Resistance analysis in patients with genotype 1-6 HCV infection treated with sofosbuvir/velpatasvir in the phase III studies

Prevalence of Drug Resistance Associated Substitutions in Persons With Chronic Hepatitis C Infection and Virological Failure Following Initial or Re-treatment With Pan-genotypic Direct-Acting Antivirals: A Systematic Review and Meta-analysis

BACKGROUND

The advent of short-course, curative treatment with direct-acting antivirals (DAA) has given promise for the global elimination of hepatitis C virus (HCV) infections by 2030. Virological failure occurs in 2%-12% of persons receiving curative DAA treatment and may be presaged by pre-existing polymorphisms or result from selection of drug resistant variants during therapy.

METHODS

We conducted a systematic review to assess the prevalence of HCV resistance associated substitutions (RAS) among individuals with chronic hepatitis C infection who had virological failure following initial or re-treatment with pan-genotypic DAA regimens. We included 34 and 22 studies assessing RAS in people with virological failure published between January 2014 and July 2023. Pooled RAS prevalence was estimated using random-effects meta-analysis.

RESULTS

The pooled prevalence of RAS in people with virological failure following initial DAA treatment was 78.0% (95% confidence interval [CI]: 62.0-92.0) for sofosbuvir/velpatasvir, 81.0% (95% CI: 67.0-93.0) for sofosbuvir/daclatasvir, and 79.0% (95% CI: 70.0-87.0) for glecaprevir/pibrentasvir, with a high prevalence of resistance to the NS5A inhibitors. Among those with virological failure following re-treatment regimens, RAS were present in 93.0% (95% CI: 83.0-99.0) for sofosbuvir/velpatasvir/voxilepravir and in 100% (95% CI: 92.0-100) for glecaprevir/pibrentasvir, with resistance driven by RAS to NS5A inhibitors.

DISCUSSION

At least 1 RAS is present in a high proportion of the few individuals with virological failure following initial or re-treatment with pan-genotypic DAA regimens. There is a need for ongoing surveillance for DAA-associated resistance, to assess risk factors for their development and clinical impact to inform best practice strategies for re-treatment.

Use of Hepatitis C Viremic Donors to Expand the Pediatric Donor Pool

The use of hepatitis C virus (HCV)-positive donors in organ transplantation has become increasingly viable due to advancements in direct-acting antiviral (DAA) therapies, which offer high cure rates. This review aims to evaluate the current practices, benefits, and challenges of utilizing HCV-positive donors for organ transplantation. The recent data show that transplant centers are progressively accepting HCV-positive donors for various organs, including kidneys, livers, and hearts, given the efficacy of post-transplant antiviral treatment. Using these donors has helped mitigate the organ shortage crisis, increasing the donor pool and reducing waitlist times. Despite these advantages, the approach raises concerns about viral transmission, long-term outcomes, and the cost-effectiveness of post-transplant DAA therapy. Furthermore, this review highlights the ethical implications of informed consent and the monitoring of HCV-negative recipients following transplantation. The outcomes from recent studies suggest that with proper management, transplantations from HCV-positive donors to HCV-negative recipients can be safe and effective, leading to excellent graft function and patient survival. This review synthesizes existing research and offers insights into optimizing protocols for future transplants involving HCV-positive donors.

Rare HCV subtypes and retreatment outcomes in a cohort of European DAA-experienced patients

Background and Aims

Data on the prevalence and characteristics of so-called rare HCV genotypes (GTs) in larger cohorts is limited. This study investigates the frequency of rare GT and resistance-associated substitutions and the efficacy of retreatment in a European cohort.

Methods

A total of 129 patients with rare GT1-6 were included from the European resistance database. NS3, NS5A, and NS5B were sequenced and clinical parameters and retreatment efficacies were collected retrospectively.

Results

Overall 1.5% (69/4,656) of direct-acting antiviral (DAA)-naive and 4.4% (60/1,376) of DAA-failure patients were infected with rare GT. Although rare GTs were almost equally distributed throughout GT1-6 in DAA-naive patients, we detected mainly rare GT4 (47%, 28/60 GT4; of these n = 17, subtype 4r) and GT3 (25%, 15/60 GT3, of these n = 8, subtype 3b) among DAA-failures. A total of 62% (37/60) of DAA failures had not responded to first-generation regimes and the majority was infected with rare GT4 (57%, 21/37). In contrast, among patients with failure to pangenotypic DAA regimens (38%, 23/60), infections with rare GT3 were overrepresented (57%, 13/23). Although NS5A RASs were uncommon in rare GT2, GT5a, and GT6, we observed combined RASs in rare GT1, GT3, and GT4 at positions 28, 30, 31, which can be considered as inherent. DAA failures with completed follow-up of retreatment, achieved a high SVR rate (94%, 45/48 modified intention-to-treat analysis; 92%, 45/49 intention-to-treat). Three patients with GT4f, 4r, or 3b, respectively, had virological treatment failure.

Conclusions

In this European cohort, rare HCV GT were uncommon. Accumulation of specific rare GT in DAA-failure patients suggests reduced antiviral activities of DAA regimens. The limited global availability of pangenotypic regimens for first line therapy as well as multiple targeted regimens for retreatment could result in HCV elimination targets being delayed.

Impact and implications

Data on the prevalence and characteristics of rare HCV genotypes (GT) in larger cohorts are still scarce. This study found low rates of rare HCV GTs among European HCV-infected patients. In direct-acting antiviral (DAA)-failure patients, rare GT3 subtypes accumulated after pangenotypic DAA treatment and rare GT4 after first generation DAA failure and viral resistance was detected at NS5A positions 28, 30, and 31. The limited global availability of pangenotypic DAA regimens for first line therapy as well as multiple targeted regimens for retreatment could result in HCV elimination targets being delayed.

Molecular characterization of the nonstructural 5A (NS5A) region of hepatitis C virus in Thai blood donors

Direct acting antivirals (DAAs) have been developed for hepatitis C virus (HCV) therapy, and they are usually effective, however resistance to DAA regimens has also been reported to have a significant impact. Resistance associated substitutions (RASs) in the NS5A region are known to be correlated with failure of DAA therapy. HCV genotypes 3a and 1 are the most prevalent genotypes in Thailand. This study analyzed the type and frequency of RASs associated with DAA failure, focusing on the NS5A region. Serum samples of HCV genotype 3a, 1a, and 1b infection from Thai blood donors were selected. The NS5A region was amplified using reverse transcription-polymerase chain reaction (RT-PCR). A phylogenetic tree was constructed to identify the genotypes of HCV. Nucleotide sequencing and amino acid sequencing were conducted to determine the prevalence of RASs. Construction of the phylogenetic tree indicated that 29 samples were genotype 3a, 11 samples were genotype 1a, and 9 were genotype 1b. Both HCV genotypes 1a and 3a can be categorized into two subclades. Results showed that the NS5A substitutions A30V/K, A62T/V/I/M/P/S/L, and S98G were present in HCV genotype 3a. In HCV genotype 1a, only NS5A RASs H54Y was detected. NS5A amino acid substitutions Q54H and P58L were found in HCV genotype 1b. In conclusion, NS5A RASs at amino acid positions 30, 62, 54, 58, and 98 are present within HCV genotypes 3a and 1. While keeping in mind that additional information was not available on the anonymous blood donors tested in this study, these findings can contribute to understand the NS5A mutation. Further study with known patients under drug treatment is recommended.

SASLT guidelines: Update in treatment of hepatitis C virus infection, 2024

ABSTRACT

Hepatitis C virus (HCV) infection has been a major global health concern, with a significant impact on public health. In recent years, there have been remarkable advancements in our understanding of HCV and the development of novel therapeutic agents. The Saudi Society for the Study of Liver Disease and Transplantation formed a working group to develop HCV practice guidelines in Saudi Arabia. The methodology used to create these guidelines involved a comprehensive review of available evidence, local data, and major international practice guidelines regarding HCV management. This updated guideline encompasses critical aspects of HCV care, including screening and diagnosis, assessing the severity of liver disease, and treatment strategies. The aim of this updated guideline is to assist healthcare providers in the management of HCV in Saudi Arabia. It summarizes the latest local studies on HCV epidemiology, significant changes in virus prevalence, and the importance of universal screening, particularly among high-risk populations. Moreover, it discusses the promising potential for HCV elimination as a public health threat by 2030, driven by effective treatment and comprehensive prevention strategies. This guideline also highlights evolving recommendations for advancing disease management, including the treatment of HCV patients with decompensated cirrhosis, treatment of those who have previously failed treatment with the newer medications, management in the context of liver transplantation and hepatocellular carcinoma, and treatment for special populations.

