Nonstructural Protein 5A Inhibitor Research Articles

Ser235 phosphorylation of hepatitis C virus NS5A is required for NS5A dimerization and drug resistance

Hepatitis C virus (HCV) infection is recognized as a major causative agent of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. HCV non-structural protein 5A (NS5A) is a dimeric phosphoprotein with a hyperphosphorylated form to act as a switch that regulates HCV replication and assembly. NS5A inhibitors have been utilized as the scaffold for combination therapy of direct-acting antiviral agents (DAA). However, the mode of action of NS5A inhibitors is still unclear due to the lack of mechanistic detail regarding NS5A phosphorylation and dimerization in the HCV life cycle. It has been demonstrated that phosphorylation of NS5A at Ser235 is essential for RNA replication of the JFH1 strain. In this report, we found that NS5A phosphomimetic Ser235 substitution (Ser-to-Asp mutation) formed a dimer that was resistant to disruption by NS5A inhibitors as was the NS5A resistance-associated substitution Y93H. Phosphorylation of NS5A at Ser235 residue was required for the interaction of two NS5A-WT molecules in JFH1-based cell culture system but not absolutely required for dimerization of the NS5A-Y93H mutant. Interestingly, HCV nonstructural proteins from the subgenomic replicon NS3-5A was required for NS5A-WT dimerization but not required for NS5A-Y93H dimerization. Our data suggest that spontaneous Ser235 phosphorylation of NS5A and ensuing dimerization account for resistance of the JFH1/NS5A-Y93H mutant to NS5A inhibitors.

Sofosbuvir plus glecaprevir/pibrentasvir as salvage therapy after liver transplantation in NS5A inhibitor-experienced patients. A case series.

Treatment of chronic hepatitis C virus (HCV) infection with direct-acting antivirals achieves a sustained virologic response rate higher than 95%. However, virologic failure remains a clinical challenge, and data on retreatment are limited, especially in special populations such as liver transplant (LT) recipients. This study evaluated the sofosbuvir plus glecaprevir-pibrentasvir (GLE/PIB) regimen in LT recipients who had failed to a nonstructural protein 5A (NS5A) inhibitor-based regimen. Retrospective study of 111 liver transplant recipients between January 2018 and December 2020; 18 patients presented with HCV recurrent infection after LT, out of whom three had a history of at least one NS5A inhibitor-based regimen. Salvage therapy with sofosbuvir plus GLE/PIB was started for 12 weeks; baseline characteristics and outcomes were recorded. All three patients (100%) achieved an undetectable HCV viral load 12 weeks after treatment completion. No serious adverse events were observed. In our series, sofosbuvir plus GLE/PIB for 12 weeks is an effective and safe salvage therapy after LT in patients previously treated with NS5A inhibitors.

OP08 Early Access To New Direct-Acting Antiviral: A Journey On Introduction Of Ravidasvir For Hepatitis C Treatment In Malaysia

IntroductionAccess to affordable direct-acting antiviral (DAA) remains limited in developing countries, often due to high treatment cost. This study aimed to elaborate the initiatives taken by the Ministry of Health Malaysia (MoHM) to provide early access to ravidasvir, a new DAA for hepatitis C treatment, in Malaysia.MethodsMoHM collaborated with Drugs for Neglected Diseases initiative (DNDi) to develop ravidasvir, a new chemical entity of oral non-structural protein 5A (NS5A) inhibitor. MoHM co-sponsored and participated the DNDi-led Phase II/III study (STORM-C-1 trial) to assess the efficacy and safety of ravidasvir-sofosbuvir combination therapy. Agreement was signed between Pharmaniaga, Pharco Pharmaceuticals and DNDi to register and supply affordable hepatitis C treatment in Malaysia and South-East Asia. MoHM and Pharmaniaga mutually worked on the registration of ravidasvir in Malaysia. Series of pre-submission meetings took place, rolling submission was allowed and conditional registration pathway was used. As a separate initiative, MoHM partnered with the Foundation for Innovative New Diagnostics (FIND) to implement decentralization and test-and-treat strategies for screening of hepatitis C virus (HCV).ResultsFirst stage of the STORM-C-1 trial reported that the combination of ravidasvir-sofosbuvir was highly effective across all genotypes and safe. The Drug Control Authority (DCA) Malaysia has granted a conditional registration for ravidasvir hydrochloride 200mg tablet (Ravida®) in June 2021, making Malaysia as the first country in the world to approve ravidasvir. Registration process expedited and took place within 15 months. The supply of Ravida® in Malaysia is expected in near future. Meanwhile, MoHM also implemented nationwide HCV screening using rapid diagnostic test kit in private hospitals, community clinics, prisons and rehabilitation centers which previously was done only in hospitals for outreach to the targeted group.ConclusionsRavidasvir-sofosbuvir has potential as a tool to eliminate hepatitis C in Malaysia by 2030, the WHO’s global elimination targets. This alternative new drug development model was successful due to strong leadership, public-private partnership and collaborative strategies. This could also be exercised in other disease area.

