Prevention and management of treatment failure to new oral hepatitis C drugs

Self-reported and measured adherence to hepatitis C direct-acting antiviral therapy and sustained virologic response among people who inject drugs: The HERO study

BACKGROUND

Objective adherence measures, such as electronic blister pack (BP), for direct-acting antivirals (DAAs) for hepatitis C virus (HCV) treatment have high accuracy, but their use is limited in real practice settings. We examined the association of self-reported adherence using a visual analogue scale (VAS) with objective BP adherence and sustained virologic response (SVR) among people who inject drugs.

METHODS

We conducted secondary analyses using a subset of participants (N = 493) from the per-protocol sample of the HERO study, a pragmatic randomized trial of HCV treatment interventions that used both VAS and BP to measure adherence to a 12-week sofosbuvir/velpatasvir DAA regimen. Multivariable mixed-effects regression models tested the association of self-report adherence level with longitudinal weekly objective adherence. Multivariable logistic regression tested the association of self-report adherence with SVR.

RESULTS

The average VAS and BP adherences were 95.1 % (SD = 8.9 %) and 76.0 % (16.0 %), respectively, and the proportion of the participants achieving SVR was 92.9 %. The estimated adjusted mean objective adherence was significantly different (-16 %; 95 % CI: -22 %, -11 %, p < .001) between participants with 100 % and <80 % VAS adherence. The likelihood of SVR was significantly lower for those with <80 % VAS adherence [adjusted OR = 0.07; 95 % CI: 0.02, 0.24; p < .001] compared to those with 100 %.

CONCLUSION

Self-reported adherence overestimated objective adherence. However, higher self-report adherence was significantly associated with higher objective adherence. Also, self-reported adherence ≥80 % was significantly associated with SVR. Thus, the self-report measure has utility as a monitoring tool for adherence during DAA treatment.

Initiation of oral hepatitis C virus treatment: Which barriers are pertinent for ambulatory individuals with a history of illicit substance use? A qualitative interview study

Background and Aims

The World Health Organization has set a goal to eradicate hepatitis C virus (HCV) by the year 2030. Nonadherence to HCV treatment has substantial economic implications due to high treatment costs, among others. Barriers to start HCV treatment may be critical. The aim of this study was to assess pertinent barriers to HCV treatment in ambulatory patients with a history of illicit substance use and to compare them to the literature.

Methods

Barriers to HCV treatment mentioned by the key risk group (i.e., people who inject drugs) were retrieved from literature through a pragmatic literature search. From 34 published articles, we identified 80 modifiable barriers that were bundled in 23 items within the four topics "Personal difficulties and barriers to treatment," "Personal motivation to be treated," "Knowledge about the disease," and "Received information about the medicine." In-depth semistructured interviews were performed face-to-face with ambulatory patients from the University Psychiatric Clinics in Basel, Switzerland. Transcripts were coded inductively.

Results

Interviews were performed with seven individuals (mean age: 48.3 years; range: 38-63 years; one woman) treated with oral direct-acting antivirals between 2014 and 2022. Thirteen barriers to start HCV treatment were mentioned that corresponded to the five categories: information, attitudes, swallowing difficulties, social environment, and unfavorable lifestyle. The barrier "swallowing difficulties" emerged exclusively from the statements provided by the interviewees.

Conclusion

Barriers to the initiation of HCV treatment indicated by our interviewees clearly differed from the literature. Notably, the challenge of swallowing medicines may be particularly relevant for physicians prescribing and pharmacists dispensing HCV medication.

Sofosbuvir/velpatasvir/voxilaprevir for patients with chronic hepatitis C virus infection previously treated with NS5A direct-acting antivirals: a real-world multicenter cohort in Taiwan

BACKGROUND

Real-world data are scarce about the effectiveness and safety of sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) for retreating East Asian patients with hepatitis C virus (HCV) infection who previously received NS5A direct-acting antivirals (DAAs). We conducted a multicenter study to assess the performance of SOF/VEL/VOX in patients who were not responsive to prior NS5A inhibitors in Taiwan.

METHODS

Between September 2021 and May 2022, 107 patients who failed NS5A inhibitor-containing DAAs with SOF/VEL/VOX salvage therapy for 12 weeks were included at 16 academic centers. The sustained virologic response at off-treatment week 12 (SVR₁₂) was assessed in the evaluable (EP) and per-protocol (PP) populations. The safety profiles were also reported.

RESULTS

All patients completed 12 weeks of treatment and achieved an end-of-treatment virologic response. The SVR₁₂ rates were 97.2% (95% confidence interval (CI) 92.1-99.0%) and 100% (95% CI 96.4-100%) in EP and PP populations. Three (2.8%) patients were lost to off-treatment follow-up and did not meet SVR₁₂ in the EP population. No baseline factors predicted SVR₁₂. Two (1.9%) not-fatal serious adverse events (AE) occurred but were unrelated to SOF/VEL/VOX. Sixteen (15.0%) had grade 2 total bilirubin elevation, and three (2.8%) had grade 2 alanine transaminase (ALT) elevation. Thirteen (81.3%) of the 16 patients with grade 2 total bilirubin elevation had unconjugated hyperbilirubinemia. The estimated glomerular filtration rates (eGFR) were comparable between baseline and SVR₁₂, regardless of baseline renal reserve.

CONCLUSIONS

SOF/VEL/VOX is highly efficacious and well-tolerated for East Asian HCV patients previously treated with NS5A inhibitor-containing DAAs.

CLINICAL TRIALS REGISTRATION

The study was not a drug trial. There was no need for clinical trial registration.

Evaluation of machine learning algorithms for predicting direct-acting antiviral treatment failure among patients with chronic hepatitis C infection

Despite the availability of efficacious direct-acting antiviral (DAA) therapy, the number of people infected with hepatitis C virus (HCV) continues to rise, and HCV remains a leading cause of liver-related morbidity, liver transplantation, and mortality. We developed and validated machine learning (ML) algorithms to predict DAA treatment failure. Using the HCV-TARGET registry of adults who initiated all-oral DAA treatment, we developed elastic net (EN), random forest (RF), gradient boosting machine (GBM), and feedforward neural network (FNN) ML algorithms. Model performances were compared with multivariable logistic regression (MLR) by assessing C statistics and other prediction evaluation metrics. Among 6525 HCV-infected adults, 308 patients (4.7%) experienced DAA treatment failure. ML models performed similarly in predicting DAA treatment failure (C statistic [95% CI]: EN, 0.74 [0.69-0.79]; RF, 0.74 [0.69-0.80]; GBM, 0.72 [0.67-0.78]; FNN, 0.75 [0.70-0.80]), and all 4 outperformed MLR (C statistic [95% CI]: 0.51 [0.46-0.57]), and EN used the fewest predictors (n = 27). With Youden index, the EN had 58.4% sensitivity and 77.8% specificity, and nine patients were needed to evaluate to identify 1 DAA treatment failure. Over 60% treatment failure were classified in top three risk decile subgroups. EN-identified predictors included male sex, treatment < 8 weeks, treatment discontinuation due to adverse events, albumin level < 3.5 g/dL, total bilirubin level > 1.2 g/dL, advanced liver disease, and use of tobacco, alcohol, or vitamins. Addressing modifiable factors of DAA treatment failure may reduce the burden of retreatment. Machine learning algorithms have the potential to inform public health policies regarding curative treatment of HCV.

DAA Treatment Failure in a HIV/HBV/HCV Co-Infected Patient Carrying a Chimeric HCV Genotype 4/1b

Approved direct antiviral agent (DAA) combinations are associated with high rates of sustained virological response (SVR) and the absence of a detectable hepatitis C viral load 12-24 weeks after treatment discontinuation. However, a low percentage of individuals fail DAA therapy. Here, we report the case of a HIV/HBV/HCV co-infected patient who failed to respond to DAA pangenotypic combination therapy. The sequencing of NS5a, NS5b, NS3 and core regions evidenced a recombinant intergenotypic strain 4/1b with a recombination crossover point located inside the NS3 region. The identification of this natural recombinant virus underlines the concept that HCV recombination, even if it occurs rarely, may play a key role in the virus fitness and evolution.