Sofosbuvir-velpatasvir in adults with hepatitis C virus infection and compensated cirrhosis in Japan

BACKGROUND & PURPOSE

Protease-free regimens for chronic hepatitis C virus (HCV) infection are safe and effective for persons with either compensated or decompensated cirrhosis. We examined the efficacy and safety of sofosbuvir-velpatasvir in participants with HCV and compensated cirrhosis in Japan.

METHODS

This was a Phase 3, multi-center, open-label study. At 20 sites, 37 individuals with chronic HCV infection of any genotype and compensated cirrhosis received sofosbuvir-velpatasvir (400 mg/100 mg) daily for 12 weeks. Participants were treatment-naïve or treatment-experienced with interferon-based treatments with or without HCV NS3/4A protease inhibitors. Prior exposure with HCV NS5A or NS5B inhibitors was prohibited. The primary study endpoint was sustained virologic response 12 weeks after treatment (SVR12).

RESULTS

Among participants, 62% had HCV genotype 1 infection, and 38% had HCV genotype 2. More than three quarters (29/37, 78%) were HCV treatment naïve. All participants (37/37, 100%) achieved SVR12. Seventeen participants (46%) and three participants (8%) had pretreatment resistance-associated substitutions to HCV NS5A and NS5B nucleoside inhibitors respectively, yet no on-treatment breakthrough or relapse occurred. Sofosbuvir-velpatasvir for 12 weeks treatment was safe and well tolerated. The most commonly reported adverse events were headache (8%, 3/37) and diarrhea (5%, 2/37). One serious adverse event, patella fracture, occurred and was considered not treatment related. No participants discontinued study treatment due to an adverse event. Three participants (8%) had a Grade 3 laboratory abnormality; all were hyperglycemia.

CONCLUSION

Sofosbuvir-velpatasvir resulted in high SVR rates and was well tolerated among Japanese patients with HCV and compensated cirrhosis. This single-tablet regimen offers a highly effective, protease-inhibitor free regimen for treating HCV.

CLINICALTRIALS

gov Identifier: NCT04112303.

Management of hepatitis C virus (HCV) infection: an update

Million people worldwide are affected by the hepatitis C virus (HCV). The highest incidence of illness was between 1945 and 1975. It was also estimated that 70% of those people were not tested for the disease. Most recent treatment concepts are safe, highly effective and have a vital public health influence by achieving a viral constant response in a significant proportion of treated patients. It helps reduce liver fibrosis, liver cancer risk and dissemination. With its increased population incidence, HCV becomes a serious public health problem. This review discusses the current literature in this field in terms of the importance of screening of HCV, follow-up, treatment and includes considerations in specific populations such as patients with cirrhosis, with HIV/HCV co-infection, patients with HBV/HCV co-infection and with renal damage

Utilization of HCV Viremic Kidneys with Genotyping/Subtyping-Free Sofosbuvir/Velpatasvir Treatment Strategy: Experience from China

Background. Owing to the advent of pangenotypic direct-acting antiviral agents (DAAs) for hepatitis C virus (HCV) treatment, utilization of HCV-infected deceased donor kidneys with simplified genotyping/subtyping-free sofosbuvir/velpatasvir (SOF/VEL) treatment strategy is now becoming a promising strategy for expanding the organ donor pool. Methods. This retrospective, comparative, single-center study included HCV viremic donor kidneys that were transplanted to 9 HCV-positive (HCV Ab-positive) recipients (D+/R+ group) and 14 HCV-negative recipients (D+/R- group) from May 2018 to January 2021. Both groups received prophylaxis with SOF/VEL treatment within 1-week posttransplant devoid of HCV genotyping/subtyping. The primary outcomes were sustained virologic response 12 weeks after completion of therapy (SVR12) and graft survival at 1-year posttransplant. Results. Baseline characteristics were similar between the HCV D+/R- and D+/R+ groups. The mean age of all recipients was $39.09\pm 9.65$ (SD) years, and 73.9% were male. A total of 92.9% (13 out of 14) recipients had pretreatment HCV viremia in the D+/R- group. The pretreatment HCV viral load in the D+/R+ group (5.98, log 10 IU/mL; IQR, 5.28-6.53) was significantly higher than that in the D+/R- group (3.61, log 10 IU/mL; IQR, 2.57-4.57). After SOF/VEL treatment, SVR12 was achieved in all recipients, with a 100% 1-year patient and graft survival rates. The D+/R+ group had a higher incidence of abnormal liver function (44.4% vs. 7.1%). No significant difference was observed between the two groups in terms of DGF, acute rejection, ALT, serum creatinine, and eGFR within 1-year posttransplant. No severe adverse events associated with either HCV viremia or SOF/VEL were observed. Conclusions. Using a simplified genotyping/subtyping-free SOF/VEL treatment strategy, kidneys from hepatitis C viremic donors for both infected and uninfected recipients presented with safe, excellent, and comparable 1-year outcomes, which can safely expand the donor pool. HCV-positive donor kidneys should be utilized regularly, regardless of the recipient’s HCV status.

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.

Emergence and Persistence of Resistance-Associated Substitutions in HCV GT3 Patients Failing Direct-Acting Antivirals

Background: The hepatitis C virus has a high mutation rate, which results in the emergence of resistance-associated substitutions (RASs). Despite direct-acting antivirals (DAAs) efforts to treat chronically infected HCV genotype 3 (GT3) patients, there are concerns about the emergence and persistence of RASs in DAA failures. The objective of this study was to determine the prevalence of clinically relevant RASs in HCV NS5A and NS5B regions before and after treatment to better understand the role of RASs in treatment failures. Methods: Viral RNA was extracted before and after treatment from serum samples. NS5A and NS5B regions of HCV were amplified by nested PCR, followed by Sanger sequencing. The nucleotide sequences were aligned against HCV GT3 reference sequences, and amino acid substitutions were analyzed using the geno2pheno [hcv] webserver. Results: A total of 76 patients failing DAA therapy were stratified from the cohort of 1388. RASs were detected at the baseline in 15/76 patients and at relapse in 20/76 patients with cirrhosis and previously treated with interferons. The most prevalent NS5A RAS was Y93H found in all treatment-failing patients (14/54 in DCV vs. 6/22 in VEL), followed by A62S/T and A30K. No RASs were identified in NS5B. RASs that were present at the baseline persisted through the 24-week follow-up period and were enriched with emerging RASs during the treatment. The presence of RASs may be one of the causes of treatment failures in 26.3% of patients. Amino acid substitutions were present at the baseline in most of the patients with RASs against NS5A inhibitors. Patients with the baseline Y93H and/or A30K relapse more frequently than patients harboring A62S/T. Conclusion: Treatment-failing patients harbored NS5A RASs, and the most frequent were A30K (5/20), A62S/T (20/20), and Y93H (20/20). Direct resistance testing is recommended for optimizing re-treatment strategies in treatment-failing patients.

Key Role of Multidisciplinary Collaboration towards Global Elimination of HCV Infection

The elimination of HCV (hepatitis C virus) infection is, according to WHO (World Health Organization), of international interest. With new diagnostic tools and treatment possibilities, one major challenge for the elimination is to involve infected patients, especially those from socially excluded subpopulations, into HCV infection-treatment programs. The key question is how to help people who inject drugs (PWID) to engage in HCV infection-treatment programs and improve communication between PWID and hepatologists or other medical professionals involved in the treatment of chronic HCV infection. Furthermore, the medical professionals have to accept the changing spectrum of patients with chronic viral hepatitis. Without close interdisciplinary cooperation, it would be extremely difficult to achieve the WHO goal of global viral hepatitis C elimination. Here, we try to encourage our colleagues as well as addictologists and social workers to play their crucial part in the viral hepatitis C eradication process. It is extremely important for the healthcare providers to be able to communicate with addicted clients, inform PWID about the latest developments in the diagnosis and HCV infection treatment, and get them motivated to engage with specialized treatment programs.

