Ombitasvir plus paritaprevir plus ritonavir with or without ribavirin in treatment-naive and treatment-experienced patients with genotype 4 chronic hepatitis C virus infection (PEARL-I): a randomised, open-label trial

Hepatitis C Elimination in Egypt: Story of Success

Egypt has long been overwhelmed by the hepatitis C virus (HCV) infection, and it used to be the country with the world's highest prevalence rates. The disease had been a significant public health problem, affecting millions of Egyptians and posing severe economic and social challenges. By the early 2000s, it was estimated that around 10% of the Egyptian population was infected with HCV. However, in recent years, with the availability of direct-acting antiviral therapies, the country has made enormous steps in combating this public health threat. The combination of innovative health strategies and political will enabled Egypt to establish a successful model of care for HCV management and to be the first country to eliminate hepatitis C, setting a model for the rest of the world. In 2023, Egypt became the first country to fulfill the World Health Organization's set programmatic criteria of reduction of hepatitis C incidence and mortalities to levels close to elimination of disease or achieve the "gold tier" status on the path to disease elimination.

Efficacy and Safety of Ombitasvir/Paritaprevir/Ritonavir Plus Dasabuvir in Treating HCV Genotypes 1 and 4 in Patients with Advanced Chronic Kidney Disease

This study assessed the efficacy and safety of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) combined with dasabuvir (DSV) for treating hepatitis C genotype 4 (GT4) and genotype 1 (GT1) in patients with stage 4 or 5 chronic kidney disease (CKD). Among 88 patients, including treatment-naïve and Peginterferon/Ribavirin (RBV)-experienced, treated with OBV/PTV/r±RBV (dosed between 200 mg per week to daily) and additional DSV for GT1, 94.3% achieved sustained virologic response at 12 weeks (SVR12), demonstrating high efficacy. RBV was used at the discretion of the treating physician. The treatment was well-tolerated, with two non-treatment-related deaths reported. The findings suggest that a 12-week regimen of OBV/PTV/r±DSV is highly effective and safe for GT1 and GT4 patients with advanced CKD, regardless of baseline characteristics.

Chlorination of antiviral drug ribavirin: Kinetics, nontargeted identification, and concomitant toxicity evolution

Residual antiviral drugs in wastewater may increase the risk of generating transformation products (TPs) during wastewater treatment. Therefore, chlorination behavior and toxicity evolution are essential to understand the secondary ecological risk associated with their TPs. Herein, chlorination kinetics, transformation pathways, and secondary risks of ribavirin (RBV), one of the most commonly used broad-spectrum antivirals, were investigated. The pH-dependent second-order rate constants k increased from 0.18 M-1·s-1 (pH 5.8) to 1.53 M-1·s-1 (pH 8.0) due to neutral RBV and ClO- as dominant species. 12 TPs were identified using high-resolution mass spectrometry in a nontargeted approach, of which 6 TPs were reported for the first time, and their chlorination pathways were elucidated. The luminescence inhibition rate of Vibrio fischeri exposed to chlorinated RBV solution was positively correlated with initial free active chlorine, probably due to the accumulation of toxic TPs. Quantitative structure-activity relationship prediction identified 7 TPs with elevated toxicity, concentrating on developmental toxicity and bioconcentration factors, which explained the increased toxicity of chlorinated RBV. Overall, this study highlights the urgent need to minimize the discharge of toxic chlorinated TPs into aquatic environments and contributes to environmental risk control in future pandemics and regions with high consumption of antivirals.

Therapeutic Intervention of Serine Protease Inhibitors against Hepatitis C Virus

Hepatitis C virus (HCV) is a globally prevalent and hazardous disorder that is responsible for inducing several persistent and potentially fatal liver diseases. Current treatment strategies offer limited efficacy, often accompanied by severe and debilitating adverse effects. Consequently, there is an urgent and compelling need to develop novel therapeutic interventions that can provide maximum efficacy in combating HCV while minimizing the burden of adverse effects on patients. One promising target against HCV is the NS3-4A serine protease, a complex composed of two HCV-encoded proteins. This non-covalent heterodimer is crucial in the viral life cycle and has become a primary focus for therapeutic interventions. Although peginterferon, combined with ribavirin, is commonly employed for HCV treatment, its efficacy is hampered by significant adverse effects that can profoundly impact patients' quality of life. In recent years, the development of direct-acting antiviral agents (DAAs) has emerged as a breakthrough in HCV therapy. These agents exhibit remarkable potency against the virus and have demonstrated fewer adverse effects when combined with other DAAs. However, it is important to note that there is a potential for developing resistance to DAAs due to alterations in the amino acid position of the NS3-4A protease. This emphasizes the need for ongoing research to identify strategies that can minimize the emergence of resistance and ensure long-term effectiveness. While the combination of DAAs holds promise for HCV treatment, it is crucial to consider the possibility of drug-drug interactions. These interactions may occur when different DAAs are used concurrently, potentially compromising their therapeutic efficacy. Therefore, carefully evaluating and monitoring potential drug interactions are vital to optimize treatment outcomes. In the pursuit of novel therapeutic interventions for HCV, the field of computational biology and bioinformatics has emerged as a valuable tool. These advanced technologies and methodologies enable the development and design of new drugs and therapeutic agents that exhibit maximum efficacy, reduced risk of resistance, and minimal adverse effects. By leveraging computational approaches, researchers can efficiently screen and optimize potential candidates, accelerating the discovery and development of highly effective treatments for HCV, treatments.

Micro-elimination of hepatitis C in patients with chronic kidney disease: an Egyptian single-center study

Background and aims

Micro-elimination of hepatitis C in renal patients is crucial. This study aims to assess the efficacy and safety of directly acting antivirals in chronic kidney disease patients and the effect of treatment on kidney functions.

Results

This prospective cohort study included 77 chronic HCV-infected patients with chronic kidney disease. Patients were consented and treated for 12 weeks with either sofosbuvir and daclatasvir ± ribavirin if glomerular filtration rate was > 30 mL/min per 1.73m2 or ritonavir-boosted paritaprevir-ombitasvir-ribavirin if it was < 30 mL/min per 1.73m2. Patients were divided into two categories (responders versus non-responders). Predictors of response to treatment were statistically analyzed through logistic regression analysis. Sixty-two patients received ritonavir-boosted paritaprevir-ombitasvir-ribavirin, 3 received sofosbuvir and daclatasvir, and 12 received sofosbuvir and daclatasvir plus ribavirin. Most patients were on hemodialysis (n = 36) while 31 were stage 3 kidney disease. All patients completed their treatment course; ribavirin doses were adjusted or stopped in patients who developed anemia (40%). Seventy-two patients (93.5%) achieved sustained virological response 12 weeks following end-of-treatment. Five patients (6.5%) were non-responders, 4 of whom were on hemodialysis (p = 0.179). All non-responders were on ritonavir-boosted paritaprevir-ombitasvir-ribavirin. The mean serum creatinine level at weeks 4 and 8 of treatment demonstrated significant improvement compared to pretreatment values (p < 0.001) in patients on conservative therapy.

Conclusion

Treatment of chronic kidney disease patients for chronic hepatitis C with directly acting antivirals is safe, efficacious with high response rates and likely to improve renal functions if started early in the course of kidney disease.

Ritonavir Blocks Hepatitis E Virus Internalization and Clears Hepatitis E Virus In Vitro with Ribavirin

Hepatitis E virus (HEV) is increasingly recognized as the leading cause of acute hepatitis. Although HEV infections are mostly self-limiting, a chronic course can develop especially in those with immunocompromised state. Ribavirin is currently used to treat such patients. According to various reports on chronic HEV infections, a sustained virological response (SVR) was achieved in approximately 80% of patients receiving ribavirin monotherapy. To increase the SVR rate, drug combination might be a viable strategy, which we attempted in the current study. Ritonavir was identified in our previous drug screening while searching for candidate novel anti-HEV drugs. It demonstrated potent inhibition of HEV growth in cultured cells. In the present study, ritonavir blocked HEV internalization as shown through time-of-addition and immunofluorescence assays. Its combination with ribavirin significantly increased the efficiency of inhibiting HEV growth compared to that shown by ribavirin monotherapy, even in PLC/PRF/5 cells with robust HEV production, and resulted in viral clearance. Similar efficiency was seen for HEV genotypes 3 and 4, the main causes of chronic infection. The present findings provide insight concerning the advantage of combination therapy using drugs blocking different steps in the HEV life cycle (internalization and RNA replication) as a potential novel treatment strategy for chronic hepatitis E.

Real-World Outcomes of Direct-Acting Antiviral Treatment and Retreatment in United Kingdom-Based Patients Infected With Hepatitis C Virus Genotypes/Subtypes Endemic in Africa

BACKGROUND

Chronic hepatitis C virus (HCV) infection affects 71 million individuals, mostly residing in low- and middle-income countries (LMICs). Direct-acting antivirals (DAAs) give high rates of sustained virological response (SVR) in high-income countries where a restricted range of HCV genotypes/subtypes circulate.

METHODS

We studied United Kingdom-resident patients born in Africa to examine DAA effectiveness in LMICs where there is far greater breadth of HCV genotypes/subtypes. Viral genome sequences were determined from 233 patients.