Precision Medicine: Determination of Ribavirin Urinary Metabolites in Relation to Drug Adverse Effects in HCV Patients

The most commonly used antiviral treatment against hepatitis C virus is a combination of direct-acting antivirals (DAAs) and ribavirin (RBV), which leads to a shortened duration of therapy and a sustained virologic response until 98%. Nonetheless, several dose-related side effects of RBV could limit its applications. This study aims to measure the urinary concentration of RBV and its main metabolites in order to evaluate the drug metabolism ability of HCV patients and to evaluate the adverse effects, such as anemia, with respect to RBV metabolite levels. RBV and its proactive and inactive metabolites were identified and quantified in the urine of 17 HCV males with severe liver fibrosis using proton nuclear magnetic resonance (¹H-NMR) at the fourth week (TW4) and at the twelfth week of treatment (EOT). Four prodrug urinary metabolites, including RBV, were identified and three of them were quantified. At both the TW4 and EOT stages, six HCV patients were found to maintain high concentrations of RBV, while another six patients maintained a high level of RBV proactive metabolites, likely due to nucleosidase activity. Furthermore, a negative correlation between the reduction in hemoglobin (Hb) and proactive forms was observed, according to RBV-triphosphate accumulation causing the hemolysis. These findings represent a proof of concept regarding tailoring the drug dose in relation to the specific metabolic ability of the individual, as expected by the precision medicine approach.

Machine learning algorithms for predicting direct-acting antiviral treatment failure in chronic hepatitis C: An HCV-TARGET analysis

BACKGROUND AND AIMS

We aimed to develop and validate machine learning algorithms to predict direct-acting antiviral (DAA) treatment failure among patients with HCV infection.

APPROACH AND RESULTS

We used HCV-TARGET registry data to identify HCV-infected adults receiving all-oral DAA treatment and having virologic outcome. Potential pretreatment predictors (n = 179) included sociodemographic, clinical characteristics, and virologic data. We applied multivariable logistic regression as well as elastic net, random forest, gradient boosting machine (GBM), and feedforward neural network machine learning algorithms to predict DAA treatment failure. Training (n = 4894) and validation (n = 1631) patient samples had similar sociodemographic and clinical characteristics (mean age, 57 years; 60% male; 66% White; 36% with cirrhosis). Of 6525 HCV-infected adults, 95.3% achieved sustained virologic response, whereas 4.7% experienced DAA treatment failure. In the validation sample, machine learning approaches performed similarly in predicting DAA treatment failure (C statistic [95% CI]: GBM, 0.69 [0.64-0.74]; random forest, 0.68 [0.63-0.73]; feedforward neural network, 0.66 [0.60-0.71]; elastic net, 0.64 [0.59-0.70]), and all four outperformed multivariable logistic regression (0.51 [0.46-0.57]). Using the Youden index to identify the balanced risk score threshold, GBM had 66.2% sensitivity and 65.1% specificity, and 12 individuals were needed to evaluate to identify 1 DAA treatment failure. Over 55% of patients with treatment failure were classified by the GBM in the top three risk decile subgroups (positive predictive value: 6%-14%). The top 10 GBM-identified predictors included albumin, liver enzymes (aspartate aminotransferase, alkaline phosphatase), total bilirubin levels, sex, HCV viral loads, sodium level, HCC, platelet levels, and tobacco use.

CONCLUSIONS

Machine learning algorithms performed effectively for risk prediction and stratification of DAA treatment failure.

Effectiveness and Safety of Sofosbuvir/Velpatasvir/Voxilaprevir as a Hepatitis C Virus Infection Salvage Therapy in the Real World: A Systematic Review and Meta-analysis

Introduction

Sofosbuvir/Velpatasvir/Voxilaprevir (SOF/VEL/VOX) is the first direct-acting antiviral (DAA) therapy approved for patients who have previously failed a DAA-containing regimen including NS5A inhibitors. In clinical trials, SOF/VEL/VOX was associated with high rates of sustained virologic response at post-treatment week 12 (SVR12) and was well tolerated. However, the effectiveness and safety of SOF/VEL/VOX in the real world remained uncertain. We aimed to perform a systematic review and meta-analysis to assess the real world effectiveness and safety of SOF/VEL/VOX.

Methods

We systematically searched the PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov databases for relevant real world studies published before January 28, 2022. Patients with previous treatment failure who received SOF/VEL/VOX were included. The primary outcome was the percentage of patients achieving SVR12. Secondary outcome included adverse events (AEs) during treatment.

Results

Fifteen studies with a total of 1796 HCV-infected patients with previous treatment failure were included. SVR12 rates were 93% (95% CI 91–95) in the ITT populations (n = 1517, 11 cohorts) and 96% (95% CI 95–97) in the PP populations (n = 1187, 10 cohorts). SVR12 rates were significantly higher in non-GT3-infected patients (OR = 2.29, 95% CI 1.23–4.27, P = 0.009) and non-cirrhotic patients (OR = 2.22, 95% CI 1.07–4.60, P = 0.03) than in GT3-infected patients and cirrhotic patients. Furthermore, the SVR12 rates of previous treatment of SOF/VEL were significantly lower than those of other regimens in both ITT and PP populations (P ≤ 0.001). Adverse events (AEs) were reported in 30% (228/760) of patients. Serious AEs (SAEs) were reported in 3.82% (29/760) of patients. The most frequently reported AEs were headache, asthenia, nausea, fatigue, and diarrhea, which were mostly mild in severity. AE-related treatment discontinuations were reported in 0.66% (5/760) of patients.

Conclusions

Consistent with clinical trials, the real world evidence indicates that SOF/VEL/VOX is a well-tolerated and highly effective salvage therapy for HCV-infected patients with previous treatment failure. However, there may still be a risk of treatment failure for patients with GT3 infection, cirrhosis, or SOF/VEL treatment failure. The protocol of this study was registered at PROSPERO, registration no. CRD 42022306828.

Establishing a research production line in real-life settings: the case of Hepatitis C management in a viral hepatitis specialized Egyptian center

Efforts toward eradicating the Hepatitis C virus (HCV) have advanced rapidly, due to the development of direct-acting antivirals (DAAs), especially with the appearance of pan-genotypic combinations. Real-world studies, in particular, have verified the efficacy and safety of DAA combinations documented in registration trials. This review documents the results of using DAA combinations in real-life settings in everyday clinical practice in Egypt, the country with the highest prevalence of HCV. The significant number of treated patients in Egypt, which exceeded four million allowed tremendous data about the results of HCV management in real-life settings for different treatment regimens and disease conditions. DAA combinations have resulted in high sustained virologic response rates (SVR12) and few adverse reactions in real-life settings. SVR12 rates ranged from 90% to 100%, depending on the combination of drugs used, the HCV genotype, and the stage of liver disease. Most adverse reactions reported in real-world settings were mild and resulted in treatment discontinuation in only a minority of cases. Data from real-life studies covered most aspects of HCV management that were lacking after initial approval studies. More research is needed to tailor treatment and produce generic HCV combinations to overcome the residual limitations of the currently available DAAs.

Chronic Hepatitis B Treatment Strategies Using Polymerase Inhibitor-Based Combination Therapy

Viral polymerase is an essential enzyme for the amplification of the viral genome and is one of the major targets of antiviral therapies. However, a serious concern to be solved in hepatitis B virus (HBV) infection is the difficulty of eliminating covalently closed circular (ccc) DNA. More recently, therapeutic strategies targeting various stages of the HBV lifecycle have been attempted. Although cccDNA-targeted therapies are attractive, there are still many problems to be overcome, and the development of novel polymerase inhibitors remains an important issue. Interferons and nucleos(t)ide reverse transcriptase inhibitors (NRTIs) are the only therapeutic options currently available for HBV infection. Many studies have reported that the combination of interferons and NRTI causes the loss of hepatitis B surface antigen (HBsAg), which is suggestive of seroconversion. Although NRTIs do not directly target cccDNA, they can strongly reduce the serum viral DNA load and could suppress the recycling step of cccDNA formation, improve liver fibrosis/cirrhosis, and reduce the risk of hepatocellular carcinoma. Here, we review recent studies on combination therapies using polymerase inhibitors and discuss the future directions of therapeutic strategies for HBV infection.

