Sofosbuvir, Velpatasvir, and Voxilaprevir for Previously Treated HCV Infection

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.

The European Prevalence of Resistance Associated Substitutions among Direct Acting Antiviral Failures

Background: Approximately 71 million people are still in need of direct-acting antiviral agents (DAAs). To achieve the World Health Organization Hepatitis C elimination goals, insight into the prevalence and influence of resistance associated substitutions (RAS) is of importance. Collaboration is key since DAA failure is rare and real-life data are scattered. We have established a European collaboration, HepCare, to perform in-depth analysis regarding RAS prevalence, patterns, and multiclass occurrence. Methods: Data were extracted from the HepCare cohort of patients who previously failed DAA therapy. Geno—and subtypes were provided by submitters and mostly based on in-house assays. They were reassessed using the Comet HCV subtyping tool. We considered RAS to be relevant if they were associated with DAA failure in vivo previously reported in literature. Results: We analyzed 938 patients who failed DAA therapy from ten different European countries. There were 239 genotypes (GT) 1a, 380 GT1b, 19 GT2c, 205 GT3a, 14 GT4a, and 68 GT4d infections. Several unusual subtypes (n = 15) (GT1b/g/l, GT3b, GT4k/n/r/t) were present. RAS appeared in over 80% of failures and over a quarter had three or more RAS. Multiclass RAS varied over target region and genotype between 0–48%. RAS patterns such as the Q30R + L31M and Q30R + Y93H in GT1a, the L31V + Y93H and L31V + Y93H for GT1b, and A30K + L31M and A30K/V + Y93H for GT3a all occurred with a prevalence below 5%. Conclusion: RAS occur frequently after DAA failures and follow a specific genotype and drug related pattern. Interpretation of the influence of RAS on retreatment is challenging due to various patterns, patients’ characteristics, and previous treatment history. Moving towards HCV elimination, an ongoing resistance surveillance is essential to track the presence of RAS, RAS patterns and gather data for a re-treatment algorithm.

Present and future management of viral hepatitis

Viral hepatitis can result in important morbidity and mortality, with its impact on health conditioned by the specific type of hepatitis, the geographical region of presentation and the development and access to new drugs, among other factors. Most acute presentation forms are self-limiting and may even go unnoticed, with just a small percentage of cases leading to acute liver failure that may necessitate transplantation or even cause the death of the patient. However, when they become chronic, as in the case of hepatitis B virus and C virus, unless they are diagnosed and treated adequately they may have severe consequences, like cirrhosis or hepatocarcinoma. Understanding of the mechanisms of transmission, the pathogenesis, the presence of vaccinations and the development over recent years of new highly-efficient, potent drugs have meant that we are now faced with a new scenario in the management of viral hepatitis, particularly hepatitis B virus and hepatitis C virus. The spectacular advances in hepatitis C virus treatment have led the World Health Organization to propose the objective of its eradication by 2030. The key aspect to achieving this goal is to ensure that these treatments reach all the more vulnerable population groups, in whom the different types of viral hepatitis have a high prevalence and constitute a niche that may perpetuate infection and hinder its eradication. Accordingly, micro-elimination programs assume special relevance at the present time.

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.

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

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

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

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

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

Efficacy and Safety of Sofosbuvir/Velpatasvir/Voxilaprevir for Hepatitis C Virus (HCV) NS5A-Inhibitor Experienced Patients With Difficult to Cure Characteristics

BACKGROUND

In clinical trials, hepatitis C virus (HCV) salvage treatment with sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) achieved an SVR12 rate of >95% in NS5A-experienced participants. Lower SVR12 rates have been reported in real-world studies, particularly for genotype (GT)3 infection and cirrhosis. We determined the efficacy and safety of SOF/VEL/VOX in a large real-world cohort.

METHODS

We assessed the efficacy of salvage SOF/VEL/VOX for HCV infection in NS5A-inhibitor experienced participants with cirrhosis and portal hypertension, prior liver transplantation (LT) or severe extra-hepatic manifestations. SOF/VEL/VOX was available via an early access program. The primary outcome was SVR12. Secondary outcome was frequency of adverse events (AE).

FINDINGS

Ninety-seven participants were included. Median age was 58, 82% were male, 78% had cirrhosis, most with portal hypertension (61%, n = 46/76), and 18% had prior-LT. Of the cirrhotic participants, 96% were Child-Turcotte-Pugh class A, and 4% were class B. Of the 72% with GT3, 76% were also cirrhotic. By intention-to-treat analysis, SVR12 rate was 85% (n = 82/97). Per protocol, the SVR12 rate was 90%, including 91% in GT1 (GT1a n = 18/18, GT1b n = 2/4), 89% in GT3 (n = 59/66) and 100% in GT6 (n = 3/3). SVR12 in participants with GT3 and cirrhosis was 90%. No predictors of non-SVR12 were identified. There were 4 serious AEs including 1 death and 3 hepatic decompensation events. NS5A resistance-associated substitutions detected at baseline did not affect SVR12.

CONCLUSIONS

This real-world study confirms high efficacy of SOF/VEL/VOX for the treatment of difficult-to-cure NS5A-inhibitor experienced patients, including those with GT3 and cirrhosis. Treatment was well tolerated in most; however, serious AEs can occur in those with advanced liver disease.

