Subtype-Specific Prevalence of Hepatitis C Virus NS5A Resistance Associated Substitutions in Mainland China

Hepatitis C virus subtype distribution and resistance-associated substitutions in high-risk population groups in Guangdong Province, China

OBJECTIVE

In Guangdong Province, hepatitis C virus (HCV) had been found to confer resistance to direct-acting antivirals (DAAs). There were few studies of HCV subtypes and resistance-associated substitutions (RASs) of HCV in different high-risk populations. In this study, we aimed to determine the subtype distribution and the RASs in high-risk population groups, including drug users (DU), men who have sex with men (MSM), female sex workers (FSW), and male patients with sexually transmitted diseases (STD) in Guangdong Province (a highly developed province with a large population).

METHODS

Using a city-based sampling strategy,1356 samples were obtained from different population groups. Phylogenetic analyses determined subtypes based on Core, NS5B, or NS5A sequences. HCV subtype distribution and RASs in various risk groups and regions were analyzed.

RESULTS

Ten subtypes, of which 6 h and 6 k were novel in Guangdong, were identified. The primary subtype among all risk groups was 6a. RASs in 1b and 3a were different from those observed in other studies. Subtype 3b in western Guangdong was higher than the other three regions. No RASs were found in 6a or any other genotype 6.

CONCLUSIONS

The HCV subtypes are expanding in high-risk populations in Guangdong. Drug use by other risk groups and commercial sex by DU may bridge the dissemination of 6a from DU to other populations. The RAS profiles of 1b and 3a differed from those reported in studies conducted in southwestern China. Further research is required to determine the reason for this discrepancy. Moreover, the combination of RASs was high in subtype 3b. To guide HCV treatment of subtype 3b, pretreatment subtyping of HCV genotype 3 should be considered in western cities in the near future.

Personalized care approaches to hepatitis C therapy: recent advances and future directions

INTRODUCTION

The introduction of direct-acting antivirals (DAAs) has significantly transformed the therapeutic landscape for chronic C hepatitis virus (HCV) infection. However, there is still room for further improvement in optimizing therapy efficacy and minimizing adverse effects.

AREAS COVERED

This review is devoted to the rationale for adopting a personalized approach to HCV therapy. Specifically, we explore the role of host-related factors, such as sex or the presence of comorbidities. We thoroughly examine the implications of commonly encountered comorbidities, including HIV infection, chronic renal disease, liver cirrhosis, and other chronic viral hepatitis infections. Additionally, we discuss the prevalent drug-to-drug interactions between DAAs and other medications, while providing guidance on their management. Finally, we investigate viral-related issues that can influence treatment outcomes, such as viral genotype, quasi-species, and the presence of resistance-associated mutations.

EXPERT OPINION

Despite pivotal trials demonstrating efficacy rates exceeding 90% for currently available DAA regimens, there are still opportunities to optimize therapy outcomes and tailor treatment to each patient. This can be achieved through a meticulous evaluation of the patient's specific clinical conditions and comorbidities, a vigilant approach to manage potential drug interactions, and diligent patient follow-up.

Five-year follow-up of sustained virological response with hepatitis C infection after direct-acting antiviral therapy: A single-center retrospective study