RESULTS

Full-length viral genomic sequences for 26 known subtypes and 5 previously unidentified isolates covering 5 HCV genotypes were determined. From 149 patients who received DAA treatment/retreatment, the overall SVR was 93%. Treatment failure was associated primarily with 2 subtypes, gt1l and gt4r, using sofosbuvir/ledipasvir. These subtypes contain natural resistance-associated variants that likely contribute to poor efficacy with this drug combination. Treatment failure was also significantly associated with hepatocellular carcinoma.

CONCLUSIONS

DAA combinations give high SVR rates despite the high HCV diversity across the African continent except for subtypes gt1l and gt4r, which respond poorly to sofosbuvir/ledipasvir. These subtypes are widely distributed across Western, Central, and Eastern Africa. Thus, in circumstances where accurate genotyping is absent, ledipasvir and its generic compounds should not be considered as a recommended treatment option.

Three regimens for re-treatment failure of Sofosbuvir-based therapy for chronic hepatitis-C genotype-4: a cohort study

Despite the high sustained virologic response (SVR) rates of direct-acting antiviral (DAAs) therapy, a small number of patients does not eradicate the virus, and these patients represent a challenge. This study aims to compare the outcomes of three second-line regimens for DAAs-experienced patients with chronic hepatitis C (CHC). This prospective observational study was conducted at the Damanhur Viral Hepatitis Center from January 2017 to February 2020. We included patients with CHC who did not achieve SVR after the complete course of Sofosbuvir/Daclatasvir±Ribavirin (SOF/DAC±RBV). The primary endpoint was SVR-12 after re-treatment. This study included 360 patients (with a mean age of 51.53±11.38 years). Approximately 51.1% of the patients were males, and 65.5% had liver cirrhosis. All patients of group 1 (45 patients) received SOF/VEL/VOX over 12-weeks; SVR-12 was achieved in 44 patients (97.8%). Group 2 (28 patients) received SOF/DAC/RBV over 24-weeks; (one patient was lost during follow-ups and one patient discontinued treatment due to hepatic decompensation). SVR-12 was achieved in 25 patients (96.2%). Group 3 (287 patients) received SOF/Ombitasvir/Paritaprevir/Ritonavir/RBV) over 12-weeks. Eight patients were lost during follow-ups, and one patient discontinued treatment due to grade 4 adverse events. SVR-12 was achieved in 276 patients (99.3%). There was no difference between the groups regarding their age, gender distribution, baseline viral load or comorbidities. Adverse events (thrombocytopenia, anemia, hyperbilirubinaemia and prolonged INR) were significantly higher in group 3, while group 1 did not experience any. The three studied retreatment regimens can be used for DAAs treatment-experienced patients considering availability. The SOF/VEL/VOX combination had the least adverse events.

Assessment of efficacy and safety of two Egyptian protocols for treatment-experienced HCV patients: an observational study

Background

The devastating adverse effects of interferon (IFN) for the treatment of hepatitis C virus (HCV) lead to the emerging of direct acting antiviral agents (DAAs). This investigation was undertaken to assess safety and efficacy of two Egyptian DAA protocols for HCV: sofosbuvir (SOF)/daclatasvir (DCV)/simeprevir (SMV)/ribavirin (RBV) and sofosbuvir (SOF)/ombitasvir (OMB)/paritaprevir (PTV)/ritonavir (RTV)/RBV for 12 weeks in treatment-experienced HCV Egyptian patients.

Methods

It is a retrospective study where 139 patients, out of 400 patients, were divided according to their documented treatment protocol into two groups (Gp1: SOF/DCV/SMV/RBV and Gp2: SOF/PTV/OMB/RTV/RBV). All patients’ physical examination, disease history, laboratory baseline, and end of treatment data were collected from their profiles, evaluated and compared.

Results

Gp1 and Gp2 regimens had achieved sustained virologic response rates (SVR12) of 96.6% and 95.1%, respectively. Hemoglobin, ALT, and AST had decreased significantly (P < 0.05) in the two groups. Total bilirubin level had increased significantly in Gp1 and Gp2 (P = 0.002 and < 0.001, respectively). Creatinine level had increased significantly (P = 0.002) in Gp1 at end of treatment, while Gp2 remained unchanged. Headache and fatigue were the most common side effects in both protocols.

Conclusions

SOF/DCV/SMV/RBV and SOF/PTV/OMB/RTV/RBV regimens achieved high similar efficacy in Egyptian treatment-experienced HCV patients. Even though the outcome was with tolerable side effects, a better treatment regimen was recommended to abate these side effects for the welfare of Egyptian HCV patients.

High success rates for the use of ombitasvir/paritaprevir/ritonavir containing regimens in treatment of naïve and experienced chronic hepatitis C genotype 4: Real world results

INTRODUCTION AND AIMS

Treatment of hepatitis C virus (HCV) genotype 4 patient with fixed dose combination of ombitasvir-paritaprevir-ritonavir plus ribavirin (OBV/rPTV/RBV) has been proven efficacy and safety in many clinical trials. The current study reports the efficacy and safety of OBV/rPTV/RBV (for treatment-naïve), and OBV/rPTV/RBV/sofosbuvir (SOF) (for treatment-experienced), in chronic HCV genotype 4 patients in real life settings.

METHODS

Prospective cohort study including all adult chronic HCV genotype 4 patients who were scheduled to receive OBV/rPTV/RBV ± SOF for 12 or 24 weeks in New Cairo Viral Hepatitis Treatment Center. The primary efficacy endpoint was a virologic response at posttreatment week 12 (SVR12). Changes in hematological parameters, liver biochemical profile and fibrosis-4 index (FIB-4), as well as clinical and laboratory adverse events (AEs) across follow up visits (week 4, end of treatment [EOT], and SVR12), were recorded.

RESULTS

Our study included 325 patients (age; 47.63 ± 12.63 years, 55.38% [n = 180] men). Most of the included patients (89.85%, n = 292) were treatment naïve and only 7% (n = 23) had liver cirrhosis. Overall, SVR12 was attained by 98.44% (316 of 321) of the patients; 97.15% (307 of 316) of patients who received 12 weeks of OBV/rPTV/RBV ± SOF and 100% (9 of 9) of patients who received 24 weeks of OBV/rPTV/RBV as assessed by modified intention to treat analysis. There was a significant improvement of baseline alanine aminotransferase, aspartate aminotransferase, hemoglobin, FIB-4 at SVR12 (P < 0.05). The most common reported AEs were anemia (n = 106), fatigue (n = 41) and elevated indirect bilirubin (n = 37).

CONCLUSION

OBV/rPTV/RBV (±SOF) is a highly effective therapy for chronic HCV patients in real life settings.

Five-Year Follow-Up of Cured HCV Patients under Real-World Interferon-Free Therapy

(1) Background: Treatment of hepatitis C virus (HCV) infections with direct-acting antivirals (DAA) has demonstrated high efficacy and an excellent safety profile. The cured patients showed a sustained virological response and improved liver function, but also a continued risk of hepatocellular carcinoma (HCC) during the 2-3 years of follow-up after treatment; (2) Methods: A total of 192 patients out of 209 of the primary AMBER study were analyzed five years after treatment with ombitasvir/paritaprevir/ritonavir with or without dasabuvir and with or without ribavirin. Results: We confirmed that HCV clearance after DAA treatment is stable regardless of baseline liver fibrosis. We found that sustained virologic response is associated with a gradual but significant reduction in liver stiffness over 5 years. Liver function improved during the first 2 years of follow-up and remained stable thereafter. The risk of death due to HCC as well as death due to HCV persists through 5 years of follow-up after successful DAA treatment. However, in non-cirrhotic patients, it appears to clear up 3 years after treatment; (3) Conclusions: Monitoring for more than 5 years after curing HCV infection is necessary to assess the long-term risk of possible development of HCC, especially in patients with cirrhosis of the liver.

Effectiveness of Direct-Acting Antivirals in Treatment of Elderly Egyptian Chronic Hepatitis C Patients

Background: Hepatitis C virus treatment has dramatically improved by direct-acting antiviral (DAA) therapy. The aim of this study was to assess the efficacy and safety of DAA in elderly Egyptian chronic hepatitis C (CHC) patients. Methods: The study was carried out on 327 CHC elderly patients >60 years; patients were divided into 3 age subgroups (<65, 65–75 and >75 years) on DAA therapy for 12 weeks. Ninety-one patients (27.8%) were treated with dual therapy, 234 patients (71.6%) with triple therapy and 2 patients (0.6%) with quadrable therapy. Results: All patients achieved end-of-treatment virological response (100%). ALT levels normalized during therapy. The follow-up rate of sustained virological response at 12 weeks after the end of treatment (SVR12) was 100%. One hundred and two patients had missed SVR12 data due to being lost tofollow-up. Two hundred twenty-two adverse events were reported (67.8%), including anemia in 30 patients (9.1%), leucopenia in 129 patients (39.4%) and thrombocytopenia in 63 patients (19.2%). No serious side effects led to discontinuation of therapy. No hepatic decompensation was observed, and no patients died. Conclusion: Age does not influence the success of DAA treatment and all DAA regimens are well tolerated, safe and highly efficacious, even in those aged 75 years or older.