Chronic Hepatitis B Virus in Patients with Chronic Hepatitis C Virus

Many patients with hepatitis C virus (HCV) have also been exposed to hepatitis B virus (HBV). The 2 viruses interact and in most cases HCV suppresses HBV. When HCV is treated with direct antiviral agents, this suppressive effect is removed, HBV replication may increase, and a flare in liver enzymes with liver injury may occur. All patients with chronic HCV should therefore be checked for serologic evidence of HBV. Patients with hepatitis B surface antigen are at the highest risk for reactivation, and these patients should receive prophylactic treatment of HBV during and for 6 months after HCV treatment.

Inferior cure rate in pilot study of 4-week glecaprevir/pibrentasvir treatment with or without ribavirin of chronic hepatitis C

BACKGROUND & AIMS

Shortening the treatment duration for chronic hepatitis C may increase feasibility and reduce the cost of cure. The aims of this study were to compare 4 weeks of glecaprevir/pibrentasvir (GLE/PIB) treatment with and without ribavirin for patients with chronic hepatitis C and favourable baseline characteristics and to monitor the development of resistance-associated substitutions (RAS) and re-treatment outcomes if treatment failed.

METHODS

We performed an open-label single-centre randomized controlled trial, in which patients with chronic hepatitis C were randomized 1:1 to GLE/PIB ± ribavirin, stratified by genotype 3. The main inclusion criteria were treatment-naive patients, aged 18-49 with all genotypes accepted, and absence of liver fibrosis, determined by liver stiffness measurement less than 8 kPa. Viral genome sequences were determined by deep sequencing at baseline and at the time of relapse.

RESULTS

A total of 32 patients started treatment. Sustained virological response at week 12 (SVR12) was 59% (10/17) for GLE/PIB without ribavirin and 73% (11/15) for GLE/PIB with ribavirin. Drug target-specific NS5A RAS were detected at baseline for 45% (5/11) of patients with treatment failure and for 14% (3/21) of patients who achieved SVR12. Ten failure patients were retreated 12 weeks with sofosbuvir-based regimens; all have been cured.

CONCLUSIONS

In this pilot study of 4-week treatment with GLE/PIB with and without ribavirin, we found that baseline RAS were more frequent in patients with virological failure. Development of RAS did occur after short treatment but did not result in retreatment failure with a different regimen. EudraCT no: 2017-005179-21.

Cost Effectiveness of Screening for Hepatitis C Virus in Iraq in the Era of Simplified Testing and Treatment

BACKGROUND AND OBJECTIVE

Recent advances in hepatitis C virus (HCV) diagnostic testing methods allow for a one-stop simplified 'test and cure' approach. The cost effectiveness of incorporating this simplified approach into HCV screening in Iraq remains uncertain. This study aimed to compare the cost effectiveness of different HCV testing and diagnostic approaches, and screening strategies in Iraq from a health service perspective.

METHODS

A cost-effectiveness analysis was undertaken using a hybrid model comprising a screening decision tree linked to a lifetime Markov model to estimate outcomes in HCV-infected people. Cost and utility estimates were sourced from the published literature and expert guidance provided by clinicians and policy makers in Iraq. Cost estimates were reported in 2019 USD or 2019 Iraqi Dinar and both costs and benefits were discounted at 3.5% annually.

RESULTS

Strategies using a simplified approach were found to be cost saving in addition to improving patient outcomes when compared with a standard testing and diagnostic approach. When considering risk-based screening, a simplified approach was associated with a total cost saving of Iraqi Dinar 4375 billion (USD 3.7 billion) and per patient life-year and quality-adjusted life-year gains of 0.30 and 0.55, compared with a standard approach. Benefits and cost savings were driven by a 32.2% and 23.6% reduction in the incidence of cirrhosis and hepatocellular carcinoma, respectively. Estimated benefits and cost savings increased under total population screening. All screening and testing and diagnostic approaches were cost effective compared with a no screening scenario.

CONCLUSIONS

Improvements in the detection of HCV combined with a simplified one-stop testing and diagnostic approach represents an opportunity to reduce the burden of HCV in Iraq and may play a significant role in meeting World Health Organisation HCV elimination targets.

[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.

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.

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.

Machine-learning-based predictions of direct-acting antiviral therapy duration for patients with hepatitis C

INTRODUCTION

Hepatitis C, which affects 71 million persons worldwide, is the most common blood-borne pathogen in the United States. Chronic infections can be treated effectively thanks to the availability of modern direct-acting antiviral (DAA) therapies. Real-world data on the duration of DAA therapy, which can be used to optimize and guide the course of therapy, may also be useful in determining quality of life enhancements based upon total required supply of medication and long-term improvements to quality of life. We developed a machine learning model to identify patient characteristics associated with prolonged DAA treatment duration.

METHODS

A nationwide U.S. commercial managed care plan with claims data that covers about 60 million beneficiaries from 2009 to 2019 were used in the retrospective study. We examined differences in age, gender, and multiple comorbidities among patients treated with different durations of DAA treatment. We also examined the performance of machine learning models for predicting a prolonged course of DAA based on the area under the receiver operating characteristic curve (AUC).

