Resistance Analyses of Japanese Hepatitis C-Infected Patients Receiving Sofosbuvir or Ledipasvir/Sofosbuvir Containing Regimens in Phase 3 Studies

An Increase in the Prevalence of Clinically Relevant Resistance-Associated Substitutions in Four Direct-Acting Antiviral Regimens: A Study Using GenBank HCV Sequences

Direct-acting antivirals (DAAs) revolutionized the therapeutics of chronic hepatitis C. The emergence and transmission of HCV variants with resistance-associated substitutions (RASs) can undermine HCV treatment. This study aimed to assess the prevalence and temporal trends of RASs in HCV, with a particular focus on clinically relevant RASs (cr-RASs). Near-complete HCV GenBank sequences archived in the Los Alamos HCV Database were analyzed. The study period was divided into two phases: before 2011 and from 2011 onward. Identification of RASs across three DAA classes (NS3, NS5A, and NS5B inhibitors) was based on the 2020 EASL guidelines. The AASLD-IDSA recommendations were used to identify cr-RASs for three HCV genotypes/subtypes (1a, 1b, and 3) and four DAA regimens: ledipasvir/sofosbuvir; elbasvir/grazoprevir; sofosbuvir/velpatasvir; and glecaprevir/pibrentasvir. The final HCV dataset comprised 3443 sequences, and the prevalence of RASs was 50.4%, 60.2%, and 25.3% in NS3, NS5A, and NS5B, respectively. In subtype 1a, resistance to ledipasvir/sofosbuvir was 32.8%, while resistance to elbasvir/grazoprevir was 33.0%. For genotype 3, resistance to sofosbuvir/velpatasvir and glecaprevir/pibrentasvir was 4.2% and 24.9%, respectively. A significant increase in cr-RASs was observed across the two study phases as follows: for ledipasvir/sofosbuvir in subtype 1a, cr-RASs increased from 30.2% to 35.8% (p = 0.019); for elbasvir/grazoprevir in subtype 1a, cr-RASs increased from 30.4% to 36.1% (p = 0.018); In subtype 1b, neither ledipasvir/sofosbuvir nor elbasvir/grazoprevir showed any cr-RASs in the first phase, but both were present at a prevalence of 6.5% in the second phase (p < 0.001); for sofosbuvir/velpatasvir in genotype 3, cr-RASs increased from 0.9% to 5.2% (p = 0.006); and for glecaprevir/pibrentasvir, cr-RASs increased from 12.0% to 29.1% (p < 0.001). The rising prevalence of HCV RASs and cr-RASs was discernible. This highlights the necessity for ongoing surveillance and adaptation of novel therapeutics to manage HCV resistance effectively. Updating the clinical guidelines and treatment regimens is recommended to counteract the evolving HCV resistance to DAAs.

World-wide Prevalence of Substitutions in HCV Genome Associated With Resistance to Direct-Acting Antiviral Agents

BACKGROUND & AIMS

The efficacy of direct-acting antiviral agents against hepatitis C virus (HCV) infection can be compromised by substitutions in the HCV genome that occur before treatment (resistance-associated substitutions [RASs]). We performed a meta-analysis to determine the prevalence of RASs and their effects.

METHODS

We searched publication databases for studies of HCV RNA substitutions that mediate resistance to direct-acting antiviral agents. Findings from 50 studies of the prevalence of RAS in HCV, from 32 countries, were used in a meta-analysis. We retrieved the HCV RNA sequence from the Los Alamos HCV sequence database to estimate the prevalence of the RASs. The degree of resistance to treatment conferred by each RAS was determined based on fold-change in the 50% effective concentration of the drugs.

RESULTS

Our final analysis included data from 49,744 patients with HCV infection and 12,612 HCV sequences. We estimated the prevalence of 56 RASs that encoded amino acids and 114 specific RASs. The average prevalence of RASs was highest in HCV genotype (GT) 6, followed by HCV GT1a, GT2, GT1b, GT3, and GT4. The highest prevalence of RASs observed encoded Q80K in NS3 to NS4A of HCV GT1a, Y93T in NS5A of GT1a, and C316N in NS5B of GT1b. The greatest number of RASs were observed at D168 in NS3 to NS4A, at Y93 in NS5A, and at C316 in NS5B. The prevalence of RASs and mutation burdens were high in Japan, the United States, Germany, Thailand, and the United Kingdom; low in Russia, Brazil, Egypt, and India; and intermediate in China, Canada, Australia, Spain, and France.

CONCLUSIONS

In a meta-analysis, we found evidence for 114 RASs in HCV of different genotypes. Patients with HCV infection should be tested for RASs before treatment is selected, especially in regions with a high prevalence of RASs.