Comparison of liver biopsies before and after direct-acting antiviral therapy for hepatitis C and correlation with clinical outcome

Direct-acting antivirals (DAA) have replaced interferon (IFN)-based therapies for hepatitis C virus. In this retrospective clinical study, we examined differences in histopathologic features in paired liver biopsies collected from the same patient before and after DAA and correlated these findings with clinical outcome. Biopsies (n = 19) were evaluated by quantitative imaging analysis to measure steatosis and fibrosis. Most patients had decreased steatosis in their post-treatment, follow-up biopsies. However, one patient had a striking increase in steatosis (from 0.86 to 6.32%) and later developed decompensated cirrhosis and hepatocellular carcinoma (HCC). This patient had a marked increase in fibrosis between biopsies, with a CPA of 6.74 to 32.02. Another patient, who already had bridging fibrosis at the time of her pre-treatment biopsy, developed cholangiocarcinoma after DAA. Even though the overall inflammatory activity in the post-treatment biopsies significantly decreased after treatment, 60% of patients had persistent portal lymphocytic inflammation. In summary, DAAs decreased steatosis and hepatic inflammation in most patients, although some may have persistence of lymphocytic portal inflammation. Patients known to have advanced fibrosis at treatment initiation and who have other risk factors for ongoing liver injury, such as steatosis, should be followed closely for the development of adverse outcomes, such as portal hypertension and primary liver cancers.

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.

Rates of perfect self-reported adherence to direct-acting antiviral therapy and its correlates among people who inject drugs on medications for opioid use disorder: The PREVAIL study

Adequate adherence to direct-acting antivirals (DAAs) for hepatitis C virus (HCV) is critical to attaining sustained virologic response (SVR). In this PREVAIL study's secondary analyses, we explored the association between self-reported and objective DAAs adherence among a sample of people who inject drugs (PWID) receiving medications for opioid use disorder (MOUD) (N = 147). Self-reported adherence was recoded 3 times during treatment (weeks 4, 8 and 12) using a visual analog scale (VAS), whereas objective adherence was collected continuously during treatment using electronic blister packs. Participants who reported being perfectly adherent had significantly higher blister pack adherence in each period (weeks 4, 8 and 12; ps < .05) and over the 12-week study (p < .001) compared to those who reported being non-perfectly adherent. Whites were more likely to report perfect adherence (91.7%) than Blacks (48.7%), Latinos (52.2%) and other (75.0%) race groups. Participants who reported recent use of cocaine (63.9%) or polysubstance use (60.0%) and those who had a positive result for cocaine (62.8%) were more likely to be non-perfectly adherent, although none of these factors were associated with blister pack adherence. This study showed that the VAS could serve as a reliable option for assessing DAAs adherence among PWID on MOUD. The implementation of VAS may be an ideal option for monitoring adherence among PWID on MOUD, especially in clinical settings with limited resources. PWID on MOUD who are Black or other races than White, as well as those who report recent cocaine or polysubstance use may require additional support to maintain optimal DAA adherence.

Direct-acting antiviral agents in the treatment of chronic hepatitis C-Real-life experience from clinical practices in Pakistan

This study aims to evaluate the clinical effectiveness in terms of sustained virological response (SVR), predictors of SVR and safety of available second-generation generic direct-acting antivirals in Pakistani chronic hepatitis C patients. This is a retrospective study conducted in multiple centers of Pakistan from January 2015 to January 2019. The samples include patients infected with chronic hepatitis C virus, regardless of virus genotype, cirrhosis, or prior treatment. A total of 993 patients were included in the present study, with the majority receiving sofosbuvir with daclatasvir (95%), sofosbuvir with daclatasvir and ribavirin (4%), and sofosbuvir with ribavirin (1%). There were 96% cases of chronic hepatitis, 3% cases compensated cirrhosis, and 1% cases of decompensated cirrhosis. Genotype 3 (99.6%) was the most common genotype. Overall SVR after 12 weeks was 98% for all treatment regimens. High SVR12 was observed with sofosbuvir in combination with daclatasvir (98.5%), then sofosbuvir in combination with daclatasvir and ribavirin (90.2%) and sofosbuvir in combination with ribavirin (75%). SVR rates were high in chronic hepatitis C patients (98.2%) as compared with cirrhotic patients (92.1%) and it was high in treatment-naive (98.8%) then interferon experienced patients (90.1%). In multivariate binary logistic regression analysis, patients' education status, treatment strategy, viral load, and alanine aminotransferase had a statistically significant association with SVR at 12 weeks. No major adverse events occurred which required treatment discontinuation. Generic oral direct acting antiviralss (sofosbuvir with daclatasvir) achieved higher SVR12 rates and were well tolerated in this large real-world cohort of genotype 3 infected patients.

Efficacy and Safety of Generic Sofosbuvir Plus Daclatasvir and Sofosbuvir/Velpatasvir in HCV Genotype 3-Infected Patients: Real-World Outcomes From Pakistan

BACKGROUND

Direct-acting antivirals (DAAs) therapeutic regimens are highly effective against chronic hepatitis C virus (HCV) infection. However, HCV patients with genotype 3 (GT3) respond in a suboptimal way. This study aims to identify which of the DAAs-based therapeutic regimens are the best option for GT3.

METHODS

Multiple governments and private tertiary care hospitals were involved in this real-life study of HCV-GT3 patients treated with DAAs. The efficacy and safety of generic sofosbuvir+daclatasvir±ribavirin (SOF+DCV±RBV) and sofosbuvir/velpatasvir±ribavirin (SOF/VEL±RBV) were assessed under the National Hepatitis C Program of Pakistan.

RESULTS

Out of 1,388 participants, 70% of patients received SOF+DCV in government tertiary care hospitals and 30% received SOF/VEL in private tertiary care hospitals. The overall sustained virological responses (SVR) was 95.5%. The SVR rates at 12 weeks were comparable between SOF+DCV (94.4%) and SOF/VEL (94.7%) in chronic HCV patients. However, The SVR rates at 24 weeks were high in cirrhotic patients treated with SOF/VEL+RBV (88%) then SOF+DCV+RBV (83%). Non-responders were high in SOF-DCV than SOF-VEL (4.1 vs 3.8%, P = 0.05) regimen. In multivariate models, the significant predictors of non-SVR were age >60 years (odds ratio [OR] 4.46; 95% CI, 2.35-8.46, P = <0.001) and cirrhosis (OR 53.91; 95% CI, 26.49-109.6, P = <0.001). Skin rash (51 vs 44%) and oral ulcers (45 vs 40%) were high in patients receiving SOF-DCV then SOF-VEL.

CONCLUSIONS

Overall, the generic SOF+DCV ±RBV and SOF/VEL ± RBV achieved equally high SVR12 rates. However, SOF/VEL+RBV achieved a high SVR rate in cirrhotic patients then SOF+DCV+RBV. Old age and cirrhosis were significant predictors of reduced odds of SVR regardless of the regimen. Furthermore, the regimens were well tolerated in chronic HCV patients.

Value of IFNL3 genetic polymorphism in the prediction of HCV treatment response to direct-acting antiviral drugs versus interferon therapy

Background: Despite the outstanding results of direct-acting antiviral therapies (DAAs) of Hepatitis C infection (HCV), non-responders had to be more defined. Aim: assess the outcome of DAAs in linkage with Interferon lambda 3 (IFNL3) in HCV patients. Methods: This case-control-study was conducted on 495 chronic-HCV (genotype-4a), previously treated Egyptians by either DAAs (responders 195, 120 relapsers) or interferon/ribavirin (IFN/RBV) (140 responders, 60 relapsers), and 98 healthy controls. IFNL3 distribution, clinical and laboratory data were assessed. Results: CT was the most predominant genotype in Egyptians (51%). All genotypes were sensitive to DAAs mainly CT genotype (60%), even TT genotype (resistant to IFN/RBV 40%) had 29.2% sensitivity. CT genotype was predominant in sofosbuvir/Daclatasvir responders (67.6%) (OR = 0.66), while non-CT prevailed in relapsers (56.7%). TT genotype may respond to SOF/Ledi better than other regimens (66.7%). In IFN/RBV relapsers; CT genotype was commoner (50%) than others, while CC genotype predominated in responders (54.3%). The c allele was the commonest in responders to IFN/RBV (71.4%), while the T allele was resistant to treatment (65% in relapsers). Addition of RBV to SOF/DCV reported higher resistance with CT genotype (42.2%-50%) and TT genotype (17.8%-27.8%). Conclusion: This study recommended IFNL3 genotyping to be a prerequisite before stratifying treatment for HCV-4a Egyptians.

