Retreatment of patients who failed glecaprevir/pibrentasvir treatment for hepatitis C virus infection

Genotyping and treatment issues with 'unusual' HCV 1 subtypes

Unusual non 1a/1b HCV 1 subtypes are mostly prevalent in Sub-Saharan Africa. These variants harbour resistance associated substitutions as natural polymorphisms in the NS5A region and are difficult to characterize and treat. We report the HCV genome sequences from two African subjects with unusual subtype 1 g and 1e treated with the pangenotypic regimen sofosbuvir/velpatasvir with failure in the latter. Sequence analysis of different regions of the HCV genome in a subtype 1 reference panel and use of multiple subtyping tools showed that the NS5A region is the most suitable to detect these unusual HCV subtypes and assist treatment choices.

Retreatment of patients with chronic hepatitis C, subtype 3a, and cirrhosis, who previously failed a regimen containing second-generation NS5A inhibitors with sofosbuvir + glecaprevir/pibrentasvir and ribavirin for 16-24 weeks

The outcomes of retreatment patients infected with hepatitis C virus genotype 3, cirrhosis, with velpatasvir may be affected by treatment failure with velpatasvir. The efficacy of SOF+GLE/PIB+RIB 16-24 weeks of treatment has been shown. The presence of NS5A resistance-associated substitution mutations, including Y93H, and the number and regimens of the past failed therapy do not influence the likelihood of achieving sustained virological response. When velpatasvir treatment fails, pibrentasvir should be used as the first choice for retreatment.

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.

Unraveling the mechanisms of Sofosbuvir resistance in HCV NS3/4A protease: Structural and molecular simulation-based insights

Current management of HCV infection is based on Direct-Acting Antiviral Drugs (DAAs). However, resistance-associated mutations, especially in the NS3 and NS5B regions are gradually decreasing the efficacy of DAAs. Among the most effective HCV NS3/4A protease drugs, Sofosbuvir also develops resistance due to mutations in the NS3 and NS5B regions. Four mutations at positions A156Y, L36P, Q41H, and Q80K are classified as high-level resistance mutations. The resistance mechanism of HCV NS3/4A protease toward Sofosbuvir caused by these mutations is still unclear, as there is less information available regarding the structural and functional effects of the mutations against Sofosbuvir. In this work, we combined molecular dynamics simulation, molecular mechanics/Generalized-Born surface area calculation, principal component analysis, and free energy landscape analysis to explore the resistance mechanism of HCV NS3/4A protease due to these mutations, as well as compare interaction changes in wild-type. Subsequently, we identified that the mutant form of HCV NS3/4A protease affects the activity of Sofosbuvir. In this study, the resistance mechanism of Sofosbuvir at the atomic level is proposed. The proposed drug-resistance mechanism will provide valuable guidance for the design of HCV drugs.

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.

Glecaprevir-pibrentasvir for 4 weeks among people with recent HCV infection: The TARGET3D study

Background & Aims

Short duration treatment may aid HCV elimination among key populations. This study evaluated the efficacy of glecaprevir-pibrentasvir for 4 weeks among people with recent HCV infection.

Methods

In this single-arm multicentre international trial, adults with recent HCV (duration of infection <12 months) received glecaprevir-pibrentasvir 300 mg-120 mg daily for 4 weeks. Primary infection was defined as a first positive anti-HCV antibody and/or HCV RNA measurement within 6 months of enrolment and either acute clinical hepatitis within 12 months (symptomatic illness or alanine aminotransferase >10x the upper limit of normal) or antibody seroconversion within 18 months. Reinfection was defined as new positive HCV RNA within 6 months and prior clearance (spontaneous or treatment). The primary endpoint was sustained virological response at 12 weeks post-treatment (SVR12) in the intention-to-treat (ITT) and per-protocol (PP) populations.

Results

Twenty-three participants (96% men, 70% HIV, 57% ever injected drugs) received treatment, of whom 74% had genotype 1a infection and 35% recent reinfection. At baseline, median duration of infection was 17 weeks (IQR 11-29) and HCV RNA was 5.8 log10IU/ml (IQR 5.2-6.9). SVR12 was achieved by 78% (18/23; 95% CI 56-93%) and 82% (18/22; 95% CI 60-95%) of the ITT and PP populations, respectively, and in 100% (12/12; 95% CI 74-100%) of participants with baseline HCV RNA ≤6 log10. There were four cases of virological failure (relapse); three received retreatment with 12 weeks sofosbuvir-velpatasvir or grazoprevir-elbasvir (SVR, n = 2; loss to follow-up, n = 1). No serious adverse events were reported.

Conclusion

While most achieved SVR, the efficacy of a 4-week regimen of glecaprevir-pibrentasvir was lower than observed with longer treatment durations (≥6 weeks) among people with recent HCV.

Trial Registration

Clinicaltrials.gov Identifier: NCT02634008.

Impact and implications

Short duration treatment may aid HCV elimination among key populations. This investigator-initiated single-arm multicentre international pilot trial demonstrated that efficacy of glecaprevir-pibrentasvir for 4 weeks among people with recent HCV infection was sub-optimal (SVR12 78% ITT, 82% PP). Baseline HCV RNA appeared to impact response, with higher efficacy among participants with lower baseline HCV RNA (≤6 log10; SVR12 100% ITT, 12/12). While most achieved SVR, the efficacy of 4 weeks of glecaprevir-pibrentasvir was below that seen with longer treatment durations (≥6 weeks).