Efficacy and Safety of Ombitasvir plus Paritaprevir, Ritonavir and Ribavirin in Non-cirrhotic Treatment-naïve and Treatment-experienced Egyptians with Chronic HCV Genotype-4 Infection

Hepatitis C virus genotype 4 (HCV-GT4) is a risk factor for cirrhosis, hepatocellular carcinoma and liver failure. A combination of three new direct-acting antivirals ombitasvir, paritaprevir, and ritonavir has been recommended for treatment of HCV-GT4 infection. The current study was aimed to assess the efficacy and safety of this combination plus ribavirin in non-cirrhotic, treatment-naïve and -experienced Egyptians with HCV-GT4 infection in a real-world setting. A total of 255 Egyptians with HCV-GT4 infection were enrolled, including 82 treatment-experienced and 173 treatment-naïve patients. All of them completed 12-week treatment protocol of ombitasvir, paritaprevir and ritonavir as an oral dose combination with ribavirin. Virological response (VR) was measured, as well as the biochemical parameters related to treatment efficacy and adverse events at baseline and after treatment, at 4 (VR4) and 12 (VR12) weeks post-treatment. The results showed that the VR4 rates were 98.8% in both groups, and VR12 rates were 97.7% and 96.3% in treatment-naïve and -experienced patients, respectively, with no significant differences found between the groups concerning VR4 (P=0.9) and VR12 (P=0.3). The most common adverse events were headache and fatigue, which were significantly more common (P=0.001 and 0.003, respectively) in treatment-experienced than in treatment-naïve group. The quadruple regimen was well-tolerated, and the reported adverse events were generally mild to moderate. This real-world setting study confirms that the combination of ombitasvir, paritaprevir, ritonavir, and ribavirin is highly effective in the treatment of HCV- GT4 infection with a good safety and tolerability profile.

Treatment of hepatitis C virus infection with direct-acting antivirals plus ribavirin eliminates viral RNA from peripheral blood mononuclear cells and reduces virologic relapse in diverse hepatic parenchymal changes

Elimination of hepatitis C virus (HCV) may fail, leading to a non-response outcome because of inappropriate testing for viral RNA in peripheral blood mononuclear cells (PBMCs). Sequelae of HCV genotype 4 therapy with sofosbuvir and daclatasvir ± ribavirin were assessed in our study at the 12^th week after end of treatment (EOT) by screening for viral genomic RNA in serum and PBMCs with correlation to hepatic parenchymal changes. We recruited 102 out of 2165 patients who had received sofosbuvir/daclatasvir, either alone (n = 1573) or together with ribavirin (n = 592). Subjects were classified into three groups based on testing by single-step reverse transcription PCR: group I, HCV negative in both serum and PBMCs (n = 25); group II, HCV positive in PBMCs only (n = 52); and group III, HCV positive in both serum and PBMCs (n = 25). Groups I and II (n = 77) were selected out of 2102 (every 27^th subject), while group III (n = 25) were selected from every second or third serologic relapse (n = 63). The pre-sampling population (n = 2165) showed sustained virologic response (SVR) in 33.21%; serologic relapse in 2.91%; HCV RNA only in PBMCs (66.79%) compared to serologic relapses and potential cure (P < 0.0001); higher serologic (38 out of 63, P = 0.03210) and cellular (36 out of 52, P = 0.0002) relapses in dual therapy than in triple therapy. The post-sampling population (n = 102) showed more HCV relapses in dual (50 out of 60) than in triple (27 out of 42) therapy (P = 0.0351); increased HCV antisense RNA strand in relapses compared to positive-sense strands alone (P < 0.001); and significant SVR events in undetectable (15 out of 31) compared to early (10 out of 55, P = 0.0058) and cirrhotic liver tissue changes (0 out of 16, P = 0.0006). In summary, HCV treatment with sofosbuvir/daclatasvir is followed by higher rates of serologic and intracellular viral RNA relapse than treatment with sofosbuvir/daclatasvir plus ribavirin. Cellular and serum viral RNA relapses are accompanied by HCV-induced hepatic pathology. An increased SVR with no detectable liver tissue changes was observed after triple therapy due to elimination of HCV RNA from PBMCs.

Multi-factorial pharmacokinetic interactions: unraveling complexities in precision drug therapy

Introduction: Precision drug therapy requires accounting for pertinent factors in pharmacokinetic (PK) inter-individual variability (i.e., pharmacogenetics, diseases, polypharmacy, and natural product use) that can cause sub-therapeutic or adverse effects. Although each of these individual factors can alter victim drug PK, multi-factorial interactions can cause additive, synergistic, or opposing effects. Determining the magnitude and direction of these complex multi-factorial effects requires understanding the rate-limiting redundant and/or sequential PK processes for each drug.Areas covered: Perturbations in drug-metabolizing enzymes and/or transporters are integral to single- and multi-factorial PK interactions. Examples of single factor PK interactions presented include gene-drug (pharmacogenetic), disease-drug, drug-drug, and natural product-drug interactions. Examples of multi-factorial PK interactions presented include drug-gene-drug, natural product-gene-drug, gene-gene-drug, disease-natural product-drug, and disease-gene-drug interactions. Clear interpretation of multi-factorial interactions can be complicated by study design, complexity in victim drug PK, and incomplete mechanistic understanding of victim drug PK.Expert opinion: Incorporation of complex multi-factorial PK interactions into precision drug therapy requires advances in clinical decision tools, intentional PK study designs, drug-metabolizing enzyme and transporter fractional contribution determinations, systems and computational approaches (e.g., physiologically-based pharmacokinetic modeling), and PK phenotyping of progressive diseases.

Resistance-associated substitutions in patients with chronic hepatitis C virus genotype 4 infection

Data on the prevalence of resistance-associated substitutions (RASs) and their implications for treatment with direct-acting antivirals (DAAs) are sparse in European patients with HCV genotype 4. This study investigated RASs before and after DAA failure in different genotype 4 subtypes and evaluated retreatment efficacies. Samples of 195 genotype 4-infected patients were collected in the European Resistance Database and investigated for NS3, NS5A and NS5B RASs. Retreatment efficacies in DAA failure patients were analysed retrospectively. After NS5A inhibitor (NS5Ai) failure, subtype 4r was frequent (30%) compared to DAA-naïve patients (5%) and the number of NS5A RASs was significantly higher in subtype 4r compared to 4a or 4d (median three RASs vs no or one RAS, respectively, P < .0001). RASsL28V, L30R and M31L pre-existed in subtype 4r and were maintained after NS5Ai failure. Typical subtype 4r RASs were located in subdomain 1a of NS5A, close to membrane interaction and protein-protein interaction sites that are responsible for multimerization and hence viral replication. Retreatment of 37 DAA failure patients was highly effective with 100% SVR in prior SOF/RBV, PI/SOF and PI/NS5Ai failures. Secondary virologic failures were rare (n = 2; subtype 4d and 4r) and only observed in prior NS5Ai/SOF failures (SVR 90%). In conclusion, subtype 4r harboured considerably more RASs compared to other subtypes. A resistance-tailored retreatment using first- and second-generation DAAs was highly effective with SVR rates ≥90% across all subtypes and first-line treatment regimens.

Development and Validation of a New LC-MS/MS Analytical Method for Direct-Acting Antivirals and Its Application in End-Stage Renal Disease Patients

BACKGROUND AND OBJECTIVE

The effectiveness of direct-acting antivirals (DAAs) is not well established in end-stage renal disease (ESRD) patients. Assessment of the plasma concentrations may support understanding of their therapeutic outcomes in this population. The aim of this study is to develop a direct, yet matrix-effect tolerant, analytical method for determining DAAs in the plasma of ESRD patients while maintaining a moderate cost per sample and with an improved analyte extraction recovery.

METHODS

In this study, a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the analysis of ombitasvir (OMB), paritaprevir (PRT) and ritonavir (RIT) in plasma. Sample preparation was performed using the liquid-liquid extraction (LLE) method. Isocratic separation was performed using a mixture of methanol and 10 mM ammonium acetate (79:21, v/v) followed by MS/MS detection. The method was validated and applied to determine DAAs in the plasma of ESRD patients (n = 7).

RESULTS

The developed method was linear (r²> 0.995), accurate (89.4 ± 7.8 to 108.3 ± 3.0) and precise (% CV 0.9-15.0) and showed improved recovery (> 80) over previously published ones in the range 5-250, 30-1,500, 20-1,000 ng/mL for OMB, PRT and RIT, respectively. Relative matrix effect was absent, and the method accurately determined the three DAAs in real-life samples (n = 7).

CONCLUSIONS

An efficient analytical method for the determination of DAAs is presented. The method overcomes the potential analytical response fluctuation in ESRD. The developed method show improved extraction recoveries and is suitable for routine application in developing economies where hepatitis C virus is most prevalent.

Hepatitis C genotype 4: A report on resistance-associated substitutions in NS3, NS5A, and NS5B genes

AUTHOR CONTRIBUTION

FN performed the literature review and wrote the manuscript; STZ coauthored, edited, and reviewed the manuscript.

