Sofosbuvir, Velpatasvir, and Voxilaprevir for Previously Treated HCV Infection

Real-world effectiveness of sofosbuvir/velpatasvir/voxilaprevir in 573 direct-acting antiviral experienced hepatitis C patients

Sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) provides a needed hepatitis C virus (HCV) antiviral option for direct-acting antiviral (DAA)-experienced patients. We evaluated the effectiveness of SOF/VEL/VOX for 12 weeks in DAA-experienced patients with genotype 1-4 treated in clinical practice. In this observational cohort analysis from the Veterans Affairs' Clinical Case Registry, 573 DAA-experienced patients initiating SOF/VEL/VOX were included: 490 genotype 1, 20 genotype 2, 51 genotype 3 and 12 genotype 4. Rates of cirrhosis were 32.7%, 30.0%, 49.0% and 58.3%; rates of prior NS5A-experience were 100.0%, 95.0%, 90.2% and 100.0% for genotypes 1-4, respectively. Overall SVR rates were 90.7% (429/473), 90.0% (18/20), 91.3% (42/46) and 100.0% (12/12) for genotypes 1-4, respectively, and were 91.3% (274/300), 88.9% (16/18), 90.2% (37/41) and 100.0% (11/11) for those with prior NS5A + NS5B experience. For genotype 1, SVR rates were similar in patients with prior regimens of ledipasvir/SOF (90.6%, 298/329), elbasvir/grazoprevir (91.2%, 73/80) and ombitasvir/paritaprevir/ritonavir/dasabuvir (90.9%, 70/77). SVR rates in genotype 1, 2 and 3 patients with prior SOF/VEL experience were 78.9% (15/19), 86.7% (13/15) and 84.6% (11/13). In genotype 1-4 patients completing 12 weeks of SOF/VEL/VOX, overall SVR rates were 95.1% (409/430), 89.5% (17/19), 93.3% (42/45) and 100% (12/12). In this diverse real-world cohort of heavily NS5A pretreated patients, SOF/VEL/VOX SVR rates in DAA-experienced patients were high across all genotypes. Genotype 1 patients who had prior experience with the most commonly prescribed NS5A regimens achieved similarly high SVR rates when retreated with SOF/VEL/VOX. For genotypes 1, 2 and 3, patients with prior SOF/VEL experience had lower SVR rates.

In vitro resistance profile of hepatitis C virus NS5A inhibitor velpatasvir in genotypes 1 to 6

Velpatasvir is a pan-genotypic hepatitis C virus (HCV) NS5A inhibitor, which is used with sofosbuvir for treatment of infection with HCV genotypes 1-6. In vitro resistance studies were performed to characterize NS5A changes that might confer reduced velpatasvir susceptibility in vivo. Resistance selection studies using HCV replicon cells for subtypes 1a, 1b, 2a, 2b, 3a, 4a, 5a and 6a identified NS5A resistance-associated substitutions (RASs) at nine positions, most often 28M/S/T, 31F/I/M/P/V and 93D/H/N/S. In subtype 1a, RASs were selected at positions 31 and/or 93, while in subtype 1b, replicons with two or more RASs at positions 31, 54 or 93 were selected. Y93H was selected in subtypes 1a, 1b, 2a, 3a and 4a. In subtype 5a or 6a, L31P or P32L/Q was selected, respectively. Velpatasvir susceptibility of 358 replicons from genotypes 1 to 6 containing one or more NS5A RASs was also evaluated. The majority (63%) of subtypes 1a and 1b single RAS-containing replicons retained susceptibility to velpatasvir (<2.5-fold change in EC₅₀ ). High levels of resistance to velpatasvir were observed for six single mutants in subtype 1a, including M28G, A92K, Y93H/N/R/W and for one mutant, A92K, in subtype 1b. Most single mutants in subtypes 2a, 2b, 3a, 4a and 5a displayed low levels of reduced velpatasvir susceptibility. High-level resistance was observed for C92T and Y93H/N in subtype 2b, Y93H/S in 3a, and L31V and P32A/L/Q/R in 6a, and several double mutants in these subtypes. Overall, velpatasvir maintained activity against most common RASs that are known to confer resistance to first-generation NS5A inhibitors.

Glecaprevir/pibrentasvir for the treatment of chronic hepatitis C: design, development, and place in therapy

Direct-acting antiviral (DAA) therapy has changed the landscape of hepatitis C virus (HCV) management and has changed the focus to the possibility of HCV elimination in the near future. Glecaprevir, an NS3/4A protease inhibitor, and pibrentasvir, an HCV NS5A inhibitor, have addressed many of the existing shortcomings in the DAA therapy spectrum. This combination has proven to be a highly efficacious pan-genotypic DAA with a high barrier to resistance as a once-daily, all-oral medication. This review explores the design and development of glecaprevir and pibrentasvir, its place in current HCV management in the midst of a myriad of DAA therapy options, and also remaining challenges.

Interpretation of the changes in 2018 National Essential Medicine List (NEML) from the specialists

On 25 October 2018, National Essential Medicine List (NEML) of China was formally published by National Health Commission and it has been executed since 1 November. The new NEML, which includes 685 drugs with more than 1110 kinds of dosage forms and more than 1810 kinds of specifications, further standardizes dosage forms and specifications of drugs. The new catalog not only increases the number of categories, but also optimizes the structure of the drug list. It highlights the need for basic drugs in aspects of common diseases, chronic diseases, serious diseases and public health. Besides, the normalization of dosage forms and specifications, and the persistence of emphasizing the combination of Western and Chinese medicine are both the characteristics of it. This news report is composed of several parts including brief introduction of NEML, the difference between NEML and National Directory of Health Insurance (NDHI) which is likely to be confused with NEML, the dissection of the change of medicine varieties, relevant policies and potential issues of NEML. We intend to give a comprehensive interpretation of NEML from different perspectives.

Profile of sofosbuvir/velpatasvir/voxilaprevir in the treatment of hepatitis C

The treatment of chronic hepatitis C has been revolutionized with the introduction of direct-acting antivirals (DAAs). However, some patients are not cured with first-line treatment. Sofosbuvir/velpatasvir/voxilaprevir is a fixed-dose combination of a polymerase inhibitor, an NS5A inhibitor, and a protease inhibitor with activity against strains of the hepatitis C virus that show resistance to other first-line antiviral regimens. Sofosbuvir/velpatasvir/voxilaprevir has been studied in four Phase III randomized trials: POLARIS-1, −2, −3, and −4, which enrolled both treatment naïve and experienced patients with and without compensated cirrhosis. In these trials, at least 95% of patients treated with sofosbuvir/velpatasvir/voxilaprevir achieved sustained virological response (SVR). This includes favorable treatment outcomes in patients who had previously failed a regimen containing sofosbuvir or an NS5A inhibitor. Patient-reported outcomes also improved during and after treatment with sofosbuvir/velpatasvir/voxilaprevir. Treatment with sofosbuvir/velpatasvir/voxilaprevir is well tolerated, with the most commonly reported adverse events being headache, fatigue, diarrhea, and nausea. The approval of sofosbuvir/velpatasvir/voxilaprevir allows a treatment option for patients who have failed treatment with certain DAA regimens.

The remarkable history of the hepatitis C virus

The infection with the hepatitis C virus (HCV) is an example of the translational research success. The reciprocal interactions between clinicians and scientists have allowed in 30 years the initiation of empirical treatments by interferon, the discovery of the virus, the development of serological and virological tools for diagnosis but also for prognosis (the non-invasive biochemical or morphological fibrosis tests, the predictors of the specific immune response including genetic IL28B polymorphisms). Finally, well-tolerated and effective treatments with oral antivirals inhibiting HCV non-structural viral proteins involved in viral replication have been marketed this last decade, allowing the cure of all infected subjects. HCV chronic infection, which is a public health issue, is a hepatic disease which may lead to a cirrhosis and an hepatocellular carcinoma (HCC) but also a systemic disease with extra-hepatic manifestations either associated with a cryoglobulinemic vasculitis or chronic inflammation. The HCV infection is the only chronic viral infection which may be cured: the so-called sustained virologic response, defined by undetectable HCV RNA 12 weeks after the end of the treatment, significantly reduces the risk of morbidity and mortality associated with hepatic and extra-hepatic manifestations which are mainly reversible. The history of HCV ends with the pangenotypic efficacy of the multiple combinations, easy to use for 8-12 weeks with one to three pills per day and little problems of tolerance. This explains the short 30 years from the virus discovery to the viral hepatitis elimination policy proposed by the World Health Organization (WHO) in 2016.