Follow-Up of Patients Who Achieved Sustained Virologic Response after Interferon-Free Treatment against Hepatitis C Virus: Focus on Older Patients

Background and Objectives: Direct-acting antiviral agents (DAAs) have improved sustained virologic response (SVR) rates in patients with chronic hepatitis C virus (HCV) infection. Our aim was to elucidate the occurrence of hepatocellular carcinoma (HCC) and to compare the outcomes of patients aged 75 years or older (older group) with those of patients younger than 75 years (younger group) after SVR. Materials and Methods: Among 441 patients treated with interferon-free DAA combinations, a total of 409 SVR patients were analyzed. We compared the two age groups in terms of HCC incidence and mortality rates. Results: Older and younger groups consisted of 68 and 341 patients, respectively. Occurrence of HCC after SVR did not differ between the two groups of patients with a history of HCC. Occurrence of HCC after SVR was observed more in younger patients without a history of HCC (p < 0.01). Although older patients without a history of HCC had a higher mortality rate (p < 0.01), their causes of death were not associated with liver diseases. Among younger patients without a history of HCC, none died. Conclusions: After SVR, liver disease may not be a prognostic factor in older HCV patients without a history of HCC.

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.

Prevalence of HCV resistance-associated substitutions among treatment-failure patients receiving direct-acting antiviral agents

Direct-acting antiviral (DAA) failure, which is mainly associated with the selection of resistance-associated substitutions (RASs), is not rare in HCV treatment. RAS data collected from published literature and RAS prevalence were integrated using meta-analysis. DAA-failure-associated RASs were identified by comparing their prevalence between DAA-failure and DAA-naïve patients. Prevalences of emerging RASs that occurred during treatment were also estimated. A total of 2932 DAA-naïve patients and 1466 DAA-failure patients were included. Significant differences in the prevalence of RASs were found in 76 scenarios that involved 34 RASs (11 in NS3, 18 in NS5A and 5 in NS5B), 4 genotypes (GTs) (GT1a, GT1b and GT3-4) and 14 DAAs (6 NS3 protease inhibitors [PIs], 6 NS5A inhibitors and 2 NS5B inhibitors). For NS3, the DAA-failure-associated RASs included V36L, Y56H, Q80K/R, R155K, A156T and D168A/E/L/T/V/Y. Substitutions at R155 and D168 were dominant for most NS3 PIs. For NS5A, DAA-failure-associated RASs included K24R, Q30R, L31M, and P32L in GT1a; R30Q/H, L31F/I/M/V, P58S, and Y93H in GT1b; A30K, L31M and Y93H in GT3; and M31V and Y93H in GT4. Y93H was the most prevalent RAS for NS5A inhibitors. DAA-failure-associated RASs were found at only five positions in NS5B. The majority of DAA-failure patients relapsed. A significant difference was detected for only four RAS sites between relapse patients and nonresponse/breakthrough patients. The RAS prevalence in DAA-failure patients varied among the HCV GTs and DAA regimens. The identified treatment-selected resistance patterns for broadly used DAA regimens will enable the selection of optimized retreatment options.

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.

Resistance-associated substitution and ledipasvir/sofosbuvir therapy in Mongolian chronic hepatitis C patients

BACKGROUND

Mongolia has the highest prevalence of hepatitis C virus (HCV) infection worldwide. Ledipasvir/sofosbuvir (LDV/SOF) was introduced to Mongolia since 2016 for HCV eradication. It has been reported that HCV resistance-associated substitutions (RASs) would affect the effectiveness of LDV/SOF in western chronic hepatitis C (CHC) patients. We thus investigated the effectiveness of LDV/SOF and the impact of RAS on the treatment outcome in Mongolian CHC patients.

METHODS

Patients with genotype (GT) 1b HCV infection were prospectively enrolled in Mongolia and treated with LDV/SOF for 12 weeks. The proportion of pre-treatment NS5A Y93H RAS in viral quasispecies was measured with next-generation sequencing. The endpoint of LDV/SOF effectiveness was sustained virological response at post-treatment week 12 (SVR12).

RESULTS

A total of 94 CHC patients were evaluated. The baseline Y93H proportion was <1% in 74 patients, 1-15% in 7, 15-50% in 2, and ≥50% in 11. All patients completed 12-week LDV/SOF treatment and the SVR rate was 90.4%. The rate of failure to achieve SVR12 for patients with Y93H < 1%, 1-15%, and ≥15% were 0%, 14.3%, and 61.5%, respectively (p for trend = 0.001). In univariable analysis, older age, baseline alanine transaminase level <40 U/mL, and a higher proportion of Y93H were associated with treatment failure. In multivariable analysis, only a higher proportion of Y93H was associated with treatment failure (p = 0.022).

CONCLUSION

LDV/SOF therapy achieves a high SVR rate in Mongolian CHC GT1b patients without baseline Y93H RAS. A higher proportion of Y93H may severely undermine the effectiveness of LDV/SOF.