Resistance-associated substitutions (RASs) to HCV direct-acting antivirals (DAAs) at baseline of treatment in thalassemia patients: a referral center study

Patients with thalassemia major are at high risk of hepatitis C through blood transfusion from donors infected by hepatitis C virus (HCV). The use of direct-acting antiviral (DAA) therapy against such HCV infections has increased in different populations. However, resistant viral variants can affect treatment outcomes, and therefore improved surveillance strategies are needed. Accordingly, we aimed to evaluate resistance-associated substitutions (RASs) to HCV DAAs at the baseline of treatment in thalassemia patients in a referral center. Out of 89 thalassemia patients who suffered from HCV infection and were referred to our center between 2016 and 2017, 43 underwent further analysis of the HCV nonstructural proteins NS5A and NS5B using polymerase chain reaction (PCR) sequencing methods. Unique primers were designed using bioinformatics software for separate detection of HCV subtypes 1a, 3a, and 1b. Detection of RASs was performed based on previously published literature. Statistical analysis was carried out using SPSS version 19. The participants, 60.4% (26/43) of whom were male, had a mean age ± standard deviation (SD) of 33.0 ± 5.0 years. HCV subtype 1a was found in 27 cases, 3a in 13, and 1b in three. In HCV subtype 1a there were 163 mutations in NS5A and 212 mutations in NS5B. The frequency of RASs was 20.9% (8 RASs in 9 patients), including M28V and H58P in subtype 1a, L28M, R30Q, C316N, and C316S in subtype 1b, and S24F in subtype 3a. Statistically, the subtype 1b and a higher mutation rate in NS5A were associated with RASs (p-value < 0.05). The emergence of natural RASs to HCV DAAs serves as a warning of the risk of drug resistance in response to the broad usage of antivirals. However, relapses in these DAA-treated HCV-infected thalassemia patients are rarely reported. Our findings indicate that the prevalence of RASs prevalence at baseline was 20.9% in these patients, and this calls for extrapolation to a larger population study, as highlighted in other studies, with larger sample sizes, high-throughput methods, and follow-up in order to fully evaluate treatment outcomes in RASs-detected individuals. Optimized therapeutic strategies, particularly in complex, difficult-to-cure patients, can effectively prevent DAA treatment failure as a result of selection for RASs.

Ineffective Absorption? Failure of Direct-Acting Therapy for Chronic Hepatitis C in Cirrhotic Patients With Roux-en-Y Gastric Bypass

In this era of direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) infection, treated patients have extremely high rates of sustained virologic response to short courses of therapy regardless of stage of fibrosis. Treatment failure is uncommon and often attributed to medication noncompliance or viral resistance to drug. This report describes 2 Child-Pugh-A cirrhotic patients who failed to clear HCV in response to therapy with DAAs. Each patient had Roux-en-Y gastric bypass (RYGB) surgery preceding DAA therapy. RYGB may create multiple barriers to adequate DAA absorption as a result of changes in gastrointestinal physiology. Treatment monitoring and duration should be carefully considered in this unique patient population.

Provider Perceptions of Hepatitis C Treatment Adherence and Initiation

BACKGROUND

Significant disparities in hepatitis C (HCV) treatment existed in the interferon treatment era, such that patients with mental health and substance use disorders were less likely to be treated. We aimed to evaluate whether these perceptions continue to influence HCV treatment decisions.

METHODS

We e-mailed HCV providers a survey to assess their perceptions of barriers to HCV treatment adherence and initiation. We assessed the frequency of perceived barriers and willingness to initiate HCV treatment in patients with these barriers. We identified a group of providers more willing to treat patients with perceived barriers to adherence and determined the associated provider characteristics using Spearman's rho and Wilcoxon rank-sum tests.

RESULTS

A total of 103 providers (29%) responded to the survey. The most commonly endorsed perceived barriers to adherence were homelessness (65%), ongoing drug (58%), and ongoing alcohol use (33%). However, 90%, 68%, and 90% of providers were still willing to treat patients with these comorbidities, respectively. Ongoing drug use was the most common reason providers were never or rarely willing to initiate HCV treatment. Providers who were less willing to initiate treatment more frequently endorsed patient-related determinants of adherence, while providers who were more willing to initiate treatment more frequently endorsed provider-based barriers to adherence (e.g., communication).

CONCLUSIONS

Most responding providers were willing to initiate HCV treatment in all patients, despite the presence of perceived barriers to adherence or previous contraindications to interferon-based treatments. Ongoing substance use remains the most prominent influencer in the decision not to treat.

Retreatment of chronic hepatitis C patients who failed previous therapy with directly acting antivirals: A multicenter study

AIM OF THE STUDY

The current study aimed to evaluate the efficacy of different DAAs regimens in the treatment of chronic hepatitis C (CHC) Egyptian patients who failed to achieve SVR after their treatment with SOF-based regimens.

METHODS

This was a retrospective observational multicenter study that included CHC patients that failed to achieve cure on SOF-based regimens who were re-treated using different DAAs regimen and were allocated according to national guidelines for the treatment of hepatitis C. Primary outcome was to assess the SVR12 rate among prior non-responders after retreatment with a second course of DAAs.

RESULTS

Our study included 172 patients who failed to achieve SVR after treatment with SOF-based treatment regimen [age: 51.2 ± 11.3, 58.7% men]. Included patients were retreated using SOF/DCV/RBV, SOF/ r/PAR /OMB /RBV, SOF/DCV/SIM, SOF/LDV ± RBV or SIM/SOF. SVR12 was successfully attained in 95.35% (164/172) of the included non-responders.

CONCLUSION

The current multicenter study proved the efficacy of various DAAs regimens issued by the National Committee for Control of Viral Hepatitis for retreatment of relapsed CHC Egyptian patients.

Integrated Care for the Use of Direct-acting Antivirals in Patients With Chronic Hepatitis C and Substance Use Disorder

OBJECTIVES

Since little is currently known about predictors of response to direct-acting antiviral agents (DAAs) in people who inject drugs, we undertook an analysis of patients attending a hepatitis clinic with addiction services (outpatient clinics and inpatient services) to examine the outcomes associated with the treatment of difficult-to-manage patients with substance use. Our experience was based on integrated care.

METHOD

A retrospective analysis was undertaken of 50 patients with hepatitis C virus (HCV) and a history of addiction who received treatment with DAAs, according to European guidelines. These regimens were sofosbuvir/ledipasvir for 8 weeks (n = 3), sofosbuvir/ledipasvir ± ribavirin for 12 weeks (n = 19), sofosbuvir/daclatasvir for 12 weeks (n = 20), sofosbuvir/simeprevir (n = 1), or sofosbuvir/daclatasvir for 24 weeks (n = 7). Characteristics of patients who did versus did not achieve a sustained virologic response (SVR) 12 weeks after treatment were compared by univariate analysis.

RESULTS

Forty-two patients (84%) were male; mean age was 46.2 ± 7.3 years. Genotypes were 1 (n = 21), 2 (n = 4), 3 (n = 18), 4 (n = 6), or 6 (n = 1). Most patients were treatment-naïve (n = 38). Five patients had coinfection with human immunodeficiency virus (n = 4) or hepatitis B (n = 1), 28 (56%) had evidence of cirrhosis on FibroScan (>12.5 kPa), and 34 (68%) were receiving opioid substitution therapy. Psychiatric disease, illicit drug use, unemployment, and homelessness/precarious housing were common. Forty-five patients (90%) achieved SVR, 2 were lost to follow-up, and 3 had treatment relapse.

CONCLUSIONS

SVR was not significantly associated with sociodemographic or virological characteristics, treatment, social environment, alcohol/drug use, and adherence. Although adherence was slightly worse than in "usual" patients, it did not affect the SVR rate. In these difficult-to-manage patients with HCV and substance use disorder, the real-world SVR rate (90%) was similar to that in nonaddicted populations.