ABSTRACT

Treatment response in Hepatitis C virus (HCV) has generated varied effects in patients. Recently, nonresponsive and relapse patients related to host and genotype variabilities have been reported in clinical trials. However, these trials included minimal sample sizes of patients with genotype 4, the most prevalent genotype in Egypt and the Middle East, compared with genotypes 1 and 2. The genetic variabilities that have been detected within the HCV genes, especially the ones associated with genotype 4, and are linked to treatment response, will be the focus of this review with emphasis on direct acting antiviral agents. In addition, the major studies and clinical trials performed globally and their inclusivity of genotype 4 are reported. This review also delineates future study areas and missing data that need further investigation when it comes to genotype 4.

2020 Taiwan consensus statement on the management of hepatitis C: part (I) general population

Hepatitis C virus (HCV) infection remains a major public health issue with high prevalence in Taiwan. Recently, the advent of direct-acting antiviral (DAA) agents, with higher efficacy, excellent safety profile, and truncated treatment duration, has revolutionized the paradigm of hepatitis C treatment and made HCV elimination possible. To provide timely guidance for optimal hepatitis C management, the Taiwan Association for the Study of the Liver (TASL) established an expert panel to publish a 2-part consensus statement on the management of hepatitis C in the DAA era. After comprehensive literature review and a consensus meeting, patient-oriented, genotype-guided recommendations on hepatitis C treatment for the general and special populations have been provided based on the latest indications and scientific evidence. In the first part of this consensus, we present the epidemiology and treatment situation of hepatitis C in Taiwan, the development of DAA, pre-treatment evaluation, post sustained virologic response (SVR) monitoring, and most importantly the treatment recommendations for the general population with compensated liver disease. The second part will focus on the treatment recommendations for the special populations.

Real-world efficacy, safety, and clinical outcomes of ombitasvir/paritaprevir/ritonavir ± dasabuvir ± ribavirin combination therapy in patients with hepatitis C virus genotype 1 or 4 infection: The Turkey experience experience

BACKGROUND/AIMS

mbitasvir/paritaprevir/ritonavir (OMV/PTV/r) ± dasabuvir (DSV) ± ribavirin (RBV) combination has demonstrated excellent rates of sustained virologic response (SVR) and a very good safety profile in patients with the chronic hepatitis C virus (HCV) genotype 1 or 4 infections. We aimed to investigate the effectiveness and safety of OMV/PTV/r ± DSV ± RBV combination regimen in a real-world clinical practice.

MATERIALS AND METHODS

Data from HCV genotype 1 and 4 patients treated with OMV/PTV/r ± DSV ± RBV (n=862) in 34 centers across Turkey between April 1, 2017 and August 31, 2018 were recorded in a large national database. Demographic, clinical, and virologic data were analyzed.

RESULTS

The mean age of the patients was 55.63, and 430 patients (49.9%) were male. The majority had HCV genotype 1b infection (77.3%), and 66.2% were treatment-naïve. Non-cirrhosis was present at baseline in 789 patients (91.5%). SVR12 rate was 99.1% in all patients. Seven patients had virologic failure. No significant differences were observed in SVR12 according to HCV genotypes. HCV RNA was undetectable at treatment week 4 in 90.9%, at treatment week 8 in 98.5%, and at the end of treatment (EOT) in 98.9%. SVR12 ratio was significantly higher in the non-cirrhotic patients compared to that in the compensated cirrhotic patients. Rates of adverse events (AEs) in the patients was 59.7%.

CONCLUSION

The present real-life data of Turkey for the OBV/PTV/r ± DSV ± RBV treatment of patients with HCV genotype 1b, 1a, or 4 infection from 862 patients demonstrated high efficacy and a safety profile.

Screening for Hepatitis C Virus Infection in Adolescents and Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

A 2013 review for the US Preventive Services Task Force (USPSTF) of hepatitis C virus (HCV) screening found interferon-based antiviral therapy associated with increased likelihood of sustained virologic response (SVR) and an association between achieving an SVR and improved clinical outcomes. New direct-acting antiviral (DAA) regimens are available.

OBJECTIVE

To update the 2013 review on HCV screening to inform the USPSTF.

DATA SOURCES

Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews through February 2019, with surveillance through September 2019.

STUDY SELECTION

Randomized clinical trials (RCTs) and nonrandomized treatment studies of HCV screening and DAA therapy; cohort studies on screening, antiviral therapy, and the association between an SVR after antiviral therapy and clinical outcomes.

DATA EXTRACTION AND SYNTHESIS

One investigator abstracted data; a second checked accuracy. Two investigators independently rated study quality.

MAIN OUTCOMES AND MEASURES

Mortality, morbidity, quality of life, screening and treatment harms, and screening diagnostic yield.

RESULTS

Eight RCTs of DAA therapy vs placebo or an outdated antiviral regimen, 48 other treatment studies, and 33 cohort studies, with a total of 179 230 participants, were included. No study evaluated effects of HCV screening vs no screening. One new study since the 2013 review (n = 5917) found similar diagnostic yield of risk-based screening (sensitivity, 82%; number needed to screen to identify 1 HCV case, 15) and birth cohort screening (sensitivity, 76%; number needed to screen, 29), assuming perfect implementation. Ten open-label studies (n = 3292) reported small improvements in some quality-of-life and functional outcomes (eg, less than 3 points on the 0 to 100 36-Item Short Form Health Survey physical and mental component summary scales) after DAA treatment compared with before treatment. Two cohort studies (n = 24 686) found inconsistent associations of antiviral therapy vs no therapy with risk of hepatocellular carcinoma. Forty-nine treatment studies (n = 10 181) found DAA regimens associated with pooled SVR rates greater than 95% across genotypes, and low short-term rates of serious adverse events (1.9%) and withdrawal due to adverse events (0.4%). An SVR after antiviral therapy was associated with decreased adjusted risk of all-cause mortality (13 studies, n = 36 986; pooled hazard ratio [HR], 0.40 [95% CI, 0.28-0.56) and hepatocellular carcinoma (20 studies, n = 84 491; pooled HR, 0.29 [95% CI, 0.23 to 0.38]) vs no SVR.

CONCLUSIONS AND RELEVANCE

Direct evidence on the effects of HCV screening on clinical outcomes remains unavailable, but DAA regimens were associated with SVR rates greater than 5% and few short-term harms relative to older antiviral therapies. An SVR after antiviral therapy was associated with improved clinical outcomes compared with no SVR.

Safety, efficacy and cost of two direct-acting antiviral regimens: A comparative study in chronic hepatitis C Egyptian patients

WHAT IS KNOWN AND OBJECTIVE

Direct-acting antivirals (DAAs) have become the most widely used treatment of chronic hepatitis C infection. Comparative studies on DAAs regimens approved by the Egyptian Ministry of Health for easy-to-treat genotype 4 (G4) Egyptian patients are still deficient. In this prospective study, we compared the efficacy and cost of two DAA regimens that are used in the treatment of Egyptian chronic hepatitis C virus (HCV) G4. The cost-saving regimen is determined.

METHODS

Eligible patients were randomized into 2 groups. Group 1 (Gp 1) received sofosbuvir plus daclatasvir, and group 2 (Gp 2) received ombitasvir, paritaprevir and ritonavir plus ribavirin (RBV) for 12 weeks. Data were collected and evaluated at baseline and at weeks 4, 8 and 12. Sustained virologic response 12 weeks after the end of treatment (SVR₁₂ ) was evaluated. Cost-minimization analysis (CMA) was performed.

RESULTS AND DISCUSSION

Eligibility was achieved in 107 patients, Gp1 included 57 patients, and Gp 2 included 50 patients. Two patients dropped out from Gp 2 due to non-compliance. All patients in the two groups showed negative HCV blood levels at the end of treatment. At the 24th week, 3 relapsers (5.2%) were detected in Gp1 and 2 relapsers (4.1%) were detected in Gp 2. SVR₁₂ was 54/57 (94.7%) and 46/48 (95.8%) for Gp 1 and Gp 2, respectively. After the 12th week of treatment, a significant decrease in aspartate aminotransferase (AST), alanine aminotransferase (ALT) and haemoglobin levels were observed in both groups. Albumin levels declined in Gp 2 only. CMA showed higher cost in Gp 2 than Gp 1, although similar efficacy and safety.

WHAT IS NEW AND CONCLUSION

The two DAA regimens showed high SVR₁₂ and safety in Egyptian HCV G4 patients. Sofosbuvir plus daclatasvir is the cost-saving regimen.

Overview of hepatitis C infection, molecular biology, and new treatment

The World Health Organization estimates that 71 million people worldwide have chronic hepatitis C viral infection. A major challenge is overall lack of public awareness of hepatitis C, particularly among infected people of their infection status. Chronic hepatitis C infection is associated with advanced liver disease, is the main cause of hepatocellular carcinoma and causes many extra-hepatic manifestations. The existence of seven viral genotypes complicates targeting of treatment. Recent years have seen the approval of many direct acting antivirals targeted at hepatitis C virus non-structural proteins. These have revolutionized therapy as they allow achievement of extremely high sustained virologic responses. Of great significance is the development of pan-genotypic drug combinations, including the NS3/4A-NS5A inhibitor combinations sofosbuvir-velpatasvir and glecaprevir-pibrentasvir. However, resistance-associated mutations can result in failure of these treatments in a small number of patients. This, combined with the high costs of treatment, highlights the importance of continued research into effective anti-hepatitis C therapies, for example aimed at viral entry. Recent developments include identification of the potential of low-cost anti-histamines for repurposing as inhibitors of hepatitis C viral entry. In this review we focus on molecular biology of hepatitis C virus, and the new developments in hepatitis C treatment.