Hepatitis C

Hepatitis C virus (HCV) is a hepatotropic RNA virus that can cause acute and chronic hepatitis, with progressive liver damage resulting in cirrhosis, decompensated liver disease, and hepatocellular carcinoma. In 2016, WHO called for the elimination of HCV infection as a public health threat by 2030. Despite some progress, an estimated 57 million people were living with HCV infection in 2020, and 300 000 HCV-related deaths occur per year. The development of direct-acting antiviral therapy has revolutionised clinical care and generated impetus for elimination, but simplified and broadened HCV screening, enhanced linkage to care, and higher coverage of treatment and primary prevention strategies are urgently required.

Direct-Acting Antiviral Therapy for Treatment of Acute and Recent Hepatitis C Virus Infection: A Narrative Review

Following the discovery of hepatitis C virus (HCV) in 1989, 3 decades of basic, translational, and clinical research culminated in the development of direct-acting antiviral (DAA) therapy-curative oral treatment for HCV infection. The availability of DAA therapy revolutionized HCV clinical management, including acute (duration of infection <6 mo) and recent (duration of infection <12 mo) infection. Several DAA regimens, including the contemporary pan-genotypic combinations of sofosbuvir-velpatasvir and glecaprevir-pibrentasvir, have been shown to be safe and effective among people with acute and recent HCV infection, highlighting their potential in an HCV controlled human infection model. This article describes the natural history and management of acute and recent HCV infection in the era of DAA therapy and outlines a strategy for use of DAA therapies in the setting of an HCV controlled human infection model.

Controlled Human Infection Model for Hepatitis C Virus Vaccine Development: Trial Design Considerations

The design of a clinical trial for a controlled human infection model (CHIM) to accelerate hepatitis C virus (HCV) vaccine development requires careful consideration. The design of a potential approach to HCV CHIM is outlined, involving initial sentinel cohorts to establish the safety and curability of the viral inoculum followed by larger cohorts to establish the spontaneous clearance rate for each inoculum. The primary endpoint would be HCV clearance by 24 weeks post-inoculation, recognizing that the prevention of chronic infection would be the primary goal of HCV vaccine candidates. Additional considerations are discussed, including the populations to be enrolled, the required monitoring approach, indications for antiviral therapy, and the required sample size for different CHIM approaches. Finally, safety considerations for CHIM participants are discussed.

Clinical Practice Guidelines of the Russian Society for the Study of the Liver, the Russian Gastroenterological Association, the National Scientific Society of Infectious Disease Specialists for the Diagnosis and Treatment of Chronic Hepatitis C

Аim:diagnosis and treatment algorithms in the clinical recommendations intended for general practitioners, gastroenterologists, infectious disease specialists, hepatologists on the of chronic hepatitis C are presented.

Summary.Chronic viral hepatitis C is a socially significant infection, the incidence of which in the Russian Federation remains significantly high. Over the past 10 years, great progress has been made in the treatment of hepatitis C — direct acting antiviral drugs have appeared. The spectrum of their effectiveness allows to achieve a sustained virological response in more than 90 % of cases, even in groups that were not previously considered even as candidates for therapy or were difficult to treat — patients receiving renal replacement therapy, after liver transplantation (or other organs), at the stage of decompensated liver cirrhosis, HIV co-infected, etc. Interferons are excluded from the recommendations due to their low effectiveness and a wide range of adverse events. The indications for the treatment have been expanded, namely, the fact of confirmation of viral replication. The terms of dispensary observation of patients without cirrhosis of the liver have been reduced (up to 12 weeks after the end of therapy). Also, these recommendations present approaches to active screening of hepatitis in risk groups, preventive and rehabilitation measures after the end of treatment.

Conclusion.Great success has been achieved in the treatment of chronic hepatitis C. In most cases, eradication of viral HCV infection is a real task even in patients at the stage of cirrhosis of the liver, with impaired renal function, HIV co-infection, after solid organs transplantation.

Hepatitis C Guidance 2023 Update: AASLD-IDSA Recommendations for Testing, Managing, and Treating Hepatitis C Virus Infection

The Infectious Diseases Society of America and the American Association for the Study of Liver Diseases have collaboratively developed evidence-based guidance regarding the diagnosis, management, and treatment of hepatitis C virus (HCV) infection since 2013. A panel of clinicians and investigators with extensive infectious diseases or hepatology expertise specific to HCV infection periodically review evidence from the field and update existing recommendations or introduce new recommendations as evidence warrants. This update focuses on changes to the guidance since the previous 2020 published update, including ongoing emphasis on recommended universal screening; management recommendations for incomplete treatment adherence; expanded eligibility for simplified chronic HCV infection treatment in adults with minimal monitoring; updated treatment and retreatment recommendations for children as young as 3 years old; management and treatment recommendations in the transplantation setting; and screening, treatment, and management recommendations for unique and key populations.

