acting antiviral regimen containing an NS5A inhibitor. We aimed to assess the efficacy and safety of sofosbuvir-velpatasvir-voxilaprevir in patients from the deferred treatment group of POLARIS-1, who were initially assigned to masked placebo treatment.

METHODS

This open-label, deferred treatment substudy was done at 73 clinical sites (hospitals and clinics) in the USA, France, Canada, the UK, Germany, Australia, and New Zealand. Patients who received placebo in the primary study and who did not have a new clinically significant illness at the post-treatment week 4 assessment were eligible to enter this substudy. Participants received a combination tablet of sofosbuvir (400 mg), velpatasvir (100 mg), and voxilaprevir (100 mg) once daily for 12 weeks. The primary efficacy outcome was achievement of sustained virological response (defined as HCV RNA concentration below the lower limit of quantification) 12 weeks after the end of treatment (SVR12). The primary safety outcome was the proportion of patients who discontinued treatment due to adverse events. This study is registered with ClinicalTrials.gov, number NCT02607735, and the EU Clinical Trials Register, number 2015-003455-21.

FINDINGS

152 patients received placebo in the primary study and were potentially eligible for participation in the open-label substudy, of whom 147 were enrolled from March 30, 2016, to Oct 12, 2016. All 147 patients completed treatment, and 143 (97%; 95% CI 93-99) achieved SVR12. Four (3%) patients had virological relapse; all had HCV genotype 1a infection and one also had compensated cirrhosis. The most common adverse events were fatigue (31 [21%]), headache (29 [20%]), diarrhoea (28 [19%]), and nausea (21 [14%]). No deaths, treatment discontinuations, or treatment-related serious adverse events occurred.

INTERPRETATION

Supporting the results from the blinded portion of the phase 3 primary study, the single-tablet regimen of sofosbuvir-velpatasvir-voxilaprevir for 12 weeks was safe, well tolerated, and highly effective in patients with chronic HCV infection who had previous treatment failure with NS5A inhibitor-containing regimens. A salvage regimen for this population represents an important advance for patients with limited retreatment options.

FUNDING

Gilead Sciences.

The presence of multiple NS5A RASs is associated with the outcome of sofosbuvir and ledipasvir therapy in NS5A inhibitor-naïve patients with chronic HCV genotype 1b infection in a real-world cohort

It is unclear whether multiple nonstructural (NS) 5A resistance-associated substitutions (RASs) correlate with the outcome of sofosbuvir (SOF) and ledipasvir (LDV) therapy. We investigated the effects of multiple NS5A RASs in NS5A inhibitor-naïve patients with chronic hepatitis C virus genotype 1b infection treated with SOF/LDV. In 313 patients treated with SOF/LDV, we assessed the effects of multiple NS5A RASs on the sustained virological response (SVR). RASs at L28, R30, L31, Q54, P58, Q62, A92, and Y93 in the NS5A region were examined by direct sequencing. The prevalence of RASs was as follows: 2.6% at L28, 8.7% at R30, 6.1% at L31, 48.7% at Q54, 9.9% at P58, 9.9% at Q62, 5.1% at A92, 13.8% at Y93, and 19.2% at L31 or Y93. A total of 133 patients had no RASs. SVR was achieved in 98.7% of the patients. SVR rates significantly differed between patients with and without the L31 or Y93 RAS (93.0% [53/57] vs 100% [250/250], P = .0011). In addition, among patients with the L31 or Y93 RAS, 29.8%, 45.6% and 24.6% had one, two and three or more NS5A RASs, respectively. The SVR rate was significantly lower in patients with the L31 or Y93 RAS with more than three NS5A RASs compared to those with fewer than three NS5A RASs (71.4% [10/14] vs 100% [43/43], P = .0025). Although the prevalence of multiple NS5A RASs at baseline was low in NS5A inhibitor-naïve patients, the presence of multiple NS5A RASs was associated with the effectiveness of SOF/LDV therapy.

Prevalence of NS5A resistance associated variants in NS5A inhibitor treatment failures and an effective treatment for NS5A-P32 deleted hepatitis C virus in humanized mice

Patients with chronic hepatitis C virus (HCV) infection who have failed to respond to direct-acting antiviral (DAA) treatment often acquire drug resistance-associated variants (RAVs). The NS5A-P32 deletion (P32del) RAV confers potent resistance to NS5A inhibitors; therefore, patients who acquire this deletion are likely to fail to respond to DAA re-treatment. We investigated the prevalence of N55A-P32del in patients who failed to respond to prior NS5A inhibitor treatment using direct sequencing and analyzed the efficacy of DAA combination treatment in the presence of NS5A-P32del RAVs using human hepatocyte transplanted mice. NS5A-P32del was detected in one of 23 (4.3%) patients who had failed to respond to prior NS5A inhibitor treatment. Although four weeks of NS3/4A protease inhibitor glecaprevir plus NS5A inhibitor pibrentasvir treatment effectively suppressed HCV replication in wild-type HCV-infected mice, serum HCV RNA never became negative in P32del HCV-infected mice. When P32del HCV-infected mice were treated with four weeks of glecaprevir plus pibrentasvir combined with the NS5B polymerase inhibitor sofosbuvir, serum HCV RNA became negative, and the virus was eliminated from the liver in three out of four mice. We conclude that the combination of sofosbuvir and glecaprevir plus pibrentasvir may be an effective new treatment option for patients with NS5A-P32del.