Direct-Acting Antiviral Therapy for Hepatitis C Infection in a Large Immigrant Community

Hepatitis C treatment has rapidly evolved with the arrival of direct-acting antiviral therapy. Sustained virologic response (SVR) rates in clinical trials are high but it is unknown how this translates to the immigrant community. Data from December 2013 to September 2015 was collected from a Midwest academic and community practice with a large immigrant population. There were 802 patients with an overall SVR rate of 88%. Ledipasvir/sofosbuvir was associated with favorable response among genotype 1 and 4 patients compared to other regimens (p < 0.001 and p = 0.05). Factors associated with treatment failure included advanced liver disease, male gender, East African/Middle Eastern ethnicity, and non-compliance. Patients with genotype 4 had lower SVR rates than other genotypes (58% vs. 89%, p < 0.001), particularly among East Africans (40% vs. 82% for other ethnicities). Our SVR rate for genotype 4 infection is lower than clinical trials and may be related to cultural, biologic and socioeconomic factors.

Real-world evidence of the effectiveness of ombitasvir-paritaprevir/r ± dasabuvir ± ribavirin in patients monoinfected with chronic hepatitis C or coinfected with human immunodeficiency virus-1 in Spain

Aim

We describe the effectiveness and safety of the interferon-free regimen ombitasvir/paritaprevir/ritonavir plus dasabuvir with or without ribavirin (OBV/PTV/r ± DSV ± RBV) in a nationwide representative sample of the hepatitis C virus (HCV) monoinfected and human immunodeficiency virus-1/hepatitis C virus (HIV/HCV) coinfected population in Spain.

Material and methods

Data were collected from patients infected with HCV genotypes 1 or 4, with or without HIV-1 coinfection, treated with OBV/PTV/r ± DSV ± RBV at 61 Spanish sites within the initial implementation year of the first government-driven “National HCV plan.” Effectiveness was assessed by sustained virologic response at post-treatment week 12 (SVR12) and compared between monoinfected and coinfected patients using a non-inferiority margin of 5% and a 90% confidence interval (CI). Sociodemographic and clinical characteristics or patients and adverse events (AEs) were also recorded.

Results

Overall, 2,408 patients were included in the intention-to-treat analysis: 386 (16%) were patients with HIV/HCV. Patient selection reflected the real distribution of patients treated in each participating region in Spain. From the total population, 96.6% (95% CI, 95.8–97.3%) achieved SVR12. Noninferiority of SVR12 in coinfected patients was met, with a difference between monoinfected and coinfected patients of −2.2% (90% CI, −4.5% - 0.2%). Only genotype 4 was associated with non-response to OBV/PTV/r ± DSV ± RBV treatment (p<0.001) in the multivariate analysis. Overall, 286 patients (11.9%) presented AEs potentially related to OBV/PTV/r ± DSV, whereas 347 (29.0%) presented AEs potentially related to ribavirin and 61 (5.1%) interrupted ribavirin.

Conclusions

Our results confirm that OBV/PTV/r ± DSV ± RBV is effective and generally well tolerated in a representative sample of the HCV monoinfected and HCV/HIV coinfected population in Spain within the experience of a national strategic plan to tackle HCV.

Citius, Altius, Fortius: The New Paradigm in the Treatment of Chronic Hepatitis C Disease

With the advent of the direct-acting antiviral agents (DAAs) for chronic hepatitis C infection, the treatment paradigm has dramatically changed, especially the duration, tolerability, and response to therapy. The DAAs fall into several classes and are variously indicated in the treatment of one or more genotypes of infection. All these agents are orally administered and, as they are largely renally eliminated (with exceptions), do not require adjustment in mild to moderate renal insufficiency. Most of these agents demonstrate a high barrier to resistance and are extremely well-tolerated by patients. Overall efficacy rates are ≥90%.

High rate of acute kidney injury in patients with chronic kidney disease and hepatitis C virus genotype 4 treated with direct-acting antiviral agents

BACKGROUND

Direct-acting antivirals (DAAs) have significantly improved the efficacy and safety of treating chronic hepatitis C (CHC), but their effectiveness and safety among patients with chronic kidney disease (CKD) remains poorly understood. Sofosbuvir/daclatasvir regimen is supposed to be used for patients with creatinine clearance more than 30 mL/min, while ombitasvir/paritaprevir/ritonavir regimen is used for patients with creatinine clearance less than 30 mL/min.

AIM

The aim of the study was to assess the safety and efficacy of DAAs among patients with CKD.

METHODS

Eighteen CKD stage 2-3b patients received sofosbuvir for 3 months. In addition, 42 CKD stage-4 patients received ritonavir-boosted paritaprevir plus ombitasvir for 3 months. Finally, ribavirin was added for 30 of them.

RESULTS

The patients'age was 49.2 ± 12 years. Baseline serum creatinine was 3.76 ± 1.67 mg/dL. Fifty patients were HCV genotype 4. A 3-month sustained viral response was achieved in 56 patients and 49 patients achieved a 6-month viral response. There were 11 relapsers. Acute kidney injury (AKI) upon CKD (AKI/CKD) occurred in 28 patients, of which 20 needed hemodialysis. Fifteen/28 recovered from AKI, whereas 13 were maintained on hemodialysis. In multivariate analysis, there were only two independent risk factors for developing AKI/CKD, i.e., being cirrhotic as defined by baseline abdominal ultrasound findings [odds ratio 4.15 (1.33-12.97); p = 0.013] and having had as DAA therapy OMV/PTV/RTV [odds ratio 7.35 (1.84-29.35); p = 0.001].

CONCLUSION

Treatment of HCV among stage 2, 3a, and 3b patients was achieved safely with a sofosbuvir-based regimen. We recommend that stage-4 patients wait until starting hemodialysis or transplantation.

Treatment optimisation for hepatitis C in the era of combination direct-acting antiviral therapy: a systematic review and meta-analysis

Background: Prior to direct-acting antiviral (DAA) therapy, personalised medicine played an important role in the treatment of hepatitis C virus (HCV). Whilst simplified treatment strategies are central to treatment scale-up, some patients will benefit from treatment optimisation. This systematic review and meta-analysis explores treatment optimisation strategies in the DAA era. Methods: We systematically searched Medline, Embase, and Web of Science for studies that adopted a stratified or personalised strategy using a licensed combination DAA regimen, alone or with additional agents. We performed a thematic analysis to classify optimisation strategies and a meta-analysis of sustained virologic response rates (SVR), exploring heterogeneity with subgroup analyses and meta-regression. Results: We included 64 studies (9450 participants). Thematic analysis found evidence of three approaches: duration, combination, and/or dose optimisation. We separated strategies into those aiming to maintain SVR in the absence of predictors of failure, and those aiming to improve SVR in the presence of predictors of failure. Shortened duration regimens achieve pooled SVR rates of 94.2% (92.3-95.9%) for 8 weeks, 81.1% (75.1-86.6%) for 6 weeks, and 63.1% (39.9-83.7%) for ≤4 weeks. Personalised strategies (100% vs 87.6%; p<0.001) and therapy shortened according to ≥3 host/viral factors (92.9% vs 81.4% or 87.2% for 1 or 2 host/viral factors, respectively; p=0.008) offer higher SVR rates when shortening therapy. Hard-to-treat HCV genotype 3 patients suffer lower SVR rates despite treatment optimisation (92.6% vs 98.2%; p=0.001). Conclusions: Treatment optimisation for individuals with multiple predictors of treatment failure can offer high SVR rates. More evidence is needed to identify with confidence those individuals in whom SVR can be achieved with shortened duration treatment.

FDA Breakthrough Therapy Designation: Evaluating the Quality of the Evidence behind the Drug Approvals

The United States Food and Drug Administration (FDA) has created approval pathways and designations to accelerate access to medications indicated for serious or life-threatening conditions with limited treatment options. Implemented in 2012, the most recent of these is the breakthrough therapy designation (BTD). The purpose of this article was to review the evidence surrounding approval of medications with nononcology indications approved with the BTD designation from 2012 to 2016. Fifteen medications were identified for eight conditions, ranging from conditions that are relatively common, such as chronic hepatitis C infection, to those that are extremely rare, such as lysosomal acid lipase deficiency. The quality of evidence behind these approvals was highly heterogeneous. Much remains unknown about the safety and efficacy of many agents approved through the BTD. Health care professionals should be aware of these limitations to better educate patients and other providers appropriately.