Identifying Different Mutation Sites Leading to Resistance to the Direct-Acting Antiviral (DAA) Sofosbuvir in Hepatitis C Virus Patients from Egypt

The hepatitis C virus (HCV) is a major global health challenge and a leading cause of morbidity and mortality. Many direct-acting antivirals (DAAs) target essential macromolecules involved in the virus’ life cycle. Although such DAAs achieve great success in reducing the viral load in genotype 1 infections, other genotypes demonstrate different levels of response. This study focused on mutation sites associated with patients with genotype 4a infections that failed to respond to treatment with sofosbuvir. The genotyping of HCV samples from patients with virological failure, and responder patients, was conducted using Geno2Pheno webserver-based full NS5B sequences. We constructed 3D structural models for all the samples and used structural analysis to investigate the effect of amino acid substitution on the observed resistance to SOF-based treatment, and the docking of sofosbuvir into the active sites of the 10 models was performed. Finally, 10 molecular dynamic (MD) simulation experiments were conducted to compare the stability of the 3D models of the resistant samples against the stability of the 3D models of the responder samples. The results highlighted the presence of HCV subtype 4a in all ten samples; in addition, an amino acid (aa) substitution in the palm region may hinder HCV polymerase activity. In this study, we provide evidence that a mutation in the NS5B gene that induces resistance to sofosbuvir in patients with the S282T/C/R mutant virus is present in the Egyptian population. Overall, the docking and MD results support our findings and highlight the significant impact of the identified mutations on the resistance of HCV NS5B RNA-dependent RNA polymerase to direct-acting antivirals (DAAs).

Simultaneous determination of HCV genotype and NS5B resistance associated substitutions using dried serum spots from São Paulo state, Brazil

Hepatitis C virus (HCV) is responsible for more than 180 million infections worldwide, and about 80 % of infections are reported in Low and Middle-income countries (LMICs). Therapy is based on the administration of interferon (INF), ribavirin (RBV) or more recently Direct-Acting Antivirals (DAAs). However, amino acid substitutions associated with resistance (RAS) have been extensively described and can contribute to treatment failure, and diagnosis of RAS requires considerable infrastructure, not always locally available. Dried serum spots (DSS) sampling is an alternative specimen collection method, which embeds drops of serum onto filter paper to be transported by posting to a centralized laboratory. Here, we assessed feasibility of genotypic analysis of HCV from DSS in a cohort of 80 patients from São Paulo state Brazil. HCV RNA was detected on DSS specimens in 83 % of samples of HCV infected patients. HCV genotypes 1a, 1b, 2a, 2c and 3a were determined using the sequence of the palm domain of NS5B region, and RAS C316N/Y, Q309R and V321I were identified in HCV 1b samples. Concerning therapy outcome, 75 % of the patients who used INF +RBV as a previous protocol of treatment did not respond to DAAs, and 25 % were end-of-treatment responders. It suggests that therapy with INF plus RBV may contribute for non-response to a second therapeutic protocol with DAAs. One patient that presented RAS (V321I) was classified as non-responder, and combination of RAS C316N and Q309R does not necessarily imply in resistance to treatment in this cohort of patients. Data presented herein highlights the relevance of studying circulating variants for a better understanding of HCV variability and resistance to the therapy. Furthermore, the feasibility of carrying out genotyping and RAS phenotyping analysis by using DSS card for the potential of informing future treatment interventions could be relevant to overcome the limitations of processing samples in several location worldwide, especially in LMICs.

Real-world efficacy and safety of direct-acting antiviral drugs in patients with chronic hepatitis C and inherited blood disorders

BACKGROUND

Patients with inherited blood disorders (IBLD) have a high risk of hepatitis C virus (HCV) infection. The aim of this work was to assess the efficacy and safety of HCV direct-acting antiviral (DAA)-based treatment in patients with IBLD and chronic HCV infection.

METHODS

Twenty-seven patients (25 with sickle cell disease, 1 with β-thalassemia and 1 with hemoglobin D-Punjab), including 3 with compensated cirrhosis, were included. They were treated with sofosbuvir in combination with ribavirin, daclatasvir, ledipasvir, or velpatasvir or with grazoprevir/elbasvir for 8 or 12 weeks. In the case of treatment failure, in-vitro assessment of resistance-associated substitutions (RASs) and full-length genome sequence analysis by means of deep sequencing were performed.

RESULTS

Treatment was safe and well-tolerated and there were no drug discontinuations due to DAA-related adverse events. Twenty-five out of the 27 patients (93%) achieved sustained virological response 12 weeks post-treatment. One patient discontinued after 18 days due to adverse events unrelated to the antiviral treatment. One patient infected with 'unusual' genotype 2 subtype 2m relapsed. Subtype 2m naturally carries the NS5A L31M RAS. In a genotype 2a subgenomic replicon model, L31M increased daclatasvir effective concentration 50% (EC50) by 97-fold, but velpatasvir EC50 by only 3-fold, without altering the replication capacity. This patient was successfully retreated with sofosbuvir/velpatasvir for 12 weeks.

CONCLUSION

DAA-based regimens are well tolerated and highly efficacious in patients with chronic hepatitis C and IBLD in the real-world setting. Thus, DAA-based antiviral treatment should be prioritized in this thus far neglected population of HCV-infected patients.

Sofosbuvir-velpatasvir in Mexican patients with hepatitis C: A retrospective review

INTRODUCTION

The sofosbuvir-velpatasvir (SOF/VEL) combination is a direct-acting antiviral therapy that is authorized and available in Mexico, making the performance of a real-world multicenter study that evaluates the sustained virologic response at 12 weeks post-treatment a relevant undertaking.

METHODS

A retrospective review of the case records of 241 patients seen at 20 hospitals in Mexico was conducted to assess hepatitis C treatment with the SOF/VEL combination (n = 231) and the sofosbuvir/velpatasvir/ribavirin (SOF/VEL/RBV) combination (n = 10). The primary efficacy endpoint was the percentage of patients that achieved SVR at 12 weeks after the end of treatment.

RESULTS

Overall SVR was 98.8% (95% CI 97.35-100%). Only three patients did not achieve SVR, two of whom had cirrhosis and a history of previous treatment with peg-IFN. Of the subgroups analyzed, all the patients with HIV coinfection, three patients with genotype 3, and the patients treated with the SOF/VEL/RBV combination achieved SVR. The subgroups with the lower success rates were patients that were treatment-experienced (96.8%) and patients with F1 fibrosis (95.5%). The most frequent adverse events were fatigue, headache, and insomnia. No serious adverse events were reported.

CONCLUSION

Treatments with SOF/VEL and SOF/VEL/RBV were highly safe and effective, results coinciding with those of other international real-world studies.

The Role of RASs /RVs in the Current Management of HCV

The approval of combination therapies with direct-acting antiviral (DAA) regimens has led to significant progress in the field of hepatitis C virus (HCV) treatment. Although most patients treated with these agents achieve a virological cure, resistance to DAAs is a major issue. The rapid emergence of resistance-associated substitutions (RASs), in particular in the context of incomplete drug pressure, has an impact on sustained virological response (SVR) rates. Several RASs in NS3, NS5A and NS5B have been linked with reduced susceptibility to DAAs. RAS vary based on HCV characteristics and the different drug classes. DAA-resistant HCV variant haplotypes (RVs) are dominant in cases of virological failure. Viruses with resistance to NS3-4A protease inhibitors are only detected in the peripheral blood in a time frame ranging from weeks to months following completion of treatment, whereas NS5A inhibitor-resistant viruses may persist for years. Novel agents have been developed that demonstrate promising results in DAA-experienced patients. The recent approval of broad-spectrum drug combinations with a high genetic barrier to resistance and antiviral potency may overcome the problem of resistance.

Linkage of resistance-associated substitutions in GT1 sofosbuvir + NS5A inhibitor failures treated with glecaprevir/pibrentasvir

BACKGROUND & AIMS

Retreatment with glecaprevir/pibrentasvir (G/P) resulted in a rate of sustained virologic response 12 weeks after treatment completion (SVR12) of >90% in HCV genotype 1 (GT1) patients who previously failed a regimen of sofosbuvir plus an NS5A inhibitor (NS5Ai). This study investigated the prevalence and impact of baseline NS3 and NS5A resistance-associated substitutions (RASs) on the efficacy of G/P in prior GT1 sofosbuvir+NS5Ai failures and the persistence of treatment-emergent RASs.