Exploring the hepatitis C virus genome using single molecule real-time sequencing

Single molecular real-time (SMRT) sequencing, also called third-generation sequencing, is a novel sequencing technique capable of generating extremely long contiguous sequence reads. While conventional short-read sequencing cannot evaluate the linkage of nucleotide substitutions distant from one another, SMRT sequencing can directly demonstrate linkage of nucleotide changes over a span of more than 20 kbp, and thus can be applied to directly examine the haplotypes of viruses or bacteria whose genome structures are changing in real time. In addition, an error correction method (circular consensus sequencing) has been established and repeated sequencing of a single-molecule DNA template can result in extremely high accuracy. The advantages of long read sequencing enable accurate determination of the haplotypes of individual viral clones. SMRT sequencing has been applied in various studies of viral genomes including determination of the full-length contiguous genome sequence of hepatitis C virus (HCV), targeted deep sequencing of the HCV NS5A gene, and assessment of heterogeneity among viral populations. Recently, the emergence of multi-drug resistant HCV viruses has become a significant clinical issue and has been also demonstrated using SMRT sequencing. In this review, we introduce the novel third-generation PacBio RSII/Sequel systems, compare them with conventional next-generation sequencers, and summarize previous studies in which SMRT sequencing technology has been applied for HCV genome analysis. We also refer to another long-read sequencing platform, nanopore sequencing technology, and discuss the advantages, limitations and future perspectives in using these third-generation sequencers for HCV genome analysis.

Identification of 19 Novel Hepatitis C Virus Subtypes-Further Expanding HCV Classification

Background

Hepatitis C virus (HCV) is currently classified into 8 genotypes and 86 subtypes. The objective of this study was to characterize novel HCV subtypes and to investigate the impact of subtypes on treatment outcome.

Methods

Full-genome sequencing was performed on HCV plasma samples with <85% sequence homology of NS3, NS5A, and/or NS5B to HCV genotype (GT) 1–8 reference strains.

Results

A total of 14 653 patients with GT1–6 HCV infection were enrolled in clinical studies of sofosbuvir-based regimens. For the majority of the patients, a specific subtype could be assigned based on a close genetic relationship to previously described subtypes. However, for 19 patients, novel subtypes were identified with <85% homology compared with previously described subtypes. These novel subtypes had the following genotypes: 9 in GT2, 5 in GT4, 2 in GT6, and 1 each in GT1, GT3, and GT5. Despite the presence of polymorphisms at resistance-associated substitution positions, 18 of the 19 patients treated with sofosbuvir-containing therapy achieved SVR12.

Conclusions

Nineteen novel HCV subtypes were identified, suggesting an even greater genetic diversity of HCV subtypes than previously recognized.

Sustained virologic response after eight weeks of treatment with sofosbuvir, ledipasvir, and ribavirin in a decompensated cirrhotic patient with hepatitis C virus genotype 1b

A 68-year-old Japanese man with decompensated cirrhosis due to hepatitis C virus (HCV) genotype 1b infection was treated with sofosbuvir (SOF; 400 mg/day), ledipasvir (LDV; 90 mg/day), and ribavirin (RBV; 400 mg/day). Before treatment, his Child-Pugh and Model for End-Stage Liver Disease (MELD) scores were 10 (class C) and 13 points, respectively. Although RBV was initially given at two-thirds the normal dose due to anemia, his hemoglobin level gradually declined, and RBV was reduced to 200 mg daily on day 11, and 200 mg every other day on day 14. His alanine aminotransferase level gradually decreased during combination therapy; and HCV-RNA was undetectable on day 28. He complained of fatigue from day 49, and RBV was ceased. On day 56, he asked to discontinue treatment because of strong fatigue and insomnia. As hepatic encephalopathy occurred just after the cessation of direct-acting antivirals, diuretics were discontinued, and treatment with synthetic disaccharides and intractable antibiotics were given, after which his consciousness returned to normal. Ascites gradually disappeared, and a sustained virologic response (SVR) was achieved. At 1.5 years after treatment, his Child-Pugh and MELD scores had improved to 6 (class A) and 10 points, respectively. Although he did not experience hepatic encephalopathy during the observation period, his blood ammonia concentration persistently increased. We reported a case of decompensated cirrhosis in a patient who achieved SVR with SOF/LDV plus RBV for 8 weeks. Although his liver function improved after treatment, careful long-term observation is required for complications of liver cirrhosis, even after HCV elimination.

Overview of Direct-Acting Antiviral Drugs and Drug Resistance of Hepatitis C Virus

The advent of direct-acting antivirals (DAAs) has brought about a sudden renaissance in the treatment of chronic hepatitis C virus (HCV) infection with SVR rates now routinely >90%. However, due to the error-prone nature of the HCV RNA polymerase, resistance-associated substitutions (RASs) to DAAs may be present at baseline and can result in a significant effect on treatment outcomes and hamper the achievement of sustained virologic response. By further understanding the patterns and nature of these RASs, it is anticipated that the incidence of treatment failure will continue to decrease in frequency with the development of drug regimens with increasing potency, barrier to resistance, and genotypic efficacy. This review summarizes our current knowledge of RASs associated with HCV infection as well as the clinical effect of RASs on treatment with currently available DAA regimens.