Real-world safety and effectiveness of ombitasvir/paritaprevir/ritonavir ± dasabuvir ± ribavirin in hepatitis C virus genotype 1- and 4-infected patients with diverse comorbidities and comedications: A pooled analysis of post-marketing observational studies from 13 countries

Ombitasvir/paritaprevir/ritonavir ± dasabuvir ± ribavirin (OBV/PTV/r ± DSV ± RBV) regimens show high efficacy and good tolerability in clinical trials for chronic hepatitis C virus (HCV) genotypes (GT) 1 or 4. To evaluate whether these results translate to clinical practice, data were pooled from observational studies across 13 countries. Treatment-naïve or -experienced patients, with or without cirrhosis, received OBV/PTV/r ± DSV ± RBV according to approved local labels and clinical practice. Sustained virologic response at post-treatment Week 12 (SVR12), adverse events (AEs) and comedication management were assessed for patients initiating treatment before 1 June 2017. The safety population included 3850 patients who received ≥1 dose of study drug. The core population (N = 3808) further excluded patients with unknown GT or cirrhosis status, or who received off-label treatment. Patients had HCV GT1a (n = 732; 19%), GT1b (n = 2619; 69%) or GT4 (n = 457; 12%). In 3546 patients with sufficient follow-up data at post-treatment Week 12, the SVR12 rate was 96% (n/N = 3401/3546 [95% CI 95.2-96.5]). In patients with or without cirrhosis, SVR12 was comparable (96%). In patients with HCV GT1a, GT1b or GT4, SVR12 rates were 93%, 97% and 94%. In GT1b-infected patients with planned treatment for 8 weeks, SVR12 was 96%. In patients with ≥1 comorbidity (67%), SVR12 was 95%. 58% of patients received ≥1 comedication, and there was minimal impact on SVR12 rates using comedications for peptic ulcers and gastro-esophageal reflux disease, statins, antipsychotics or antiepileptics. Most comedications were maintained during treatment although 58% of patients changed their statin medication. AEs and serious AEs occurred in 26% and 3% of patients. Post-baseline Grade 3-4 laboratory abnormalities were rare (<3%), and discontinuation rates were low (<4%). Real-world evidence confirms the effectiveness of OBV/PTV/r ± DSV ± RBV in patients with HCV GT1 or GT4, regardless of common comorbidities or comedications, and is consistent with clinical trial results. Adverse safety outcomes may be limited by underreporting in the real-world setting.

Ledipasvir/sofosbuvir with or without ribavirin for 8 or 12 weeks for the treatment of HCV genotype 4 infection: results from a randomised phase III study in Egypt

OBJECTIVE

We evaluated the efficacy and safety of ledipasvir/sofosbuvir alone and with ribavirin for 8 and 12 weeks in Egyptian patients with and without cirrhosis, who were infected with hepatitis C virus (HCV) genotype 4, including those who had failed previous treatment with sofosbuvir regimens.

DESIGN

In this open-label, multicentre, phase III study, treatment-naive patients were randomised to receive 8 or 12 weeks of ledipasvir/sofosbuvir±ribavirin. Interferon treatment-experienced patients were randomised to receive 12 weeks of ledipasvir/sofosbuvir±ribavirin, while sofosbuvir-experienced or ledipasvir/sofosbuvir-experienced patients received 12 weeks of ledipasvir/sofosbuvir+ribavirin. Randomisation was stratified by cirrhosis status. The primary endpoint was sustained virological response 12 weeks post-treatment (SVR12).

RESULTS

We enrolled 255 patients from four centres in Egypt. Among treatment-naive patients, SVR12 rates were 95% and 90% for those receiving 8 weeks of ledipasvir/sofosbuvir alone and with ribavirin, respectively, and 98% for those receiving 12 weeks of ledipasvir/sofosbuvir both alone and with ribavirin. Among interferon-experienced patients, SVR rates were 94% for those receiving 12 weeks of ledipasvir/sofosbuvir and 100% for those receiving 12 weeks of ledipasvir/sofosbuvir plus ribavirin. All patients previously treated with sofosbuvir regimens who received ledipasvir/sofosbuvir plus ribavirin achieved SVR12. The most common adverse events, headache and fatigue, were more common among patients receiving ribavirin.

CONCLUSION

Among non-cirrhotic treatment-naive patients with HCV genotype 4, 8 weeks of ledipasvir/sofosbuvir±ribavirin was highly effective. Twelve weeks of ledipasvir/sofosbuvir±ribavirin was highly effective regardless of presence of cirrhosis or prior treatment experience, including previous treatment with sofosbuvir or ledipasvir/sofosbuvir.

TRIAL REGISTRATION NUMBER

NCT02487030.

Direct-acting antiviral therapy for chronic hepatitis C virus genotype 4 infection: Exploring new regimens

The optimal antiviral regimen for hepatitis C virus (HCV) genotype 4 is still a subject of investigation. The report in this issue of Health Science Reports by Asselah and colleagues investigated the additional benefit of extending treatment duration of the ombitasvir/paritaprevir/ritonavir plus ribavirin regimen to up to 24 weeks for patients with HCV genotype 4 and compensated cirrhosis.

Ombitasvir/paritaprevir/ritonavir plus ribavirin for 24 weeks in patients with HCV GT4 and compensated cirrhosis (AGATE-I Part II)

BACKGROUND AND AIMS

AGATE-I Part I previously reported high sustained virologic response rates in hepatitis C genotype 4 patients with cirrhosis, with 12 and 16 weeks' treatment with a combination of two direct-acting antivirals, ombitasvir and paritaprevir (codosed with ritonavir), plus ribavirin. Part II, reported here, extended the trial to include a 24-week treatment arm to fully assess treatment duration in patients with chronic hepatitis C genotype 4 infection and compensated cirrhosis.

METHODS

Enrollment took place between June and November of 2015. Treatment-naive and interferon-experienced patients with chronic hepatitis C genotype 4 infection and compensated cirrhosis were enrolled into Arm C; patients previously treated with a sofosbuvir-based regimen were enrolled into Arm D. All patients received a 24-week treatment with ombitasvir, paritaprevir, and ritonavir plus ribavirin. The primary outcome was the proportion of patients with a sustained virologic response (hepatitis C virus RNA < 25 IU/mL) at posttreatment week 12 in the intention-to-treat population. The safety population included all patients who received at least one dose of study drug.

RESULTS

In total, 64 patients were enrolled into AGATE-I Part II. Sustained virologic response at posttreatment week 12 was achieved in 57 of 61 patients (93.4%; 97.5% confidence interval, 92.6-97.7) in Arm C and 3 of 3 patients (100%) in Arm D. Two patients were missing SVR12 data, and two prematurely discontinued treatment. The most common adverse events for Arm C were fatigue (16 [26%]) and asthenia (15 [25%]). Results were comparable with those reported in Part I.

CONCLUSIONS

AGATE-I Part II indicates that extending treatment beyond 12 weeks in genotype 4-infected patients with compensated cirrhosis does not offer additional benefit.

Efficacy of ombitasvir/paritaprevir/ritonavir/ribavirin in management of HCV genotype 4 and end-stage kidney disease

BACKGROUND

Till now, pooled data about the safety and efficacy of different direct-acting antiviral (DAAs) regimens in different renal situations are still under evaluation.

AIM

To evaluate a real-life experience of the efficacy and safety of ombitasvir/paritaprevir/ritonavir plus ribavirin (OBV/PTV/r plus RIB) in patients with end-stage kidney disease (ESKD).

PATIENTS AND METHODS

Between January 2017 and January 2018, an open-label multicenter prospective study was designed to enroll all consecutive patients with proven CHC genotype 4 infections and concomitant ESKD based on estimated glomerular filtration rate (eGFR) with (HD group) or without hemodialysis (non-HD group). Patients were given a co-formula of OBV/PTV/r (25/150/100 mg) once-daily plus RIB was given for 12 weeks. Sustained virologic response (SVR 12) was the primary endpoint.

RESULTS

A total of 110 patients were enrolled. An overall SVR 12 was reported in 104 (94.5%) patients, and treatment failure were reported in 6 patients [2 patients (1.8%) were relapsed, and 4 patients (3.6%) patients were non-responders]. SVR12 was 96% in HD and 91.4% in non-HD patients (P = 0.286). There were no reported serious adverse events. Anemia was reported in 66.6% (n = 50) in HD group and in 31.4% (n = 11) in non-HD group.

CONCLUSION

Although it is still challenging, achievement of SVR12 in patients with chronic HCV and concomitant end-stage kidney disease in the era of DAAs became possible with a 12 weeks course of a co-formula of ombitasvir/paritaprevir /ritonavir plus ribavirin. CLINICALTRIALS.

GOV ID

NCT03341988.

Frequent Antiviral Treatment Failures in Patients Infected With Hepatitis C Virus Genotype 4, Subtype 4r

Hepatitis C virus (HCV) genotype 4 is highly heterogeneous. HCV subtype 4r has been suggested to be less responsive to direct-acting antiviral (DAA) drug treatment than other genotype 4 subtypes. Among 537 DAA-treated patients who experienced a virological failure (VF) in France between 2015 and 2018, 121 (22.5%) were infected with genotype 4 and 27 of them (22.3%) with subtype 4r; subtype 4r was thus over-represented as compared to its prevalence in the French general population. Population sequencing of the nonstructural protein (NS) 3, NS5A, and NS5B genes was performed in all subtype 4r patients at treatment failure and in 6 at baseline, whereas full-length HCV genome sequencing was performed in two baseline and three treatment failure samples by means of an original shotgun metagenomics method based on deep sequencing. At treatment failure, all subtype 4r patients harbored two to three dominant NS5A resistance-associated substitutions (RASs), including at least L28A/C/I/M/V and L30R. Among 13 patients exposed to sofosbuvir and an NS5A inhibitor (daclatasvir, ledipasvir, or velpatasvir), 5 (38.5%) also harbored NS5B S282C/T RASs at treatment failure. An additional patient harbored S282C/T RASs at treatment failure by deep sequencing. Prevalence of S282C/T RASs at treatment failure was significantly higher in patients infected with genotype 4r than with other genotypes, including other subtypes of genotype 4. Conclusion: The lower rates of sustained virological response in patients infected with subtype 4r are related to the frequent preexistence at treatment baseline and subsequent selection by DAA treatment of both NS5A and NS5B S282 RASs. Our study suggests that these patients should be identified and receive a triple DAA combination regimen as first-line treatment.