METHODS

Longitudinal samples from 177 patients enrolled in a phase IIIb, randomized pragmatic clinical trial were analyzed. Patients without cirrhosis were randomized to 12 or 16 weeks of G/P, and patients with compensated cirrhosis were randomized to G/P and ribavirin for 12 weeks or G/P for 16 weeks. Linkage of RAS was identified using Primer-ID next-generation sequencing at a 15% cut-off.

RESULTS

Of 177 patients, 169 (95.5%) were PI-naïve. All 33 GT1b-infected patients achieved SVR12. In GT1a-infected patients, baseline NS5A RASs were prevalent (74.5%, 105/141) but NS3 RASs were uncommon. Baseline NS3 RASs had no impact on G/P efficacy and patients with baseline NS5A RASs showed a numerically but not statistically significantly lower SVR12 rate compared to those without NS5A RASs (89% vs. 97%). SVR12 was achieved in 34 of 35 (97%) patients without NS5A baseline substitution, and 53 of 57 (93%), 35 of 40 (88%), 5 of 8 (63%) with single, double-linked, and triple-linked NS5A substitutions, respectively. Among 13 patients with virologic failure, 4 acquired treatment-emergent NS3 RASs and 10 acquired NS5A RASs.

CONCLUSION

Baseline NS5A RASs were highly prevalent. The presence of an increasing number of linked NS5A RASs in GT1a showed a trend in decreasing SVR12 rates, although no specific NS5A RASs or their linkage pattern were associated with lower SVR12 rates.

LAY SUMMARY

Direct-acting antivirals have revolutionized the treatment of chronic hepatitis C infection, but treatment failure occurs in some patients. Retreatment of patients who previously failed a regimen consisting of sofosbuvir and an NS5A inhibitor with a regimen of glecaprevir and pibrentasvir (G/P) is >90% effective. Herein, we analyzed samples from these patients and showed that retreatment efficacy with G/P is lower in patients with double- or triple-linked NS5A resistance mutations than in patients with single or no NS5A resistance mutations.

CLINICAL TRIAL NUMBER

NCT03092375.

Hepatitis C virus treatment failure: Clinical utility for testing resistance-associated substitutions

The hepatitis C virus has a high mutation capacity that leads to the emergence of resistance-associated substitutions (RAS). However, the consequence of resistance selection during new direct-acting antiviral drug (DAA) treatment is not necessarily the therapeutic failure. In fact, DAA treatment has shown a high rate (> 95%) of sustained virological response even when high baseline RAS prevalence has been reported. In the context of RAS emergence and high rates of sustained viral response, the clinical relevance of variants harboring RAS is still controversial. Therefore, in order to summarize the data available in international guidelines, we have reviewed the clinical utility of testing RAS in the era of new pangenotypic DAA drugs.

Real world SOF/VEL/VOX retreatment outcomes and viral resistance analysis for HCV patients with prior failure to DAA therapy

Sustained viral response (SVR) rates for direct-acting antiviral (DAA) therapy for hepatitis C virus (HCV) infection routinely exceed 95%. However, a small number of patients require retreatment. Sofosbuvir, velpatasvir and voxilaprevir (SOF/VEL/VOX) is a potent DAA combination primarily used for the retreatment of patients who failed by DAA therapies. Here we evaluate retreatment outcomes and the effects of resistance-associated substitutions (RAS) in a real-world cohort, including a large number of genotype (GT)3 infected patients. 144 patients from the UK were retreated with SOF/VEL/VOX following virologic failure with first-line DAA treatment regimens. Full-length HCV genome sequencing was performed prior to retreatment with SOF/VEL/VOX. HCV subtypes were assigned and RAS relevant to each genotype were identified. GT1a and GT3a each made up 38% (GT1a n = 55, GT3a n = 54) of the cohort. 40% (n = 58) of patients had liver cirrhosis of whom 7% (n = 4) were decompensated, 10% (n = 14) had hepatocellular carcinoma (HCC) and 8% (n = 12) had received a liver transplant prior to retreatment. The overall retreatment SVR12 rate was 90% (129/144). On univariate analysis, GT3 infection (50/62; SVR = 81%, p = .009), cirrhosis (47/58; SVR = 81%, p = .01) and prior treatment with SOF/VEL (12/17; SVR = 71%, p = .02) or SOF+DCV (14/19; SVR = 74%, p = .012) were significantly associated with retreatment failure, but existence of pre-retreatment RAS was not when viral genotype was taken into account. Retreatment with SOF/VEL/VOX is very successful for non-GT3-infected patients. However, for GT3-infected patients, particularly those with cirrhosis and failed by initial SOF/VEL treatment, SVR rates were significantly lower and alternative retreatment regimens should be considered.

Non-epidemic HCV genotypes in low- and middle-income countries and the risk of resistance to current direct-acting antiviral regimens

The hepatitis C virus (HCV) is an extremely diverse virus, subtypes of which are distributed variably around the world. Viral genotypes may be divided into epidemic subtypes; those that have become prevalent globally, and endemic subtypes that have a more limited distribution, mainly in Africa and Asia. The high variability of endemic strains reflects evolutionary origins in the locations where they are found. This increased genetic diversity raises the possibility of resistance to pan-genotypic direct-acting antiviral regimens. While many endemic subtypes respond well to direct-acting antiviral therapies, others, for example genotypes 1l, 3b and 4r, do not respond as well as predicted. Many genotypes that are rare in high-income countries but common in other parts of the world have not yet been fully assessed in clinical trials. Further sequencing and clinical studies in sub-Saharan Africa and Asia are indicated to monitor response to treatment and to facilitate the World Health Organization's 2030 elimination strategy.

Progress and challenges in the comprehensive management of chronic viral hepatitis: Key ways to achieve the elimination

Chronic viral hepatitis is a significant health problem throughout the world, which already represents high annual mortality. By 2040, chronic viral hepatitis due to virus B and virus C and their complications cirrhosis and hepatocellular carcinoma will be more deadly than malaria, vitellogenesis-inhibiting hormone, and tuberculosis altogether. In this review, we analyze the global impact of chronic viral hepatitis with a focus on the most vulnerable groups, the goals set by the World Health Organization for the year 2030, and the key points to achieve them, such as timely access to antiviral treatment of direct-acting antiviral, which represents the key to achieving hepatitis C virus elimination. Likewise, we review the strategies to prevent transmission and achieve control of hepatitis B virus. Finally, we address the impact that the coronavirus disease 2019 pandemic has had on implementing elimination strategies and the advantages of implementing telemedicine programs.

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.

Treatment failure with DAA therapy: Importance of resistance

Viral resistance is a major reason for virological failure in patients being treated with direct-acting antivirals (DAAs) for chronic HCV infection. However, the importance of viral resistance mainly depends on the DAA regimen and HCV genotype. For first-line therapy with glecaprevir/pibrentasvir (G/P) or velpatasvir/sofosbuvir (VEL/SOF) no general baseline resistance analysis is required because of the high antiviral activity and high barrier to resistance. If available, resistance testing may help to optimise therapy in certain subgroups of patients with HCV genotype 3 and other rare HCV geno/subtypes. Voxilaprevir/velpatasvir/sofosbuvir (VOX/VEL/SOF) is the first choice for the second-line treatment of patients following a previous DAA failure, with rates of viral eradication above 90% irrespective of the presence of resistance-associated substitutions (RASs). However, in resource-limited settings, only first-generation DAAs may be available for second-line therapy. Here, RASs selected during initial antiviral therapy should be considered if testing is available and rescue treatment should include a switch to a regimen with a new DAA class to optimise treatment response. Patients with HCV genotype 3 are overrepresented in the group who experience DAA treatment failure. Limited data are available for third-line therapies, but promising results have been achieved with G/P plus SOF or VOX/VEL/SOF with or without ribavirin for 12 to 24 weeks; these regimens should be administered irrespective of a patient's RAS profile.