Clinical Cases in Hepatitis: Towards improving liver disease management in Australia

Clinical Cases in Hepatitis 2018 was an interactive educational program for Australian physicians (gastroenterologists, hepatologists, and infectious disease specialists) actively involved in the treatment of liver diseases including hepatitis C virus, hepatitis B virus, and non-alcoholic steatohepatitis. This educational program sponsored by Gilead Sciences took place on October 12-13, 2018, and provided timely, informative case-based, and practical education to Australian physicians. This report summarizes keynote lectures from international leaders in the field of hepatitis C virus, hepatitis B virus, and non-alcoholic steatohepatitis and practical clinical case studies designed to inform and educate Australian physicians on managing challenging patients.

[Current drug treatment of hepatitis C : Useful therapy algorithms taking into consideration economical aspects]

Treatment of chronic hepatitis C (HCV) has changed dramatically since the approval of the direct-acting antivirals (DAA). Depending on the HCV genotype and the stage of liver disease, sustained HCV clearance can be achieved in more than 95% of patients with a treatment duration of 8-12 weeks in most of the cases. The selection and combination of the drugs depends on previous antivirals therapies, the stage of liver fibrosis, HCV genotype and subtype, viral load at baseline, and renal function. Nowadays, potent antiviral therapy with minimal side effects can be offered to almost every patient. In the real-world setting, a high quality of HCV therapy considering economic aspects has been documented in the German Hepatitis C Registry. A reduction of clinical complications of chronic liver disease by clearance of HCV has already been documented.

A Cost-Effectiveness Analysis of Shortened Direct-Acting Antiviral Treatment in Genotype 1 Noncirrhotic Treatment-Naive Patients With Chronic Hepatitis C Virus

BACKGROUND

Direct-acting antivirals are successful in curing hepatitis C virus infection in more than 95% of patients treated for 12 weeks, but they are expensive. Shortened treatment durations, which may have lower cure rates, have been proposed to reduce costs.

OBJECTIVES

To evaluate the lifetime cost-effectiveness of different shortened treatment durations for genotype 1 noncirrhotic treatment-naive patients.

METHODS

Assuming a UK National Health Service perspective, we used a probabilistic decision tree and Markov model to compare 3 unstratified shortened treatment durations (8, 6, and 4 weeks) against a standard 12-week treatment duration. Patients failing shortened first-line treatment were re-treated with a 12-week treatment regimen. Parameter inputs were taken from published studies.

RESULTS

The 8-week treatment duration had an expected incremental net monetary benefit of £7737 (95% confidence interval £3242-£11 819) versus the standard 12-week treatment, per 1000 patients. The 6-week treatment had a positive incremental net monetary benefit, although some uncertainty was observed. The probability that the 8- and 6-week treatments were the most cost-effective was 56% and 25%, respectively, whereas that for the 4-week treatment was 17%. Results were generally robust to sensitivity analyses, including a threshold analysis that showed that the 8-week treatment was the most cost-effective at all drug prices lower than £40 000 per 12-week course.

CONCLUSIONS

Shortening treatments licensed for 12 weeks to 8 weeks is cost-effective in genotype 1 noncirrhotic treatment-naive patients. There was considerable uncertainty in the estimates for 6- and 4-week treatments, with some indication that the 6-week treatment may be cost-effective.

Sofosbuvir/Velpatasvir/Voxilaprevir for patients with HCV who previously received a Sofosbuvir/Velpatasvir-containing regimen: Results from a retreatment study

This study evaluated 12-week retreatment with sofosbuvir/velpatasvir/voxilaprevir in patients with chronic hepatitis C virus (HCV) infection who did not achieve sustained virologic response after previous treatment with a sofosbuvir- and velpatasvir-containing regimen. All 31 patients maintained a sustained virologic response 12 weeks after the last sofosbuvir/velpatasvir/voxilaprevir dose.

Economic evaluation of direct-acting antivirals for the treatment of genotype 3 hepatitis C infection in Singapore

BACKGROUND AND AIM

The prohibitively high cost of direct-acting antivirals (DAA) for hepatitis C virus (HCV) infection remains a barrier to treatment access in Singapore. We aimed to evaluate whether DAA as first-line therapy would be cost-effective for genotype 3 (GT3) HCV patients compared with pegylated interferon and ribavirin (PR).

METHODS

A decision tree analysis was used to compare the costs and outcomes of DAA and PR as first-line therapy. Treatment effectiveness, defined as sustained virological response, was assessed using a retrospective cohort of treated GT3 HCV patients. Direct medical costs were estimated from the payer's perspective using billing information. We obtained health utilities from published literature. We performed extensive one-way sensitivity analyses and probabilistic sensitivity analyses to account for uncertainties regarding the model parameters.

RESULTS

In base case analysis, first-line therapy with DAA and PR yielded quality-adjusted life years (QALYs) of 0.69 and 0.62 at a cost of USD 54 634 and USD 23 857, respectively. The resultant incremental cost-effectiveness ratio (ICER) (USD 449 232/QALY) exceeded the willingness-to-pay threshold (USD 53 302/QALY). The ICER was robust for uncertainties regarding the model parameters. The cost of DAA is the key factor influencing the cost-effectiveness of HCV treatment. At current price, DAA as first-line therapy is not cost-effective compared with PR, with or without consideration of retreatment. Threshold analysis suggested that DAA can be cost-effective if it costs less than USD 17 002 for a 12-week treatment course.

CONCLUSION

At current price, DAA as first-line therapy is not cost-effective compared with PR in GT3 HCV patients in Singapore.

Optimal timing of hepatitis C treatment among HIV/HCV coinfected ESRD patients: Pre- vs posttransplant

Patients with end-stage renal disease (ESRD) who are coinfected with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) have access to effective treatment options for HCV infection. However, they also have access to HCV-infected kidneys, which historically afford shorter times to transplantation. Given the high waitlist mortality and rapid progression of liver fibrosis among coinfected kidney-only transplant candidates, identification of the optimal treatment strategy is paramount. Two strategies, treatment pre- and posttransplant, were compared using Monte Carlo microsimulation of 1 000 000 candidates. The microsimulation was stratified by liver fibrosis stage at waitlist addition and wait-time over a lifetime time horizon. Treatment posttransplant was consistently cost-saving as compared to treatment pretransplant due to the high cost of dialysis. Among patients with low fibrosis disease (F0-F1), treatment posttransplant also yielded higher life months (LM) and quality-adjusted life months (QALM), except among F1 candidates with wait times ≥ 18 months. For candidates with advanced liver disease (F2-F4), treatment pretransplant afforded more LM and QALM unless wait time was <18 months. Moreover, treatment pretransplant was cost-effective for F2 candidates with wait times >71 months and F3 candidates with wait times >18 months. Thus, optimal timing of HCV treatment differs based on liver disease severity and wait time, favoring pretransplant treatment when cirrhosis development prior to transplant seems likely.

Treatment of Chronic Hepatitis C: Efficacy, Side Effects and Complications

Background

Chronic hepatitis C virus (HCV) infection can lead to liver cirrhosis and its complications. Viral eradication is essential to prevent disease progression and reduces liver-related mortality and morbidity. Since the availability of direct-acting antivirals (DAA), HCV treatment has changed significantly. Current treatment strategies for different groups of patients as well as potential risks and caveats will be discussed in this review.