Discovery of SARS-CoV-2 antiviral synergy between remdesivir and approved drugs in human lung cells

SARS coronavirus 2 (SARS-CoV-2) has caused an ongoing global pandemic with significant mortality and morbidity. At this time, the only FDA-approved therapeutic for COVID-19 is remdesivir, a broad-spectrum antiviral nucleoside analog. Efficacy is only moderate, and improved treatment strategies are urgently needed. To accomplish this goal, we devised a strategy to identify compounds that act synergistically with remdesivir in preventing SARS-CoV-2 replication. We conducted combinatorial high-throughput screening in the presence of submaximal remdesivir concentrations, using a human lung epithelial cell line infected with a clinical isolate of SARS-CoV-2. This identified 20 approved drugs that act synergistically with remdesivir, many with favorable pharmacokinetic and safety profiles. Strongest effects were observed with established antivirals, Hepatitis C virus nonstructural protein 5A (HCV NS5A) inhibitors velpatasvir and elbasvir. Combination with their partner drugs sofosbuvir and grazoprevir further increased efficacy, increasing remdesivir’s apparent potency > 25-fold. We report that HCV NS5A inhibitors act on the SARS-CoV-2 exonuclease proofreader, providing a possible explanation for the synergy observed with nucleoside analog remdesivir. FDA-approved Hepatitis C therapeutics Epclusa® (velpatasvir/sofosbuvir) and Zepatier® (elbasvir/grazoprevir) could be further optimized to achieve potency and pharmacokinetic properties that support clinical evaluation in combination with remdesivir.

IP-10 Interferes With the Antiviral Response of Direct-Acting Antiviral Agents for Hepatitis C Virus Infection.

BackgroundIncreased interferon (IFN)-gamma inducible protein-10 (IP-10) level has been shown to be associated with sustained virologic responses (SVRs) to pegylated interferon-alpha 2a/ribavirin-based therapy in patients with chronic hepatitis C (CHC). We investigated the relationship between IP-10 and treatment response in patients with CHC treated with direct-acting antiviral agents (DAAs) therapy.MethodsWe measured the dynamic changes of IP-10 in samples from 90 patients with CHC. The serum IP-10 levels, intrahepatic expressions of IP-10 mRNA, and protein were determined, respectively. For the in vitro experiments, the expression changes of IP-10 in hepatitis C virus (HCV)-replicating Huh-7 cells with or without non-structural protein 5A (NS5A) inhibitor were analyzed using real-time reverse transcription-polymerase chain reaction and Western blotting.ResultsPatients with chronic hepatitis C had increased baseline IP-10 levels, intrahepatic IP-10 mRNA, and protein expression. After initiating DAAs therapy, serum IP-10 levels decreased gradually in patients who achieved cure, whereas in patients who failed the therapy, IP-10 levels did not change significantly or recovered from the initial decline. Multivariate logistic regression analysis confirmed that baseline IP-10 level ≤ 450 pg/ml and decline >30% at 12 weeks independently predicted the SVR in patients with CHC who received DAAs. In vitro, the expression of IP-10 mRNA and protein in HCV-replicating Huh-7 cells increased significantly. However, such activities were downregulated by NS5A inhibitor, followed by the reduction of HCV RNA levels and a decline in IP-10 levels.ConclusionIP-10 interfered with HCV replication in hepatocytes and the dynamic decline in IP-10 levels during DAA treatment predicted the SVR in patients with CHC.

Design and Synthesis of Novel Bis-Imidazolyl Phenyl Butadiyne Derivatives as HCV NS5A Inhibitors.

In today’s global plan to completely eradicate hepatitis C virus (HCV), the essential list of medications used for HCV treatment are direct-acting antivirals (DAAs), as interferon-sparing regimens have become the standard-of-care (SOC) treatment. HCV nonstructural protein 5A (NS5A) inhibitors are a very common component of these regimens. Food and Drug Administration (FDA)-approved NS5A inhibitors, although very potent, do not have the same potency against all eight genotypes of HCV. Therefore, this study aims to synthesize NS5A inhibitor analogues with high potency pan-genotypic activity and high metabolic stability. Starting from an NS5A inhibitor scaffold previously identified by our research group, we made several modifications. Two series of compounds were created to test the effect of changing the length and spatial conformation (para-para vs. meta-meta-positioned bis-imidazole-proline-carbamate), replacing amide groups in the linker with imidazole groups, as well as different end-cap compositions and sizes. The frontrunner inhibits genotype 1b (Con1) replicon, with an EC50 value in the picomolar range, and showed high genotypic coverage with nanomolar range EC50 values against four more genotypes. This together with its high metabolic stability (t½ > 120 min) makes it a potential preclinical candidate.