Ribavirin induces hepatitis C virus genome mutations in chronic hepatitis patients who failed to respond to prior daclatasvir plus asunaprevir therapy

Ribavirin (RBV) induces nucleotide (nt) substitutions in hepatitis C virus (HCV) genome nonstructural (NS) regions. Although emergence of drug resistance-associated variants is associated with direct-acting antiviral treatment failure, the effect of RBV on genome substitutions in such patients is unknown. Genotype 1b HCV subgenomic replicon cells were treated with RBV for 120 hours. Six patients with chronic genotype 1b with HCV-infected patients who failed to respond to prior daclatasvir plus asunaprevir (DCV/ASV) therapy were treated with 12 weeks of sofosbuvir and ledipasvir plus RBV after 4 weeks of RBV monotherapy. RBV-induced genome mutations in the HCV NS region (nt3493-9301) in replicon cells and in patients during 4 weeks of RBV monotherapy were analyzed by deep sequencing. RBV-associated G-to-A and C-to-U transitions increased in a dose-dependent manner in HCV replicon cells after the RBV treatment. In patients with prior DCV/ASV treatment failures, the median serum HCV RNA level was 6.25 ± 0.31 log IU/mL at the start of RBV therapy and decreased significantly to 5.95 ± 0.4 log IU/mL (P = .03) after 4 weeks of RBV monotherapy. Although predominant HCV genome substitutions rates were similar between nontreatment and RBV-treatment periods (0.042 and 0.031 per base pair, respectively; P  = .248), the frequencies of G-to-A and C-to-U transitions significantly increased after RBV monotherapy. These transitions were enriched, particularly within the HCV NS3 region in all patients. RBV treatment induces G-to-A and C-to-U transitions in the HCV genome even in chronic patients with hepatitis C with prior DCV/ASV treatment failures.

Worldwide prevalence of baseline resistance-associated polymorphisms and resistance mutations in HCV against current direct-acting antivirals

BACKGROUND

HCV infections can now be completely cured, thanks to the currently marketed direct-acting antivirals (DAAs). It is known that HCV patients carry viral populations with baseline polymorphisms and/or mutations that make them resistant against some of these DAAs, which can negatively impact the patient's treatment outcome. Using complete HCV coding sequences isolated from 1,306 treatment-naive patients of genotypes (GTs) 1, 2, 3, 4 and 6 from around the globe, we studied the prevalence of baseline resistance-associated polymorphisms (RAPs) and resistance mutations (RMs) against DAAs that are currently on the market or in clinical trials.

METHODS

The HCV genome sequences used in this study were retrieved from the NCBI database. RAPs and RMs, with reference to HCV GT1a, were identified using the HCV Geno2pheno web server.

RESULTS

Nearly 50% of the total amino acid positions (including NS3 protease, NS5A and NS5B) studied are baseline polymorphisms that differentiated one GT from the rest. A proportion of these baseline polymorphisms and baseline non-polymorphic RMs could confer a significant increase in resistance against DAAs.

CONCLUSIONS

In this study, we show the presence and prevalence of RAPs and RMs in DAA treatment-naive patients against currently used DAAs or DAAs in clinical trials. Our study suggests that RAPs and RMs profiling of HCV patients should be performed before the start of the therapy. Our results should be relevant especially in low- and middle-income countries, where the patients have a large variation of GTs and subtypes, and where the generic HCV treatment is now increasingly available.

Viral dynamics among HCV infected patients with different genotypes treated with genotypic specific or pan-genotypic direct-acting antiviral agent combinations

BACKGROUND

New hepatitis C virus (HCV) therapies have improved efficacy, allowed pangenotypic applications, increased barriers to drug resistance and shortened therapy duration.

METHODS

Patients infected with different HCV genotypes were divided into two groups: group 1 included 169 patients receiving genotypic specific regimens (GSR), while group 2 included 186 patients receiving pan-genotypic regimens (PGR). Patient's HCV RNA was quantified and sequenced.

RESULTS

Comparable sustained viral response (SVR) rates were observed in both GSR and PGR treated patients. Nevertheless, even if not significant, a greater proportion of non-detectable levels (NDL) of HCV RNA was observed in patients treated with PGR as compared with GSR. Overall, among patients in the GSR and PGR groups with residual viremia, 124/169 (73.4%) and 125/186 (67.2%) at four weeks, and 66/169 (39.1%) and 58/186 (31.2%) at eight weeks, achieved SVR. No difference was observed in the clinical outcome comparing patients in the GSR and PGR groups according to genotype. While, comparing patients between the two groups, the proportion of patients with NDL HCV RNA at four and eight weeks was higher in patients infected with genotype 1b treated with PGR (p=0.0015). A significantly higher number of patients infected with 1b had RASs at baseline (p=0.0001). In addition, the proportion of patients with treatment failure was higher in patients with RASs at baseline compared with those without (p=0.012). Overall, 2.5% patients failed to achieve SVR after DAA treatment.

CONCLUSION

A sharp HCV RNA decrease was observed in patients treated with both GSR and PGR. However, even if comparable, a slightly greater number of patients treated with PGR achieved NDL HCV RNA as compared with GSR. A significant difference was observed in patients with baseline RASs, both in relation to treatment failure and genotype. In conclusion, the use of new DAA combinations helps patients achieve a more rapid virologic response.

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.

Efficacy and safety of alisporivir for the treatment of hepatitis C infection

Alisporivir (ALV) (previously known as Debio 025) is a potent, pangenotypic host-targeting antiviral oral agent acting on cyclophilin A, which is necessary for HCV replication. Areas covered: This article reviews the therapeutic efficacy and safety of ALV for the treatment of HCV infection. Expert opinion: Direct-acting antivirals (DAAs) have revolutionized the HCV antiviral treatment paradigm with success rates well above 95% for all HCV genotypes. However, challenges still remain in certain patient populations such as those who have developed resistance and have experienced multi-DAA failure. To cure HCV infection, a treatment regimen must combine antiviral potency and a high barrier to resistance. ALV fulfills this need as shown by the studies evaluating its clinical efficacy. Nevertheless, ALV missed the chance to be included in the HCV treatment armamentarium after the FDA halted clinical studies following reports of serious side effects (three cases of pancreatitis, one lethal). However, it is possible that ALV could still be considered for HCV-infected non-cirrhotic patients that are infected with a multiresistant virus or with HCV genotype 3, although it must be said that the drug industry would be reluctant to invest in new antivirals if the current clinical need is effectively met.

New Direct-Acting Antivirals for the Treatment of Patients With Hepatitis C Virus Infection: A Systematic Review of Randomized Controlled Trials

BACKGROUND

New direct-acting antiviral agents (DAAs) approved for the treatment of patients infected by Hepatitis C virus (HCV) are well tolerated and increase sustained virological response (SVR) rate. We summarize current evidence on the efficacy and safety from comparative randomized controlled trials (RCTs) of DAAs.

METHODS

We systematically searched MEDLINE, Embase, Scopus, CENTRAL, and Lilacs as well as a list of reference literature. We included RCTs comparing DAAs with placebo or active control and reporting response rates and adverse events according to antiviral regimens. Risk ratios (RRs) were pooled as appropriate. We assessed the risk of bias of included studies and graded the quality of evidence according to the GRADE method.

RESULTS

We included 28 RCTs, enrolling more than 7000 patients. The quality of evidence was generally low. Twelve-week treatment with DAAs in naïve patients significantly increased SVR12 and SVR24 compared with placebo (RR 1.4, 95% CI 1.3-1.6; RR 1.5, 95% CI 1.4-1.6, respectively). This means that for every 1000 patients, 240 or 260 more patients experienced SVR12 or SVR24 if treated with any DAAs. We could not find RCTs assessing progression of liver disease or development of hepatocellular carcinoma. DAAs were not associated with higher incidence of serious adverse events or discontinuation due to adverse events.

CONCLUSIONS

This systematic review confirms that new DAAs are more effective in inducing SVR than placebo. Outside clinical trials, in real word, HCV cure with DAA regimens occurs in less than 90% of patients, so further comparative evaluations are needed to establish their long-term effects.

Anti-E1E2 antibodies status prior therapy favors direct-acting antiviral treatment efficacy

INTRODUCTION

Presence of anti-E1E2 antibodies was previously associated with spontaneous cure of hepatitis C virus (HCV) and predictive before treatment of a sustained virological response (SVR) to bi- or tri-therapy in naïve or experienced patients, regardless of HCV genotype. We investigated the impact of anti-E1E2 seroprevalence at baseline on treatment response in patients receiving direct-acting antiviral (DAA) therapy.