Summary

Interferon-free (IFN-free) treatment not only shortens treatment duration, but also achieves high rates of viral clearance and is overall well tolerated. Genotype-restricted but also pangenotypic combinations are available. Usually two DAA of different drug classes are combined. For the majority of the patients, treatment duration ranges from 8 to 12 weeks. Liver and kidney function as well as prior treatment experience and potential drug-drug interactions influence substance choices and treatment duration. However, modern IFN-free treatment is not only safer, but also overall far more simplified and effective. Global HCV eradication might be an ambitious but not completely unrealistic goal to pursue.

Key Messages

IFN-free antiviral treatment is safe and well tolerated. Patients can be treated almost independently of liver function or concomitant disease. Viral eradication is associated with reduced morbidity and mortality and better quality of life.

Solid organ transplantation of viral hepatitis C positive donor organs into viral hepatitis C negative recipients

PURPOSE OF REVIEW

Strategies are needed to reduce waitlist mortality and increase transplantation rates. Advances in hepatitis C therapy has allowed the transplant community to look toward utilization of grafts from hepatitis C viremic donors to expand the organ pool. Use of such grafts for hepatitis C-negative patients is being evaluated and debated, and early trial data are emerging.

RECENT FINDINGS

Both hepatitis C antibody-positive/nucleic acid test-negative and viremic donors are currently underutilized. Outcomes for viral hepatitis C (HCV) viremic transplant recipients are improving in the setting of direct-acting antiviral therapy. Optimization of graft utilization from HCV 'positive' donors and expansion to use of viremic donors for HCV-negative recipients will likely reduce waitlist mortality and result in net overall reduction in healthcare expenditures.

SUMMARY

Herein, we provide a review of recent advancements relating to hepatitis C in solid organ transplant and outline future directions. A primary future focus will be data collection of outcomes of transplantation of grafts from HCV 'viremic' donors to nonviremic recipients in formal clinical trial protocols.

Glecaprevir/Pibrentasvir Induced Cholestatic Jaundice in a HCV Patient with Renal Failure. A Case Presentation

BACKGROUND

Direct-acting Antivirals (DAA) are currently used in the treatment of chronic HCV infection. In patients with renal failure Glecaprevir/Pibrentasvir (genotype 1-6) is recommended for its safety and efficacy.

CASE PRESENTATION

Although these pharmacological characteristics, an adverse drug reaction (ADR) has been reported during Glecaprevir/Pibrentasvir treatment, such as the development of cholestatic jaundice in an elderly patient with chronic HCV (genotype 2) infection. At examination, patient was jaundiced associated with intense pruritus.

RESULTS

Ultrasound and laboratory biochemical tests excluded a liver failure (e.g. liver cancer, and liver lithiasis) or pancreatic cancer while Naranjo probability scale (score 6) suggested an association between cholestatic jaundice and Glecaprevir/Pibrentasvir administration. About 1 month after drug discontinuation, an improvement has been documented in both jaundice and pruritus, with a normalization in bilirubin levels (total bilirubin: 0.96 mg/dL), HCV-RNA was undetected also. It is worth mentioning that although we reported the development of cholestatic jaundice upon treatment with Glecaprevir/Pibrentasvir we recorded a clinical efficacy (HCV-RNA <15 IU/L) after 4 weeks from the beginning of the treatment, with a complete remission of clinical symptoms until 7 months after drug discontinuation.

CONCLUSION

These data support the clinical efficacy of Glecaprevir/Pibrentasvir association in elderly patients, despite the sub-optimal period of treatment.

Upcoming direct acting antivirals for hepatitis C patients with a prior treatment failure

Despite the high efficacy of direct acting antivirals (DAAs) not all patients successfully clear hepatitis C virus infection, in fact, approximately 1-3% fail to reach a sustained virological response 12 weeks after end of treatment. DAA failures are characterized by advanced liver disease, specific genotypes/subtypes and resistance associated substitutions to the DAA class they have been treated with. Current European Association for the Study of the Liver guidelines recommend three therapeutic options for such patients. The first is a 12 week course of sofosbuvir (SOF), velpatasvir (VEL) and voxilaprevir (VOX), which has shown to be effective in 90-99% of patients and was granted A1 level recommendation. The second option, reserved for patients who have predictors of failure consists in 12 weeks regimen with glecaprevir (GLE) and pibrentasvir (PIB), effective in 90-97%. Finally, although not supported by published data, for especially difficult to treat patients there should theoretically be a benefit in prolonged combinations of SOF+GLE/PIB or SOF/VEL/VOX±ribavirin. This review presents the latest evidence from both clinical trials and real-life on such therapeutic strategies.

Pharmacokinetics and drug interactions of medications used to treat hepatitis C virus infection in the setting of chronic kidney disease and kidney transplantation

Hepatitis C infection in patients with chronic kidney disease or kidney transplant carries higher morbidity and mortality compared to noninfected patients. Historically, patients with advanced kidney disease and kidney transplant recipients were undertreated given the multiple adverse effects and limited efficacy of interferon-based therapies for chronic hepatitis C. The development of direct-acting antivirals in the past few years has opened an unprecedented opportunity for treating these populations. However, the impaired renal clearance of some of these medications in patients with kidney disease, and the potential interactions of antiviral therapies with immunosuppressants after kidney transplantation, present some challenges in choosing the proper regimen. This review provides an overview of the essential pharmacokinetics and drug interactions of relevant antiviral therapies in the treatment of chronic hepatitis C in patients with advanced kidney disease and after kidney transplantation.

Early HCV viral kinetics under DAAs may optimize duration of therapy in patients with compensated cirrhosis

BACKGROUND & AIMS

Detailed hepatitis C virus (HCV) kinetics modelling is scarce in patients with advanced liver disease receiving direct-acting antivirals (DAAs). Due to budget restrictions, patients and health systems would benefit from the shortest possible treatment course. We investigated whether modelling very early HCV kinetics in cirrhotic patients under DAAs therapy could be used to individualize care and reduce treatment duration to achieve cure.

METHODS

We included 74 patients with HCV-related cirrhosis who received interferon-free treatments for 12-24 weeks. HCV genotype, liver disease stage and treatment regimen were recorded. Viral load was determined prospectively at very frequent intervals until target not detected (TND, <15 IU/mL). A viral kinetic model was used to predict time to cure based on HCV clearance in extracellular body fluid (CL-EF).

RESULTS

Sixty-eight patients (92%) achieved cure. Thirteen (18%) had MELD ≥15, 35 (47%) were Child-Pugh (CTP) ≥7. Median time to reach TND was 2 weeks (IQR: 1-4 weeks). Modelling indicated an average DAAs efficacy in blocking viral production of ε = 99.1%. HCV half-life (t1/2 ) was significantly shorter in patients with CTP <7, LSM <21 kPa or MELD <15 (1.5 vs 2.5 hours; P = 0.0057). The overall median CL-EF was 5.6 weeks (4.1-7.8). A CTP >7 and a LSM ≥21 kPa were significantly (P = 0.016) associated with longer CL-EF.

CONCLUSIONS

The study provides insights into HCV dynamics during DAAs therapy in patients with compensated and decompensated cirrhosis. Viral kinetics modelling suggests that treatment duration may be optimized in patients with compensated cirrhosis.

NS5A-P32 deletion as a factor involved in virologic failure in patients receiving glecaprevir and pibrentasvir

BACKGROUND

This study sought to clarify the factors involved in virologic failure in patients with HCV receiving retreatment with glecaprevir/pibrentasvir (GLE/PIB) in real-world practice.

METHODS

Forty-two patients who had previously received direct-acting antivirals (DAAs) therapies consisting of 35, 3, 3, and 1 patient(s) with genotype (GT)-1b, GT-2a, GT-2b, and GT-3b HCV, respectively, received GLE/PIB for 12 weeks. Resistance-associated substitutions (RASs) at baseline were evaluated, and the dynamics of NS5A-RASs were assessed by deep sequencing in patients showing virologic failure.