Efficacy and safety of glecaprevir/pibrentasvir in HCV-infected Japanese patients with prior DAA experience, severe renal impairment, or genotype 3 infection

BACKGROUND

Once-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).

METHODS

This 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).

RESULTS

The 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.

CONCLUSIONS

G/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.

Integrated Resistance Analysis of CERTAIN-1 and CERTAIN-2 Studies in Hepatitis C Virus-Infected Patients Receiving Glecaprevir and Pibrentasvir in Japan

Glecaprevir and pibrentasvir are hepatitis C virus (HCV) pangenotypic inhibitors targeting NS3/4A protease and NS5A, respectively. This once-daily, fixed-dose combination regimen demonstrated high sustained virologic response 12 weeks postdosing (SVR12) rates in CERTAIN-1 and CERTAIN-2 studies in Japanese HCV-infected patients, with a low virologic failure rate (1.2%). There were no virologic failures among direct-acting antiviral (DAA)-treatment-naive genotype 1a (GT1a) (n = 4)-, GT1b (n = 128)-, and GT2 (n = 97)-infected noncirrhotic patients treated for 8 weeks or among GT1b (n = 38)- or GT2 (n = 20)-infected patients with compensated cirrhosis treated for 12 weeks. Two of 33 DAA-experienced and 2 of 12 GT3-infected patients treated for 12 weeks experienced virologic failure. Pooled resistance analysis, grouped by HCV subtype, treatment duration, prior treatment experience, and cirrhosis status, was conducted. Among DAA-naive GT1b-infected patients, the baseline prevalence of NS3-D168E was 1.2%, that of NS5A-L31M was 3.6%, and that of NS5A-Y93H was 17.6%. Baseline polymorphisms in NS3 or NS5A were less prevalent in GT2, with the exception of the common L/M31 polymorphism in NS5A. Among DAA-experienced GT1b-infected patients (30/32 daclatasvir plus asunaprevir-experienced patients), the baseline prevalence of NS3-D168E/T/V was 48.4%, that of NS5A-L31F/I/M/V was 81.3%, that of the NS5A P32deletion was 6.3%, and that of NS5A-Y93H was 59.4%. Common baseline polymorphisms in NS3 and/or NS5A had no impact on treatment outcomes in GT1- and GT2-infected patients; the impact on GT3-infected patients could not be assessed due to the enrollment of patients infected with diverse subtypes and the limited number of patients. The glecaprevir-pibrentasvir combination regimen allows a simplified treatment option without the need for HCV subtyping or baseline resistance testing for DAA-naive GT1- or GT2-infected patients. (The CERTAIN-1 and CERTAIN-2 studies have been registered at ClinicalTrials.gov under identifiers NCT02707952 and NCT02723084, respectively.).

Integrated Resistance Analysis of CERTAIN-1 and CERTAIN-2 Studies in Hepatitis C Virus-Infected Patients Receiving Glecaprevir and Pibrentasvir in Japan

Glecaprevir and pibrentasvir are hepatitis C virus (HCV) pangenotypic inhibitors targeting NS3/4A protease and NS5A, respectively. This once-daily, fixed-dose combination regimen demonstrated high sustained virologic response 12 weeks postdosing (SVR₁₂) rates in CERTAIN-1 and CERTAIN-2 studies in Japanese HCV-infected patients, with a low virologic failure rate (1.2%). There were no virologic failures among direct-acting antiviral (DAA)-treatment-naive genotype 1a (GT1a) (n = 4)-, GT1b (n = 128)-, and GT2 (n = 97)-infected noncirrhotic patients treated for 8 weeks or among GT1b (n = 38)- or GT2 (n = 20)-infected patients with compensated cirrhosis treated for 12 weeks. Two of 33 DAA-experienced and 2 of 12 GT3-infected patients treated for 12 weeks experienced virologic failure. Pooled resistance analysis, grouped by HCV subtype, treatment duration, prior treatment experience, and cirrhosis status, was conducted. Among DAA-naive GT1b-infected patients, the baseline prevalence of NS3-D168E was 1.2%, that of NS5A-L31M was 3.6%, and that of NS5A-Y93H was 17.6%. Baseline polymorphisms in NS3 or NS5A were less prevalent in GT2, with the exception of the common L/M31 polymorphism in NS5A. Among DAA-experienced GT1b-infected patients (30/32 daclatasvir plus asunaprevir-experienced patients), the baseline prevalence of NS3-D168E/T/V was 48.4%, that of NS5A-L31F/I/M/V was 81.3%, that of the NS5A P32deletion was 6.3%, and that of NS5A-Y93H was 59.4%. Common baseline polymorphisms in NS3 and/or NS5A had no impact on treatment outcomes in GT1- and GT2-infected patients; the impact on GT3-infected patients could not be assessed due to the enrollment of patients infected with diverse subtypes and the limited number of patients. The glecaprevir-pibrentasvir combination regimen allows a simplified treatment option without the need for HCV subtyping or baseline resistance testing for DAA-naive GT1- or GT2-infected patients. (The CERTAIN-1 and CERTAIN-2 studies have been registered at ClinicalTrials.gov under identifiers NCT02707952 and NCT02723084, respectively.).