Decade of optimizing therapy with direct-acting antiviral drugs and the changing profile of patients with chronic hepatitis C

Chronic infection with the hepatitis C virus (HCV) remains a major health problem affecting approximately 58 million people worldwide. In the era of interferon (IFN)-based regimens, patients particularly infected with genotypes 1 and 4 achieved a low response rate. The implementation of direct-acting antivirals changed the landscape of HCV treatment. The increase in effectiveness provided us with the hope of eliminating HCV as a significant public threat by 2030. In the following years, there was an observed improvement in the treatment of HCV with genotype-specific regimens and highly effective pangenotypic options that are the most recent stage of the revolution. The optimization of therapy was accompanied by changes in the patient profile from the beginning of the IFN-free era over time. Patients treated with antiviral therapies were younger in successive periods, less burdened with comorbidities and comedications, more frequently treatment-naïve and had less advanced liver disease. Before the IFN-free era, specific subpopulations such as patients with HCV/HIV coinfection, those with a history of previous treatment, patients with renal impairment or with cirrhosis had lower chances for a virologic response. Currently, these populations should no longer be considered difficult to treat. Despite the high effectiveness of HCV therapy, there is a small percentage of patients with treatment failure. However, they can be effectively retreated with pangenotypic rescue regimens.

Best therapy for the easiest to treat hepatitis C virus genotype 1b-infected patients

BACKGROUND

The revolution in treatment of patients with chronic hepatitis C virus (HCV) infection dates back to the introduction of direct-acting antivirals (DAAs). The increase in efficacy was most pronounced in patients infected with genotype (GT) 1b, as this was the most poorly responsive population to treatment during the interferon era.

AIM

To identify the most effective interferon-free therapy for GT1b-infected patients and to determine positive and negative predictors of virological response.

METHODS

This real-world retrospective analysis included patients chronically infected with GT1b HCV whose data were obtained from the multicenter observational EpiTer-2 database. Treatment effectiveness was evaluated for each therapeutic regimen as the percentage of sustained virological responses (SVR). Assessment of the safety was based on the evaluation of the course of therapy, the occurrence of adverse events including serious ones, deaths during treatment and in the post 12-wk follow-up period.

RESULTS

The studied population consisted of 11385 patients with a mean age of 53 ± 14.8 years and a female predominance (53.4%). The majority of them were treatment-naïve (74.6%) and patients with cirrhosis accounted for 24.3%. Of the DAA regimens used, 76.9% were GT-specific with ombitasvir/paritaprevir/ritonavir + dasabuvir ± ribavirin being the most used option (32.4%). A total of 10903 patients responded to treatment resulting in a 98.1% in the per-protocol analysis after excluding 273 patients without SVR data. The effectiveness of all regimens exceeded 90% and the highest SVR of 98.9% was achieved in patients treated with a combination of glecaprevir/pibrentasvir. Logistic regression analyses showed that the virologic response was independently associated with female sex [odds ratio (OR) = 1.67], absence of decompensated cirrhosis at baseline (OR = 2.42) and higher baseline platelets (OR = 1.004 per 1000/μL increase), while the presence of human immunodeficiency virus (HIV) coinfection significantly decreased the odds of response (OR = 0.39). About 95%-100% of patients completed therapy irrespective of the drug regimen. At least one adverse effect occurred in 10.9%-36.3% and most of them were mild. No treatment related deaths have been reported.

CONCLUSION

We documented very high effectiveness and a good safety profile across all DAA regimens. Positive predictors of SVR were female sex, absence of decompensated cirrhosis at baseline and higher platelet count while HIV coinfection reduced the effectiveness.

Direct-acting antiviral retreatment patterns for hepatitis C

BACKGROUND: Despite the strong efficacy of direct-acting antivirals (DAAs) against the hepatitis C virus, many patients require a second regimen of DAA treatment. However, limited research exists to characterize rates of retreatment across different DAA agents or potential factors that may increase retreatment risk. OBJECTIVE: To characterize patterns and predictors of DAA retreatment among a large, generalizable, commercially insured US population of patients. METHODS: Using the IBM MarketScan Commercial Claims and Encounters data source, this retrospective cohort study examined retreatment patterns among patients receiving DAAs between 2013 and 2019. Descriptive statistics were used to compare patient characteristics predictive of retreatment risk and to examine rates of retreatment in patients initiating different DAA treatments. RESULTS: Among 31,553 DAA users, a total of 1,017 (3.2%) required DAA retreatment. Among the 1,017 patients re-treated, 44 (4.3%) received a third treatment regimen and 2 patients received a fourth treatment regimen. The average total cost for a retreatment regimen was $109,683, with patient out-of-pocket costs totaling $1,287 Patients requiring retreatment had higher rates of hypertension (32.0% vs 26.7%; P < 0.001), diabetes (16.9% vs 11.9%; P < 0.001), coagulopathy (9.9% vs 4.5%; P < 0.001), deficiency anemia (11.1% vs 7.4%; P < 0.001), alcohol abuse (3.3% vs 2.3%; P = 0.038), prior liver transplantation (3.4% vs 2.3%; P = 0.024), and hepatocellular carcinoma (6.1% vs 1.9%; P < 0.001) compared with patients not requiring retreatment. CONCLUSIONS: Although uncommon, some patients receiving DAAs require a second regimen of DAA treatment at substantial cost to both health plans and patients. These patients tend to have more comorbidities and markers of hepatic disease severity. Patients with high retreatment risk may benefit from careful monitoring for occurrences of retreatment.