RESULTS

Baseline NS5A-RASs were found in all the patients with GT-1b HCV including 16 patients with NS3-RASs. In contrast, both NS5A-RASs and NS3-RASs were absent in 3 and 2 patients with GT-2a and GT-2b HCV, respectively. Virologic failure occurred in 3 patients with GT-1b HCV with NS5A-P32del, while a sustained virologic response (SVR) was achieved in the remaining 39 patients including those with GT-1b HCV carrying NS5A-L31V + Y93H and NS5A-A92K. Virologic failure even occurred in a patient in whom the NS5A-P32del HCV strains had become undetectable by direct sequencing, and the percentage of such strains relative to the total HCV strains was 10%, as determined by deep sequencing. In the other patient with GT-1b HCV with NS5A-P32del, NS3-A156A/V/S were found at 4 weeks after GLE/PIB therapy, but had disappeared at 11 weeks, as determined by direct sequencing.

CONCLUSIONS

GLE/PIB was effective for patients with HCV who failed to achieve an SVR after prior DAA therapies except in those with GT-1b HCV carrying NS5A-P32del even when such strains became undetectable by direct sequencing.

Combinations of two drugs among NS3/4A inhibitors, NS5B inhibitors and non-selective antiviral agents are effective for hepatitis C virus with NS5A-P32 deletion in humanized-liver mice

BACKGROUND

The emergence of a deletion mutant at hepatitis C virus (HCV) NS5A-P32 (P32del) has recently been reported in a subset of chronic hepatitis C patients who experience virologic failure after direct-acting antiviral drug (DAA) treatment. This mutation confers extremely high resistance to NS5A inhibitors. No effective treatment has been established for cases with this mutation.

METHODS

We used a JFH1-based recombinant virus with NS5A from a genotype 1b strain to introduce a P32del mutation. We inoculated human hepatocyte chimeric mice with sera from a patient with ledipasvir/sofosbuvir therapy failure carrying a genotype 1b HCV with NS5A L31M and P32del or from a DAA-naïve patient carrying wild-type virus.

RESULTS

JFH1-based chimeric viruses with P32del showed sufficient levels of replication for in vitro assay despite the suppression of viral growth and infectious virus production. Variants with P32del exhibited severe resistance to all tested NS5A inhibitors, including daclatasvir, ledipasvir, elbasvir and velpatasvir, but were as susceptible to NS3/4A inhibitors, NS5B inhibitors, interferon alfa-2b, and ribavirin as wild-type viruses in the in vitro assay. The P32del mutant virus caused persistent infection in all inoculated chimeric mice with high viral titer and frequency. The virus was resistant to the ledipasvir/GS-558093 (a nucleotide analog inhibitor of NS5B polymerase) regimen but susceptible to either simeprevir plus GS-558093 or peg-interferon alfa-2b, compared to the wild-type virus.

CONCLUSION

Therapies combining at least two drugs among NS3/4A inhibitors, NS5B inhibitors and non-selective antiviral agents may be effective for HCV-infected patients with NS5A-P32del.

Resistance analysis of genotype 3 hepatitis C virus indicates subtypes inherently resistant to nonstructural protein 5A inhibitors

Hepatitis C virus (HCV) genotype (gt) 3 is highly prevalent globally, with non-gt3a subtypes common in Southeast Asia. Resistance-associated substitutions (RASs) have been shown to play a role in treatment failure. However, the role of RASs in gt3 is not well understood. We report the prevalence of RASs in a cohort of direct-acting antiviral treatment-naive, gt3-infected patients, including those with rarer subtypes, and evaluate the effect of these RASs on direct-acting antivirals in vitro. Baseline samples from 496 gt3 patients enrolled in the BOSON clinical trial were analyzed by next-generation sequencing after probe-based enrichment for HCV. Whole viral genomes were analyzed for the presence of RASs to approved direct-acting antivirals. The resistance phenotype of RASs in combination with daclatasvir, velpatasvir, pibrentasvir, elbasvir, and sofosbuvir was measured using the S52 ΔN gt3a replicon model. The nonstructural protein 5A A30K and Y93H substitutions were the most common at 8.9% (n = 44) and 12.3% (n = 61), respectively, and showed a 10-fold and 11-fold increase in 50% effect concentration for daclatasvir compared to the unmodified replicon. Paired RASs (A30K + L31M and A30K + Y93H) were identified in 18 patients (9 of each pair); these combinations were shown to be highly resistant to daclatasvir, velpatasvir, elbasvir, and pibrentasvir. The A30K + L31M combination was found in all gt3b and gt3g samples. Conclusion: Our study reveals high frequencies of RASs to nonstructural protein 5A inhibitors in gt3 HCV; the paired A30K + L31M substitutions occur in all patients with gt3b and gt3g virus, and in vitro analysis suggests that these subtypes may be inherently resistant to all approved nonstructural protein 5A inhibitors for gt3 HCV. (Hepatology 2018).

The remarkable history of the hepatitis C virus

The infection with the hepatitis C virus (HCV) is an example of the translational research success. The reciprocal interactions between clinicians and scientists have allowed in 30 years the initiation of empirical treatments by interferon, the discovery of the virus, the development of serological and virological tools for diagnosis but also for prognosis (the non-invasive biochemical or morphological fibrosis tests, the predictors of the specific immune response including genetic IL28B polymorphisms). Finally, well-tolerated and effective treatments with oral antivirals inhibiting HCV non-structural viral proteins involved in viral replication have been marketed this last decade, allowing the cure of all infected subjects. HCV chronic infection, which is a public health issue, is a hepatic disease, which may lead to a cirrhosis and an hepatocellular carcinoma (HCC) but also a systemic disease with extra-hepatic manifestations either associated with a cryoglobulinemic vasculitis or chronic inflammation. The HCV infection is the only chronic viral infection, which may be cured: the so-called sustained virologic response, defined by undetectable HCV RNA 12 weeks after the end of the treatment, significantly reduces the risk of morbidity and mortality associated with hepatic and extra-hepatic manifestations, which are mainly reversible. The history of HCV ends with the pangenotypic efficacy of the multiple combinations, easy to use for 8-12 weeks with one to three pills per day and little problems of tolerance. This explains the short 30 years from the virus discovery to the viral hepatitis elimination policy proposed by the World Health Organization (WHO) in 2016.

Safety and efficacy of the combination simeprevir-sofosbuvir in HCV genotype 1- and 4-mono-infected patients from the French ANRS CO22 hepather cohort

BACKGROUND

Although real-life results of sofosbuvir/simeprevir have been extensively reported from the United States, data from other geographical areas are limited. In the French observational cohort, ANRS CO22 HEPATHER, 9432 patients were given the new oral antivirals from December 2013 to June 30, 2018. We report the results of sofosbuvir/simeprevir in genotypes 1- and 4-infected patients.

METHODS

Demographics and history of liver disease were collected at entry in the cohort. Clinical, adverse events, and virological data were collected throughout treatment and post-treatment follow-up. The choice of treatment duration or addition of ribavirin was left up to the physician.

RESULTS

Five hundred ninety-nine HCV (467 genotype 1 and 132 genotype 4) mono-infected, naïve for all oral-DAAs regimen patients were given sofosbuvir/simeprevir with (n = 63) or without ribavirin (n = 536) for 12 or 24 weeks; 56% had cirrhosis (4% decompensated) and 71% had prior treatment failure to interferon-based regimen. 7 patients (1.16%) were lost to follow-up. The overall SVR12 rate was 92.6%. The SVR12 was 90% in GT1a, 94.2% in GT1b and 91.6% in GT4 with no significant difference for genotype, treatment duration or ribavirin addition. Severity of liver disease was not associated with a lower SVR12 rate on multivariate analysis but was associated with a higher rate of severe side effects. Early treatment discontinuations were rare; no new safety signals were reported.

CONCLUSION

In this real life, observational, prospective cohort study, the 12-week sofosbuvir/simeprevir+/-ribavirin combination appears to be efficient and safe.

TRIAL REGISTRATION

Trial registration with ClinicalTrials.gov NCT01953458 .