Utilization and efficacy of elbasvir/grazoprevir for treating hepatitis C virus infection after liver transplantation

AIM

Recently, elbasvir/grazoprevir combination therapy (EBR/GZR) was reported to have excellent antiviral effects for chronic genotype 1 hepatitis C virus (HCV) infection. However, it has not been recommended for patients with post-liver transplant (LT) HCV re-infections because of a lack of evidence for effectiveness and drug-drug interactions.

METHODS

We report the usage of EBR/GZR in five post-LT HCV re-infected patients with the kinetics of renal function and tacrolimus trough levels during and after therapy. Furthermore, to evaluate the antiviral effects, we examined the HCV kinetics during and after therapy and compared this with other interferon-free therapy in post-LT patients (n = 19).

RESULTS

All patients treated with EBR/GZR therapy obtained rapid virologic response and sustained at 12 weeks post-treatment. There was no evidence of worsening estimated glomerular filtration rates. Three patients were given tacrolimus as immunosuppressive therapy and its trough levels were controllable with dosage adjustments. One patient developed grade 1 diarrhea 3 days after therapy induction. To evaluate the antiviral effects of EBR/GZR therapy for these patients, we compared them to the effects of daclatasvir/asunaprevir combination therapy (n = 8) and sofosbuvir/ledipasvir combination therapy (n = 11). The EBR/GZR combination was not inferior to other therapies in its early phase and late-phase antiviral effects.

CONCLUSIONS

Although further studies with a larger number of patients are required, we suggest that EBR/GZR therapy is an alternative therapy for patients with post-LT genotype 1 HCV re-infection.

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.

Prediction of the very early occurrence of HCC right after DAA therapy for HCV infection

BACKGROUND

Although direct-acting antiviral (DAA) developments make most of hepatitis C virus (HCV) infection curable, some HCV patients develop hepatocellular carcinoma (HCC) after curative treatment of HCV. There is much dispute whether the rapid clearance of the virus enhances the HCC development. In advance of the dispute, we should make clear the characteristics of the patients with very early occurrence and recurrence of HCC after DAA therapy because it was still unclear.

METHODS

We prospectively followed consecutive patients with HCV who had received sofosbuvir (SOF)-based treatment at two hospitals. The baseline characteristics, laboratory data, and liver imaging findings were acquired. We evaluated the rate of HCC occurrence and recurrence within 1-year after DAA therapy and analyzed the associated factors of very early HCC occurrence and recurrence right after SOF therapy.

RESULTS

Between July 2013 and October 2016, we studied two cohorts with HCV infection that received SOF therapy. 402 and 462 patients in Yamanashi Central Hospital and Chiba University Hospital were included in this analysis, respectively. The SVR12 rates of genotypes 1 and 2 were 98.9% (561/567) and 96.0% (285/297), respectively. 41 patients developed HCC within 1 year after SOF therapy. The cumulative HCC occurrence and recurrence rate after SOF therapy was 5.0%. The common associated factor of 1-year HCC occurrence and recurrence in all cohorts was the existence of imaging "dysplastic nodule".

CONCLUSIONS

SOF regimens for HCV also have very high rates of SVR 12 in the post-market distribution. The appearance of imaging "dysplastic nodule" was an associated factor of 1-year HCC occurrence and recurrence. To investigate existence of "dysplastic nodule" by imaging surveillance before DAA treatment is useful to detect high-risk patients of very early HCC occurrence and recurrence and it should be performed.

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.

The co-existence of NS5A and NS5B resistance-associated substitutions is associated with virologic failure in Hepatitis C Virus genotype 1 patients treated with sofosbuvir and ledipasvir

OBJECTIVE

The present study aimed to reveal the factors associated with virologic failure in sofosbuvir and ledipasvir (SOF/LDV)-treated patients, and identify baseline NS5A or NS5B resistance-associated substitutions (RASs).

METHODS

Four hundred ninety-three patients with Hepatitis C Virus (HCV) genotype 1b infection were treated with SOF/LDV; 31 had a history of interferon (IFN)-free treatment with daclatasvir and asunaprevir. The effect of baseline RASs on the response to SOF/LDV therapy was analyzed.

RESULTS

Overall, a sustained virologic response at 12 weeks (SVR12) was achieved in 476 patients (96.6%). The SVR12 rates in the patients with IFN-free treatment-naïve and retreatment were 97.6% and 80.6%, respectively. HCV elimination was not achieved in 17 patients, 11 (including 5 with IFN-free retreatment) of whom had virologic failure. Eight patients had coexisting NS5A RASs of Q24, L28 and/or R30, L31, or Y93 and one patient had coexisting NS5A RASs of P32L and A92K. Interestingly, 10 and 8 patients had NS5B A218S and C316N RAS respectively. According to a multivariate analysis, coexisting NS5A RASs, NS5A P32 RAS, NS5B A218 and/or C316 RASs, and γ-glutamyltranspeptidase were associated with virologic failure. In the naïve patients, all patients without NS5B A218 and/or C316 RAS achieved an SVR12. Notably, the SVR12 rates of patients with coexisting NS5A and NS5B RASs were significantly lower (83.3%).