RESULTS

We identified 3943 cases with hepatitis C who received sofosbuvir/ledipasvir as the first course of DAA and were eligible for the study. Patients receiving prolonged treatment (n = 240, 6.1%) were more likely to have compensated cirrhosis, decompensated cirrhosis, and other comorbidities (P < 0.001). For distinguishing patients who received prolonged DAA treatment for hepatitis C from patients received standard treatment, the optimal predictive model, constructed with XGBoost, had an AUC of 0.745 ± 0.031 (P < 0.001).

CONCLUSIONS

The risk of antiviral resistance and the cost of DAA are strong motivators to ensure that first-round DAA therapy is effective. For the dominant DAA treatment during the course of this analysis, we present a model that identifies factors already captured in established guidelines and adds to those age, comorbidity burden, and type 2 diabetes status; patient characteristics that are predictive of extended treatment.

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.

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

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

Resistance-associated substitutions after sofosbuvir/velpatasvir/voxilaprevir triple therapy failure

Direct-acting antivirals (DAAs) resolve chronic HCV infection in >95% of patients, but a small percentage do not respond to DAA-based therapy. These may be difficult to treat because of resistance-associated substitutions (RAS) emerging after treatment failure. Triple therapy with sofosbuvir (SOF)/velpatasvir (VEL)/voxilaprevir (VOX) is the recommended retreatment after DAA-based failure. However, in rare cases, failure to triple therapy occurs, and there is little information characterizing the viruses that relapse. To determine the RAS profile after failing SOF/VEL/VOX, and seek suitable alternatives for retreatment, samples from 5 patients were analysed using MiSeq Illumina deep sequencing before and after triple therapy. All patients were men, aged 59-78 years, 2 HCV genotype (G) 1b and 3 G3a. The most prevalent NS3 substitutions after SOF/VEL/VOX failure were Y56F and A166T. Four patients had the NS5A RAS, Y93H, after triple failure, and Y93H was observed in both G1b patients before retreatment and after SOF/ledipasvir failure. In 2 G3a patients, Y93H appeared at triple failure, and on the other G3a, A30K persisted in 100% of viral genomes. Finally, G1b patients showed C316N in NS5B, associated with SOF failure, but G3a patients had no known NS5B substitutions. HCV RAS analysis identified the following substitutions present at higher rates after triple failure: Y56F in NS3 (G1b), A166T in NS3 (G3a), A30K or Y93H in NS5A, and C316N in NS5B (G1b). A RAS-based salvage treatment (SOF + glecaprevir/pibrentasvir + RBV) was successfully used in one G3a patient.

Real-world re-treatment outcomes of direct-acting antiviral therapy failure in patients with chronic hepatitis C

Direct-acting antiviral (DAA) drugs are associated with high (>95%) sustained virological response at 12 weeks (SVR12) in chronic hepatitis C (CHC) patients. There is a paucity of data regarding the characteristics and re-treatment outcomes of DAA treatment failure patients. In a retrospective analysis of the prospectively collected database, we assessed the outcomes of re-treatment among patients with previous DAA failure. Patients' characteristics, viral characteristics, including resistance-associated substitutions (RAS) in a subgroup of patients, SVR12, and clinical outcomes were studied. Of 40 patients with DAA failure, among whom 36 were retreated, mean age was 45.7 years, 63.9% (n = 23) were male, 63.9% (n = 23) had a genotype-3 infection and 63.9% (n = 23) were cirrhotic. The re-treatment regimens included a combination of pan-genotypic DAA, mainly sofosbuvir and velpatasvir with or without ribavirin. Three patients who declined retreatment and one who was still on treatment was excluded. For patients who completed re-treatment, SVR12 was 100% irrespective of genotypes. SVR12 among genotype 3 was 75% (15 of 20) when lost to follow-up was considered a treatment failure. Six patients died due to liver-related causes, including five (83.3%) with hepatocellular carcinoma. RAS analysis in 17 randomly selected patients did not reveal any dominant substitutions in NS5A or NS5B region affecting SVR12, though several novel mutations were observed. In conclusion, re-treatment of CHC patients with prior DAA failure using pan-genotypic DAA is associated with high SVR12 rates irrespective of genotype or the presence of RAS.

Current therapeutics against HCV

Hepatitis C is a positive stranded enveloped RNA virus belonging to the Flaviviridae family. HCV infection leads to severe liver diseases, cirrhosis and hepatocellular carcinoma worldwide. Although treatments have been available for a while, due to its complexity and genetic diversity, only few are reported to be effective against all HCV genotypes. Here, we review the HCV life cycle and its immunogenic potential and various mechanisms via which the virus interferes in the signalling process. A comprehensive overview of current anti-HCV therapeutics, such as, Direct Acting Antiviral (DAA) as well as Host Targeting Agents (HTA), along with their scope, known mechanism of action and limitations are presented.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-021-00697-0.

Salvage Therapy with Sofosbuvir/Velpatasvir/Voxilaprevir in DAA-experienced Patients: Results from a Prospective Canadian Registry

BACKGROUND

Despite the current highly effective therapies with direct-acting antiviral agents (DAAs), some patients with chronic hepatitis C virus (HCV) infection still do not achieve sustained virological response (SVR) and require retreatment. Sofosbuvir/velpatasvir/voxilaprevir (SVV) is recommended as the first-line retreatment option for most patients. The aim of this study was to evaluate the efficacy of SVV as salvage therapy after at least one course of DAA.