Cost Effectiveness of Universal Screening for Hepatitis C Virus Infection in the Era of Direct-Acting, Pangenotypic Treatment Regimens

BACKGROUND & AIMS

Most persons infected with hepatitis C virus (HCV) in the United States were born from 1945 through 1965; testing is recommended for this cohort. However, HCV incidence is increasing among younger persons in many parts of the country and treatment is recommended for all adults with HCV infection. We aimed to estimate the cost effectiveness of universal 1-time screening for HCV infection in all adults living in the United States and to determine the prevalence of HCV antibody above which HCV testing is cost effective.

METHODS

We developed a Markov state transition model to estimate the effects of universal 1-time screening of adults 18 years or older in the United States, compared with the current guideline-based strategy of screening adults born from 1945 through 1965. We compared potential outcomes of 1-time universal screening of adults or birth cohort screening followed by antiviral treatment of those with HCV infection vs no screening. We measured effectiveness with quality-adjusted life-years (QALY), and costs with 2017 US dollars.

RESULTS

Based on our model, universal 1-time screening of US residents with a general population prevalence of HCV antibody greater than 0.07% cost less than $50,000/QALY compared with a strategy of no screening. Compared with 1-time birth cohort screening, universal 1-time screening and treatment cost $11,378/QALY gained. Universal screening was cost effective compared with birth cohort screening when the prevalence of HCV antibody positivity was greater than 0.07% among adults not in the cohort born from 1945 through 1965.

CONCLUSIONS

Using a Markov state transition model, we found a strategy of universal 1-time screening for chronic HCV infection to be cost effective compared with either no screening or birth cohort-based screening alone.

Rescue therapy for chronic hepatitis C virus infection after repeated treatment failures: Impact on disease progression and risk of hepatocellular carcinoma

AIM

Retreatment after previous failure of direct-acting antivirals for hepatitis C virus (HCV) infection is a challenging decision. The importance of achieving viral eradication on modification of disease progression and outcome, including the risk of hepatocellular carcinoma (HCC), remains a critical issue to be evaluated.

METHODS

One hundred patients with repeated failure of sofosbuvir and ribavirin or triple therapy with sofosbuvir, ribavirin, and daclatasvir were divided into a study group (n = 50) given rescue therapy (sofosbuvir, daclatasvir, simeprevir, and ribavirin) or a control group (n = 50) matched for age, sex, and pretreatment variables (Child-Turcotte-Pugh score and Fibrosis-4 score). Follow-up was undertaken after the last non-response to detect serious adverse events, such as hepatic decompensation and development of HCC.

RESULTS

The study group achieved sustained virologic response (SVR) in 47 of 50 (94%) patients. The control group had significantly higher HCC rates than the study group (7 vs. 1 patients), with an odds ratio of 5.44. The rescue therapy was associated with significantly longer time to the occurrence of adverse events. Repeated treatment failures were associated with progression of FibroScan values in the control group (21 ± 4.5 vs. 10 ± 1.5 kPa, P = 0.001); achieving SVR in the study group stopped fibrosis progression despite non-significant increase from baseline (13.2 ± 3.2 vs. 10.6 ± 0.6, P = 0.12).

CONCLUSIONS

Rescue treatment for HCV infection was highly effective in achieving SVR, less expensive than the newer agents, and is associated with diminished risk of serious adverse events, mainly HCC in these patients.

In Vitro Susceptibility of Hepatitis C Virus Genotype 1 through 6 Clinical Isolates to the Pangenotypic NS3/4A Inhibitor Voxilaprevir

Voxilaprevir is a direct-acting antiviral agent (DAA) that targets the NS3/4A protease of hepatitis C virus (HCV). High sequence diversity of HCV and inadequate drug exposure during unsuccessful treatment may lead to the accumulation of variants with reduced susceptibility to DAAs, including NS3/4A protease inhibitors such as voxilaprevir. The voxilaprevir susceptibility of clinical and laboratory strains of HCV was assessed. The NS3 protease regions of viruses belonging to 6 genotypes and 29 subtypes from 345 DAA-naive or -experienced (including protease inhibitor) patients and 344 genotype 1 to 6 replicons bearing engineered NS3 resistance-associated substitutions (RASs) were tested in transient-transfection assays. The median voxilaprevir 50% effective concentration against NS3 from protease inhibitor-naive patient samples ranged from 0.38 nM for genotype 1 to 5.8 nM for genotype 3. Voxilaprevir susceptibilities of HCV replicons with NS3 RASs were dependent on subtype background and the type and number of substitutions introduced. The majority of RASs known to confer resistance to other protease inhibitors had little to no impact on voxilaprevir susceptibility, except A156L, T, or V in genotype 1 to 4 which conferred >100-fold reductions but exhibited low replication capacity in most genotypes. These data support the use of voxilaprevir in combination with other DAAs in DAA-naive and DAA-experienced patients infected with any subtype of HCV.

Comparative effectiveness of pan-genotypic therapies for the treatment of patients with hepatitis C virus infection in Bulgaria

Hepatitis C virus (HCV) is a positive-stranded RNA virus which belongs to the family of Flaviviridae, predominantly infecting liver hepatocytes. HCV infection is a major cause for morbidity worldwide. Aim: The primary objective was to evaluate the comparative effectiveness of pan-genotypic therapies for the treatment of patients with HCV infection in Bulgaria. Materials & methods: The databases MEDLINE, EMBASE, Cochrane Library, PubMed and clinicaltrials.gov were searched to identify studies evaluating the therapeutic efficacy of sofosbuvir/velpatasvir/voxilaprevir, sofosbuvir/velpatasvir and glecaprevir/pibrentasvir for the treatment of HCV patients. Results: The range of sustained virologic response rates among all genotypes achieved after therapy with sofosbuvir/velpatasvir/voxilaprevir was 92-100% (8-week therapy) in treatment-naive patients and 99-100% (12-week therapy) in experienced patients. The range of sustained virologic response rates with glecaprevir/pibrentasvir was 91-100% (12-week therapy) and 97-100% (12-week therapy) with sofosbuvir/velpatasvir. Conclusion: Sofosbuvir/velpatasvir/voxilaprevir is a noninferior therapy offering a simple and short-term treatment regimen with high efficacy, favorable safety profile and good tolerability.

Is the conquest of Hepatitis C imminent?

Hepatitis C virus represents a global pathogen of human health significance. In the space of less than three decades, we have witnessed the discovery of the virus, a growing understanding of the structure and biology of the viral-encoded proteins and their interaction with the host cell and the sequencing of the viral genome. Most importantly, we have moved from early therapeutic strategies aimed at crude boosting of host anti-viral immunity, limited by side effects and with poor response rates, to therapies that directly exploit our understanding of viral biology. In this review, we discuss the significance of the virus, its' discovery and outline the advances in the molecular characterisation of the virus, before setting these within the context of contemporary and emerging therapeutic strategies as well as viral resistance mechanisms.

Discovery of the pan-genotypic hepatitis C virus NS3/4A protease inhibitor voxilaprevir (GS-9857): A component of Vosevi®

Treatment of hepatitis C virus (HCV) infection has been historically challenging due the high viral genetic complexity wherein there are eight distinct genotypes and at least 86 viral subtypes. While HCV NS3/4A protease inhibitors are an established treatment option for genotype 1 infection, limited coverage of genotypes 2 and/or 3 combined with serum alanine transaminase (ALT) elevations for some compounds has limited the broad utility of this therapeutic class. Our discovery efforts were focused on identifying an NS3/4A protease inhibitor with pan-genotypic antiviral activity, improved coverage of resistance associated substitutions, and a decreased risk of hepatotoxicity. Towards this goal, distinct interactions with the conserved catalytic triad of the NS3/4A protease were identified that improved genotype 3 antiviral activity. We further discovered that protein adduct formation strongly correlated with clinical ALT elevation for this therapeutic class. Improving metabolic stability and decreasing protein adduct formation through structural modifications ultimately resulted in voxilaprevir. Voxilaprevir, in combination with sofosbuvir and velpatasvir, has demonstrated pan-genotypic antiviral clinical activity. Furthermore, hepatotoxicity was not observed in Phase 3 clinical trials with voxilaprevir, consistent with our design strategy. Vosevi^® (sofosbuvir, velpatasvir, and voxilaprevir) is now an approved pan-genotypic treatment option for the most difficult-to-cure individuals who have previously failed direct acting antiviral therapy.