Effectiveness of ombitasvir/paritaprevir/ritonavir, dasabuvir for HCV in HIV/HCV coinfected subjects: a comprehensive analysis

Background

Data on the treatment of patients with hepatitis C virus (HCV)/human immunodeficiency virus (HIV) coinfection remains limited. A comprehensive analysis was performed to evaluate the efficacy and safety of ombitasvir (OBV)/paritaprevir (PTV)/ritonavir(r) ± dasabuvir (DSV) ± ribavirin (RBV) for treatment in HCV/HIV coinfected patients.

Methods

We systematically searched and included studies that enrolled patients with HIV/HCV coinfection using the OBV/PTV/r ± DSV ± RBV regimens and reported sustained virological response after 12 weeks (SVR12) end-of-treatment. Heterogeneity of results was assessed and pooled SVR rates were computed with 95% confidence intervals (95%CI). Subgroup analysis and assessment of publication bias through Egger’s test were further performed.

Results

Ten studies containing 1358 coinfected patients were included in this study. The pooled estimate of SVR12 was 96.3% (95%CI: 95.1–97.4). Subgroup analysis showed that pooled SVR12 rate was 96.2% (95% CI: 94.8–97.4) for patients with genotype (GT) 1 and 98.8% (95% CI: 95.1–100.0) for those with GT4. The SVR12 rates for the treatment-naïve (TN) and treatment-experienced (TE) patients were 96.8% (95% CI, 94.8–98.5) and 98.9% (95% CI, 96.4–100.0), respectively. Pooled SVR12 rate was 97.8(95%CI: 94.6–99.8) for patients with cirrhosis and 96.7% (95%CI: 95.3–97.8) without cirrhosis. The pooled incidence of any adverse events (AEs) and serious adverse events (SAEs) was 73.9% (95%CI: 38.1–97.6) and 2.7% (95%CI: 0.0–9.5). Publication bias did not exist in this study.

Conclusions

The comprehensive analysis showed high efficacy for the OBV/PTV/r ± DSV ± RBV regimen in patients coinfected with HIV and HCV, regardless of genotypes, history of treatment and the presence or absence of cirrhosis.

Electronic supplementary material

The online version of this article (10.1186/s12985-018-1114-4) contains supplementary material, which is available to authorized users.

Treatment efficacy of ledipasvir/sofosbuvir for 8 weeks in non-cirrhotic chronic hepatitis C genotype 4 patients

BACKGROUND/AIMS

Ledipasvir/sofosbuvir (LDV/SOF) combination is administered for 12 to 24 weeks to treat hepatitis C virus (HCV); guidelines recommend 8 weeks treatment duration for HCV genotype (GT) 1 infection based on the patient's baseline characteristics. Data on treating HCV GT4 with LDV/SOF are limited. In this prospective cohort study, the efficacy and safety of 8 weeks treatment duration with LDV/SOF was evaluated in HCV GT4 patients in Saudi Arabia.

PATIENTS AND METHODS

Treatment-naïve, non-cirrhotic HCV GT4 patients received LDV/SOF for 8 weeks. HCV RNA levels and laboratory evaluations were recorded at baseline and at Weeks 4, 8, and 20. The primary endpoint was sustained virologic response 12 weeks after the end of the treatment (SVR12). Safety data were also recorded.

RESULTS

Forty-five patients with a mean age of 43.9 ± 17.2 years participated, of whom 57.8% were male. Mean log₁₀HCV RNA was 6.26 ± 6.32 IU/mL and most (91.1%) had baseline HCV RNA levels <6 million IU/mL. The most frequent comorbidities were hypertension and diabetes mellitus (20.0% each). Concomitant medication was taken by 18 patients (40.0%), of whom two took proton pump inhibitors. Overall, SVR12 was 97.8% (95% confidence interval [CI]: 88.2%-99.9%); one patient (2.2%) relapsed post treatment. No serious adverse events or discontinuations were reported. Eighteen patients (44.4%) had 38 adverse events related to LDV/SOF; the most frequent was headache.

CONCLUSIONS

An 8-week regimen of LDV/SOF was well tolerated and efficacious in this treatment-naïve, non-cirrhotic HCV GT4-infected population. This study provides valuable information on a short treatment regimen for HCV GT4 infection in a real-world setting.

Use of Ribavirin for Hepatitis C Treatment in the Modern Direct-acting Antiviral Era

Ribavirin, once a staple of hepatitis C treatment, has significant drawbacks, including treatment-limiting side effects, the requirement for intensive laboratory monitoring, the need for frequent dose adjustments, and teratogenicity. These factors make it difficult to escalate ribavirin-based HCV treatment to most infected patients globally. Most studies have shown comparable response rates between ribavirin-inclusive and ribavirin-sparing regimens in uncomplicated patient populations. However, ribavirin is still used in the management of patients who have failed previous therapy as well as those with decompensated liver disease. In this review, we explore the evidence supporting the use of ribavirin in the current climate of hepatitis C treatment with oral combination direct-acting antiviral agents.

Evolution of efficacious pangenotypic hepatitis C virus therapies

Hepatitis C compromises the quality of life of more than 350 million individuals worldwide. Over the last decade, therapeutic regimens for treating hepatitis C virus (HCV) infections have undergone rapid advancements. Initially, structure-based drug design was used to develop molecules that inhibit viral enzymes. Subsequently, establishment of cell-based replicon systems enabled investigations into various stages of HCV life cycle including its entry, replication, translation, and assembly, as well as role of host proteins. Collectively, these approaches have facilitated identification of important molecules that are deemed essential for HCV life cycle. The expanded set of putative virus and host-encoded targets has brought us one step closer to developing robust strategies for efficacious, pangenotypic, and well-tolerated medicines against HCV. Herein, we provide an overview of the development of various classes of virus and host-directed therapies that are currently in use along with others that are undergoing clinical evaluation.

Treatment of hepatitis C virus genotype 4 in the DAA era

The recently approved interferon-free DAA (direct antiviral agents) regimens have shown not only to be effective in terms of sustained virological response (SVR) rates (> 90%) but also well tolerated in most hepatitis C virus (HCV) infected patients. Nevertheless HCV genotypes are different and only a small percentage of trials consider genotype 4 (GT4), which was associated with lower rates of SVR compared with other genotypes before the arrival of the DAA's. In this review, we discuss the efficacy of DAA therapy in GT4 HCV infection with specific reference to more recent studies, including those conducted in a 'field-practice' scenario. Overall, DAA-based regimens appear more effective also in the poorly-explored setting of patients with HCV GT4 infection. Despite an overall limited number of patients was evaluated, favorable results are being derived from studies on ombitasvir/paritaprevir/ritonavir, sofosbuvir and velpatasvir, whether or not in association with voxilaprevir, and with the new combined therapy glecaprevir + pibentasvir.

Minor contribution of CYP3A5 to the metabolism of hepatitis C protease inhibitor paritaprevir in vitro

Paritaprevir (PTV) is a non-structural protein 3/4A protease inhibitor developed for the treatment of hepatitis C disease as a fixed dose combination of ombitasvir (OBV) and ritonavir (RTV) with or without dasabuvir. The aim of this study was to evaluate the effects of cytochrome P450 (CYP) 3A5 on in vitro PTV metabolism using human recombinant CYP3A4, CYP3A5 (rCYP3A4, rCYP3A5) and human liver microsomes (HLMs) genotyped as either CYP3A5*1/*1, CYP3A5*1/*3 or CYP3A5*3/*3. The intrinsic clearance (CL_int, V_max/K_m) for the production of a metabolite from PTV in rCYP3A4 was 1.5 times higher than that in rCYP3A5. The PTV metabolism in CYP3A5*1/*1 and CYP3A5*1/*3 HLMs expressing CYP3A5 was comparable to that in CYP3A5*3/*3 HLMs, which lack CYP3A5. CYP3A4 expression level was significantly correlated with PTV disappearance rate and metabolite formation. In contrast, there was no such correlation found for CYP3A5 expression level. This study represents that the major CYP isoform involved in PTV metabolism is CYP3A4, with CYP3A5 having a minor role in PTV metabolism. The findings of the present study may provide foundational information on PTV metabolism, and may further support dosing practices in HCV-infected patients prescribed PTV-based therapy.