In recent years, direct-acting antivirals (DAAs) have dramatically improved the sustained virological response (SVR) rates in chronic hepatitis C (CHC) patients with their favorable safety and efficacy. However, there is a lack of data on the long-term prognosis of DAA therapy for CHC patients after achieving SVR in the real world. The aim of this study was to evaluate the long-term clinical prognosis of patients with chronic hepatitis C treated by DAA after achieving SVR. This study was a single-center, retrospective, observational study that included 243 CHC patients who reached SVR after DAA treatment in the Third Affiliated Hospital of Sun Yat-sen University from January 2017 to December 2021, with a median follow-up period (FUP) of 24 months, to assess the long-term prognosis and clinical outcomes of CHC patients who reached SVR by DAA treatment. A total of 243 patients were enrolled in this study, 151 patients were male, the mean age of this study was 46.7 ± 12.3 years old, and 23.0% (n = 56) patients were cirrhosis in the baseline. At the end of follow-up, 9 patients (3.7%) progressed to hepatocellular carcinoma (HCC), and patients with cirrhosis at baseline (n = 5) had a significantly higher risk of HCC compared with noncirrhotic patients (n = 4; OR = 4.485, 95% CI: 1.162-17.318, P = .029); 2.9% patients (n = 7) relapsed at the median FUP of 12 months, and patients with genotype 3b had a significantly higher risk of relapsing than those without genotype 3b (OR = 18.48, P = .002, 95% CI: 2.866-119.169). ALT, AST, and ALB all showed improvement at the end of treatment compared with the baseline, remaining at normal levels during FUP meanwhile. The DAA-induced SVR was durable, with conspicuous improvement in clinical outcomes. Nevertheless, patients, especially patients with cirrhosis, still exist the risk of appearance of HCC after reaching SVR. Therefore, regular surveillance and monitoring is necessary even after patients reached SVR.

Molecular Mechanisms of Resistance to Direct-Acting Antiviral (DAA) Drugs for the Treatment of Hepatitis C Virus Infections

Hepatitis C virus (HCV) is a hepatotropic virus that affects millions of human lives worldwide. Direct-acting antiviral (DAA) regimens are the most effective HCV treatment option. However, amino acid substitution-dependent resistance to DAAs has been a major challenge. This study aimed to determine the increasing risk of DAA resistance due to substitutions in DAA target non-structural proteins (NS3/4A, NS5A, and NS5B). Using a Sequence Retrieval System (SRS) at the virus pathogen resource (ViPR/BV-BRC), n = 32763 target protein sequences were retrieved and analyzed for resistance-associated amino acid substitutions (RAASs) by the Sequence Feature Variant Type (SFVT) antiviral-resistance assessment modeling tool. Reference target protein sequences with 100% identity were retried from UniProt following NCBI BLAST. The types and locations of RAASs were identified and visualized by AlphaFold and PyMol. Linux-r-base/R-studio was used for the data presentation. Multi-drug-resistant variants of NS3/4A in genotype 1 (n = 9) and genotype 5 (n = 5) along with DAA-specific NS3/4A, NS5A, and NS5B variants were identified pan-genotypically. A total of 27 variants (RAASs) of all the targets were identified. Fourteen genotype 1-specific substitutions: V1196A, V1158I, D1194A/T/G, R1181K, T1080S, Q1106R, V1062A, S1148G, A1182V, Y2065N, M2000T, and L2003V were identified. The most frequent substitutions were V1062L and L2003M, followed by Q2002H. L2003V, Q2002H, M2000T, Y2065N, and NL2003M of NS5A and L2003M of NS5B conferred resistance to daclatasvir. S2702T NS5B was the sofosbuvir-resistant variant. D1194A NS3/4A was triple DAA (simeprevir, faldaprevir, and asunaprevir) resistant. The double-drug resistant variants R1181K (faldaprevir and asunaprevir), A1182V and Q1106K/R (faldaprevir and simeprevir), T1080S (faldaprevir and telaprevir), and single drug-resistant variants V1062L (telaprevir), D1194E/T (simeprevir), D1194G (asunaprevir), S1148A/G (simeprevir), and Q1106L (Boceprevir) of NS3/4A were determined. The molecular phenomenon of DAA resistance is paramount in the development of HCV drug candidates. RAASs in NS3, NS5A, and NS5B reduce the susceptibility to DAAs; therefore, continuous RAAS-dependent resistance profiling in HCV is recommended to minimize the probability of DAA therapeutic failure.