METHODS

Data were collected on all HCV-infected patients who failed DAAs and were prescribed SVV from a prospective Canadian registry (CANUHC) including 17 sites across Canada. Factors associated with failure to achieve SVR with SVV therapy and the utility of RAS testing and ribavirin use were evaluated.

RESULTS

A total of 128 patients received SVV after non-SVR with DAA treatment: 80% male, median age 57.5 (31-86), 44% cirrhotic, and 17 patients post liver transplant. First line regimens included: sofosbuvir/velpatasvir (27.3%), sofosbuvir/ledipasvir (26.5%), grazoprevir/elbasvir (12.5%), other (33.5%). Ribavirin was added to SVV in 26 patients due to past sofosbuvir/velpatasvir use (n = 8), complex resistance associated substitution profiles (n = 16) and/or cirrhosis (n = 9). Overall SVR rate was 96% (123/128). Of 35 patients who previously failed sofosbuvir/velpatasvir, 31 (88.5%) achieved SVR compared to 92 of 93 (99%) among those receiving any other regimen (P = .01).

CONCLUSIONS

Similar to reports from phase 3 clinical trials, SVV proved highly effective as salvage therapy for patients who failed a previous DAA therapy. Those who failed SVV had at least 2 of the following factors: genotype 3, presence of cirrhosis, past liver transplantation, past exposure to sofosbuvir/velpatasvir and/or complex resistance profiles.

Treatment of hepatitis C virus infection

Hepatitis C virus infection affects 71 million people worldwide. It is at the origin of a multi-organ disease associating hepatic manifestations, cryoglobulinemic vasculitis and general manifestations linked to chronic inflammation (diabetes, cardio-, reno- or cerebrovascular manifestations, extra-hepatic cancers including non-Hodgkin's lymphoma). The significant morbidity and mortality linked to the hepatitis C virus therefore justify its screening and access to treatments which have increased considerably over the past two decades. Understanding the replicative cycle of the hepatitis C virus has enabled the development of direct HCV-specific antivirals targeting viral proteins (NS3/4A protease, NS5B polymerase and the multifunctional NS5A replication complex). The combination of two to three specific inhibitors often co-formulated in a capsule, without pegylated interferon and most often without ribavirin, allows high antiviral efficacy (more than 97% cure) for a treatment duration of 8-12 weeks with satisfactory tolerance. HCV infection is the only chronic viral infection that can be cured and the hepatic or extrahepatic manifestations are mainly reversible. This underlines the importance of strengthening screening and access to care policies in order to achieve the elimination of viral infection C in the short term, in 2030, as expected from the program of the World Health Organization. If this elimination is possible in some countries (Iceland, France, Germany …), it seems compromised in others where prevention (USA), screening and/or access to care are still insufficient (Sub-Saharan Africa, Russia…).

Evolution of liver stiffness and post-treatment surveillance by liver elastography for HCV patients in the DAA era

OBJECTIVE

Baseline liver stiffness (LS) is prognostically relevant in patients with chronic hepatitis C virus (HCV) infection but may change after successful HCV eradication. Data on post-treatment LS for a further risk stratification remain scarce. Here, we study the kinetics of LS and laboratory parameters in patients undergoing HCV treatment and analyze the association of post-treatment LS with outcome parameters.

METHODS

In a cohort of 1011 chronic HCV patients undergoing DAA treatment, we identified 404 patients with sequential LS and laboratory assessments with or without viral eradication. Additionally, outcome parameters were correlated with post-treatment LS after successful HCV therapy.

RESULTS

LS significantly decreased from a median of 8.8 to 6.1 kPa in 346 patients after HCV eradication, but significantly increased from a median of 10.5 to 11.9 kPa in 58 patients without viral clearance. In 78 patients with two sequential post-treatment measurements, LS decreased from 12.6 to 8.7 kPa after a median 344 d, with a further decrease to 7.0 kPa after a median of 986 d after end of treatment (EoT). In 400 patients with a post-treatment LS assessment after viral eradication, only 9 liver-related events occurred over a median follow-up (FU) of 23 months. All events were observed in patients with a post-treatment LS >20 kPa.

CONCLUSIONS

After successful HCV eradication, LS improves sequentially, suggesting an initial phase of necroinflammation regression followed by a second phase of true fibrosis regression. Overall, liver-related events were rarely observed and seem to be limited to patients with a post-treatment LS >20 kPa, so that these patients require a closer clinical monitoring.

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.

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.

Efficacy of sofosbuvir/velpatasvir/voxilaprevir in direct-acting antiviral experienced patients with hepatitis C virus

AIMS

Report the real-world experience of the efficacy and safety of sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) in chronic hepatitis C virus (HCV) infected patients who have previously experienced a direct-acting antiviral (DAA) containing regimen.

METHODS

Consecutive patients who have previously failed or did not tolerate a DAA containing regimen for chronic HCV who was treated with SOF/VEL/VOX were studied. Baseline clinical and laboratory data including NS5A RAS mutation testing were collected.

RESULTS

SOF/VEL/VOX resulted in an end of treatment undetectable HCV viral load in all patients and a sustained virologic response 12 rate of 100% despite the presence of NS5A RAS mutation, HIV infection, and cirrhosis. Treatment with SOF/VEL/VOX was well tolerated and there were no adverse events.