HCV genome-wide analysis for development of efficient culture systems and unravelling of antiviral resistance in genotype 4

OBJECTIVE

HCV-genotype 4 infections are a major cause of liver diseases in the Middle East/Africa with certain subtypes associated with increased risk of direct-acting antiviral (DAA) treatment failures. We aimed at developing infectious genotype 4 cell culture systems to understand the evolutionary genetic landscapes of antiviral resistance, which can help preserve the future efficacy of DAA-based therapy.

DESIGN

HCV recombinants were tested in liver-derived cells. Long-term coculture with DAAs served to induce antiviral-resistance phenotypes. Next-generation sequencing (NGS) of the entire HCV-coding sequence identified mutation networks. Resistance-associated substitutions (RAS) were studied using reverse-genetics.

RESULT

The in-vivo infectious ED43(4a) clone was adapted in Huh7.5 cells, using substitutions identified in ED43(Core-NS5A)/JFH1-chimeric viruses combined with selected NS5B-changes. NGS, and linkage analysis, permitted identification of multiple genetic branches emerging during culture adaptation, one of which had 31 substitutions leading to robust replication/propagation. Treatment of culture-adapted ED43 with nine clinically relevant protease-DAA, NS5A-DAA and NS5B-DAA led to complex dynamics of drug-target-specific RAS with coselection of genome-wide substitutions. Approved DAA combinations were efficient against the original virus, but not against variants with RAS in corresponding drug targets. However, retreatment with glecaprevir/pibrentasvir remained efficient against NS5A inhibitor and sofosbuvir resistant variants. Recombinants with specific RAS at NS3-156, NS5A-28, 30, 31 and 93 and NS5B-282 were viable, but NS3-A156M and NS5A-L30Δ (deletion) led to attenuated phenotypes.

CONCLUSION

Rapidly emerging complex evolutionary landscapes of mutations define the persistence of HCV-RASs conferring resistance levels leading to treatment failure in genotype 4. The high barrier to resistance of glecaprevir/pibrentasvir could prevent persistence and propagation of antiviral resistance.

Breakthroughs in hepatitis C research: from discovery to cure

In the 1970s, an unknown virus was suspected for documented cases of transfusion-associated hepatitis, a phenomenon called non-A, non-B hepatitis. In 1989, the infectious transmissible agent was identified and named hepatitis C virus (HCV) and, soon enough, the first diagnostic HCV antibody test was developed, which led to a dramatic decrease in new infections. Today, HCV infection remains a global health burden and a major cause of liver cirrhosis, hepatocellular carcinoma and liver transplantation. However, tremendous advances have been made over the decades, and HCV became the first curable, chronic viral infection. The introduction of direct antiviral agents revolutionized antiviral treatment, leading to viral eradication in more than 98% of all patients infected with HCV. This Perspective discusses the history of HCV research, which reads like a role model for successful translational research: starting from a clinical observation, specific therapeutic agents were developed, which finally were implemented in national and global elimination programmes.

[Glecaprevir/Pibrentasvir + Sofosbuvir + Ribavirin as a salvage regimen after Sofosbuvir + Velpatasvir + Voxilaprevir re-treatment failure]

Antiviral therapy of chronic hepatitis C virus (HCV) achieves sustained virological response (SVR) in the majority of patients. Even after initial virological failure, re-treatment with the combination of sofosbuvir+velpatasvir+voxilaprevir (SOF/VEL/VOX) has been established as an effective second line regimen. However, some patients fail to achieve SVR after a second antiviral course with SOF/VEL/VOX. These patients are considered difficult-to-cure. Currently, the optimal regimen for antiviral re-re-treamtent is a matter of debate and European and American guidelines suggest the combination of SOF+glecaprevir/pibrentasvir (G/P) + Ribavirin as a salvage regimen. However, there is only little evidence to support this. In this study, data of two patients with genotype 3 chronic HCV infection, liver cirrhosis and virological failure after re-treatment with SOF/VEL/VOX that successfully achieved SVR with the combination of SOF+G/P ± RBV. Importantly, one patient had Child B cirrhosis to the time of treatment initiation. No adverse events were reported. Thus, our data support the use of SOF + G/P + RBV as a salvage regimen after re-treatment failure with SOF/VEL/VOX.

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.

The outcome of re-treatment of relapsed hepatitis C virus infection in a resource-limited setting

The aim of this study was to compare efficacy and safety of different combination regimens in re-treatment of HCV in the setting of inaccessibility of resistance testing. This real-life prospective study included 86 chronic HCV infected patients who experienced failure of treatment treated at Faculty of Medicine Ain shams Research Institute (MASRI) since 2018. 64% of the patients were males, with median age 50.2 years. They were re-treated using 1 of 3 proposed regimens of DAA combinations. One group received PAR/OMB/SOF/RBV for 12 weeks, another group received SOF/DAC/SIM/RBV for 12 weeks and a third received SOF/DAC/RBV for 24 weeks. Response to different regimens was assessed by comparing sustained virologic response (SVR) of each. Monitoring the occurrence of adverse events was performed. SVR was achieved in all but 3 patients (96.5% SVR), one in the SOF/DAC/SIM/RBV group and two in the SOF/DAC/RBV group. The group receiving RBV had more anaemia and hyperbilirubinemia. The first treatment regimen used was a significant predictor to SVR achievement. This study presents alternative treatment regimens for re-treatment of HCV patients in areas with limited resources in the case of non-availability of other regimens as velpatasvir, voxilaprevir, grazoprevir, elbasvir.