MATERIAL AND METHODS

We screened anti-E1E2 antibodies by ELISA in serum samples collected at treatment initiation for two groups of patients: 59 with SVR at the end of DAA treatment and 44 relapsers after DAA treatment. Nineteen patients received a combination of ribavirin (RBV) or PEG-interferon/ribavirin with sofosbuvir or daclatasvir and others received interferon-free treatment with DAA±RBV. HCV viral load was measured at different time points during treatment in a subgroup of patients.

RESULTS

A significant association was observed between presence of anti-E1E2 and HCV viral load<6log10 prior treatment. Among patients with anti-E1E2 at baseline, 70% achieved SVR whereas among patients without anti-E1E2, only 45% achieved SVR. Conversely, 66% of patients experiencing DAA-failure were anti-E1E2 negative at baseline. In the multivariate analysis, presence of anti-E1E2 was significantly associated with SVR after adjustment on potential cofounders such as age, sex, fibrosis stage, prior HCV treatment and alanine aminotransferase (ALT) level.

CONCLUSIONS

The presence of anti-E1E2 at treatment initiation is a predictive factor of SVR among patients treated with DAA and more likely among patients with low initial HCV viral load (<6log10). Absence of anti-E1E2 at baseline could predict DAA-treatment failure.

Evolution of patients' socio-behavioral characteristics in the context of DAA: Results from the French ANRS CO13 HEPAVIH cohort of HIV-HCV co-infected patients

BACKGROUND

Direct-acting antivirals (DAA) have dramatically increased HCV cure rates with minimal toxicity in HIV-HCV co-infected patients. This study aimed to compare the socio-behavioral characteristics of patients initiating pegylated-interferon (PEG-IFN)-based HCV treatment with those of patients initiating DAA-based treatment.

METHODS

ANRS CO13 HEPAVIH is a national multicenter prospective cohort started in 2005, which enrolled 1,859 HIV-HCV co-infected patients followed up in French hospital outpatient units. Both clinical/biological and socio-behavioral data were collected during follow-up. We selected patients with socio-behavioral data available before HCV treatment initiation.

RESULTS

A total of 580 patients were included in this analysis. Of these, 347 initiated PEG-IFN-based treatment, and 233 DAA-based treatment. There were significant differences regarding patient mean age (45 years±6 for the PEG-IFN group vs. 52 years±8 for the DAA group, p<0.001), unstable housing (21.4% vs. 11.2%, p = 0.0016), drug use (44.7% vs. 29.6%, p = 0.0003), regular or daily use of cannabis (24.3% vs. 15.6%, p = 0.0002), a history of drug injection (68.9% vs 39.0%, p<0.0001) and significant liver fibrosis (62.4% vs 72.3%, p = 0.0293). In multivariable analysis, patients initiating DAA-based treatment were older than their PEG-IFN-based treatment counterparts (aOR = 1.17; 95%CI [1.13; 1.22]). Patients receiving DAA treatment were less likely to report unstable housing (0.46 [0.24; 0.88]), cannabis use (regular or daily use:0.50 [0.28; 0.91]; non-regular use: 0.41 [0.22; 0.77]), and a history of drug injection (0.19 [0.12; 0.31]).

CONCLUSION

It is possible that a majority of patients who had socio-economic problems and/or a history of drug injection and/or a non-advanced disease stage were already treated for HCV in the PEG-IFN era. Today, patients with unstable housing conditions are prescribed DAA less frequently than other populations. As HCV treatment is prevention, improving access to DAA remains a major clinical and public health strategy, in particular for individuals with high-risk behaviors.

Pharmacokinetic and pharmacodynamic evaluation of daclatasvir, asunaprevir plus beclabuvir as a fixed-dose co-formulation for the treatment of hepatitis C

INTRODUCTION

Many reports have evaluated the clinical efficacy and safety of the fixed-dose all-oral combination of daclatasvir, asunaprevir, and beclabuvir (DCV-TRIO), which was approved in Japan in December 2016 for the treatment of hepatitis C genotype (GT)-1 infection. Areas covered: This article reviews the pharmacodynamic and pharmacokinetic properties of the DCV-TRIO combination. The topics covered include data regarding the drug's absorption, distribution, metabolism, excretion, and antiviral activity strategies. Its therapeutic efficacy and safety in GT-1 infection from phase 2/3 clinical trials are also discussed. Expert opinion: The ideal regimen for the treatment of Hepatitis C virus infection should be potent, pangenotypic, Ribavirin-free, safe, co-formulated, and affordable. Considering these characteristics, DCV-TRIO is neither pangenotypic nor potent enough against GT-1a, regardless of the presence or absence of cirrhosis. Other potential limitations of this regimen are its dosification (twice-daily), and the fact that since it includes a protease inhibitor, it is contraindicated in decompensated cirrhosis. For these reasons, it has only been approved in Japan, where more than 70% of the patients are infected with GT-1b. However, this co-formulation might still have a place in the treatment of non-cirrhotic patients infected with GT-1b provided that massive access to treatment is facilitated.

Host-targeting therapies for hepatitis C virus infection: current developments and future applications

Chronic hepatitis C virus (HCV) infection is a leading cause of chronic liver diseases and hepatocellular carcinoma (HCC) worldwide. In the past few years, anti-HCV therapies have undergone a revolution with the approval of multiple direct-acting antivirals (DAAs), which enable interferon-free treatments with considerable improvement of sustained virologic response in patients. Today, DAAs have become the standard of care for HCV therapy. However, several limitations remain, which include access to therapy, treatment failure in a subset of patients and persistent risk of HCC development following cure in patients with advanced fibrosis. By targeting conserved host proteins involved in the HCV life cycle, host-targeting agents (HTAs) offer opportunities for pan-genotypic antiviral approaches with a high barrier to drug resistance. Moreover, when applied in combination with DAAs, HTAs could improve the management of difficult-to-treat patients by acting through a complementary mechanism of action. In this review, we summarize the different HTAs evaluated in preclinical and clinical development and discuss their potential role for anti-HCV therapies.

Rationale, design, and methodology of a trial evaluating three models of care for HCV treatment among injection drug users on opioid agonist therapy

BACKGROUND

People who inject drugs (PWID) constitute 60% of the approximately 5 million people in the U.S. infected with hepatitis C virus (HCV). Treatment of PWID is complex due to addiction, mental illness, poverty, homelessness, lack of positive social support, poor adherence-related skills, low motivation and knowledge, and poor access to and trust in the health care system. New direct-acting antiviral medications are available for HCV with high cure rates and few side effects. The life expectancy and economic benefits of new HCV treatments will not be realized unless we determine optimal models of care for the majority of HCV-infected patients. The purpose of this study is to evaluate the effectiveness of directly observed therapy and group treatment compared with self-administered individual treatment in a large, urban opioid agonist therapy clinic setting in the Bronx, New York.

METHODS/DESIGN

In this randomized controlled trial 150 PWID with chronic HCV were recruited from opioid agonist treatment (OAT) clinics and randomized to one of three models of onsite HCV treatment in OAT: 1) modified directly observed therapy; 2) group treatment; or 3) control - self-administered individual treatment. Participants were age 18 or older, HCV genotype 1, English or Spanish speaking, treatment naïve (or treatment experienced after 12/3/14), willing to receive HCV treatment onsite, receiving methadone or buprenorphine at the medication window at least once per week, and able to provide informed consent. Outcomes of interest include adherence (as measured by self-report and electronic blister packs), HCV treatment completion, sustained virologic response, drug resistance, and cost-effectiveness.

DISCUSSION

This paper describes the design and rationale of a randomized controlled trial comparing three models of care for HCV therapy delivered in an opioid agonist treatment program. Our trial will be critical to rigorously identify models of care that result in high adherence and cure rates. Use of blister pack technology will help us determine the role of adherence in successful cure of HCV. Moreover, the trial methodology outlined here can serve as a template for the development of future programs and studies among HCV-infected drug users receiving opioid agonist therapy, as well as the cost-effectiveness of such programs.