CONCLUSIONS

SOF/VEL/VOX is well tolerated and effective in treating patients who have been exposed to prior DAA therapy outside of clinical trials. SOF/VEL/VOX should be considered as the first-line regimen in HCV infected patients who have experienced prior DAA failure.

HCV resistance-associated substitutions following direct-acting antiviral therapy failure - Real-life data from Poland

BACKGROUND

This study analysed the NS3 and NS5A mutation frequencies, persistence and drug susceptibility in a cohort of real-life patients, with failed hepatitis C virus (HCV) therapy following directly acting antiviral (DAA) treatment.

METHODS

NS3/NS5A Sanger sequences from 105 patients infected with HCV genotype (G) 1a (6,5.7%), G1b (94,89.5%), G3a (4,3.8%), and G4 (1,1.0%) post DAA treatment failure were analysed. NS3 and NS5A resistance-associated substitutions (RASs) were identified using the geno2pheno algorithm and associated with clinical variables. Time trends were examined using logistic regression.

RESULTS

NS5A RAS were found in 87.9% of sequences derived from patients exposed to this class of agents, whereas NS3 RAS was found in 59.1% of HCV protease-exposed subjects. The frequency of the NS3 RAS increased with fibrosis stage, from 40.0% among F0/F1 individuals to 81.8% among patients with liver cirrhosis (F4, p = 0.094). NS5A mutation frequencies were 7.6% for 28A/V/M, 10.6% for 30 K/Q/R, 42.4% for 31I/F/M/V, and 75.8% for 93H. For NS3, the most common RASs were 56F-23.7%, 168A/E/I/Y/T/V-14.0%, and 117H-5.4%. Susceptibility to glecaprevir/pibrentasvir, velpatasvir/voxlaprevir, and elbasvir/grazoprevir was retained in 92.9%, 43.4%, and, 25.3% of patients, respectively. The frequency of NS3 RAS decreased with time elapsed from failure to sampling (p = 0.034 for trend). NS5A RAS frequency remained stable over the 24-months.

CONCLUSIONS

Following DAA treatment failure, NS5A and NS3 RASs were common with increasing frequency among patients with advanced liver disease. In most cases, despite the presence of RASs, susceptibility to DAA combinations with higher genetic barrier was retained.

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.

Could Histamine H1 Receptor Antagonists Be Used for Treating COVID-19?

COVID-19 has rapidly become a pandemic worldwide, causing extensive and long-term health issues. There is an urgent need to identify therapies that limit SARS-CoV-2 infection and improve the outcome of COVID-19 patients. Unbalanced lung inflammation is a common feature in severe COVID-19 patients; therefore, reducing lung inflammation can undoubtedly benefit the clinical manifestations. Histamine H1 receptor (H1 receptor) antagonists are widely prescribed medications to treat allergic diseases, while recently it has emerged that they show significant promise as anti-SARS-CoV-2 agents. Here, we briefly summarize the novel use of H1 receptor antagonists in combating SARS-CoV-2 infection. We also describe the potential antiviral mechanisms of H1 receptor antagonists on SARS-CoV-2. Finally, the opportunities and challenges of the use of H1 receptor antagonists in managing COVID-19 are discussed.

Drug combination therapy for emerging viral diseases

Effective therapeutics to combat emerging viral infections are an unmet need. Historically, treatments for chronic viral infections with single drugs have not been successful, as exemplified by human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections. Combination therapy for these diseases has led to improved clinical outcomes with dramatic reductions in viral load, morbidity, and mortality. Drug combinations can enhance therapeutic efficacy through additive, and ideally synergistic, effects for emerging and re-emerging viruses, such as influenza, severe acute respiratory syndrome-coronavirus (SARS-CoV), Middle East respiratory syndrome (MERS)-CoV, Ebola, Zika, and SARS-coronavirus 2 (CoV-2). Although novel drug development through traditional pipelines remains a priority, in the interim, effective synergistic drug candidates could be rapidly identified by drug-repurposing screens, facilitating accelerated paths to clinical testing and potential emergency use authorizations.

Blinding in Clinical Trials for Chronic Liver Diseases

Within the field of randomized clinical trials (RCTs), the randomized double-blind placebo-controlled clinical trial is considered the most efficient means of simultaneously assessing the efficacy and safety of a medical therapy in a single trial. While many RCTs are conducted without blinding (open label), it is rare to encounter a blinded trial that does not randomize its subjects. Clinical trials for chronic liver diseases have adopted many of the practices set forth by RCTs in other chronic diseases, but blinding has often been difficult to properly implement. This review examines the rationale for blinding, common challenges to successful blinding, different mechanisms of unintentional unblinding in clinical trials for viral hepatitis and nonalcoholic steatohepatitis, and recommendations for blinding and design in future trials of treatments for liver disease.