A Review of Hepatitis B Virus and Hepatitis C Virus Immunopathogenesis

Despite the advances in therapy, hepatitis B virus (HBV) and hepatitis C virus (HCV) still represent a significant global health burden, both as major causes of cirrhosis, hepatocellular carcinoma, and death worldwide. HBV is capable of incorporating its covalently closed circular DNA into the host cell's hepatocyte genome, making it rather difficult to eradicate its chronic stage. Successful viral clearance depends on the complex interactions between the virus and host's innate and adaptive immune response. One encouraging fact on hepatitis B is the development and effective distribution of the HBV vaccine. This has significantly reduced the spread of this virus. HCV is a RNA virus with high mutagenic capacity, thus enabling it to evade the immune system and have a high rate of chronic progression. High levels of HCV heterogeneity and its mutagenic capacity have made it difficult to create an effective vaccine. The recent advent of direct acting antivirals has ushered in a new era in hepatitis C therapy. Sustained virologic response is achieved with DAAs in 85-99% of cases. However, this still leads to a large population of treatment failures, so further advances in therapy are still needed. This article reviews the immunopathogenesis of HBV and HCV, their properties contributing to host immune system avoidance, chronic disease progression, vaccine efficacy and limitations, as well as treatment options and common pitfalls of said therapy.

Prevalence of resistance-associated substitutions and retreatment of patients failing a glecaprevir/pibrentasvir regimen

OBJECTIVES

To investigate resistance-associated substitutions (RASs) as well as retreatment efficacies in a large cohort of European patients with failure of glecaprevir/pibrentasvir.

METHODS

Patients were identified from three European Resistance Reference centres in Spain, Italy and Germany. Sequencing of NS3, NS5A and NS5B was conducted and substitutions associated with resistance to direct antiviral agents were analysed. Clinical and virological parameters were documented retrospectively and retreatment efficacies were evaluated.

RESULTS

We evaluated 90 glecaprevir/pibrentasvir failures [3a (n = 36), 1a (n = 23), 2a/2c (n = 20), 1b (n = 10) and 4d (n = 1)]. Ten patients were cirrhotic, two had previous exposure to PEG-interferon and seven were coinfected with HIV; 80 had been treated for 8 weeks. Overall, 31 patients (34.4%) failed glecaprevir/pibrentasvir without any NS3 or NS5A RASs, 62.4% (53/85) showed RASs in NS5A, 15.6% (13/83) in NS3 and 10% (9/90) in both NS5A and NS3. Infection with HCV genotypes 1a and 3a was associated with a higher prevalence of NS5A RASs. Patients harbouring two (n = 34) or more (n = 8) RASs in NS5A were frequent. Retreatment was initiated in 56 patients, almost all (n = 52) with sofosbuvir/velpatasvir/voxilaprevir. The overall sustained virological response rate was 97.8% in patients with end-of-follow-up data available.

CONCLUSIONS

One-third of patients failed glecaprevir/pibrentasvir without resistance. RASs in NS5A were more prevalent than in NS3 and were frequently observed as dual and triple combination patterns, with a high impact on NS5A inhibitor activity, particularly in genotypes 1a and 3a. Retreatment of glecaprevir/pibrentasvir failures with sofosbuvir/velpatasvir/voxilaprevir achieved viral suppression across all genotypes.

Management and Treatment of Hepatitis C: Are There Still Unsolved Problems and Unique Populations?

Direct-acting antivirals (DAA) have revolutionized the treatment of patients with chronic hepatitis C virus (HCV) infection, possibly leading to HCV elimination by 2030 as endorsed by the World Health Organization (WHO). However, some patients belonging to the so-called unique or special populations are referred to as difficult-to-treat due to unreached sustained virological response, potential drug side effects or interactions or co-morbidities. Several years after the DAA introduction and on the basis of excellent findings in terms of efficacy and safety, some doubts arise around the exact meaning of the special population designation and whether this group of patients actually exists. The aim of this review is to discuss and analyze current evidence on the management and treatment of the so-called "unique populations". We placed particular emphasis on patients with decompensated cirrhosis, chronic kidney disease (CKD), coinfections, rare genotypes, and previous treatment failure, in order to provide physicians with an updated overview of the actual problems and needs in the current scenario.

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.

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%).

Drug Design Strategies to Avoid Resistance in Direct-Acting Antivirals and Beyond

Drug resistance is prevalent across many diseases, rendering therapies ineffective with severe financial and health consequences. Rather than accepting resistance after the fact, proactive strategies need to be incorporated into the drug design and development process to minimize the impact of drug resistance. These strategies can be derived from our experience with viral disease targets where multiple generations of drugs had to be developed to combat resistance and avoid antiviral failure. Significant efforts including experimental and computational structural biology, medicinal chemistry, and machine learning have focused on understanding the mechanisms and structural basis of resistance against direct-acting antiviral (DAA) drugs. Integrated methods show promise for being predictive of resistance and potency. In this review, we give an overview of this research for human immunodeficiency virus type 1, hepatitis C virus, and influenza virus and the lessons learned from resistance mechanisms of DAAs. These lessons translate into rational strategies to avoid resistance in drug design, which can be generalized and applied beyond viral targets. While resistance may not be completely avoidable, rational drug design can and should incorporate strategies at the outset of drug development to decrease the prevalence of drug resistance.