Ombitasvir/paritaprevir/ritonavir and dasabuvir with or without sofosbuvir for patients with hepatitis C virus genotype 1 infection who failed a prior course of direct-acting antiviral therapy

INTRODUCTION

Despite high efficacy of current direct-acting antiviral agents (DAAs) in treating chronic hepatitis C virus (HCV) infection, a small portion of patients fail treatment. QUARTZ-I was a phase 2, open-label, multicenter, two-part study that assessed the safety and efficacy of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) with dasabuvir (DSV) with or without the addition of sofosbuvir (SOF) and/or ribavirin (RBV) in DAA treatment-experienced adults with chronic HCV GT1 infection.

MATERIALS AND METHODS

Genotype 1 HCV-infected patients with or without compensated cirrhosis had prior treatment failure to any DAA (part 1) or ledipasvir/SOF (part 2). Patients received OBV/PTV/r + DSV ± SOF with or without RBV for 12 or 24 weeks. The primary endpoint of this study is the percentage of patients achieving sustained virologic response at post-treatment week 12 (SVR12).

RESULTS

In part 1 of the study, 95.5% (21/22) of patients achieved SVR12, and in part 2, the SVR12 rate was 85.7% (6/7). Most adverse events (AEs) were mild and moderate in severity. Two serious AEs occurred and were assessed as not being related to study drug, of which one resulted in study drug discontinuation. Two patients experienced grade 3 elevations of serum alanine aminotransferase, and no other grade ≥3 laboratory abnormalities were observed.

CONCLUSION

The multi-targeted regimen of OBV/PTV/r + DSV ± SOF with or without RBV was effective in the treatment of patients who failed previous DAA regimens including NS3/4A protease and NS5A and NS5B polymerase inhibitors. These results provide a promising outcome for patients that traditionally had limited treatment options.

Transjugular Intrahepatic Portosystemic Shunt: A Possible Risk Factor for Direct-Acting Antiviral Treatment Failure in Patients With Hepatitis C?

Direct‐acting antiviral (DAA) therapies have revolutionized the treatment of chronic hepatitis C virus infection, achieving sustained virological response (SVR) rates of >90% even in patients with advanced liver cirrhosis. Having observed an unusual case of repeated DAA therapy failures in a patient with a transjugular intrahepatic portosystemic shunt (TIPS), we assessed a possible association between prior TIPS placement and DAA failure. A structured search of our clinical database revealed 10 patients who had received DAA therapy after TIPS placement. At the time of therapy, most patients (8; 80%) presented with a Child‐Pugh score B, and the following DAA regimens were used: sofosbuvir/ledipasvir ± ribavirin (5 patients), sofosbuvir/daclatasvir ± ribavirin (3), sofosbuvir/velpatasvir (2), and sofosbuvir/velpatasvir/voxilaprevir (1). In total, 5 patients (50%) achieved an SVR, whereas a virological relapse occurred in the other half of the cases, including 2 patients with multiple relapses. In this patient cohort, SVR rates were unusually low for all regimens: sofosbuvir/ledipasvir ± ribavirin, 3/5 (60%); sofosbuvir/daclatasvir ± ribavirin, 2/3 (66%); sofosbuvir/velpatasvir, 0/2 (0%); and sofosbuvir/velpatasvir/voxilaprevir, 0/1 (0%), and patients with a TIPS made up a relevant proportion of DAA failures in patients with cirrhosis at our center: sofosbuvir/ledipasvir, 2/18 (11%); sofosbuvir/daclatasvir, 1/4 (25%); sofosbuvir/velpatasvir, 2/3 (66%); and sofosbuvir/velpatasvir/voxilaprevir, 1/1 (100%). Conclusion: We observed a high rate of virological relapse in patients with a TIPS who received DAA treatment and therefore postulate that TIPS placement may be a possible risk factor for DAA failure due to the profound hemodynamic changes evoked by the intervention. Longer treatment duration or addition of ribavirin might be warranted in these patients.

Real World Experience of Chronic Hepatitis C Retreatment with Genotype Specific Regimens in Nonresponders to Previous Interferon-Free Therapy

Background and Aim

The development of interferon- (IFN-) free regimens substantially improved efficacy of treatment for HCV, but despite excellent effectiveness the failures still occur. The aim of our study was to evaluate the efficacy of retreatment with genotype specific direct acting antivirals- (DAA-) based regimens in nonresponders to previous IFN-free therapy.

Materials and Methods

Analysed population consisted of 31 nonresponders to IFN-free regimen, which received second IFN-free rescue therapy, selected from 6228 patients included in a national database EpiTer-2.

Results

Age and gender distribution were similar, whereas proportion of genotype 1b was slightly higher and genotype 4 lower in the whole population compared to studied one. Patients included in the study demonstrated much more advanced fibrosis. Primary therapy was discontinued in 12 patients, which were recognized as failures due to nonvirologic reason, whereas virologic reason of therapeutic failure was recognized in 19 patients which completed therapy. Overall sustained virologic response (SVR) rate was 81% and 86% in intent-to-treat (ITT) and modified ITT analysis, respectively (74% and 78% in virologic failures, 92% and 100% in nonvirologic failures). Resistance-associated substitutions (RAS) testing was carried out in 8 patients from the group of completed primary therapy and three of them had potential risk for failure of rescue therapy due to NS5A association, while two of them achieved SVR.

Conclusions

We demonstrated moderate effectiveness of genotype specific rescue therapy in failures due to virologic reason and high in those who discontinued primary therapy. Therefore rescue therapy with genotype specific regimens should be considered always if more potent regimens are not available.

Systematic review: epidemiology and response to direct-acting antiviral therapy in genotype 6 chronic hepatitis C virus infection

BACKGROUND

Hepatitis C virus (HCV) genotype 6 (GT6) is predominantly encountered in Southeast Asia and data on GT6 response to direct-acting antiviral (DAA) therapy are relatively limited.

AIM

To review the epidemiology and virologic outcome of DAA regimens in HCV GT6 patients.

METHODS

Electronic literature search of PubMed, EMBASE, and The Cochrane Library databases were conducted.

RESULTS

Hepatitis C virus genotype 6 is the most genetically diverse, has a prevalence of 19.9%-95.6% in HCV infected patients in Southeast Asia and has been associated with a higher risk of HCC in those with cirrhosis. After an extensive literature review, a total of 20 studies were selected to assess study population and treatment outcomes (total of 938 GT6 patients were included); 12 were clinical trials and eight were observational studies. Sustained virologic response at week 12 (SVR 12) following glecaprevir/pibrentasvir (n = 4; 108 patients), ledipasvir/sofosbuvir (n = 8; 427 patients), sofosbuvir/velpatasvir with or without voxilaprevir (n = 5; 171 patients), sofosbuvir/daclatasvir (n = 3; 172 patients) and sofosbuvir with ribavirin (n = 3; 60 patients) was 98%-100%, 64%-100%, 100%, 88%-94% and 100%, respectively. Failure was mostly in those with cirrhosis and prior treatment experience. DAA therapy was well tolerated and with a serious adverse event rate of <5%.

CONCLUSIONS

Hepatitis C virus genotype 6 is genetically diverse and is highly prevalent in Asia. While SVR rates have been high, cirrhosis and prior treatment experience marginally compromise response to DAAs. Large scale and exclusive studies in HCV genotype 6 prevalent areas are needed, while the current evidence suggests that DAAs are highly effective and safe.