Recent advances in the treatment of hepatitis C virus infection for special populations and remaining problems

Hepatitis C virus (HCV) infection is one of the primary causes of liver cirrhosis, hepatocellular carcinoma (HCC), and liver transplantation (LT). The rate of HCV infection is high in patients on hemodialysis and in patients infected with human immunodeficiency virus (HIV). In liver transplant patients with HCV infection, recurrent HCV infection of the transplanted liver is universal and results in rapid liver fibrosis progression. In patients with HCV/HIV coinfection as well, liver fibrosis advances rapidly. Thus, there is an urgent need for prompt HCV infection treatment in these special populations (i.e. HIV/HCV coinfection, HCV infection after LT, and dialysis patients). Interferon (IFN)-based therapy for HCV infection could not achieve a high rate of sustained viral response and could cause severe adverse events in the aforementioned special populations. Direct-acting antivirals (DAAs) have recently been developed, and clinical trials have shown that IFN-free DAA-based therapies are associated with a significantly better safety and therapeutic profile than IFN-based therapies. However, the majority of the initial DAA trials excluded special populations; thus, the efficacy and safety of IFN-free DAA-based therapy in special populations remained to be clearly established. Although recent clinical trials and clinical studies have shown the high efficacy and safety of this therapy even in special populations, several unresolved problems, including emergence of resistance-associated variants after failure to respond to DAAs and HCC occurrence after DAA therapy, still exist. Hence, in this review, we discuss the recent advances in anti-HCV therapy for special populations and the remaining problems regarding this therapy.

Hepatitis C: A Pharmacological Therapeutic Update

(1) Background: Hepatitis C is a high-prevalence disease, representing a global impact health problem. Lately, many changes have been made in treatment guidelines because of the commercialization of second-generation direct-acting antivirals due to their high effectiveness, few side effects and pangenotypic action. We address the pharmacological possibilities available and compare them with the current recommendations of the World Health Organization (WHO). (2) Methods: The search for articles was made through the PubMed database using different search strategies and we consulted technical data sheets of the treatments that have been included in the study. (3) Results: Combinations of "glecaprevir/pibrentasvir", "sofosbuvir/velpatasvir" and "sofosbuvir/velpatasvir/voxilaprevir" have been recently incorporated. Phase II studies have shown that they are safe and effective therapies with very comfortable posologies and easy therapeutic adherence; furthermore, they suppose shorter treatment duration. Subsequently, phase III studies have shown they were effective for previously treated or compensated cirrhotic patients that previously had more complex treatment regimens. (4) Conclusions: These results suppose a simplification in Hepatitis C therapeutic approach, and open new study possibilities.

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%).

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.

Age and gender-specific hepatitis C continuum of care and predictors of direct acting antiviral treatment among persons who inject drugs in Seattle, Washington

BACKGROUND

Direct acting antivirals (DAAs) have revolutionized management of hepatitis C virus (HCV), but treatment uptake remains low among persons who inject drugs (PWID). We report the continuum of care for HCV and describe predictors of treatment with DAAs among PWID in Seattle.

METHODS

We analyzed data from the 2018 Seattle area National HIV Behavioral Surveillance (NHBS) survey of PWID. Persons ≥18 years of age who injected drugs in the past year and completed the core NHBS survey, a local survey supplement, and rapid HCV antibody testing were included. Among those who screened HCV antibody positive, we calculated proportions and 95 % confidence intervals for self-reported steps along the HCV care continuum. Multivariable logistic regression was used to calculate the adjusted odds (AOR) of having received DAA therapy.

RESULTS

The sample included 533 PWID, 376 (71 %) of whom tested positive for antibodies to HCV. Among those who were HCV antibody positive, 94 % reported any prior HCV test, 81 % reported a prior confirmatory test, and 68 % reported a prior HCV diagnosis. Of those diagnosed, 26 % had undergone treatment and 18 % had been cured. In a multivariate model, being one year older (AOR 1.05 per year, 1.01-1.08) was predictive of DAA treatment, while homelessness (AOR 0.39, 0.19-0.80) and female gender (AOR 0.36, 0.16-0.78) were associated with a lower odds of DAA therapy.

CONCLUSIONS

Despite widespread HCV testing among PWID in Seattle, treatment uptake remains low in the DAA era. In particular, treatment of women, younger adults and persons living homeless is lagging behind.

Guidelines Have a Key Role in Driving HCV Elimination by Advocating for Simple HCV Care Pathways

The availability of pangenotypic direct-acting antivirals for treatment of hepatitis C (HCV) has provided an opportunity to simplify patient pathways. Recent clinical practice guidelines have recognised the need for simplification to ensure that elimination of HCV as a public health concern remains a priority. Despite the move towards simplified treatment algorithms, there remains some complexity in the recommendations for the management of genotype 3 patients with compensated cirrhosis. In an era where additional clinical trial data are not anticipated, clinical guidance should consider experience gained in real-world settings. Although more experience is required for some pangenotypic therapeutic options, on the basis of published real-world data, there is already sufficient evidence to consider a simplified approach for genotype 3 patients with compensated cirrhosis. The coronavirus disease 2019 (COVID-19) pandemic has highlighted the need to minimise the need for complex patient pathways and clinical practice guidelines need to continue to evolve in order to ensure that patient outcomes remain optimised.