CONCLUSIONS

Although SOF/LDV therapy resulted in a high SVR12 rate, coexisting NS5A and NS5B RASs were associated with virologic failure. These results might indicate that the coexisting baseline RASs influence the therapeutic effects of SOF/LDV.

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.

Efficacy and safety of ledipasvir/sofosbuvir for genotype 1b chronic hepatitis C patients with moderate renal impairment

BACKGROUND/AIM

To evaluate the efficacy and safety of ledipasvir and sofosbuvir therapy for genotype 1b in chronic hepatitis C patients with chronic kidney disease (CKD) stage 3.

METHODS

In a multicenter collaborative retrospective study, 706 patients who have received ledipasvir which is NS5A inhibitor, and sofosbuvir 400 mg which is NS5B nucleoside polymerase inhibitor daily for 12 weeks between September 2015 and January 2017 were subjected to this analysis. Virologic response and adverse events in patients with CKD stage 3 were compared with those in patients with CKD stages 1 and 2.

RESULTS

The rates of sustained virologic response (SVR) were 97.0% in patients with CKD stage 1, 97.1% in patients with CKD stage 2, and 94.7% in patients with CKD stage 3, respectively. There were no significant differences in the SVR rates between CKD stages 1 and 2, and CKD stage 1 and stage 3. The incidence of adverse events over than grade 2 was 0% in patients with CKD stage 1, 0.5% in patients with CKD stage 2, and 3.0% in patients with CKD stage 3, respectively. For treatment and follow-up period, eGFR levels in the patients with CKD stage 3 were not worsened compared to those at baseline.

CONCLUSION

This study suggested that the virologic response of ledipasvir and sofosbuvir in patients with CKD stage 3 was not inferior to those with CKD stages 1 and 2. In addition, administration of ledipasvir and sofosbuvir did not affect eGFR levels in the patients with CKD stage 3.

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.).

Efficacy of direct-acting antiviral treatment for chronic hepatitis C: A single hospital experience

AIM

To evaluate the efficacy of direct-acting antivirals (DAAs) in Kanto Rosai Hospital.

METHODS

All patients with hepatitis C virus (HCV) who underwent DAA prescription were enrolled in this study. The present study was a single center retrospective analysis using patients infected with HCV genotype 1 or 2. Resistance analysis was performed by using direct sequencing and cycleave PCR in genotype 1 patients treated with interferon (IFN)-free DAA. The primary endpoint was sustained virologic response at 12 wk after therapy (SVR12).

RESULTS

A total of 117 patients participated in the study, including 135 with genotype 1 and 42 with genotype 2. Of the 135 patients with genotype 1, 16 received protease inhibitor + IFN + ribavirin and all achieved SVR. Of the 119 patients who received IFN-free DAA (in different combinations), 102 achieved SVR and 9 failed (7/9 were on daclatasvir/asunaprevir and 2/9 on ledipasvir/sofosbuvir). Efficacy analysis was done only for 43 patients who received daclatasvir/asunaprevir. From this analysis, Y93 resistance-associated substitutions were significantly correlated with SVR.

CONCLUSION

The SVR rate was 98% for genotype 1 and 100% for genotype 2. However, caution is needed for HCV NS5A resistance-associated substitutions that are selected by HCV NS5A inhibitors because cerebrovascular adverse events are induced by some DAA drugs.

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.).

Efficacy and safety of sofosbuvir and ledipasvir in Japanese patients aged 75 years or over with hepatitis C genotype 1

AIM

To evaluate the efficacy and safety of a regimen containing sofosbuvir (SOF) and ledipasvir (LDV) in Japanese patients aged ≥ 75 years with hepatitis C genotype 1.

METHODS

This multicenter, retrospective study consisted of 246 Japanese patients with HCV genotype 1 at nine centers in Miyazaki prefecture in Japan. Demographic, clinical, virological, and adverse effects (AE)-related data obtained during and after SOF/LDV therapy were collected from medical records. These patients were divided into two groups, younger (aged < 75 years) and elderly (aged ≥ 75 years). Virological data and AEs were analyzed by age group.

RESULTS

The sustained virological response (SVR) rates at 12 wk after treatment were 99.2%, 99.4%, and 98.7% in the overall population and in patients aged < 75 and ≥ 75 years, respectively. Common AEs during therapy were headache, pruritus, constipation, and insomnia. These occurred in fewer than 10% of patients, and their incidence was not significantly different between the younger and elderly groups. Two patients discontinued treatment, one due to a skin eruption and the other due to cerebral bleeding.