Genotype 3-hepatitis C virus’ last line of defense

Chronic infection with hepatitis C virus (HCV) is one of the leading causes of liver disease globally, affecting approximately 71 million people. The majority of them are infected with genotype (GT) 1 but infections with GT3 are second in frequency. For many years, GT3 was considered to be less pathogenic compared to other GTs in the HCV family due to its favorable response to interferon (IFN)-based regimen. However, the growing evidence of a higher rate of steatosis, more rapid progression of liver fibrosis, and lower efficacy of antiviral treatment compared to infection with other HCV GTs has changed this conviction. This review presents the specifics of the course of GT3 infection and the development of therapeutic options for GT3-infected patients in the era of direct-acting antivirals (DAA). The way from a standard of care therapy with pegylated IFN-alpha (pegIFNα) and ribavirin (RBV) through a triple combination of pegIFNα + RBV and DAA to the highly potent IFN-free pangenotypic DAA regimens is discussed along with some treatment options which appeared to be dead ends. Although the implementation of highly effective pangenotypic regimens is the most recent stage of revolution in the treatment of GT3 infection, there is still room for improvement, especially in patients with liver cirrhosis and those who fail to respond to DAA therapies, particularly those containing inhibitors of HCV nonstructural protein 5A.

Virological Factors Associated with Failure to the Latest Generation of Direct Acting Agents (DAA) and Re-Treatment Strategy: A Narrative Review

The availability of all oral direct acting antiviral agents (DAAs) has revolutionized the management of HCV infections in recent years, allowing to achieve a sustained virological response (SVR) in more than 95% of cases, irrespective of hepatitis C Virus (HCV) genotype or staging of liver disease. Although rare, the failure to the latest-generation regimens (grazoprevir/elbasvir, sofosbuvir/velpatasvir, pibrentasvir/glecaprevir) represents a serious clinical problem, since the data available in the literature on the virological characteristics and management of these patients are few. The aim of the present narrative review was to provide an overview of the impact of baseline RASs in patients treated with the latest-generation DAAs and to analyze the efficacy of the available retreatment strategies in those who have failed these regimens.

Effect of baseline resistance-associated substitutions on the efficiency of glecaprevir/pibrentasvir in chronic hepatitis C subjects: A meta-analysis

The effect of baseline resistance-associated substitutions on the sustained virologic response at 12 weeks in chronic hepatitis C subjects has drawn considerable attention. However, it has been reported that the relationship between such substitutions and sustained virologic response at 12 weeks in chronic hepatitis C subjects is variable in different treatments. This meta-analysis was performed to evaluate this relationship in subjects treated with glecaprevir/pibrentasvir. A systematic literature search up to May 2020 was done, and 17 studies were identified with 6501 chronic hepatitis C subjects. They were reporting relationships between baseline resistance-associated substitutions and sustained virologic response at 12 weeks in chronic hepatitis C subjects treated with glecaprevir/pibrentasvir. The odds ratio (OR) with 95% confidence intervals (CIs) was calculated to evaluate the prognostic role of baseline resistance-associated substitutions on the sustained virologic response at 12 weeks in chronic hepatitis C subjects treated with glecaprevir/pibrentasvir using the dichotomous method with a random or fixed-effect model. Lower sustained virologic response at 12 weeks post-treatment in chronic hepatitis C subjects was significantly related to baseline resistance-associated substitutions in overall genotypes (OR, 0.03; 95% CI, 0.15-0.61, P < .001), baseline NS5a resistance-associated substitutions in genotype-1 (OR, 0.16; 95% CI, 0.04-0.57, P = .005), baseline resistance-associated substitutions in genotype-3 (OR, 0.14; 95% CI, 0.05-0.38, P < .001), and baseline NS5a resistance-associated substitutions in genotype-3 (OR, 0.21; 95% CI, 0.09-0.49, P < .001). Sustained virologic response at 12 weeks in chronic hepatitis C subjects was not significantly related to the baseline NS5a resistance-associated substitutions (OR, 0.61; 95% CI, 0.17-2.22, P = .45), and baseline resistance-associated substitutions in genotype-1 (OR, 0.35; 95% CI, 0.12-1.088, P = .07). In conclusion, the impact of baseline resistance-associated substitutions on the sustained virologic response at 12 weeks in chronic hepatitis C subjects treated with glecaprevir/pibrentasvir may have a great prognostic effect, especially in genotype-3 as a tool to improve treatment prediction. Chronic hepatitis C subjects with baseline resistance-associated substitutions may have an independent risk relationship with poor treatment outcomes. This relationship forces us to recommend testing prior to treatment selection to avoid any possible treatment failure.

Hepatitis C Virus Treatment: Simplifying the Simple and Optimizing the Difficult

The availability of safe, efficacious, oral direct-acting antivirals (DAAs) have ushered in a new era of hepatitis C treatment with potential to eliminate hepatitis C as a public health threat. To achieve population-level effectiveness of these oral DAAs, hepatitis C treatment by a wide range of providers in different settings will be essential to increase the number of persons treated. We provide a clinical review of hepatitis C treatment with a focus on practical tools for management of hepatitis C in majority of currently infected individuals who can be easily cured and optimization of treatment for those in whom treatment may not be as simple.