A Population-Based Intervention to Improve Care Cascades of Patients With Hepatitis C Virus Infection

Hepatitis C virus (HCV) infection is common in the United States and leads to significant morbidity, mortality, and economic costs. Simplified screening recommendations and highly effective direct-acting antivirals for HCV present an opportunity to eliminate HCV. The objective of this study was to increase testing, linkage to care, treatment, and cure of HCV. This was an observational, prospective, population-based intervention program carried out between September 2014 and September 2018 and performed in three community health centers, three large multiclinic health care systems, and an HCV patient education and advocacy group in King County, WA. There were 232,214 patients included based on criteria of documented HCV-related diagnosis code, positive HCV laboratory test or prescription of HCV medication, and seen at least once at a participating clinical site in the prior year. Electronic health record (EHR) prompts and reports were created. Case management linked patients to care. Primary care providers received training through classroom didactics, an online curriculum, specialty clinic shadowing, and a telemedicine program. The proportion of baby boomer patients with documentation of HCV testing increased from 18% to 54% during the project period. Of 77,577 baby boomer patients screened at 87 partner clinics, 2,401 (3%) were newly identified HCV antibody positive. The number of patients staged for treatment increased by 391%, and those treated increased by 1,263%. Among the 79% of patients tested after treatment, 95% achieved sustained virologic response. Conclusion: A combination of EHR-based health care system interventions, active linkage to care, and clinician training contributed to a tripling in the number of patients screened and a more than 10-fold increase of those treated. The interventions are scalable and foundational to the goal of HCV elimination.

Evolution of Hepatitis C Virus Treatment During the Era of Sofosbuvir-Based Therapies: A Real-World Experience in France

BACKGROUND

Treatment of hepatitis C virus (HCV) has been dramatically improved with the introduction of direct-acting antiviral agents (DAAs). Universal access to pangenotypic DAAs was provided in France from 2017, expanding the type of patients treated. Real-world studies are important to confirm effectiveness and safety in clinical practice, particularly in vulnerable populations.

AIMS

To assess real-world effectiveness and safety of sofosbuvir-based therapy in adults with chronic HCV infection before and after universal access to DAAs in France.

METHODS

This multicenter, non-interventional, prospective study assessed the effectiveness, safety, patient-reported outcomes and adherence with sofosbuvir-based regimens from October 2015 to July 2016 (Period 1: sofosbuvir-based therapy excluding sofosbuvir/velpatasvir) and from October 2017 to July 2018 (Period 2: pangenotypic sofosbuvir/velpatasvir-based therapy).

RESULTS

Baseline data were documented for 1029 patients. Overall, 797 (77%) had sustained virologic response data available ≥ 9 weeks after treatment completion. Per protocol response was high (97%) irrespective of age, alcohol consumption, recreational drug use, or HIV/HCV coinfection. Adverse events occurred in approximately 25% of patients with the majority experiencing Grade 1 or 2 events. Sofosbuvir-based regimens improved health-related quality of life from baseline to end of treatment in patients with data at all timepoints. Overall, 99% of patients reported total or almost total adherence to therapy.

CONCLUSIONS

Sofosbuvir-based therapy, including pangenotypic sofosbuvir/velpatasvir, is effective for the treatment of HCV in real-world clinical practice. This is an important step towards HCV elimination.

Consensus Guidelines: Best Practices for Detection, Assessment and Management of Suspected Acute Drug-Induced Liver Injury During Clinical Trials in Adults with Chronic Viral Hepatitis and Adults with Cirrhosis Secondary to Hepatitis B, C and Nonalcoholic Steatohepatitis

With the widespread development of new drugs to treat chronic liver diseases (CLDs), including viral hepatitis and nonalcoholic steatohepatitis (NASH), more patients are entering trials with abnormal baseline liver tests and with advanced liver injury, including cirrhosis. The current regulatory guidelines addressing the monitoring, diagnosis, and management of suspected drug-induced liver injury (DILI) during clinical trials primarily address individuals entering with normal baseline liver tests. Using the same laboratory criteria cited as signals of potential DILI in studies involving patients with no underlying liver disease and normal baseline liver tests may result in premature and unnecessary cessation of a study drug in a clinical trial population whose abnormal and fluctuating liver tests are actually due to their underlying CLD. This position paper focuses on defining best practices for the detection, monitoring, diagnosis, and management of suspected acute DILI during clinical trials in patients with CLD, including hepatitis C virus (HCV) and hepatitis B virus (HBV), both with and without cirrhosis and NASH with cirrhosis. This is one of several position papers developed by the IQ DILI Initiative, comprising members from 16 pharmaceutical companies in collaboration with DILI experts from academia and regulatory agencies. It is based on an extensive literature review and discussions between industry members and experts from outside industry to achieve consensus regarding the recommendations. Key conclusions and recommendations include (1) the importance of establishing laboratory criteria that signal potential DILI events and that fit the disease indication being studied in the clinical trial based on knowledge of the natural history of test fluctuations in that disease; (2) establishing a pretreatment value that is based on more than one screening determination, and revising that baseline during the trial if a new nadir is achieved during treatment; (3) basing rules for increased monitoring and for stopping drug for potential DILI on multiples of baseline liver test values and/or a threshold value rather than multiples of the upper limit of normal (ULN) for that test; (4) making use of more sensitive tests of liver function, including direct bilirubin (DB) or combined parameters such as aspartate transaminase:alanine transaminase (AST:ALT) ratio or model for end-stage liver disease (MELD) to signal potential DILI, especially in studies of patients with cirrhosis; and (5) being aware of potential confounders related to complications of the disease being studied that may masquerade as DILI events.