An update on the management of hepatitis C virus and human immunodeficiency virus co-infection

An estimated 2.3 million people globally are co-infected with HIV and HCV. Liver disease is now a leading cause of non-AIDS-related mortality among HIV-infected patients. The development of direct-acting antiviral agents has revolutionized the treatment of HIV/HCV co-infection with sustained virologic response response rates above 95% in most patient populations. This article provides an update on the management of acute and chronic HCV in patients co-infected with HIV including a section on drug–drug interactions.

Glecaprevir/Pibrentasvir in patients with chronic HCV genotype 3 infection: An integrated phase 2/3 analysis

Glecaprevir coformulated with pibrentasvir (G/P) is approved to treat hepatitis C virus (HCV) infection and was highly efficacious in phase 2 and 3 studies. Treating HCV genotype (GT) 3 infection remains a priority, as these patients are harder to cure and at a greater risk for liver steatosis, fibrosis progression and hepatocellular carcinoma. Data were pooled from five phase 2 or 3 trials that evaluated 8-, 12- and 16-week G/P in patients with chronic HCV GT3 infection. Patients without cirrhosis or with compensated cirrhosis were either treatment-naïve or experienced with interferon- or sofosbuvir-based regimens. Safety and sustained virologic response 12 weeks post-treatment (SVR12) were assessed. The analysis included 693 patients with GT3 infection. SVR12 was achieved by 95% of treatment-naïve patients without cirrhosis receiving 8-week (198/208) and 12-week (280/294) G/P. Treatment-naïve patients with cirrhosis had a 97% (67/69) SVR12 rate with 12-week G/P. Treatment-experienced, noncirrhotic patients had SVR12 rates of 90% (44/49) and 95% (21/22) with 12- and 16-week G/P, respectively; 94% (48/51) of treatment-experienced patients with cirrhosis treated for 16 weeks achieved SVR12. No serious adverse events (AEs) were attributed to G/P; AEs leading to study drug discontinuation were rare (<1%). G/P was well-tolerated and efficacious for patients with chronic HCV GT3 infection, regardless of cirrhosis status or prior treatment experience. Eight- and 12-week durations were efficacious for treatment-naïve patients without cirrhosis and with compensated cirrhosis, respectively; 16-week G/P was efficacious in patients with prior treatment experience irrespective of cirrhosis status.

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

Background

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

Methods

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

Results

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

Conclusions

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

Sofosbuvir, ribavirin and pegylated interferon for a daclatasvir-resistent genotype 3 hepatitis C virus: case report and review

Chronic Hepatitis C relapse after liver transplantation can lead to graft failure within a short time period. The high efficacy and good safety profile of direct-acting antivirals has led to consensual recommendations for using interferon-free treatment after liver transplantation. However, pegylated interferon may still be required for genotype 3 non-responders. We treated a liver graft recipient with grade 1 fibrosis in the biopsy with daclatasvir and sofosbuvir for 12 weeks. He did not respond and progressed to grade 3 fibrosis. Lacking other options, we obtained a sustained virological response with pegylated interferon, ribavirin and sofosbuvir for 12 weeks. The combination of pegylated interferon, ribavirin and sofosbuvir is a viable option after the failure of direct acting antivirals in economically disadvantaged countries.

Pharmacokinetics of Daclatasvir, Sofosbuvir, and GS-331007 in a Prospective Cohort of Hepatitis C Virus-Positive Kidney Transplant Recipients

BACKGROUND

Limited data exist on the pharmacokinetic profile of novel direct-acting antivirals in kidney transplant recipients. Daclatasvir is primarily eliminated through the biliary route and sofosbuvir through the renal route; here, we report the pharmacokinetic profile of combined treatment with these compounds in a prospective study of hepatitis C virus (HCV)-positive kidney transplant recipients (EudraCT: 2014-004551-32).

METHODS

In this study, plasma samples of 16 HCV-positive kidney transplant recipients receiving daclatasvir and sofosbuvir were collected at 4 time points at days 1, 7, 14, 21, 56, and 84 after start of treatment. Inclusion criteria were stable graft function and an estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m. Daclatasvir, sofosbuvir, and GS-331007 (inactive metabolite of sofosbuvir) plasma concentrations were determined using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry.

RESULTS

All patients showed a rapid virological response with HCV RNA below the detection limit 21 days after the start of therapy (medium time to viral clearance). No difference of the areas under the concentration-time curve (AUC) of daclatasvir, sofosbuvir, and GS-331007 was observed between patients with an eGFR below or ≥60 mL/min. For GS-331007, no relevant changes of trough levels were observed over time. Mean GS-331007 trough levels were 339.5 ± 174.9 ng/mL in patients with an eGFR ≥60 mL/min and 404.3 ± 226 ng/mL in patients with an eGFR <60 mL/min at day 7 (P = 0.52). At day 84, GS-331007 trough levels were 357.8 ± 200.8 and 404.2 ± 70.2 ng/mL in patients with an eGFR ≥60 mL/min and in patients with an eGFR <60 mL/min, respectively (P = 0.51). The accumulation ratios of renally eliminated GS-331007 for AUC and Cmax did not significantly differ between the 2 eGFR groups at day 7.

CONCLUSIONS

An impaired eGFR (30-60 mL/min) does not lead to a dose accumulation of daclatasvir, sofosbuvir, and GS-331007. This study provides the rationale for future studies investigating the pharmacokinetic profile of sofosbuvir-based HCV treatment in kidney transplant recipients with an eGFR <30 mL/min.

Geographic Distribution of HCV-GT3 Subtypes and Naturally Occurring Resistance Associated Substitutions

Background: Little is known about the frequency or geographic distributions of naturally occurring resistance-associated substitutions (RASs) in the nonstructural protein 5A (NS5A) domain of hepatitis-C virus (HCV) genotype-3 (GT-3) different subtypes. We investigated naturally occurring GT-3 RASs that confer resistance to NS5A inhibitors. Methods: From a publicly accessible database, we retrieved 58 complete GT-3 genomes and an additional 731 worldwide NS5A sequences from patients infected with GT-3 that were naive to direct-acting antiviral treatment. Results: We performed a phylogenetic analysis of NS5A domains in complete HCV genomes to determine more precisely HCV-GT-3 subtypes, based on commonly used target regions (e.g., 5′untranslated region and NS5B partial domain). Among 789 NS5A sequences, GT-3nonA subtypes were more prevalent in Asia than in other geographic regions (p < 0.0001). The A30K RAS was detected more frequently in HCV GT-3nonA (84.6%) than in GT-3A subtypes (0.8%), and the amino acid change was polymorphic in isolates from Asia. Conclusions: These results provided information on the accuracy of HCV-3 subtyping with a phylogenetic analysis of the NS5A domain with data from the Los Alamos HCV genome database. This information and the worldwide geographic distribution of RASs according to HCV GT-3 subtypes are crucial steps in meeting the challenges of treating HCV GT-3.

Sofosbuvir/Velpatasvir/Voxilaprevir: A Review in Chronic Hepatitis C

A fixed-dose combination of the hepatitis C virus (HCV) NS5B polymerase inhibitor sofosbuvir, the HCV NS5A inhibitor velpatasvir and the HCV NS3/4A protease inhibitor voxilaprevir (sofosbuvir/velpatasvir/voxilaprevir; Vosevi^®) is approved in the EU for the treatment of chronic HCV genotype 1, 2, 3, 4, 5 or 6 infection in adults. In the phase III POLARIS trials, in patients who had HCV genotype 1-6 infection with or without compensated cirrhosis, overall rates of sustained virological response at 12 weeks post-treatment (SVR₁₂) with sofosbuvir/velpatasvir/voxilaprevir were high after 8 weeks of treatment in direct-acting antiviral (DAA)-naïve patients and 12 weeks of treatment in DAA-experienced patients. However, 8 weeks of sofosbuvir/velpatasvir/voxilaprevir was inferior to 12 weeks of sofosbuvir/velpatasvir in cirrhotic or non-cirrhotic DAA-naïve patients with HCV genotype 1, 2, 4, 5 or 6 infection and non-cirrhotic DAA-naïve patients with HCV genotype 3 infection, mostly due to an insufficient treatment period. Sofosbuvir/velpatasvir/voxilaprevir was generally well tolerated, with most adverse events being of mild or moderate intensity. The most common adverse events included headache, fatigue, nausea and diarrhoea. In conclusion, sofosbuvir/velpatasvir/voxilaprevir is an important and effective option for the treatment of HCV genotype 1-6 infection in adults, especially those who have previously failed a DAA therapy with or without an HCV NS5A inhibitor.