Durability of virologic response, risk of de novo hepatocellular carcinoma, liver function and stiffness 2 years after treatment with ombitasvir/paritaprevir/ritonavir±dasabuvir±ribavirin in the AMBER, real-world experience study

We followed for 2 years patients treated with direct-acting agents (DAA) to assess long-term durability of virologic response, improvement of liver function, reduction in liver stiffness (LS) and risk of hepatocellular carcinoma (HCC). The study included patients from 16 hepatologic centres involved in the AMBER, investigator-initiated study on treatment of chronic hepatitis C patients within a programme preceding EU registration of ombitasvir/paritaprevir/ritonavir±dasabuvir±ribavirin. A total of 204 patients among 209 from the primary study were enrolled, 200 with available testing at 2-year follow-up (2yFU) with undetectable HCV RNA (198 responders and 2 nonresponders retreated). During 2yFU, 4 patients died, 17 had hepatic decompensation and 3 needed liver transplantation. De novo hepatocellular carcinoma was diagnosed in 4 and its recurrence in 3 patients. Significant decreases in bilirubin, MELD, Child-Pugh scores and liver stiffness, and increases in albumin level were observed during 2yFU. Strengths of the study were a fixed period of post-treatment follow-up, prospective character of the study and high proportion of available patients from the primary study. The major weaknesses were lack of a comparative arm and relatively insufficient number of patients for subsets analysis. In conclusion, 2-year follow-up confirmed durability of virologic response after treatment of HCV infection with ombitasvir/paritaprevir/ritonavir±dasabuvir±ribavirin. It was accompanied by significant improvement of major measures of hepatic function and reduction of hepatic stiffness. Successful therapy did not prevent hepatic decompensation, HCC or death in cirrhotics that support the need for longer than 2-year monitoring for possible disease progression.

Ombitasvir/Paritaprevir/Ritonavir With or Without Dasabuvir and With or Without Ribavirin for Adolescents With HCV Genotype 1 or 4

In adults, treatment of hepatitis C virus (HCV) infection with ombitasvir (OBV)/paritaprevir (PTV)/ritonavir (r) with or without dasabuvir (DSV) and ±ribavirin (RBV) results in high rates of sustained virologic response (SVR). However, these regimens have not been investigated in adolescents. This ongoing, open-label, phase 2/3 study evaluated the pharmacokinetics, safety, and efficacy of OBV/PTV/r+DSV±RBV treatment for 12 weeks in adolescents infected with HCV genotype (GT) 1 without cirrhosis (part 1) and the safety and efficacy of OBV/PTV/r±DSV±RBV treatment for 12 or 24 weeks in adolescents infected with GT1 or GT4 without cirrhosis or with compensated cirrhosis (parts 1 and 2). Patients were 12-17 years of age and treatment naive or interferon experienced. Treatment regimens were based on HCV GT and cirrhosis status. Endpoints were SVR at posttreatment week 12 (SVR12), adverse events (AEs), and pharmacokinetic parameters. Thirty-eight adolescents were enrolled, 66% were female patients, and 76% were White; 42%, 40%, and 18% of patients had HCV GT1a, GT1b, and GT4 infections, respectively. Median age was 15 years (range, 12-17 years), and 1 patient had cirrhosis. The SVR12 rate was 100% (38/38; 95% confidence interval [CI], 90.8%-100%). No treatment-emergent grade 3 or 4 laboratory abnormalities were reported. No serious AEs occurred on treatment, and no AEs led to study drug discontinuation. The most common AEs were headache (21%), fatigue (18%), nasopharyngitis (13%), pruritus (13%), and upper respiratory tract infection (11%). Intensive pharmacokinetic results showed OBV, PTV, DSV, and ritonavir drug exposures were comparable to those seen in adults. Conclusion: Treatment with OBV/PTV/r±DSV±RBV was well tolerated and highly efficacious in adolescents with HCV GT1 or GT4 infection.

Detection of anti-protease inhibitors resistance mutations in HCV strains infecting treatment-naïve chronic patients from Romania

Background: Severe complications of chronic hepatitis C – i.e. cirrhosis and hepatocellular carcinoma – are important causes of morbidity and mortality worldwide. Despite the overwhelming rates of sustained virologic response achieved after therapy with different combinations of direct-acting antiviral drugs (DAAs), treatment failure is still recorded, and is due to the mutations harboured by hepatitis C virus (HCV) resistance associated variants (RAVs) selected during therapy. Baseline RAVs testing was found significant for guiding treatment in the cases of treatment failure and, sometimes, in naïve patients.

Methods: Romanian chronic hepatitis C patients unexposed to DAAs and infected with subtype 1b HCV were studied. Serum samples were used for Sanger population sequencing of a fragment containing NS3 viral protease, known to harbour resistance mutation against protease inhibitors (PIs).

Results: Catalytic triad and zinc-binding site in the studied sequences were conserved. Low-intermediate resistance mutations to first generation PIs were detected either alone or in conjunction with resistance substitutions associated with second generation PIs. Cross-resistance and reduced susceptibility to certain DAAs were observed.

Discussion: This study focused on HCV patients infected with subtype 1b strains, the most prevalent in Romania. The rate of RAVs found in this work is consistent with the results reported by similar studies from other countries. Noticeably, numerous polymorphisms of unknown significance to DAAs resistance, but reflecting the high genetic variability of HCV, were found in the studied sequences. Testing for RAVs can be a useful method for guiding treatment in a cost-efficient manner in developing countries where access to DAAs is limited.

Expert opinion on the management of hepatitis C infection in Kuwait

Chronic hepatitis C virus (HCV) infection is a leading cause of death, especially in immunocompromised patients. The lack of clear prevalence data in the Middle East makes it difficult to estimate the true morbidity and mortality burden of HCV. In Kuwait, estimating the burden of disease is complicated by the constant flow of expatriates, many of whom are from HCV-endemic areas. The development of new and revolutionary treatments for HCV necessitates the standardization of clinical practice across all healthcare institutions. While international guidelines from the American Association for the Study of Liver Diseases (AASLD) and European Association for the Study of the Liver (EASL) do address this evolving treatment landscape, the cost-driven treatment prioritization of patients by these guidelines and unique HCV genotype presentation in the Kuwaiti population prompted the development of a more tailored approach. The predominant HCV genotypes prevalent in Kuwait are genotypes 4 and 1. The Kuwait Hepatology Club (KHC), comprising hepatologists across all major institutions in Kuwait, conducted several consensus meetings to develop the scoring criteria, evaluate all current evidence, and propose screening, diagnosis, and treatment suggestions for the management of HCV in this population. While these treatment suggestions were largely consistent with the 2016 AASLD and 2015 EASL guidelines, they also addressed gaps in the unmet needs of the Kuwaiti population with HCV.

Pharmacokinetic Enhancers (Boosters)-Escort for Drugs against Degrading Enzymes and Beyond

Pharmacokinetic enhancers (boosters) are compounds used in combination with a primary therapeutic agent (drug) and are not used for their direct effects on the disease but because they enhance or restore the activity of the primary agent. Hence, in certain cases, they represent an indispensable escort for enzyme-labile drugs. Pharmacokinetic enhancers can exert their activity on different ways. In the most common case, they inhibit enzymes such as human cytochrome P450 enzymes in the liver or other organs and, thereby, block or reduce undesired metabolism and inactivation of the primary drug. In this review, an overview will be given on the therapeutically most important classes of pharmacokinetic enhancers like β-lactamase inhibitors, inhibitors of CYP (cytochrome P450) enzymes in HIV therapy and hepatitis C, boosters for fluoropyrimidine-type anticancer agents, compounds utilized for enabling therapy of Parkinson's disease with levodopa, and others. Inhibitors of efflux pumps in both pathogenic bacteria and tumor cells will be addresses shortly.

Characterization of demographics and NS5A genetic diversity for hepatitis C virus genotype 4-infected patients with or without cirrhosis treated with ombitasvir/paritaprevir/ritonavir

Hepatitis C virus (HCV) genotype 4 (GT4) is genetically diverse with 17 confirmed and 4 provisional subtypes. In this report, HCV GT4-infected patient samples from Phase 2/3 clinical studies were analysed to characterize global demographics and genetic diversity of GT4 infection among patients treated with ombitasvir (OBV, NS5A inhibitor) plus paritaprevir/r (NS3/4A inhibitor codosed with ritonavir). Among 17 subtypes isolated from GT4-infected patients in the PEARL-I and AGATE-I studies, subtype prevalence by country of enrolment and country of origin suggested that subtypes 4a and 4d were likely circulating in Europe, while heterogeneous GT4 subtypes and a portion of GT4a detected in European and North American countries were likely due to immigration of HCV-infected patients from Africa. The distributions of birth cohort and race were also significantly different across GT4 subtypes 4a, 4d, and non-4a/4d. In addition, phylogenetic analyses of NS5A sequences revealed clustering within subtype 4a which segregated by the patient-reported country of origin and the presence of the L30R/S polymorphism. HCV NS5A sequences derived from GT4a-infected patients who originated from Europe and the United States clustered separately from sequences derived from patients who originated from Egypt, suggesting that genetically distinct strains of subtype 4a may be circulating globally. Finally, NS5A baseline polymorphisms were frequently detected at amino acid positions of interest for the inhibitor-class and OBV retained activity against 37 of 39 NS5A GT4 clinical isolates, with no impact on treatment outcome in the PEARL-I and AGATE-I studies.