Interferon-Free Hepatitis C Virus Therapy

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease, with ∼71 million chronically infected individuals worldwide. Treatment of patients with HCV-related liver disease has advanced considerably thanks to the development of new direct-acting antiviral drugs that are now administered as highly potent, safe, and well-tolerated combinations with a high barrier to resistance. International organizations, such as the European Association for the Study of the Liver, the American Association for the Study of Liver Diseases jointly with the Infectious Diseases Society of America, or the World Health Organization have published detailed treatment guidelines. With these therapies becoming more and more widely available, elimination of hepatitis C as a public health threat by 2030 can now be envisaged in several countries. In other regions, better screening, diagnosis, and linkage to care will be necessary to achieve this ambitious goal.

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.

Management of Direct-Acting Antiviral Failures

Answer questions and earn CME.

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.

2020 Taiwan consensus statement on the management of hepatitis C: Part (II) special populations

Hepatitis C virus (HCV) infection is a silent killer that leads to rapid progression of liver cirrhosis and hepatocellular carcinoma (HCC). High prevalence of HCV infection has been reported in Taiwan, especially in high-risk populations including people who inject drugs (PWID) and patients requiring dialysis. Besides, certain populations merit special considerations due to suboptimal outcome, potential drug-drug interaction, or possible side effect. Therefore, in the second part of this 2-part consensus, the Taiwan Association for the Study of the Liver (TASL) proposes the treatment recommendations for the special population in order to serve as guidance to optimizing the outcome in the direct-acting antiviral (DAA) era. Special populations include patients with acute or recent HCV infection, previous DAA failure, chronic kidney disease, decompensated cirrhosis, HCC, liver and other solid organ transplantations, receiving an HCV viremic organ, hepatitis B virus (HBV) and HCV dual infection, HCV and human immunodeficiency virus (HIV) coinfection, active tuberculosis infection, PWID, bleeding disorders and hemoglobinopathies, children and adolescents, and pregnancy. Moreover, future perspectives regarding the management of hepatitis C are also discussed and summarized in this consensus statement.

Re-treatment of Hepatitis C Infection After Multiple Failures of Direct-Acting Antiviral Therapy

BACKGROUND

Direct-acting antiviral (DAA) therapies for hepatitis C virus (HCV) result in initial cure rates of 95% to 99% and re-treatment cure rates of 95%. Nevertheless, given the sheer magnitude of infected persons, some will ultimately fail multiple DAA therapies, and re-treatment of these persons has not been adequately studied.

METHODS

We evaluated treated an HIV-infected man with cirrhosis from genotype 1b HCV who had failed 3 DAA regimens.

RESULTS

We treated and cured our "particularly difficult-to-cure" patient with sofosbuvir plus glecaprevir/pibrentasvir plus ribavirin for 24 weeks. We discuss the literature on potential biological factors behind his treatment failures such as lack of HCV seroconversion during his infection course, and multiple failures of hepatitis B seroconversion after vaccination, and the rationale for choosing his curative salvage regimen.

DISCUSSION

There are no clinical trials-proven re-treatment regimens for "particularly difficult-to-cure" patients. Multiple patient- and virus-related factors that do not affect cure rates in treatment-naive patients may need to be considered in choosing a re-treatment regimen for these patients. These regimens may need to include combinations drugs that are not available in single-tablet form, addition of ribavirin, and longer durations of treatment than standard.

Avoiding Drug Resistance by Substrate Envelope-Guided Design: Toward Potent and Robust HCV NS3/4A Protease Inhibitors

Hepatitis C virus (HCV) infects millions of people worldwide, causing chronic liver disease that can lead to cirrhosis, hepatocellular carcinoma, and liver transplant. In the last several years, the advent of direct-acting antivirals, including NS3/4A protease inhibitors (PIs), has remarkably improved treatment outcomes of HCV-infected patients. However, selection of resistance-associated substitutions and polymorphisms among genotypes can lead to drug resistance and in some cases treatment failure. A proactive strategy to combat resistance is to constrain PIs within evolutionarily conserved regions in the protease active site. Designing PIs using the substrate envelope is a rational strategy to decrease the susceptibility to resistance by using the constraints of substrate recognition. We successfully designed two series of HCV NS3/4A PIs to leverage unexploited areas in the substrate envelope to improve potency, specifically against resistance-associated substitutions at D168. Our design strategy achieved better resistance profiles over both the FDA-approved NS3/4A PI grazoprevir and the parent compound against the clinically relevant D168A substitution. Crystallographic structural analysis and inhibition assays confirmed that optimally filling the substrate envelope is critical to improve inhibitor potency while avoiding resistance. Specifically, inhibitors that enhanced hydrophobic packing in the S4 pocket and avoided an energetically frustrated pocket performed the best. Thus, the HCV substrate envelope proved to be a powerful tool to design robust PIs, offering a strategy that can be translated to other targets for rational design of inhibitors with improved potency and resistance profiles.IMPORTANCE Despite significant progress, hepatitis C virus (HCV) continues to be a major health problem with millions of people infected worldwide and thousands dying annually due to resulting complications. Recent antiviral combinations can achieve >95% cure, but late diagnosis, low access to treatment, and treatment failure due to drug resistance continue to be roadblocks against eradication of the virus. We report the rational design of two series of HCV NS3/4A protease inhibitors with improved resistance profiles by exploiting evolutionarily constrained regions of the active site using the substrate envelope model. Optimally filling the S4 pocket is critical to avoid resistance and improve potency. Our results provide drug design strategies to avoid resistance that are applicable to other quickly evolving viral drug targets.