Prevention of Hepatitis C Virus Infection and Liver Cancer

Hepatocellular carcinoma (HCC) is the fifth most prevalent cancer and the second leading cause of cancer-related death worldwide.

Late-stage difluoromethylation: concepts, developments and perspective

This review describes the conceptual advances that have led to the multiple difluoromethylation processes making use of well-defined CF₂H sources.

Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.^1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.^4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.⁸ However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

Anno 2021: Which antivirals for the coming decade?

Despite considerable progress in the development of antiviral drugs, among which anti-immunodeficiency virus (HIV) and anti-hepatitis C virus (HCV) medications can be considered real success stories, many viral infections remain without an effective treatment. This not only applies to infectious outbreaks caused by zoonotic viruses that have recently spilled over into humans such as severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), but also ancient viral diseases that have been brought under control by vaccination such as variola (smallpox), poliomyelitis, measles, and rabies. A largely unsolved problem are endemic respiratory infections due to influenza, respiratory syncytial virus (RSV), and rhinoviruses, whose associated morbidity will likely worsen with increasing air pollution. Furthermore, climate changes will expose industrialized countries to a dangerous resurgence of viral hemorrhagic fevers, which might also become global infections. Herein, we summarize the recent progress that has been made in the search for new antivirals against these different threats that the world population will need to confront with increasing frequency in the next decade.

Therapy Implications of Hepatitis C Virus Genetic Diversity

Hepatitis C virus (HCV) is an important human pathogen with a high chronicity rate. An estimated 71 million people worldwide are living with chronic hepatitis C (CHC) infection, which carries the risk of progression to hepatic fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Similar to other RNA viruses, HCV has a high rate of genetic variability generated by its high mutation rate and the actions of evolutionary forces over time. There are two levels of HCV genetic variability: intra-host variability, characterized by the distribution of HCV mutant genomes present in an infected individual, and inter-host variability, represented by the globally circulating viruses that give rise to different HCV genotypes and subtypes. HCV genetic diversity has important implications for virus persistence, pathogenesis, immune responses, transmission, and the development of successful vaccines and antiviral strategies. Here we will discuss how HCV genetic heterogeneity impacts viral spread and therapeutic control.

Safety and efficacy of sofosbuvir/velpatasvir/voxilaprevir in post-liver transplant patients with previous direct-acting antiviral failure: Six case reports

BACKGROUND

Direct-acting antiviral (DAA) therapy regimens are highly effective at eliminating hepatitis C virus (HCV) infection but rates of sustained virologic response (SVR) are lower in patients with decompensated cirrhosis or hepatocellular carcinoma. Since many of these patients will be referred for liver transplant, they will require retreatment after transplantation. Sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) is recommended by guidelines as the preferred regimen to treat HCV in DAA-experienced patients following liver transplant however there is limited data.

CASE SUMMARY

We present the cases of six liver transplant recipients who had previous treatment failure with sofosbuvir-based DAA therapy prior to transplantation and who then received SOF/VEL/VOX after transplant.

CONCLUSION

This case series demonstrate the real-world efficacy and safety of SOF/VEL/VOX in the post liver transplant setting. Treatment was successful with all patients achieving SVR, it was well tolerated, and there were minimal drug-drug interactions with their immunosuppressants.

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.

Effectiveness and safety of direct-acting antivirals in hepatitis C infected patients with mental disorders: Results in real clinical practice

The aim of this study is to analyze the effectiveness and safety of direct-acting antivirals (DAAs) in psychiatric patients with chronic hepatitis C (CHC). Secondary objectives included adherence and drug-drug interaction (DDIs) evaluations. Prospective observational comparative study carried out during 3 years. Psychiatric patients were included and mental illness classified by a psychiatric team based on clinical records. Main effectiveness and safety variables were sustained virologic response (SVR) at posttreatment week 12 (SVR12) and rate of on-treatment serious drug-related adverse events (AEs), respectively. A total of 242 psychiatric and 900 nonpsychiatric patients were included. SVR12 by intention-to-treat (ITT) analysis of psychiatric vs nonpsychiatric patients was 92.6% (95% confidence interval [CI], 89.1-96.1) vs 96.2% (95% CI, 94.9-97.5) (P = .02). SVR12 by modified-ITT analysis was 97.8% (95% CI, 95.0-99.3) vs 98.4% (95% CI, 97.5-99.3) (P = .74). 92.2% of psychiatric patients with mental disorders secondary to multiple drug use (MDSDU) and 93.0% of psychiatric patients without MDSDU vs 96.2% of nonpsychiatric patients reached SVR12 (P = .05 and P = .20, respectively). The percentage of adherent patients to DAAs did not show differences between cohorts (P = .08). 30.2% of psychiatric patients and 27.6% of nonpsychiatric patients presented clinically relevant DDIs (P = .47). 1.7% vs 0.8% of psychiatric vs nonpsychiatric patients developed serious AEs (P = .39); no serious psychiatric AEs were present. DAAs have shown a slightly lower effectiveness in psychiatric patients with CHC, as a result of loss of follow up, which justifies the need for integrated and multidisciplinary health care teams. DAAs safety, adherence, and DDIs, however, are similar to that of nonpsychiatric patients.