Naturally Occurring Resistance Associated Substitutions in Non-Cirrhotic, Treatment Naive HCV-HIV Co-Infected Patients Does Not Affect the Treatment Response for Anti-HCV Antiviral Therapy

Purpose

Limited literature on the prevalence of baseline resistance associated substitutions (BL-RAS) among HCV–HIV co-infected patients and their association with treatment outcomes is available especially from India. Hence, the present study aimed to study naturally occurring RAS among non-cirrhotic HCV–HIV co-infected patients and their impact on the response to anti-HCV therapy.

Patients and Methods

In this retrospective study, archived blood samples of 80 HCV–HIV co-infected patients, before anti-HCV therapy initiation, were tested for substitutions at the drug acting sites (NS5a and NS5b) in the HCV genome by direct PCR sequencing.

Results

BL-RAS were seen in 19 (23.7%) patients. As well as BL-RAS, all patients were given sofosbuvir (SOF) 400 mg+ daclatasvir (DCV) 60 mg for 12 weeks. Overall, sustained virological response (SVR) was achieved in 63 (78.8%) patients, in 13 with BL-RAS and in 50 without BL-RAS. All the SVR failure cases (n=17) were retreated with SOF (400 mg) +DCV (60 mg)+ ribavirin (RBV) for 24 weeks. SVR was eventually attained in 14 (82.3%) patients, in 4/6 (66.6%) with BL-RAS and in 10/11 (91%) without BL-RAS. On univariate analysis, age more than 30 years (OR: 11.6; 95% CI: 3.0–45.5, p-value<0.001) and female gender (OR: 8.6; 95% CI: 1.1−69, p-value <0.009) were found to be significant factors associated with the attainment of SVR.

Conclusion

BL-RAS are common in HCV–HIV co-infected patients. The existence of BL-RAS, however, did not affect the attainment of SVR among non-cirrhotic, treatment naive HCV–HIV co-infected patients.

Failure on voxilaprevir, velpatasvir, sofosbuvir and efficacy of rescue therapy

BACKGROUND & AIMS

There are limited data on patients with chronic HCV infection in whom combination voxilaprevir (VOX), velpatasvir (VEL), sofosbuvir (SOF) retreatment fails. Thus, we aimed to assess treatment failure and rescue treatment options in these patients.

METHODS

Samples from 40 patients with HCV genotypes (GT) 1-4 in whom VOX/VEL/SOF retreatment failed were collected within the European Resistance Study Group. Population-based resistance analyses were conducted and clinical parameters and retreatment efficacies were evaluated retrospectively in 22 patients.

RESULTS

Most VOX/VEL/SOF failure patients were infected with HCV GT3a (n = 18, 45%) or GT1a (n = 11, 28%) and had cirrhosis (n = 28, 70%). Previous treatments included an NS3-inhibitor (30%), an NS5A-inhibitor (100%) and SOF (85%). Baseline RAS data from a subgroup of patients before VOX/VEL/SOF retreatment (78%) showed few NS3 RASs apart from Q80K in GT1a (40%), typical NS5A RAS patterns in most patients (74%) and no S282T in NS5B. Sequencing after VOX/VEL/SOF failure was available in 98% of patients and showed only minor changes for NS3 and NS5A RASs. In 22 patients, rescue treatment was initiated with glecaprevir, pibrentasvir alone (n = 2) or with SOF±ribavirin (n = 15), VOX/VEL/SOF±ribavirin (n = 4) or VEL/SOF and ribavirin (n = 1) for 12 to 24 weeks. Sustained virologic response was achieved in 17/21 (81%) patients with a final treatment outcome. Of these, 2 GT3a-infected patients had virologic failure after rescue treatment with VEL/SOF or glecaprevir/pibrentasvir+SOF+ribavirin, and 2 patients with cirrhosis died during treatment or before reaching SVR12.

CONCLUSIONS

VOX/VEL/SOF failure was mainly observed in HCV GT3- and GT1a-infected patients with cirrhosis and was not associated with specific RAS patterns within NS3, NS5A or NS5B target regions. Rescue treatment with multiple targeted therapies was effective in most patients.

LAY SUMMARY

The advent of direct-acting antivirals has enabled the effective cure of chronic hepatitis C in most patients. However, treatment failure occurs in some patients, who are often retreated with a combination regimen called VOX/VEL/SOF, which is associated with very high rates of cure. However, VOX/VEL/SOF retreatment also fails in some patients. Herein, we analysed samples from patients in whom VOX/VEL/SOF retreatment failed and we assessed the efficacy of different rescue therapies, showing that rescue treatment is effective in most patients (81%).

Sofosbuvir/velpatasvir for patients with chronic hepatitis C virus infection and compensated liver disease: real-world data in Taiwan

BACKGROUND

Data regarding the real-world effectiveness and safety of sofosbuvir/velpatasvir (SOF/VEL) for East Asian patients with chronic hepatitis C virus (HCV) infection and compensated liver disease are limited. We evaluated the performance of SOF/VEL for 12 weeks for HCV-infected patients with compensated liver disease in a large real-world cohort in Taiwan.

METHODS

Between July 2019 and March 2020, 1880 HCV-infected patients with compensated liver disease who received SOF/VEL 400/100 mg once daily for 12 weeks were included at 15 academic centers in Taiwan. The sustained virologic response at off-treatment week 12 (SVR12) was assessed for evaluable (EP) and per-protocol populations (PP). The tolerance was also reported.

RESULTS

The SVR12 rates by EP and PP analyses were 95.6% [1798 of 1880 patients; 95% confidence interval (CI) 94.6-96.5%] and 99.3% (1798 of 1811 patients; 95% CI 98.8-99.6%), respectively. Among 82 patients who failed to achieve SVR12, 13 (15.9%) were attributed to virologic failures. The SVR12 rates were comparable regardless of baseline characteristics. A total of 1859 (98.9%) patients completed 12-week SOF/VEL treatment. Four (0.2%) patients discontinued treatment due to adverse events (AEs). All patients with serious AEs or deaths were judged not related to SOF/VEL. The AEs occurring in ≥ 10% included headache (16.8%), fatigue (16.2%), nausea (11.8%), and insomnia (11.1%). Nine (0.5%) and 2 (0.1%) patients had grade 3 total bilirubin and alanine aminotransferase elevations.

CONCLUSIONS

SOF/VEL for 12 weeks is efficacious and well-tolerated by chronic HCV-infected patients with compensated liver disease in Taiwan.

Effectiveness of retreatment with ombitasvir/paritaprevir/ritonavir and dasabuvir+sofosbuvir+ribavirin in patients with chronic hepatitis C, subtype 1b, and cirrhosis, who failed previous treatment with first- and second-generation NS5A inhibitors

The use of direct-acting antiviral agents (DAAs) in patients with chronic HCV genotype (GT) 1 infection results in sustained virologic response (SVR) rates of 95%-97%, but 3%-5% of patients experience virologic failure. We observed 41 patients infected with HCV subtype 1b who failed previous treatment with DAAs, including 37 subjects (90.2%) with liver cirrhosis. In total, 30 (73.2%) subjects previously received NS5A inhibitors of the first generation (ledipasvir, daclatasvir, or ombitasvir) and 11 subjects (26.8%) received NS5A inhibitors of the second generation (velpatasvir). All patients received retreatment with a combination of ombitasvir/paritaprevir/ritonavir and dasabuvir (3D) with sofosbuvir (SOF) and ribavirin (RBV). We compared SVR12 rates depending on fibrosis stage, presence of just single or double NS5A mutation (L31M/V/I and/or Y93H), and the generation of previously used NS5A inhibitors. Observed SVR12 rates were as follows: 97.6% (40/41 patients) overall; 100% in patients without cirrhosis (n = 4) versus 97.3% in those with cirrhosis (n = 37); 100% with single L31M/V/I or Y93H mutation (n = 22) versus 94.4% with double mutations (n = 18); 100% in patients who failed previous treatment with first-generation (n = 30) versus 90.9% in those who failed previous treatment with second-generation NS5A inhibitors (n = 11). Retreatment with 3D + SOF + RBV was highly effective and safe in patients with chronic HCV GT1b infection, including those with liver cirrhosis, who failed previous treatment with DAA containing NS5A inhibitors. Fibrosis stage and single or simultaneous presence of NS5A RASs L31M/V/I and Y93H at the baseline, as well as the generation of previously used NS5A inhibitors, did not impact SVR12 rates.