Phylogenetic signature and prevalence of natural resistance-associated substitutions for hepatitis C virus genotypes 3a and 3b in southwestern China

Background

Patients infected with hepatitis C (HCV) genotype (GT) 3, especially GT3b, are still difficult to cure. GT3b is more common than GT3a in southwestern China. Here we aimed to investigate the prevalence of naturally occurring RASs in HCV GT3 in southwestern China and performed phylogenetic analysis.

Methods

Serum samples were collected from patients with HCV GT3 infection. Sanger sequencing was used to validate resistance-associated substitutions (RASs). Phylogenetic analysis was performed using MEGA X and the observed-minus-expected-squared algorithm was used to analyze amino acid covariance.

Results

A total of 136 patients were enrolled, including 41 HCV GT3a and 95 GT3b infected patients. In the NS5A region, the proportion of RASs found in GT3b (99%) was notably higher than in GT3a (9%). In the NS3 region, RASs prevalence in GT3b (5%) was lower than in GT3a (24%). NS5B-specific RASs were rare. Both the NS5A30k and L31 M substitutions occurred in 96% of GT3b sequences. The A30K + L31M combination was found in 94% of GT3b isolates, however, there were no A30K or L31M mutations observed in the GT3a sequence.

Conclusions

Significant differences were observed between HCV GT3a and GT3b in terms of RAS prevalence. The origin of GT3a appears to be more diverse compared with GT3b in southern China. Studies specifically aimed at HCV GT3b infection should be initiated to gain more insight into this subtype.

Efficacy and safety of direct-acting antiviral therapies and baseline predictors for treatment outcomes in hepatitis C patients: a multi-center, real-world study in Guangdong, China

 : The data on direct acting antivirals (DAA) in chronic hepatitis C (CHC) patients in southern China with multiple genotypes circulating are limited. This study aims to evaluate the efficacy and safety of DAA regimens among CHC patients in Guangdong, China. A total of 220 patients receiving a variety of DAA were enrolled. The primary outcome was sustained virologic response (SVR) at 12 weeks. Resistance associated substations (RAS) were evaluated by deep sequencing. The overall SVR rate was 96.4%, and was 97.7% for genotype 1, 100% for genotype 2, 91.9% for genotype 3, 95.7% for genotype 6, and 100% for untyped. The overall incidence of adverse events (AEs) was 8.2% (18/220) and all the AEs were mild. Nonstructural protein 5A RAS, 30K/31M and Y93H, were most prevalent at baseline and the end of treatment in non-SVR patients, respectively. Logistics regression showed that elevated ALT and AST at baseline were specifically associated with non-SVR in patients with genotype 3 and 6 infections (P = 0.029 and P = 0.017) but not genotype 1 infection (P = 0.746 and P = 0.971), and baseline AST was the best predictor for SVR in genotype 3 and 6 patients (area under curve = 0.890). CONCLUSION: All DAA regimens achieved ideal SVR and were well tolerated. NS5A RAS were prevalent in non-SVR patients. ALT and AST as baseline predictors for non-SVR in genotype 3 and 6 infections warrant further research in a larger cohort. This article is protected by copyright. All rights reserved.

First report on molecular docking analysis and drug resistance substitutions to approved HCV NS5A and NS5B inhibitors amongst Iranian patients

Background

NS5A and NS5B proteins of hepatitis C virus (HCV) are the main targets of compounds that directly inhibit HCV infections. However, the emergence of resistance-associated substitutions (RASs) may cause substantial reductions in susceptibility to inhibitors.

Methods

Viral load and genotyping were determined in eighty-seven naïve HCV-infected patients, and the amplified NS5A and NS5B regions were sequenced by Sanger sequencing. In addition, physicochemical properties, structural features, immune epitopes, and inhibitors-protein interactions of sequences were analyzed using several bioinformatics tools.

Results

Several amino acid residue changes were found in NS5A and NS5B proteins; however, we did not find any mutations related to resistance to the treatment in NS5B. Different phosphorylation and few glycosylation sites were assessed. Disulfide bonds were identified in both proteins that had a significant effect on the function and structure of HCV proteins. Applying reliable software to predict B-cell epitopes, 3 and 5 regions were found for NS5A and NS5B, respectively, representing a considerable potential to induce the humoral immune system. Docking analysis determined amino acids involved in the interaction of inhibitors and mentioned proteins may not decrease the drug efficiency.