CONCLUSION

Compared with younger patients, elderly patients had a similar virological response and tolerance to SOF/LDV therapy.

"Reversi-type virologic failure" involved in the development of non-structural protein 5A resistance-associated variants (RAVs) in patients with genotype 1b hepatitis C carrying no signature RAVs at baseline

AIMS

The therapeutic efficacy of daclatasvir/asunaprevir was inferior in patients with non-structural protein 5A (NS5A)-R30Q mutant hepatitis C virus strains at baseline, compared with those with wild-type strains, even though the half maximal effective concentration of NS5A inhibitors was lower in mutant strains than in wild-type strains. In these patients, R30Q and Y93H mutant strains, which are highly resistant to NS5A inhibitors, emerged at virologic failure. The mechanisms involved in such virologic failure were examined.

METHODS

The NS5A resistance-associated variants were evaluated using direct sequencing in 88 patients with virologic failure after daclatasvir/asunaprevir therapy. In patients with R30Q and Y93H mutant strains at virologic failure, the original strains responsible for the multiple mutations were evaluated using baseline sera samples.

RESULTS

L28 M and/or R30Q, L31 M, and Y93H mutant strains were found in 36, 46, and 65 patients, respectively, and R30Q and Y93H mutants were seen in 23 patients. R30Q mutant strains were detected in baseline sera samples available from eight of these patients; cycling-probe real-time polymerase chain reaction showed that the Y93H mutant strain to total strain ratio was less than 1% in four patients and ranged from 1% to 98% in four patients. A phylogenetic tree analysis undertaken after deep sequencing revealed that the R30Q and Y93H mutant strains originated from minor strains with both mutations at baseline, even in patients with a ratio of less than 1%.

CONCLUSION

In patients with genotype 1b hepatitis C virus strains with R30Q mutation, minor strains with Y93H as well as R30Q mutations contributed to the development of virologic failure after treatment with NS5A inhibitors.

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.

Asunaprevir and daclatasvir for recurrent hepatitis C after liver transplantation: A Japanese multicenter experience

The safety and efficacy of an IFN-free regimen using asunaprevir (ASV) and daclatasvir (DCV) for recurrent hepatitis C virus (HCV) infection after liver transplantation (LT) have not been evaluated in Japan. A multicenter study of LT recipients (n = 74) with recurrent HCV genotype 1b infection treated with ASV-DCV for 24 weeks was performed. Medical history was positive for pegylated interferon and ribavirin (Peg-IFN/RBV) in 40 (54.1%) patients, and for simeprevir (SMV) with Peg-IFN/RBV in 12 (16.2%) patients. Resistance-associated variants (RAVs) were positive at D168 (n = 1) in the NS3, and at L31 (n = 4), Y93 (n = 4), and L31/Y93 (n = 1) in the NS5A region of the HCV genome. Sixty-one (82.4%) patients completed the 24-week treatment protocol. Although sustained viral response (SVR) was achieved in 49 (80.3%) patients, it was achieved in only two (16.7%) patients among those with histories of receiving SMV (n = 12). Univariate analysis showed that a history of SMV (P < .01) and the presence of mutations in NS5A (P = .02) were the significant factors for no-SVR. By excluding the patients with either a history of SMV-based treatment or RAVs in NS3/NS5A, the SVR rate was 96.4%. By excluding the patients with a history of SMV and those with RAVs in NS3/NS5A, viral clearance of ASV-DCV was favorable, with a high SVR rate.

Synthesis and biological evaluation of tricyclic matrinic derivatives as a class of novel anti-HCV agents

Background

12N-benzyl matrinic acid analogues had been identified to be a novel scaffold of anti-HCV agents with a specific mechanism, and the representative compound 1 demonstrated a moderate anti-HCV activity. The intensive structure–activity relationship of this kind of compounds is explored so as to obtain anti-HCV candidates with good druglike nature.

Results

Taking compound 1 as the lead, 32 compounds (of which 27 were novel) with diverse structures on the 11-side chain, including methyl matrinate, matrinol, matrinic butane, (Z)-methyl Δ^βγ-matrinic crotonate derivatives were synthesized and evaluated for their anti-HCV activities. Among all the compounds, matrinol 7a demonstrated potential potency with a greatly improved SI value of 136. Pharmacokinetic studies of 7a showed the potential for oral administration that would allow further in vivo safety studies. The free hydroxyl arm in 7a made it possible to prepare pro-drugs for the potential in the treatment of HCV infection.