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.

Systematic review with meta-analysis: impact of baseline resistance-associated substitutions on the efficacy of glecaprevir/pibrentasvir among chronic hepatitis C patients

BACKGROUND

The effect of baseline resistance-associated substitutions (RAS) on the sustained virologic response at 12 weeks (SVR12) among chronic hepatitis C (CHC) patients receiving the second generation, pan-genotypic glecaprevir/pibrentasvir (G/P) regimen is unclear.

AIM

To assess the effect of RAS on the SVR12 in CHC patients treated with G/P regimen.

METHODS

The EMBASE, MEDLINE and Cochrane central register of controlled trials databases were searched for relevant studies published before 1 March 2019. The principal outcome was to compare the SVR12 in CHC patients with and without baseline RAS, particularly in genotype-1, genotype-3 and direct-acting anti-virals (DAAs) failure patients. The outcomes were pooled using a random-effects model and odds ratio (OR) was calculated. The risk of bias was assessed using the Cochrane risk of bias tools for randomised and nonrandomised interventional studies.

RESULTS

After initially identifying 410 studies, 3302 patients from 17 studies were included. Among 50 cases of virologic failures, 48% had genotype-3 infection, 44% genotype-1 infection and 36% DAA-failure patients. Baseline RAS were present in 44(88%) patients. The most common NS5a and NS3 mutations were Y93H and A166S respectively. The odds of SVR12 were significantly reduced in patients with any baseline RAS (NS3 and/or NS5a) (OR 0.32, 95%C I[0.15, 0.65], I²  = 0%) and NS5a substitutions (OR 0.36, 95%CI [0.18,0.73]). The impact of RAS on SVR12 was significant among genotype-3 patients, but not among genotype-1 or DAA-failure cases. The presence of Y93H and A30K mutations significantly impacted SVR12 rates in genotype-3 patients.

CONCLUSION

Baseline NS3 or NS5a RAS, especially the NS5a substitutions-A30K, Y93H, decrease the odds of achieving SVR12 in genotype-3 CHC patients.

Ultra-short duration direct acting antiviral prophylaxis to prevent virus transmission from hepatitis C viremic donors to hepatitis C negative kidney transplant recipients

We conducted an adaptive design single-center pilot trial between October 2017 and November 2018 to determine the safety and efficacy of ultra-short-term perioperative pangenotypic direct acting antiviral (DAA) prophylaxis for deceased hepatitis C virus (HCV)-nucleic acid test (NAT) positive donors to HCV negative kidney recipients (D+/R-). In Group 1, 10 patients received one dose of SOF/VEL (sofusbuvir/velpatasvir) pretransplant and one dose on posttransplant Day 1. In Group 2A (N = 15) and the posttrial validation (Group 2B; N = 25) phase, patients received two additional SOF/VEL doses (total 4) on Days 2 and 3 posttransplant. Development of posttransplant HCV transmission triggered 12-week DAA therapy. For available donor samples (N = 27), median donor viral load was 1.37E + 06 IU/mL (genotype [GT]1a: 70%; GT2: 7%; GT3: 23%). Overall viral transmission rate was 12% (6/50; Group 1:30% [3/10]; Group 2A:13% [2/15]; Group 2B:4% [1/25]). For the 6 viremic patients, 5 (83%) achieved sustained virologic response (3 with first-line DAA therapy; and two after retreatment with second-line DAA). At a median follow-up of 8 months posttransplant, overall patient and allograft survivals were 98%, respectively. The 4-day strategy reduced viral transmission to 7.5% (3/40; 95% confidence interval [CI]: 1.8%-20.5%) and could result in avoidance of prolonged posttransplant DAA therapy for most D+/R - transplants.

Salvage therapy in cancer patients with hepatitis C without sustained virologic response after direct-acting antivirals-A prospective study

Background and Aim

No information exists regarding direct‐acting antivirals (DAAs) salvage therapy for Hepatitis C (HCV)‐infected patients with any type of cancer. We prospectively evaluated the safety and efficacy (SVR12) of salvage therapy in these patients.

Methods

Patients who failed initial DAAs (01/2015–01/2018) were analyzed. Resistance‐associated substitutions to NS5A and NS3 were investigated by population sequencing.

Results

Of 164 patients enrolled, 16 (10%) experienced treatment failure. Of these, 11 patients received salvage therapy. The majority (91%) were men; 55% had genotype 1a, 45% had cirrhosis, and 45% had hepatocellular carcinoma. Four patients failed the first salvage therapy, and two of them required a second salvage therapy. Overall, 9 of 11 (82%) patients achieved SVR12. All four patients treated with sofosbuvir/velpatasvir/voxilaprevir (+/− ribavirin) achieved SVR12. The presence of resistance‐associated substitutions did not impact response. Seven patients developed grade 1/2 adverse events. No patient had grade 3/4 adverse events. No patient required interruption of DAA therapy because of clinical or laboratory abnormalities.

Conclusions

This is the first prospective study in HCV‐infected cancer patients failing DAAs. The efficacy of salvage therapy in this group appears to be lower than previously reported in non‐cancer patients, but better response rates are observed with newer regimens. Salvage therapy is associated with minimal toxicity.