TRIAL REGISTRATION

This trial was registered with ClinicalTrials.gov ( NCT01857245 ). Trial registration was obtained prospectively on May 20th, 2013.

Synthesis and Biological Characterization of Aryl Uracil Inhibitors of Hepatitis C Virus NS5B Polymerase: Discovery of ABT-072, a trans-Stilbene Analog with Good Oral Bioavailability

ABT-072 is a non-nucleoside HCV NS5B polymerase inhibitor that was discovered as part of a program to identify new direct-acting antivirals (DAAs) for the treatment of HCV infection. This compound was identified during a medicinal chemistry effort to improve on an original lead, inhibitor 1, which we described in a previous publication. Replacement of the amide linkage in 1 with a trans-olefin resulted in improved compound permeability and solubility and provided much better pharmacokinetic properties in preclinical species. Replacement of the dihydrouracil in 1 with an N-linked uracil provided better potency in the genotype 1 replicon assay. Results from phase 1 clinical studies supported once-daily oral dosing with ABT-072 in HCV infected patients. A phase 2 clinical study that combined ABT-072 with the HCV protease inhibitor ABT-450 provided a sustained virologic response at 24 weeks after dosing (SVR₂₄) in 10 of 11 patients who received treatment.

Comorbidity, concomitant medication, use of resources and healthcare costs associated with chronic hepatitis C virus carriers in Spain

OBJECTIVES

To assess the comorbidity, concomitant medications, healthcare resource use and healthcare costs of chronic hepatitis C virus patients in the Spanish population.

PATIENTS AND METHODS

Retrospective, observational, non-interventional study. Patients included were≥18 years of age who accessed medical care between 2010-2013. Patients were divided into 2 groups based on the presence or absence of liver cirrhosis. The follow-up period was 12 months. Main assessment criteria included general comorbidity level (determined by the resource utilisation band score) and prevalence of specific comorbidities, concomitant medications, healthcare resource use and healthcare costs. Statistical analysis was performed using regression models and ANCOVA, P<.05.

RESULTS

One thousand fifty-five patients were enrolled, the mean age was 57.9 years and 55.5% were male. A percentage of 43.5 of patients had a moderate level of comorbidity according to the resource utilisation band score. The mean time from diagnosis was 18.1 years and 7.5% of the patients died during the follow-up period. The most common comorbidities were dyslipidaemia (40.3%), hypertension (40.1%) and generalised pain (38.1%). Cirrhosis was associated with cardiovascular events (OR 3.8), organ failures (OR 2.2), alcoholism (OR 2.1), diabetes (OR 1.2) and age (OR 1.2); P<.05. The most commonly used medications were anti-infectives (67.8%) and nervous system medications (66.8%). The mean total cost per patient was 3,198€ (71.5% healthcare costs, 28.5% indirect/non-healthcare costs). In the corrected model, the total costs per patient-year were 2,211€ for those without cirrhosis and 7,641€ for patients with cirrhosis; P<.001.

CONCLUSIONS

Chronic hepatitis C virus patients are associated with a high level of comorbidity and the use of concomitant medications, especially in patients with liver cirrhosis. Chronic hepatitis C virus infection represents a substantial economic burden on the Spanish National Health System.

Baseline and Breakthrough Resistance Mutations in HCV Patients Failing DAAs

Sustained virologic response rates have increased dramatically following direct acting antiviral (DAA) therapy in chronic HCV infection. However, resistance-associated substitutions (RASs) may occur either prior to DAA or following drug exposure. The aim of this study was to determine RASs in DAA treatment-failing patients and the role of RASs in failure treatment. Six hundred and twenty HCV patients were evaluated. Direct sequencing of HCV genes was performed at breakthrough in all 31 patients failing DAAs, and in 19 baseline patients. Deep sequencing analysis was performed in 15/19 baseline patients. RASs were detected at breakthrough in 17/31 patients and at baseline in 11/19 patients, although, only 8/19 patients carried RASs associated with the prescribed regimen. Deep sequencing analysis showed RASs at baseline in 10/15 treatment-failing patients. No significant difference was observed with the Sanger sequencing. Treatment failure in the 14/31 patients without RASs was associated with suboptimal treatment. In 54.8% of treatment-failing patients one of the causes of failure might be the presence of RASs. In the majority of patients with RASs, mutations were present at baseline. Direct resistance test is advocated before treatment and at breakthrough in order to optimize retreatment regimens.

Baseline NS5A resistance associated substitutions may impair DAA response in real-world hepatitis C patients

Oral DAA have demonstrated high efficacy as treatment of hepatitis C. However, the presence of resistance-associated substitutions (RAS) at baseline has occasionally been associated with impaired treatment response. Herein, we examined the impact of baseline RAS at the HCV NS5A gene region on treatment response in a real-life setting. All hepatitis C patients treated with DAA including NS5A inhibitors at our institution were retrospectively examined. The virus NS5A gene was analyzed using population sequencing at baseline and after 24 weeks of completing therapy in all patients that failed. All changes recorded at positions 28, 29, 30, 31, 32, 58, 62, 92, and 93 were considered. A total of 166 patients were analyzed. HCV genotypes were as follows: G1a (31.9%), G1b (48.2%), G3 (10.2%), and G4 (9.6%). Overall, 69 (41.6%) patients were coinfected with HIV and 46.7% had advanced liver fibrosis (Metavir F3-F4). Sixty (36.1%) patients had at least one RAS at baseline, including M28A/G/T (5), Q30X (12), L31I/F/M/V (6), T58P/S (25), Q/E62D (1), A92 K (7), and Y93C/H (15). Overall, 4.8% had two or more RAS, being more frequent in G4 (12.5%) followed by G1b (6.3%) and G1a (1.9%). Of 10 (6%) patients that failed DAA therapy, five had baseline NS5A RAS. No association was found for specific baseline RAS, although changes at position 30 were more frequent in failures than cures (22.2% vs 6.4%, P = 0.074). Moreover, the presence of two or more RAS at baseline was more frequent in failures (HR: 7.2; P = 0.029). Upon failure, six patients showed emerging RAS, including Q30C/H/R (3), L31M (1), and Y93C/H (2). Baseline NS5A RAS are frequently seen in DAA-naïve HCV patients. Two or more baseline NS5A RAS were found in nearly 5% and were significantly associated to DAA failure. Therefore, baseline NS5A testing should be considered when HCV treatment is planned with NS5A inhibitors.

Validation of a questionnaire to monitor symptoms in HIV-infected patients during hepatitis C treatment

Background

Clinicians are incorporating patient-reported outcomes in the management of HIV-infected persons co-infected with hepatitis C virus (HCV), but there are no validated inventories to monitor symptoms of patients during HCV therapy.

Design

Five-year retrospective cohort analysis of persons living with HIV (PLWH) treated for HCV.

Methods

The HCV symptom-inventory (HCV-SI) was administered before, during, and after HCV treatment. Discriminant validity was assessed, separately, in mixed model linear regression of HCV-SI T-scores on treatment regimens (pegylated-interferon and ribavirin; pegylated-interferon, ribavirin, and telaprevir; and interferon-free antivirals); and side effect-related premature treatment discontinuation (SE-DC).

Results

From the 103 patients who completed the HCV-SI, 7% were female, 26% non-white, 32% cirrhotics and 91% had undetectable HIV viral loads. Most had genotype 1 (83%) and were HCV treatment-naïve (78%). We treated 19% of patients with pegylated-interferon and ribavirin, 22% with pegylated-interferon, ribavirin, and telaprevir and 59% received interferon-free antivirals. Overall, 77% achieved a sustained virologic response, and 6% discontinued HCV treatment due to side effects. In the treatment discrimination model, compared to the no treatment period, HCV-SI scores were significantly (p < 0.01) lower for interferon-free antivirals and higher for interferon-containing regimens. In the SE-DC model, the total HCV-SI, somatic and neuropsychiatric scores significantly predicted those patients who prematurely discontinued HCV treatment (P < 0.05).

Conclusions

The HCV-SI effectively differentiated among treatment regimens known to vary by side effect profiles and between patients with and without treatment discontinuation due to side effects. The HCV-SI may have value as a patient-reported outcome instrument predicting the risk of HCV treatment discontinuation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12981-017-0182-7) contains supplementary material, which is available to authorized users.