Conclusions

27 novel 12N-substituted matrinol derivatives were prepared. The SAR study indicated that the introduction of electron-donating substitutions on the benzene ring was helpful for the anti-HCV activity, and the unsaturated 11-side chain might not be favorable for the activity. This study provided powerful information on further strategic optimization and development of this kind of compounds into a novel family of anti-HCV agents. Graphical abstract

Resistance characterization of hepatitis C virus genotype 2 from Japanese patients treated with ombitasvir and paritaprevir/ritonavir

Treatment of HCV genotype (GT) 2‐infected Japanese patients with paritaprevir (NS3/4A inhibitor boosted with ritonavir) and ombitasvir (NS5A inhibitor) without ribavirin for 12 weeks in the phase 2 study M12‐536, and with ribavirin for 16 weeks in phase 3 study GIFT II resulted in SVR rates of 72.2% to 91.5%. Overall, 11 out of 125 patients with GT2a and 37 out of 79 patients with GT2b infection experienced virologic failure. The prevalence of baseline polymorphisms in NS3 and NS5A and their the impact on treatment outcome, as well as the development of viral resistance in GT2‐infected patients experiencing virologic failure were evaluated by HCV NS3 and NS5A population and clonal sequence analyses. Baseline polymorphisms in NS3 that confer resistance to paritaprevir were rare in both GT2a‐ and GT2b‐infected patients, while baseline polymorphisms in NS5A that confer resistance to ombitasvir were detected in 11.2% and 14.1% of the GT2a‐ and GT2b‐infected patients, respectively. There was no significant impact of baseline polymorphisms on treatment outcome in Japanese patients. The most common treatment‐emergent substitutions at the time of virologic failure occurred at amino acid positions 168 in NS3 and 28 in NS5A in both GT2a‐ and GT2b‐infected patients. Although there was a higher rate of virologic failure in patients with GT2b infection, the resistance analyses presented in this report support the conclusion that testing for baseline resistance‐associated polymorphisms is not warranted for HCV GT2‐infected patients treated with a regimen of ombitasvir/paritaprevir/ritonavir + ribavirin for 16 weeks.

NS5A resistance-associated variants undermine the effectiveness of ledipasvir and sofosbuvir for cirrhotic patients infected with HCV genotype 1b

BACKGROUND

Little real-world cohort data has been reported for Asians who have received interferon-free regimens with sofosbuvir (SOF) for chronic hepatitis C virus (HCV) infection. We evaluated the effectiveness and safety in clinical practice of ledipasvir (LDV) plus SOF for Japanese patients infected with HCV genotype 1.

METHODS

This large, multicenter, real-world cohort study consisted of 772 patients treatment-naive or -experienced, with or without compensated cirrhosis, who were treated with LDV (90 mg)/SOF (400 mg) for a fixed 12-week duration. Direct sequence analysis of the NS5A genes (L31 and Y93) was performed at baseline.

RESULTS

Almost all (99.6%) were infected with HCV genotype 1b. The overall sustained virological response 12 weeks after the end of treatment (SVR12) rate was 98.8% (763/772). Multivariable logistic regression analysis extracted male (odds ratio [OR] 6.62, p = 0.024), cirrhosis (OR 20.1, p = 0.0054), and baseline NS5A resistance-associated variants (RAVs) (OR 29.3, p = 0.0018) as independently associated with treatment failure. Notably, the SVR12 rate for cirrhosis patients with baseline NS5A RAVs (87.5%, 49/56) was statistically lower than for the other groups. This tendency was found except for patients with prior daclatasvir/asunaprevir failure. All patients with treatment failure had NS5A Y93H at relapse, whether or not they had NS5A RAVs at baseline. Serious adverse effects were very rare, and discontinuation was required for only five (0.6%) patients.

CONCLUSIONS

LDV/SOF for HCV genotype 1b was exceptionally effective, however, NS5A RAVs undermined the virological effect for cirrhosis patients. Moreover, LDV/SOF was shown to be safe, irrespective of age or fibrosis status.

Real-World Experiences with the Combination Treatment of Ledipasvir plus Sofosbuvir for 12 Weeks in HCV Genotype 1-Infected Japanese Patients: Achievement of a Sustained Virological Response in Previous Users of Peginterferon plus Ribavirin with HCV NS3/4A Inhibitors

The aim of this study was to characterize the treatment response and serious adverse events of ledipasvir plus sofosbuvir therapies in Japanese patients infected with hepatitis C virus (HCV) genotype 1 (GT1). This retrospective study analyzed 240 Japanese HCV GT1 patients treated for 12 weeks with 90 mg of ledipasvir plus 400 mg of sofosbuvir daily. Sustained virological response at 12 weeks post-treatment (SVR12) was achieved in 236 of 240 (98.3%) patients. Among treatment-naïve patients, SVR12 was achieved in 136 of 138 (98.6%) patients, and among treatment-experienced patients, SVR12 was achieved in 100 of 102 (98.0%) patients. In patients previously treated with peginterferon plus ribavirin with various HCV NS3/4A inhibitors, 100% SVR rates (25/25) were achieved. Two relapsers had HCV NS5A resistance-associated variants (RAVs), but no HCV NS5B-S282 was observed after they relapsed. We experienced two patients with cardiac events during treatment. In conclusion, combination of ledipasvir plus sofosbuvir for 12 weeks is a potential therapy for HCV GT1 patients. Caution is needed for HCV NS5A RAVs, which were selected by HCV NS5A inhibitors and cardiac adverse events.