Efficacy and Safety of Glecaprevir/Pibrentasvir in Patients with Chronic HCV Infection

Hepatitis C virus (HCV) infection is a major cause of end-stage liver disease, including decompensated cirrhosis and hepatocellular carcinoma. Over 95% of patients with HCV infection have achieved sustained virologic response at 12 weeks under the treatment of several pan-genotypic regimens approved for patients with HCV infection. The glecaprevir/pibrentasvir (G/P) regimen has some features that distinguish it from others and is the only 8-week regimen approved for treatment-naive patients and patients experienced in regimens containing (peg)interferon, ribavirin, and/or sofosbuvir, without an HCV NS3/4A protease inhibitor or NS5A inhibitor (except those with genotype 3). This review aims to summarize the efficacy and safety of G/P in HCV-infected patients from clinic trials and real-world studies, including those who have historically been considered difficult to cure.

Prevalence and Pattern of Resistance in NS5A/NS5B in Hepatitis C Chronic Patients Genotype 3 Examined at a Public Health Laboratory in the State of São Paulo, Brazil

Purpose

Globally, it is estimated that 71 million people are chronically infected with hepatitis C, and 10-20% of these will develop cirrhosis and hepatocellular carcinoma. The development of new direct-acting antiviral (DAA) drugs has contributed to sustained virological response (SVR), eliminating the infection and achieving cure of chronic hepatitis C. However, treated patients can develop HCV resistance to DAAs, which can contribute to the failure of treatment. Here, we aimed to evaluate the prevalence and specific pattern of NS5A and NS5B resistance-associated substitutions (RAS) in samples from patients chronically infected with HCV genotype 3a at a public health laboratory, Instituto Adolfo Lutz, São Paulo, Brazil.

Patients and Methods

Serum samples from the enrolled individuals were submitted to "in-house" polymerase chain reaction amplification of NS5A and NS5B non-structural protein genes, which were then sequenced by Sanger method.

Results

A total of 170 and 190 samples were amplified and analyzed for NS5A and NS5B, respectively. For NS5A, 20 (12.0%) samples showed some important RAS; 16 (9.0%) showed some type of substitution and 134 (79.0%) showed no polymorphism. No sample showed any RAS for NS5B.

Conclusion

This study found important RAS in samples from naïve chronic HCV patients in some areas from São Paulo. The most prevalent were A62S, A30K, and Y93H, which could indicate an increase in resistance to some DAAs used in HCV treatment.

Low level of baseline resistance in recently HCV-infected men who have sex with men with high-risk behaviours

OBJECTIVES

Presence of baseline hepatitis C virus (HCV) resistance-associated substitutions (RASs) can impair treatment outcome of direct-acting antivirals. We investigated the prevalence of pre-treatment HCV resistance among recently HCV-infected men who have sex with men (MSM) with high risk behaviours, either human immunodeficiency virus (HIV) co-infected or at high risk of HIV acquisition and under pre-exposure prophylaxis (PrEP).

METHODS

NS5A and NS3 fragments were deep sequenced on pre-treatment samples of 72 subjects using Illumina MiSeq paired-end sequencing technology. Ultra-deep sequencing data were analysed by SmartGene® platform. RASs mentioned in the literature were analysed and interpreted depending on genotype (GT) at 10% cut-off.

RESULTS

HCV genotyping showed 36 (50.0%) GT1a, 31 (43.1%) GT4d and 5 (6.9%) GT3a infections. Fifty-five patients (76.4%) were co-infected with HIV and 15 (20.8%) received PrEP. In GT1a viruses, NS3 RASs were found in 4/30 viruses (13.3%; S122 G/N, R155 K and I170 V) and Q80 K polymorphism was present in 14/30 viruses (46.7%). No NS3 RASs were detected in GT4d and GT3a viruses. NS5A RASs were detected in 3/36 GT1a viruses (8.3%; Q30E/R, L31 M and H58 L). NS5A subtype-specific polymorphisms L30R and T58 P were found at high frequencies in 31/31 (100%) and 16/31 (51.6%) GT4d viruses, respectively. One RAS M31 L was also observed along with the polymorphisms L30R and T58 P. No NS5A RASs were detected in GT3a viruses.

CONCLUSION

A low level of RASs to NS3 and NS5A inhibitors in pre-treatment samples was detected in the study population. Our findings reassure the clinical management of HCV infection in this high-risk population.

Sofosbuvir-velpatasvir in Mexican patients with hepatitis C: A retrospective review

INTRODUCTION

The sofosbuvir-velpatasvir (SOF/VEL) combination is a direct-acting antiviral therapy that is authorized and available in Mexico, making the performance of a real-world multicenter study that evaluates the sustained virologic response at 12 weeks post-treatment a relevant undertaking.

METHODS

A retrospective review of the case records of 241 patients seen at 20 hospitals in Mexico was conducted to assess hepatitis C treatment with the SOF/VEL combination (n = 231) and the sofosbuvir/velpatasvir/ribavirin (SOF/VEL/RBV) combination (n = 10). The primary efficacy endpoint was the percentage of patients that achieved SVR at 12 weeks after the end of treatment.

RESULTS

Overall SVR was 98.8% (95% CI 97.35-100%). Only three patients did not achieve SVR, two of whom had cirrhosis and a history of previous treatment with peg-IFN. Of the subgroups analyzed, all the patients with HIV coinfection, three patients with genotype 3, and the patients treated with the SOF/VEL/RBV combination achieved SVR. The subgroups with the lower success rates were patients that were treatment-experienced (96.8%) and patients with F1 fibrosis (95.5%). The most frequent adverse events were fatigue, headache, and insomnia. No serious adverse events were reported.

CONCLUSION

Treatments with SOF/VEL and SOF/VEL/RBV were highly safe and effective, results coinciding with those of other international real-world studies.

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.

Clinical Experience of Patients With Hepatitis C Treated With Direct-Acting Antivirals After Heart Transplantation

BACKGROUND

Hepatitis C increases the mortality and morbidity of patients after heart transplant. Direct-acting antivirals (DAAs) are the primary drugs for hepatitis C treatment. However, such drugs are expensive and frequently unaffordable for patients. In DAA treatment, the assessment of drug interaction is crucial.

METHODS

We investigated a retrospective case series study from January 2017 to December 2019. Sustained virologic response 12 (SVR12) was used to assess the effectiveness of DAA treatment. Data on patients' demographic information, timing of hepatitis C virus (HCV) infection (before or after heart transplant), HCV genotypes and viral loads, DAAs used (branded drugs or generic drugs), and drug interaction assessments were collected.

RESULTS

Fifteen heart transplant patients received hepatitis C treatments during the study period, 11 of whom were infected because their donors had hepatitis C. After DAA treatment, HCV was undetectable in all patients, and 93.3% of them achieved SVR12. Nine patients used the generic sofosbuvir/velpatasvir, and 88.9% of them achieved SVR12. A total of 256 drugs were used with DAAs; 51 records of drug interactions were noted, 3 of which were contraindications, and the remaining records were potential interactions. Patients who used sofosbuvir or elbasvir/grazoprevir experienced fewer drug interactions.

CONCLUSIONS

DAA treatment is effective for hepatitis C treatment in patients after heart transplant. Patients who cannot afford branded drugs because of their prices can use generic drugs as an alternative. Drug interactions must be surveyed during DAA treatment.

Sofosbuvir/velpatasvir/voxilaprevir plus ribavirin for chronic hepatitis C patients with direct acting antiviral failures: Implications for viral elimination in Taiwan

Despite the excellent antiviral effects of direct acting antivirals (DAAs) for hepatitis C virus (HCV) infection with subsequent decrease of morbidity and mortality, a small proportion (5%) of the treated patients do not respond to first-line DAAs and have persistent viremia. Rescue therapy for patients with DAA failures is thus mandatory from both clinical and public health perspectives. Sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX), a fixed-dose pangenotypic rescue agent, has been approved by the Food and Drug Administration (FDA) and European Medical Agency (EMA) for retreating HCV patients who fail prior DAA therapies. However, this agent has not been licensed by health authorities of Taiwan. Herein we reported two cases who successfully cleared HCV by using SOF/VEL/VOX plus ribavirin (RBV) after virologic failures to first-line pangenotypic SOF/VEL. Furthermore, we discussed the current unmet medical needs and clinical implications of SOF/VEL/VOX on the perspectives of HCV elimination in Taiwan.