Conclusions

Strong interactions between inhibitors, NS5A and NS5B proteins and the lack of efficient drug resistance mutations in the analyzed sequences may confirm the remarkable ability of NS5A and NS5B inhibitors to control HCV infection amongst Iranian patients. The results of bioinformatics analysis could unveil all features of both proteins, which can be beneficial for further investigations on HCV drug resistance and designing novel vaccines.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01988-y.

Cost-Effectiveness of Testing for NS5A Resistance to Optimize Treatment of Elbasvir/Grazoprevir for Chronic Hepatitis C in China

Objectives: Baseline presence of nonstructural protein 5A (NS5A) resistance-associated variants can attenuate the efficacy of new direct-acting antivirals. A potential method to attain the higher efficacy would be to screen for NS5A polymorphisms prior to the initiation of therapy and to adjust the treatment length based on the test results. However, baseline testing adds additional costs and it is unclear whether this would represent a high value strategy for chronic hepatitis C in China.

Methods: A hybrid model compared 1) standard 12-weeks treatment (no testing), 2) shortened 8-weeks treatment (no testing), and 3) baseline testing with 12-/8-weeks treatment for those with/without NS5A polymorphisms from a lifetime Chinese health care payer perspective. All model inputs were retrieved from clinical trials and publically available literature. And sensitivity analyses were also conducted to assess the impact of uncertainty.

Results: Baseline testing was associated with overall increase in total health care cost of USD 13.50 and in QALYs of 0.002 compared with standard 12-weeks treatment (no testing), yielded in an ICER of USD 6750/QALY gained. Scenario analyses suggested that shortened 8-weeks treatment (no testing) was found to be lower costs and great QALYs compared with other two strategies when the sustained virologic response (SVR) rate increased to 95%. Sensitivity analyses indicated that the results were robust.

Conclusions: Our results suggest prior assessment of NS5A sensitivity followed by optimizing treatment duration was an economic strategy. In addition, shortened 8-weeks treatment (no testing) was shown to be dominant with the SVR rate increased to 95%.

Prevalence of resistance-associated substitutions and phylogenetic analysis of hepatitis C virus infection in Russia

OBJECTIVES

Due to limited hepatitis C virus (HCV) sequence availability from patients in Russia, the relationship between subtypes and baseline resistance-associated substitutions (RAS) to direct antiretroviral treatment outcome is not fully understood.

METHODS

Deep sequencing of HCV NS3, NS5A, and NS5B sequences was performed on plasma HCV samples from 412 direct-acting antiviral (DAA)-naïve patients from Russia. Phylogenetic analysis was performed to investigate sequence similarities between HCV strains from Russia, Asia, Europe, and North America. Pretreatment HCV RAS was assessed with a 15% cutoff.

RESULTS

HCV genotype GT1b and GT3a sequences in Russia were related to strains in Europe and Asia. The prevalence of GT1a and GT2a was low in Russia. In GT1b, the prevalence of NS5A Y93H was lower in Russia (6%) compared with Asia (15%). The prevalence of NS5B L159F was similar between Russia and Europe (26-39%). GT3a RAS prevalence was similar between Russia and Asia, Europe, and North America. The 2k/1b recombinant strain in Russia was related to strains from Europe. A higher prevalence of the NS5A RAS L31M (10%) was observed in 2k/1b sequences compared to GT1b (1-6%).

CONCLUSIONS

The prevalence of RASs and the phylogenetic analysis showed similarities in HCV strains between Russia, Europe, and North America. This information may be useful for HCV regimens in Russia.