Evolution of matrinic ethanol derivatives as anti-HCV agents from matrine skeleton

Twenty-two novel 12N-substituted matrinic ethanol derivatives were synthesized and evaluated for their antiviral activities against HCV taking compound 1 as the lead. The SAR study indicated that the shortening of the 11-butyl chain to ethyl chain did not affect the activity significantly. Out of the target compounds, matrinic ethanol 6a demonstrated a potential anti-HCV effect with an EC₅₀ value of 3.2μM and a SI value of 96.6. The free hydroxyl arm in 6a made it possible as a parent structure to prepare pro-drug for the potential application in HCV treatment. This study provided powerful information on further strategic optimization and development of this kind of compounds into a novel family of anti-HCV agents.

Effectiveness and safety of daclatasvir plus asunaprevir for hepatitis C virus genotype 1b: Systematic review and meta-analysis

BACKGROUND AND AIM

Daclatasvir plus asunaprevir (DCV + ASV) has demonstrated potent antiviral activity in patients with hepatitis C virus (HCV) genotype 1b infection. A definite conclusion about efficacy and safety of DCV + ASV in patients with HCV genotype 1b is not available. A meta-analysis was conducted to evaluate outcomes of all-oral treatment with DCV + ASV in terms of sustained virological response at 12 (SVR₁₂ ) and 24 (SVR₂₄ ) weeks and adverse effects after the end of treatment.

METHODS

PUBMED, MEDLINE, and EMBASE databases were searched in May 2016. The data were analyzed with Review Manager 5.3.

RESULTS

Nine trials (n = 1690) met entry criteria. SVR₁₂ was achieved by 89.9% of treatment-naïve patients, 84.7% of interferon-ineligible/intolerant patients, and 81.9% of nonresponder patients. Moreover, 89.0% of interferon-ineligible/intolerant patients and 83.1% of nonresponder patients achieved SVR₂₄ . Baseline characteristics, including gender, race, advanced age, non-CC IL28B genotype, and cirrhosis, did not appear to impact SVR rates. However, the rate of SVR₁₂ in all patients with viral load < 8 × 10⁵ was higher than that of all those with viral load ≥ 8 × 10⁵ (151/162 vs 625/753). Moreover, pre-existing nonstructural protein 5A resistance-associated variants (RAVs) were associated with virological failure during DCV + ASV therapy, resulting in the emergence of multiple RAVs. Treatment with DCV + ASV was well tolerated, with low incidences of serious adverse effects, discontinuations, and grade 3 or 4 laboratory abnormalities in all patients.

CONCLUSIONS

Daclatasvir plus asunaprevir provides a highly effective and well-tolerated treatment option for patients with HCV genotype 1b. However, patients with nonstructural protein 5A RAVs at baseline should be assessed to optimize more potent direct antiviral agent therapies.

Management of hepatitis C virus infection in the Asia-Pacific region: an update

The Asia-Pacific region has disparate hepatitis C virus (HCV) epidemiology, with prevalence ranging from 0·1% to 4·7%, and a unique genotype distribution. Genotype 1b dominates in east Asia, whereas in south Asia and southeast Asia genotype 3 dominates, and in Indochina (Vietnam, Cambodia, and Laos), genotype 6 is most common. Often, availability of all-oral direct-acting antivirals (DAAs) is delayed because of differing regulatory requirements. Ideally, for genotype 1 infections, sofosbuvir plus ledipasvir, sofosbuvir plus daclatasvir, or ombitasvir, paritaprevir, and ritonavir plus dasabuvir are suitable. Asunaprevir plus daclatasvir is appropriate for compensated genotype 1b HCV if baseline NS5A mutations are absent. For genotype 3 infections, sofosbuvir plus daclatasvir for 24 weeks or sofosbuvir, daclatasvir, and ribavirin for 12 weeks are the optimal oral therapies, particularly for patients with cirrhosis and those who are treatment experienced, whereas sofosbuvir, pegylated interferon, and ribavirin for 12 weeks is an alternative regimen. For genotype 6, sofosbuvir plus pegylated interferon and ribavirin, sofosbuvir plus ledipasvir, or sofosbuvir plus ribavirin for 12 weeks are all suitable. Pegylated interferon plus ribavirin has been replaced by sofosbuvir plus pegylated interferon and ribavirin, and all-oral therapies where available, but cost and affordability remain a major issue because of the absence of universal health coverage. Few patients have been treated because of multiple barriers to accessing care. HCV in the Asia-Pacific region is challenging because of the disparate epidemiology, poor access to all-oral therapy because of availability, cost, or regulatory licensing. Until these problems are addressed, the burden of disease is likely to remain high.