EASL recommendations on treatment of hepatitis C: Final update of the series☆

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease, with approximately 71 million chronically infected individuals worldwide. Clinical care for patients with HCV-related liver disease has advanced considerably thanks to an enhanced understanding of the pathophysiology of the disease, as well as developments in diagnostic procedures and improvements in therapy and prevention. These therapies make it possible to eliminate hepatitis C as a major public health threat, as per the World Health Organization target, although the timeline and feasibility vary from region to region. These European Association for the Study of the Liver recommendations on treatment of hepatitis C describe the optimal management of patients with recently acquired and chronic HCV infections in 2020 and onwards.

Real-world efficacy of sofosbuvir plus velpatasvir therapy for patients with hepatitis C virus-related decompensated cirrhosis

AIM

Combination therapy with sofosbuvir (SOF) plus velpatasvir (VEL) is approved for patients with hepatitis C virus (HCV)-related decompensated cirrhosis. We analyzed the real-world efficacy of SOF/VEL therapy.

METHODS

Thirty-three patients with HCV-related decompensated cirrhosis (25 and eight patients with Child B and C, respectively) were treated with SOF/VEL for 12 weeks. The HCV non-structural protein (NS)5A and NS5B drug resistance-associated substitutions (RASs) were determined by direct sequencing.

RESULT

Thirty-two of 33 patients completed the treatment, but the remaining patient discontinued the therapy during third week of the treatment due to aggravation of hepatic encephalopathy. Serum HCV-RNA became negative during the treatment in all patients but relapsed after the end of therapy in five patients. In total, 28 out of 33 patients (85%) achieved sustained virological response 12 weeks following completion of treatment (SVR12). The SVR12 rate was 96% in patients with Child B, but significantly lower, at 50%, in patients with Child C (P < 0.05). In genotype 1b HCV-infected patients, all eight patients without baseline NS5A RASs, but only three of seven patients with RASs, achieved SVR12. Multivariate analysis identified Child B (odds ratio, 35.8 for Child C; P = 0.045) as an independent predictor of SVR12. Median serum albumin levels significantly increased only in patients who achieved SVR12. Child-Pugh scores improved in 16 of 28 patients (57%) following achievement of SVR12.

CONCLUSION

The effect of SOF/VEL therapy is lower for patients with Child C. Improvement of hepatic function is expected after viral eradication with SOF/VEL therapy in patients with decompensated cirrhosis.

Global real-world evidence of sofosbuvir/velpatasvir as simple, effective HCV treatment: Analysis of 5552 patients from 12 cohorts

BACKGROUND AND AIMS

Achieving sustained virological response (SVR; cure) in hepatitis C patients using a simple regimen is key to making elimination by 2030 possible. In the largest real-world analysis to date, the effectiveness of pangenotypic, panfibrotic, single-tablet, sofosbuvir/velpatasvir (SOF/VEL) once-daily for 12 weeks was assessed in 12 clinical real-world cohorts from various geographical areas, settings and treatment practices. Factors affecting risk of not achieving SVR were assessed.

METHODS

Adults treated with SOF/VEL 400/100 mg, without ribavirin, were included. All HCV patients reaching Week 12 or 24 post-treatment were assessed for SVR12/24. Factors associated with not achieving SVR12/24 for virological reasons were evaluated using logistic regression analysis.

RESULTS

Overall, 5552 patients were included: 13.3% treatment-experienced; 20.7% compensated cirrhotic; 30.2% genotype 1; 29.5% genotype 2; 32.9% genotype 3; 4.7% genotype 4; 3.7% HIV coinfection; 13.4% current/former intravenous drug use. Of the 5196 patients evaluated for effectiveness, 98.9% achieved SVR12/24. High SVR12/24 rates occurred in all genotypes including genotype 3 (98.3%; 1649/1677) and in those with compensated cirrhosis (97.9; 1055/1078). Only 55 patients did not achieve SVR12/24 due to a virological reason; the only factor statistically significantly associated with an increased risk of not achieving SVR12/24 was compensated cirrhosis (P = .002). Overall, 6% (332/5552) of patients did not achieve SVR12/24 for non-virological reasons (67% lost to follow-up; 26.5% early treatment discontinuation).

CONCLUSIONS

In this large cohort, representative of clinical practice, a simple 12-week regimen of SOF/VEL without ribavirin resulted in high SVR12/24 rates in diverse patient populations, even among those with compensated cirrhosis.

Treatment outcomes in hepatitis C virus genotype 1a infected patients with and without baseline NS5A resistance-associated substitutions

BACKGROUND&AIMS

The presence of baseline resistance-associated substitutions (RASs) reduced sustained virologic response (SVR) rates in chronic hepatitis C virus (HCV) genotype 1a infected patients treated with Elbasvir/Grazoprevir (EBR/GZR). This study aimed to evaluate the frequency of NS5A RASs and treatment outcomes in patients for whom EBR/GZR was intended.

METHODS

We sequenced NS5A in 832 samples from German genotype1a-infected DAA-naïve patients population-based, which were collected in the European Resistance Database. Treatment outcomes and clinical parameters were evaluated in 519 of these patients retrospectively.

RESULTS

Overall, 6.5% of patients harbored EBR-specific NS5A RASs at baseline, including Q30H/R (3.3%), L31M (1.8%), Y93H (1.6%) and other individual variants. Antiviral treatment, including EBR/GZR, was initiated in 88% of patients. In the absence of RASs, the majority of patients received EBR/GZR for 12 weeks (57%) and the SVR rate was 97% compared to 99% SVR achieved using other DAA regimens (LDV/SOF±RBV, G/P, PrOD+RBV, VEL/SOF). Various regimens were used in the presence of RASs and SVR rates were high following treatment with LDV/SOF (100%), G/P (83%), PrOD/RBV (100%), VEL/SOF (100%), SMV/SOF (100%) and EBR/GZR+RBV for 16 weeks (100%). However, two patients received EBR/GZR for 16 weeks without RBV and one relapsed.

CONCLUSIONS

EBR/GZR treatment with or without RBV for 12 or 16 weeks according to a baseline RAS analysis was highly effective with ≥97% SVR in patients with genotype 1a. EBR/GZR without RBV should be avoided in patients with RASs. High SVR rates were also achieved using other 8 or 12 weeks DAA regimens.

Unmet needs of chronic hepatitis C in the era of direct-acting antiviral therapy

The treatment of chronic hepatitis C (CHC) has been revolutionized in an era of all-oral direct-acting antivirals (DAAs) since 2014. Satisfactory treatment efficacy and tolerability can be provided by novel DAAs. Nevertheless, there are still some unmet needs and emerging issues in the treatment of CHC in the DAA era. Certain hard-to-cure populations are prone to have inferior treatment responses, including patients with severe liver decompensation, active hepatocellular carcinoma (HCC), and hepatitis C virus (HCV) genotype 3 (HCV-3) infection and those who experience multiple DAA treatment failures. Hepatitis B virus (HBV) reactivation during and after DAA treatment has raised concern regarding the use of prophylactic antivirals against HBV throughout DAA treatment. However, the standard strategy for the use of prophylactic antivirals is not uniform across regional guidelines. In the post-sustained virological response (SVR) period, HCC still occurs in a substantial proportion of patients. Due to the relatively short follow-up period, the net benefit of the achievement of an SVR by DAAs in the reduction of extrahepatic manifestations has not yet been determined. Attention must also be paid to HCV reinfection, particularly in high-risk populations. The most critical and unmet need for HCV elimination is the large gap in the HCV care cascade at the population level. To accomplish the World Health Organization (WHO)'s goal for HCV elimination by 2030, the expansion of access to HCV care requires a continuous effort to overcome practical and political challenges.