Direct-acting Antiviral Regimens for Patients with Chronic Infection of Hepatitis C Virus Genotype 3 in China

Hepatitis C virus (HCV) genotype (GT)3 infection is associated with a more rapid hepatic disease progression than the other genotypes. Hence, early HCV clearance slows down the disease progression and is important for improving prognosis in GT3-infected patients. Nevertheless, compared with other genotypes, GT3 is difficult-to-treat with direct-acting antivirals, especially in the presence of cirrhosis. Current guidelines recommend several regimens which have been proven to be effective in GT3-infected patients from the Western world (North America, Europe, and Oceania). In China, GT3 infection comprises 8.7-11.7% of the 10 million patients infected with HCV and has strikingly different characteristics from that in Western countries. Unlike the Western countries, where GT3a is the predominant subtype, GT3a and 3b each affect roughly half of Chinese GT3-infected patients, with 94-96% of the GT3b-infected patients carrying A30K+L31M double NS5A resistance-associated substitutions. Phase 3 clinical trials including GT3b-infected patients have suggested that GT3b infection is difficult to cure, making the regimen choice for GT3b-infected patients an urgent clinical gap to be filled. This review includes discussions on the epidemiology of HCV GT3 in China, recommendations from guidelines, and clinical data from both Western countries and China. The aim is to provide knowledge that will elucidate the challenges in treating Chinese GT3-infected patients and propose potential solutions and future research directions.

Prevalence of Naturally-Occurring NS5A and NS5B Resistance-Associated Substitutions in Iranian Patients With Chronic Hepatitis C Infection

BACKGROUND

Hepatitis C virus (HCV), non-structural 5A (NS5A), and non-structural 5B (NS5B) resistance-associated substitutions (RASs) are the main causes of failure to direct-acting antiviral agents (DAAs). NS5A and NS5B RASs can occur in patients with HCV infection naturally and before exposure to DAAs.

OBJECTIVES

This study aimed to evaluate naturally-occurring NS5A and NS5B RASs in Iranian patients with HCV genotype 1a (HCV-1a) and -3a infections.

METHODS

In this cross-sectional study, viral RNA was extracted from serum specimens. NS5A and NS5B regions were amplified using RT-PCR followed by DNA sequencing. The results of nucleotide sequences were aligned against reference sequences of HCV-1a and -3a and the amino acid substitutions were analyzed using geno2pheno [hcv] web application.

RESULTS

Among 135 patients with hepatitis C, NS5A amino acid substitutions/RASs were identified in 26.4% and 15.9% of patients with HCV-1a and -3a infections, respectively. The identified amino acid substitutions/RASs in the NS5A region of patients with HCV-1a infection were M28T/V/I 11.1%, Q30R/H 4.2%, L31M 1.4%, and H58Y/P/C/D/Q/S/T 16.7%. Y93H substitution was not found in HCV-1a sequences. In patients with HCV-3a infection, NS5A amino acid substitutions/RASs were A30T/K 9.5%, L31F 1.6%, P58S/T/C 3.2%, Y93H 3.2%, and Y93N 3.2%. No resistance substitutions were identified in NS5B sequences from patients with HCV-1a and -3a infections.

CONCLUSION

In this study, baseline amino acid substitutions/RASs were only identified in the NS5A region in Iranian patients with HCV-1a and -3a infections, and the prevalence of these amino acid substitutions/RASs were in accordance with similar studies. There were no RASs in the HCV-1a and -3a NS5B region.

Coblopasvir and sofosbuvir for treatment of chronic hepatitis C virus infection in China: A single-arm, open-label, phase 3 trial

BACKGROUND & AIM

An affordable, pangenotypic regimen remains as an unmet medical need for chronic hepatitis C patients in China. This single-arm, open-label, multicenter, phase 3 trial evaluated the efficacy and safety of coblopasvir, a pangenotypic non-structural protein 5A (NS5A) inhibitor, combined with sofosbuvir for treating Chinese patients with chronic hepatitis C virus (HCV) infection.