A prospective study of daclatasvir and sofosbuvir in chronic HCV-infected kidney transplant recipients

BACKGROUND

Only a few prospective trials exist regarding the use of novel direct-acting antiviral agents (DAAs) in kidney transplant recipients (KTR) with chronic hepatitis C virus (HCV) infection.

METHODS

This prospective single-center trial evaluated treatment with daclatasvir (DCV) and sofosbuvir (SOF) over 12 weeks in 16 adult chronic HCV infected KTR and eGFR > 30 ml/min/1.73m². Primary endpoint was sustained virological response 12 weeks after end of therapy (SVR12). Beside baseline liver biopsy, hepatic function and glucose metabolism were regularly assessed.

RESULTS

Four of 16 study patients had previously failed interferon-based HCV treatment. Liver biopsy showed mostly moderate fibrosis score before therapy with DCV/SOF was initiated at a median of 10.3 years after transplantation. In total, 15 of 16 KTR achieved SVR12. One patient showed early viral relapse because of resistance-associated variants (RAVs) in the HCV NS5A region. Rescue treatment with SOF/velpatasvir/voxilaprevir resulted in SVR12. DAAs treatment led to significant improvement of liver metabolism and glucose tolerance accompanied with no therapy-associated major adverse events and excellent tolerability.

CONCLUSIONS

Our study demonstrates safety, efficacy and functional benefit of DCV/SOF treatment in KTR with chronic HCV infection. We provide data on rescue strategies for treatment failures due to present RAVs and amelioration of hepatic function and glucose tolerance.

TRIAL REGISTRATION

Registry name: European Clinical Trials Register; Trial registry number (Eudra-CT): 2014-004551-32 , Registration date: Aug 28th 2015.

Sofosbuvir/velpatasvir/voxilaprevir in the treatment of chronic hepatitis C infection

The landscape of HCV treatment has been entirely transformed due to the development of direct-acting antivirals (DAAs), but there are limited data guiding salvage therapy in patients who previously failed an NS5A inhibitor-containing DAA regimen. We review the preclinical and clinical data for sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX), an interferon-free, oral, once daily, pan-genotypic treatment for chronic HCV infection. This combination is a highly effective, well-tolerated and safe 12-week treatment regimen for patients with any genotype, including genotype-3 patients with baseline resistance-associated substitutions (RAS). Its most distinctive role is in patients who have previously failed treatment with advanced DAA regimens. Its efficacy is not significantly affected by RASs, and treatment-emergent RASs are uncommon.

Efficacy and Pharmacokinetics of Glecaprevir and Pibrentasvir With Concurrent Use of Acid-Reducing Agents in Patients With Chronic HCV Infection

BACKGROUND & AIMS

Proton pump inhibitors (PPIs) are commonly prescribed to treat acid-related disorders. Some direct-acting antiviral regimens for chronic hepatitis C virus (HCV) infection have reduced efficacy in patients taking concomitant acid-reducing agents, including PPIs, due to interactions between drugs. We analyzed data from 9 multicenter, phase 2 and 3 trials to determine the efficacy and pharmacokinetics of an HCV therapeutic regimen comprising glecaprevir and pibrentasvir (glecaprevir/pibrentasvir) in patients taking concomitant acid-reducing agents.

METHODS

We analyzed data from 2369 patients infected with HCV genotypes 1-6 and compensated liver disease treated with an all-oral regimen of glecaprevir/pibrentasvir for 8-16 weeks. We compared efficacy and pharmacokinetics among patients receiving at least 1 dose of an acid-reducing agent (a PPI, an H2 blocker, or antacid). High-dose PPI was defined as daily dose greater than 20 mg omeprazole dose equivalent. The objectives were to evaluate rate of sustained virologic response 12 weeks post-treatment (SVR12) and to assess steady-state glecaprevir and pibrentasvir exposures in patients on acid-reducing agents.

RESULTS

Of the 401 patients (17%) who reported use of acid-reducing agents, 263 took PPIs (11%; 109 patients took a high-dose PPI and 154 patients took a low-dose PPI). Rates of SVR12 were 97.0% among patients who used acid-reducing agents and 97.5% among those not using acid-reducing agents (P = .6). An SVR12 was achieved in 96.3% taking a high-dose PPI and 97.4% taking a low-dose PPI, with no virologic failures in those receiving a high-dose PPI (P = .7). Glecaprevir, but not pibrentasvir, bioavailability was affected; its exposure decreased by 41% in patients taking a high-dose PPI.

CONCLUSIONS

In an analysis of data from 9 clinical trials, we observed a high rate of SVR12 (approximately 97%) among patients treated with glecaprevir/pibrentasvir for HCV infection-even among patients taking concomitant ARA or high-dose PPI. This was despite decreased glecaprevir exposures in patients when on high-dose PPIs. ClinicalTrials.gov numbers, NCT02243280 (SURVEYOR-I), NCT02243293 (SURVEYOR-II), NCT02604017 (ENDURANCE-1), NCT02640482 (ENDURANCE-2), NCT02640157 (ENDURANCE-3), NCT02636595 (ENDURANCE-4), NCT02642432 (EXPEDITION-1), NCT02651194 (EXPEDITION-4), NCT02446717 (MAGELLAN-I).

Potentials of CRISPR in liver research and therapy

The CRISPR technology is rapidly transforming the field of liver research by its versatility and easy use. In vivo gene editing of hepatocytes in adult mice can be achieved using a broad toolbox for both fundamental research and development of therapeutic strategies for future clinical applications. Recent studies showed that CRISPR has a real potential to treat hereditary liver diseases as well as virally induced pathologies. This short review recapitulates very recent advancements regarding the use of CRISPR in liver research and therapy.

Sofosbuvir-Based Therapy in Hepatitis C Virus-Infected Cancer Patients: A Prospective Observational Study

BACKGROUND

Data are sparse on treatment of chronic hepatitis C virus (HCV) in cancer patients. We evaluated the efficacy and safety of sofosbuvir-based therapy (SOFBT) in cancer patients.

METHODS

Patients treated with SOFBT at our center during 2014-2017 were included in a prospective observational study. Efficacy [sustained virologic response at 12 weeks after the end of treatment (SVR12)], cancer-related outcomes and adverse events (AEs) were assessed.

RESULTS

We included 153 patients. Most were men (109; 71%), white (92; 60%), non-cirrhotic (105; 69%), and with HCV genotype 1 (110; 72%). The most common cancers were hepatocellular carcinoma (HCC) (27; 18%) and multiple myeloma (14; 9%). The overall SVR12 rate was 91% (128/141). SVR12 was 100% in patients treated with ledipasvir/sofosbuvir for 8 weeks. Of the 32 patients initially excluded from cancer clinical trials because of HCV, 27 (84%) were granted cancer therapy access after starting SOFBT. Six patients with indolent non-Hodgkin's lymphoma (NHL) received SOFBT without cancer treatment. Two achieved complete remission, one had partial remission, and two had stable cancer. Within 6 months after SOFBT, 5% (6/121) of patients in remission or with stable cancer, had progression or recurrence (two with HCC and one each with esophageal cancer, cholangiocarcinoma, NHL, and tonsillar cancer). No de novo HCCs occurred. AEs were most commonly grade 1-2 (90%).

CONCLUSIONS

SOFBT in HCV-infected cancer patients is effective and safe, may permit access to investigational cancer therapy expanding treatment options, may induce remission of NHL, and may be used for 8 weeks.