Pre-treatment antiviral resistance in Australians with chronic hepatitis C: prevalence of NS3 and NS5A resistance data in the state of New South Wales

BACKGROUND

Direct-acting antivirals (DAAs) have revolutionized HCV treatment, but the impact of antiviral resistance at a population level is still not clear. The majority of patients who fail DAA therapy develop resistance-associated substitutions (RASs), which can impact re-treatment. There is potential for resistance prevalence to rise in the community with treatment scale up, due to transmission of resistant virus. Monitoring for increasing antiviral resistance requires a reliable baseline, yet there are few published data on the prevalence of HCV resistance in Australia. The aim of this study was to determine the prevalence of RASs among untreated Australians with HCV genotype-1a infection, to inform ongoing surveillance.

METHODS

A cross-sectional study was performed at a single large university hospital pathology laboratory in Australia. Archived blood samples referred for HCV genotype testing were analysed. All patients were naive to DAAs. The prevalence of RASs in the HCV NS3 and NS5A regions was determined using Sanger based population sequencing.

RESULTS

Of 379 samples tested, 34% contained DAA-resistant virus: 24% had resistance to NS3 protease inhibitors, 12% had NS5A inhibitor resistance and 4% of patients had resistance to both drug classes. Clinically relevant RASs conferring resistance against NS5A inhibitors ledipasvir, daclatasvir and elbasvir were detected in 5.8% of samples.

CONCLUSIONS

This is the largest study of HCV antiviral drug resistance in Australia, which differs from resistance prevalence in the USA. The results provide valuable data on the baseline prevalence of HCV resistance, which can be used in the future to monitor for increasing antiviral resistance.

Orally bioavailable HCV NS5A inhibitors of unsymmetrical structural class

A novel unsymmetrical structural class of orally bioavailable hepatitis C virus (HCV) nonstructural 5A protein (NS5A) inhibitors has been generated by improving both the solubility and membrane permeability of the lead compound found in our previous work. The representative compound 14, with a 5-hydroxymethylpyrazine group and a 3-t-butylpropargyl group on each side of the molecule, exhibited the best oral bioavailability in this study, inhibiting not only the HCV genotype 1a, 1b, 2a, and 3a replicons with EC₅₀ values in the picomolar range, but also inhibited 1a Q30 mutants induced by launched symmetrical inhibitors with EC₅₀ values in the low nanomolar range.

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.

NS5A resistance - associated substitutions in chronic hepatitis C patients with direct acting antiviral treatment failure in Turkey

OBJECTIVES

Chronic hepatitis C (CHC) is now a more curable disease with new direct acting antivirals (DAA). Although high sustained virologic response rates, failures still occur in DAA regimens. Our objective in this study was to characterize the real-life presence of clinically relevant resistance - associated substitutions (RASs) in the HCV NS5A gene in CHC patients whose DAA regimen has failed.

METHODS

The study enrolled 53 CHC patients who experienced failure with DAA regimen as the prospective longitudinal cohort between 2017-2019. Genotypic resistance testing was performed via the viral population sequencing method and The Geno2pheno HCV tool was used for RAS analysis.

RESULTS

The most frequent failure category was relapse (88%) followed by non-responder (12%). For a total of 36% of patients, RASs was detected in NS5A, Y93H was the most detected RAS in GT1b infected patients (89%).

CONCLUSIONS

This study establishes an HCV failure registry for Turkey in which samples were combined with clinical, virologic and molecular data of adult patients whose DAA therapy failed. RASs can occur in CHC patients with DAA treatment failures. Evaluation of RAS after DAA failure is very important before re-treatment is initiated to prevent virologic failure.

Retreatment of patients with chronic hepatitis C, subtype 1b and cirrhosis, who failed previous direct-acting antiviral therapy including first- and second-generation NS5A inhibitors with ombitasvir/paritaprevir/ritonavir, dasabuvir + sofosbuvir + ribavirin

The use of direct-acting antiviral agents (DAAs) in patients with chronic HCV genotype 1 infection results in sustained virologic response (SVR) rates of 95%-97%, but 3%-5% of patients experience virologic failure. We observed 17 patients infected with HCV subtype 1b who failed previous treatment with DAA, including 13 subjects (76.5%) with liver cirrhosis. Twelve subjects (70.6%) previously received NS5A inhibitors of the first generation (ledipasvir or daclatasvir) and five subjects (29.4%) - the second generation (velpatasvir). All patients were retreated with a combination of ombitasvir/paritaprevir/ritonavir and dasabuvir (3D) with sofosbuvir (SOF) and ribavirin (RBV). We compared SVR₁₂ rates depending on fibrosis stage, presence of just single or double NS5A mutations (L31M/V/I and/or Y93H), and on the generation of previously used NS5A inhibitor. Observed SVR₁₂ rates were as follows: 94.1% (16/17 patients) overall; 100% in patients without cirrhosis (n = 4) vs 92.3% in those with cirrhosis (n = 13); 100% with single L31M/V/I or Y93H mutation (n = 7) vs 88.9% with double mutations (n = 9); 100% in patients who previously failed first generation (n = 12) vs 80.0% in those failed second-generation NS5A inhibitors (n = 5). Retreatment with 3D + 0SOF + RBV was highly effective and safe in patients with chronic HCV GT1b infection who failed previous use of NS5A inhibitors. Fibrosis stage, baseline presence of NS5A RAS mutations and the generation of previously used NS5A inhibitors may impact the probability of achieving SVR₁₂ , but statistical significance was not demonstrated in our small retrospective cohort. Further studies in a larger population are needed to confirm or not the predictive value of these baseline factors.

Impact of an Open Access Nationwide Treatment Model on Hepatitis C Virus Antiviral Drug Resistance

Direct acting antivirals (DAAs) have revolutionized hepatitis C virus (HCV) treatment, but drug resistance could undermine proposed global elimination targets. Real‐world studies are needed to inform the impact of widespread DAA treatment on antiviral resistance in the community. The prevalence and range of posttreatment resistance‐associated substitutions (RASs) was determined in Australian patients with open access to DAAs through a wide range of prescribers. NS3, NS5A, and NS5B regions were amplified by polymerase chain reaction and analyzed by population sequencing. Clinically relevant RASs were identified using online databases (ReCALL and Geno2Pheno[hcv]). Of 572 samples, 60% were from genotype 3 and 27% from genotype 1a. Ninety‐two percent of people failed a DAA regimen containing an NS5A inhibitor, including 10% with a pangenotype regimen. NS5A RASs were detected in 72% of people with genotype 1 and 80% with genotype 3. For genotype 1, there was a range of RASs across the NS5A region, while for genotype 3, the Y93H RAS predominated (72%). The prevalence of NS3 RASs was higher in people exposed to an NS3 inhibitor (35% vs. 3.9%; P < 0.0001). NS5B resistance was rare, with a single case of sofosbuvir resistance. Multiclass drug resistance was found in 33% of people exposed to both NS3 and NS5A inhibitors. Conclusion: The high prevalence of NS5A RASs among people failing DAA therapy reinforces the importance of specific retreatment regimens, ideally guided by resistance testing. The impact of multiclass drug resistance on retreatment in people exposed to both NS3 and NS5A inhibitors needs to be assessed in real‐world studies. Surveillance for increasing antiviral resistance during treatment scale‐up is essential to maintain the efficacy of current DAA regimens.

Exosomal glypican-1 for risk stratification of pancreatic cystic lesions: A case of pathological progression in the absence of any suspicious imaging finding

The clinical management of patients with pancreatic cystic lesions is of utmost importance to identify those at high risk for pathological progression. Current recommendations are guided by clinical presentation and radiologic criteria, but the results fall short for a disease that the only curative option is surgical resection. There is an urgent need for the introduction of biomarkers that can help in risk assessment of such lesions. We report a case of a pancreatic cystic lesion without imagiological findings suggestive of advanced disease, and high levels of a circulating biomarker, glypican-1 (GPC-1), which parallel those of patients with pancreatic cancer. One year after, the patient revealed malignant progression at follow-up. Our report is unprecedented in the literature. It describes a clinical case in which a biomarker was positive for a patient that only showed progression one year after its detection. This clinical information goes beyond the current knowledge in the field because it shows that the introduction of liquid biopsy and biomarkers is a highly promising clinical tool for the non-invasive assessment of pancreatic cancer precursor lesions, ultimately increasing the rate of patients eligible for surgical resection.