Sofosbuvir, velpatasvir and voxilaprevir combination for the treatment of hepatitis C

The advent of direct-acting antiviral (DAA) treatments for chronic hepatitis C virus (HCV) infection has dramatically increased rates of cure. However, there remain difficult-to-treat populations, including patients with genotype 3 infection and cirrhosis, and limited salvage treatment options for those that have failed first-line DAA therapy. Areas covered: This is a review of the preclinical and clinical development of sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX), an interferon-free, oral, once daily, pangenotypic treatment for chronic HCV infection. All relevant literature from 2015 through June of 2017 is included. Expert commentary: Voxilaprevir, a second-generation HCV protease inhibitor, in combination with the already approved combination of sofosbuvir and velpatasvir, was evaluated in the POLARIS trials and found to be a safe and effective regimen. Patients with prior DAA treatment failure, genotype 3, cirrhosis and/or unfavorable resistance profiles all achieved cure rates of 96% or greater. The most distinctive role for this potent regimen may prove to be as a salvage regimen for patients who have failed previous DAA therapy.

Treatment of hepatitis C with new fixed dose combinations

INTRODUCTION

The advent of oral direct-acting antivirals (DAA) has revolutionized the hepatitis C virus (HCV) therapeutic landscape providing cure rates over 90%. However, a subset of patients remains at higher risk for treatment failure, including those infected with: i) genotype 3 and cirrhosis; ii) resistance-associated substitutions (RAS) occurring either as natural polymorphisms or selected after prior DAA failure; and iii) poor drug adherence associated with social disabilities (homeless, psychiatric illnesses, injection drug use, alcoholism, etc.). Whereas discovery of new DAA with increased antiviral activity across all genotypes and over RAS may enhance efficacy, development of fixed dose combinations (FDC) may be the best way to improve drug adherence in difficult-to-treat HCV populations. Areas covered: Three FDC regimens are in the last steps of clinical development for treating hepatitis C. Two distinct nucleotide analogues that inhibit the HCV polymerase, sofosbuvir and uprifosbuvir, are part of the FDC from Gilead and Merck, respectively. The AbbVie dual FDC does not include a polymerase inhibitor. All three new FDC include second-generation NS3 protease inhibitors and NS5A inhibitors active across all HCV genotypes and over common RAS. Expert opinion: Hepatitis C cure rates over 95% are expected with all three next-coming DAA, even in the most difficult-to-treat and/or cure patient populations. These regimens would be particularly needed for the growing number of prior DAA failures. Co-formulations and 8-week shorter treatment lengths will help to overcome drug adherence challenges in certain populations.

Evaluation of sofosbuvir, velpatasvir plus voxilaprevir as fixed-dose co-formulation for treating hepatitis C

INTRODUCTION

The fixed-dose combination of three direct-acting antivirals (DAA), namely sofosbuvir, velpatasvir and voxilaprevir is the first pangenotypic, single tablet regimen developed for the treatment of HCV infection. Areas covered: The pharmacokinetics, pharmacodynamics, efficacy and safety of the co-formulation are reviewed. Information on drug absorption, distribution, metabolism and excretion of each of the three antivirals is evaluated. Finally, antiviral activity, safety and potential for drug interactions in phase II/III clinical trials in distinct patient populations are discussed. Expert opinion: The triple co-formulation of sofosbuvir-velpatasvir-voxilaprevir represents a major step towards HCV eradication. It depicts high efficacy even in patients infected with viruses harboring resistance-associated substitutions (RAS), including those selected after DAA failures. Likewise, very high success rates and good tolerance are seen in special patient populations, including decompensated cirrhotics, HIV coinfection, organ transplantation or renal insufficiency. A pill once daily for 8 weeks gives SVR rates above 95%. In prior DAA failures, extending treatment to 12 weeks maximizes SVR rates.

HCV intergenotype 2k/1b recombinant detected in a DAA-treated patient in Italy

Direct-acting antiviral (DAA) combinations are potent and effective drugs currently recommended for treatment of chronic HCV infection. Difficult to treat genotypes are the most important predictors of treatment failure. We report a case of DAA treatment failure in an HCV-infected patient carrying a recombinant genotype 2k/1b. This strain, first isolated from a Russian patient in 2002, has now been observed for the first time in Italy.

Impact of ITPA gene polymorphisms on the risk of ribavirin-induced haemolytic anaemia using interferon-free antivirals for chronic hepatitis C

BACKGROUND

Single nucleotide polymorphisms (SNPs) at the ITPA gene are associated with haemolytic anaemia in chronic hepatitis C patients treated with pegylated interferon-ribavirin (RBV). Information in patients treated with interferon-free, direct-acting antivirals (DAA) is scarce.

METHODS

Median haemoglobin (Hb) levels were compared at baseline and at week 4, when ribavirin concentration achieves steady state, in all consecutive chronic hepatitis C patients treated with oral DAA plus RBV at our clinic.

RESULTS

Median Hb drop in 55 patients was greater in rs1127354-CC than -CA/AA (1.8 versus 0.7 g/dl; P=0.029), and in rs6051702-AA than -AC/CC carriers (2.2 versus 1.1 g/dl; P=0.016). Eleven (20%) patients experienced severe anaemia, defined as Hb drop >3 g/dl or to <10 g/dl. All of them were rs6051702-AA.

CONCLUSIONS

Baseline testing of rs6051702 may identify the subset of patients at greatest risk for RBV-induced anaemia using interferon-free hepatitis C therapies.

Hepatitis C virus resistance to the new direct-acting antivirals

INTRODUCTION

The treatment of hepatitis C virus (HCV) infection has dramatically improved in recent years with the widespread use of interferon-free combination regimens. Despite the high sustained virological response (SVR) rates (over 90%) obtained with direct-acting antivirals (DAAs), drug resistance has emerged as a potential challenge. The high replication rate of HCV and the low fidelity of its RNA polymerase result in a high degree of genetic variability in the HCV population, which ultimately explains the rapid selection of drug resistance associated variants (RAVs).

AREAS COVERED

Results from clinical trials and real-world experience have both provided important information on the rate and clinical significance of RAVs. They can be present in treatment-naive patients as natural polymorphisms although more frequently they are selected upon treatment failure. In patients engaged in high-risk behaviors, RAVs can be transmitted.

EXPERT OPINION

Although DAA failures generally occur in less than 10% of treated chronic hepatitis C patients, selection of drug resistance is the rule in most cases. HCV re-treatment options are available, but first-line therapeutic strategies should be optimized to efficiently prevent DAA failure due to baseline HCV resistance. Considerable progress is being made and next-generation DAAs are coming with pangenotypic activity and higher resistance barrier.

Rate and predictors of treatment failure to all-oral HCV regimens outside clinical trials

BACKGROUND

Cure rates above 90% have been reported in most Phase III clinical trials using distinct all-oral direct-acting antivirals (DAAs) in chronic hepatitis C patients. Preliminary results in real-world patients have confirmed this, although efficacy tends to be lower.

METHODS

All consecutive chronic hepatitis C patients treated with all-oral DAA regimens at three hepatitis clinics in Spain were retrospectively examined. Host and viral factors were tested as predictors of treatment failure.

RESULTS

A total of 363 chronic hepatitis C patients had completed a course of all-oral DAA therapy outside clinical trials up to the end of 2015. All but 14 (4%) patients achieved sustained virological response. There were 10 failures that occurred after 12 weeks of sofosbuvir-ledipasvir, despite 5 of them being on ribavirin. All failures but one were relapses. The only patient with viral breakthrough selected NS5B L159F and NS5A Y93H. In multivariate analyses, only advanced liver fibrosis (Metavir F3-F4) and HIV coinfection were significantly associated with treatment failure. A trend towards lower response was seen for HCV genotype 4.

CONCLUSIONS

Treatment failures outside clinical trials are roughly seen in 4% of chronic hepatitis C patients who complete a course of all-oral DAA therapy, resembling what is seen in registration trials. In our series, outcomes were not significantly influenced by ribavirin addition, IL28B polymorphisms, HCV genotype, high baseline HCV RNA or prior interferon failure. However, advanced liver fibrosis and HIV coinfection were significantly associated with treatment failure. Our findings support that there is still room for individualization of current DAA therapy.