Use of a hepatitis C virus (HCV) RNA-positive donor in a treated HCV RNA-negative liver transplant recipient

The shortage of livers has led most transplant centers to use extended criteria donors. Hepatitis C virus (HCV) RNA-positive donor organs are typically not given to patients who have cleared HCV. A 64-year-old male with chronic hepatitis C, genotype 1b was listed for LT with hepatocellular carcinoma. While on the waiting list, the patient was treated with sofosbuvir, ledipasvir, and ribavirin and achieved an HCV RNA <15 IU/mL by week 10. At week 18 of a planned 24-week treatment course, the patient underwent deceased-donor LT and received an organ from an anti-HCV-positive donor. Treatment was stopped at LT. At week 3 post LT, HCV RNA was detectable and revealed a genotype 3 HCV infection, compatible with transplantation of an organ with established infection. With retreatment with sofosbuvir, daclatasvir, and ribavirin for 12 weeks, the patient achieved a sustained virologic response. This report highlights how antiviral therapies can be used to optimize the outcomes of HCV-infected transplant patients.

Clinical evaluation of sofosbuvir/ledipasvir in patients with chronic hepatitis C genotype 1 with and without prior daclatasvir/asunaprevir therapy

AIM

This study explored treatment outcomes of sofosbuvir (SOF)/ledipasvir (LDV) therapy for chronic hepatitis C patients with and without prior daclatasvir (DCV)/asunaprevir (ASV) therapy.

METHODS

Overall, 530 Japanese patients who were infected with hepatitis C virus genotype 1 received SOF/LDV therapy for 12 weeks, and resistance-associated variants (RAVs) in the hepatitis C virus non-structural protein (NS)5A and NS5B regions were assessed at baseline and virological relapse by direct sequencing.

RESULTS

Sustained virological response (SVR) rates did not significantly differ between patients with and without NS5A Y93H/N (94.2% [113/120] vs. 97.7% [345/353]), but the SVR rate was significantly lower in patients with prior DCV/ASV therapy compared to those without (69.2% [18/26] vs. 98.4% [496/504], P < 0.001). Among 26 patients with prior DCV/ASV therapy, the prevalence of NS5A multi-RAVs (≥2) was similar between responders and non-responders (61% [11/18] vs. 75% [5/8]), but all patients without RAVs achieved SVR. Multivariate analysis showed that prior DCV/ASV therapy and history of hepatocellular carcinoma were independently associated with treatment failure (odds ratio, 37.55; 95% confidence interval, 10.78-130.76; P < 0.001 for prior DCV/ASV therapy; odds ratio, 4.42; 95% confidence interval, 1.09-18.04; P = 0.03 for the history of HCC). All SOF/LDV failure patients (n = 8) with prior DCV/ASV treatment had two or more factors of cirrhosis, IL28B unfavorable genotype, and baseline NS5A multi-RAVs. The multiple NS5A RAVs had increased but NS5B substitutions, C316N/A207T/A218S or L159F, had not changed at the time of relapse.

CONCLUSIONS

Prior DCV/ASV therapy is associated with failure of SOF/LDV therapy due to multiple RAVs.

Sofosbuvir (SOF) Suppresses Ledipasvir (LDV)-resistant Mutants during SOF/LDV Combination Therapy against Genotype 1b Hepatitis C Virus (HCV)

Our objective was to identify drug interactions between ledipasvir (LDV) and sofosbuvir (SOF) against a genotype 1b replicon to determine optimal exposures for each agent that will maximize antiviral activity against susceptible and drug-resistant subpopulations. LDV and SOF were evaluated using a fully factorial experimental design in the BelloCell system. Replicon levels and drug-resistant variants were quantified at various times post-therapy for 14 days and a high-dimensional mathematical model was fit to the data. Mutations associated with SOF resistance were not detected; but LDV-resistant mutants were selected and mutant subpopulations increased as exposure intensity increased. Combination therapy was additive for the total replicon population and the LDV-resistant population, but a threshold concentration of 100 ng/ml of SOF must be attained to suppress LDV-resistant subpopulations. These novel findings hold important implications for not only improving therapeutic outcomes, but also maximizing the clinical utility of LDV and SOF combination regimens.