METHODS

Treatment-naïve and interferon-experienced adult patients, including those with advanced fibrosis (F3) or compensated cirrhosis (F4), were treated with a universal, combinational regimen of coblopasvir 60 mg and sofosbuvir 400 mg, once daily, for 12 weeks. The primary efficacy endpoint was sustained virological response at post-treatment week 12 (SVR12).

RESULTS

Overall, 371 patients (men, 51%; age, 47 ± 11 years; genotype 1a < 1%, 1b 48%, 2a 26%, 3a 6%, 3b 7% and 6 12%) were enrolled from 19 sites. Fifty-one patients (14%) had F3, 39 patients (11%) had F4 and 39 patients (11%) were interferon experienced. The overall SVR12 was 97% (95% CI, [94%, 98%]) for the full analysis set and was equal to or above 90% for all predefined subsets. Ten patients (3%) experienced virological relapse and two patients did not complete follow-up. No adverse events (AEs) occurred at a frequency ≥5%, and the most often reported AEs (≥1%) were neutropenia and fatigue. The majority of AEs were mild to moderate and transient without specific medical intervention.

CONCLUSIONS

The universal, pangenotypic combo of coblopasvir plus sofosbuvir is an efficacious and safe treatment for Chinese patients monoinfected with HCV of genotype 1, 2, 3 and 6, including those with compensated cirrhosis.

LAY SUMMARY

The regimen of coblopasvir and sofosbuvir is a safe and effective treatment for Chinese patients with genotype 1, 2, 3 and 6 HCV infection, including those with compensated cirrhosis. Therefore, this regimen would be a novel choice of treatment for this patient population.

Molecular characterization of hepatitis C virus for subtype determination and resistance-associated substitutions detection among Chinese voluntary blood donors

BACKGROUND

The high prevalence of hepatitis C virus (HCV) infection and the resulting burden of the disease are significant issues to public health worldwide. Although direct-acting antiviral drugs (DAAs) with good tolerance and bioavailability are available, resistance-associated substitutions (RASs) often jeopardize the successful sustainment of virological responses in HCV treatment. High-frequency baseline RASs in treatment-naïve patients can lead to failures in DAA treatment. Clinical data on HCV RASs in patients from China are limited and require investigations.

METHODS

262 HCV RNA positive plasma from Chinese blood donors were genotyped and amplified with subtype-specific primers for NS3 and NS5A regions. RASs were analyzed using Geno2pheno. The codon usage of each resistance-associated substitution was calculated for genetic barrier analysis.

RESULTS

The two main subtypes in mainland China were 1b and 2a, followed by subtype 6a, 3b, 3a, and 1a. In NS3 region of 1b subtype, substitutions (T54S, V55A, Y56F, Q80 K/L, S122 G/T, R117 H/C, V170I and S174A) were present in 89.7% (96/107) of the samples. Other RASs (M28L, R30Q, P58 L/S and Y93H) were observed in 22.1% (25/113) of the samples in NS5A region. A crucial RAS, Q80K, and two other mutations (S122G + V170I) was identified in the same sequence, which reduced its susceptibility to protease inhibitor ASV and resulted in resistance to SMV. In NS5A, Y93H was detected in 9.7% (11/113) of the 1b samples, leading to medium-to-high level resistance to all six commercialized NS5A inhibitors. S122G-NS3 and Y93H-NS5A occurred simultaneously in 38.1% (7/22) of the samples with mutations in both two regions. Moreover, codon usage of S122G-NS3 and Y93H-NS5A revealed that both variants had the lowest genetic barrier and required only one transition to confer resistance.

CONCLUSIONS

Low genetic barriers facilitated the generation of resistance mutants and threated the efficacy of DAA regimens. The baseline RASs posed a great challenge to real-world DAA application.

Factors Influencing the Prevalence of Resistance-Associated Substitutions in NS5A Protein in Treatment-Naive Patients with Chronic Hepatitis C

Direct-acting antivirals (DAAs) revolutionized treatment of hepatitis C virus (HCV) infection. Resistance-associated substitutions (RASs) present at the baseline impair response to DAA due to rapid selection of resistant HCV strains. NS5A is indispensable target of the current DAA treatment regimens. We evaluated prevalence of RASs in NS5A in DAA-naïve patients infected with HCV 1a (n = 19), 1b (n = 93), and 3a (n = 90) before systematic DAA application in the territory of the Russian Federation. Total proportion of strains carrying at least one RAS constituted 35.1% (71/202). In HCV 1a we detected only M28V (57.9%) attributed to a founder effect. Common RASs in HCV 1b were R30Q (7.5%), L31M (5.4%), P58S (4.4%), and Y93H (5.4%); in HCV 3a, A30S (31.0%), A30K (5.7%), S62L (8.9%), and Y93H (2.2%). Prevalence of RASs in NS5A of HCV 1b and 3a was similar to that worldwide, including countries practicing massive DAA application, i.e., it was not related to treatment. NS5A with and without RASs exhibited different co-variance networks, which could be attributed to the necessity to preserve viral fitness. Majority of RASs were localized in polymorphic regions subjected to immune pressure, with selected substitutions allowing immune escape. Altogether, this explains high prevalence of RAS in NS5A and low barrier for their appearance in DAA-inexperienced population.

The effectiveness and safety of glecaprevir/pibrentasvir in chronic hepatitis C patients with refractory factors in the real world: a comprehensive analysis of a prospective multicenter study

BACKGROUND

Direct-acting anti-virals (DAAs) have markedly improved the effectiveness of anti-viral therapy for chronic hepatitis C (CHC) patients. In a phase III trial in Japan, treatment with the NS3/4A protease inhibitor glecaprevir and the NS5A inhibitor pibrentasvir (G/P) resulted in a small number of patients with refractory factors. We aimed to evaluate the effectiveness and safety of G/P, especially among patients with these refractory factors, and the influence of these factors on treatment.

METHODS

In a prospective, multicenter study involving 33 medical institutions, 1439 patients were treated with G/P, and their efficacy, safety, and most frequent adverse effects (AEs) were analyzed.

RESULTS

Overall SVR12 rates were 99.1% (1397/1410) in the per-protocol-analysis, and genotype sustained virologic response SVR12 rates were: genotype 1, 99.4% (707/711); genotype 2, 99.4% (670/674); genotype 3, 80.0% (16/20). DAA-naïve patients (p = 0.008) with HCV genotype except 3 (genotype 1 vs. 3, p = 2.68 × 10^-5; genotype 2 vs. 3, p = 3.28 × 10^-5) had significantly higher SVR12 rates. No significant difference was observed between CKD stage 1-3 (99.1% [1209/1220]) and chronic kidney disease (CKD) stage 4-5 (98.9% [188/190]) patients, or between cirrhotic (99.0% [398/402]) and non-cirrhotic (99.1% [999/1008]) patients. Multiple logistic regression analysis revealed that genotype 3 [OR 33.404, 95% CI (7.512-148.550), p value (p = 4.06 × 10^-5)] and past experience of IFN-free DAAs [OR 3.977, 95% CI (1.153-13.725), p value (p = 0.029)] were both significantly independent predictors of non-SVR12. AEs were reported in 28.2% of patients, and 1.6% discontinued treatment owing to drug-related AEs. AEs were significantly higher in CKD stage 4-5 (41.6% [79/190]) than CKD stage 1-3 (26.1% [319/1220]) patients (p = 2.00 × 10^-5). AEs were also significantly higher in cirrhotic (38.6% [155/402]) than in non-cirrhotic (24.1% [243/1008]) (p = 2.91 × 10^-18) patients.

CONCLUSIONS

G/P regimen is highly effective and safe to treat CHC patients even with refractory factors such as CKD and advanced liver fibrosis. However, patients with past experience of IFN-free DAA treatment and genotype 3, CKD stage 4 or 5, and advanced liver fibrosis should be more closely observed.