Efficacy and safety of ravidasvir plus sofosbuvir in patients with chronic hepatitis C infection without cirrhosis or with compensated cirrhosis (STORM-C-1): interim analysis of a two-stage, open-label, multicentre, single arm, phase 2/3 trial

In low-income and middle-income countries, affordable direct-acting antivirals are urgently needed to treat hepatitis C virus (HCV) infection. The combination of ravidasvir, a pangenotypic non-structural protein 5A (NS5A) inhibitor, and sofosbuvir has shown efficacy and safety in patients with chronic HCV genotype 4 infection. STORM-C-1 trial aimed to assess the efficacy and safety of ravidasvir plus sofosbuvir in a diverse population of adults chronically infected with HCV. STORM-C-1 is a two-stage, open-label, phase 2/3 single-arm clinical trial in six public academic and non-academic centres in Malaysia and four public academic and non-academic centres in Thailand. Patients with HCV with compensated cirrhosis (Metavir F4 and Child-Turcotte-Pugh class A) or without cirrhosis (Metavir F0-3) aged 18-69 years were eligible to participate, regardless of HCV genotype, HIV infection status, previous interferon-based HCV treatment, or source of HCV infection. Once daily ravidasvir (200 mg) and sofosbuvir (400 mg) were prescribed for 12 weeks for patients without cirrhosis and for 24 weeks for those with cirrhosis. The primary endpoint was sustained virological response at 12 weeks after treatment (SVR12; defined as HCV RNA <12 IU/mL in Thailand and HCV RNA <15 IU/mL in Malaysia at 12 weeks after the end of treatment). This trial is registered with ClinicalTrials.gov, number NCT02961426, and the National Medical Research Register of Malaysia, NMRR-16-747-29183. Between Sept 14, 2016, and June 5, 2017, 301 patients were enrolled in stage one of STORM-C-1. 98 (33%) patients had genotype 1a infection, 27 (9%) had genotype 1b infection, two (1%) had genotype 2 infection, 158 (52%) had genotype 3 infection, and 16 (5%) had genotype 6 infection. 81 (27%) patients had compensated cirrhosis, 90 (30%) had HIV co-infection, and 99 (33%) had received previous interferon-based treatment. The most common treatment-emergent adverse events were pyrexia (35 [12%]), cough (26 [9%]), upper respiratory tract infection (23 [8%]), and headache (20 [7%]). There were no deaths or treatment discontinuations due to serious adverse events related to study drugs. Of the 300 patients included in the full analysis set, 291 (97%; 95% CI 94-99) had SVR12. Of note, SVR12 was reported in 78 (96%) of 81 patients with cirrhosis and 153 (97%) of 158 patients with genotype 3 infection, including 51 (96%) of 53 patients with cirrhosis. There was no difference in SVR12 rates by HIV co-infection or previous interferon treatment. In this first stage, ravidasvir plus sofosbuvir was effective and well tolerated in this diverse adult population of patients with chronic HCV infection. Ravidasvir plus sofosbuvir has the potential to provide an additional affordable, simple, and efficacious public health tool for large-scale implementation to eliminate HCV as a cause of morbidity and mortality. National Science and Technology Development Agency, Thailand; Department of Disease Control, Ministry of Public Health, Thailand; Ministry of Health, Malaysia; UK Aid; Médecins Sans Frontières (MSF); MSF Transformational Investment Capacity; FIND; Pharmaniaga; Starr International Foundation; Foundation for Art, Research, Partnership and Education; and the Swiss Agency for Development and Cooperation.

Affordable treatment and political commitment are crucial to eliminate hepatitis C globally

Affordable treatment and political commitment are crucial to eliminate hepatitis C globally

Development of a Synthesis Process for a Novel HCV NS5A Inhibitor, Emitasvir

A new approach to the synthesis of Emitasvir (DAG181), a small molecule hepatitis C virus (HCV) nonstructural protein 5A (NS5A) inhibitor, is described. Enantioselective enzymatic desymmetrization ...

Berberis lyceum and Fumaria indica: in vitro cytotoxicity, antioxidant activity, and in silico screening of their selected phytochemicals as novel hepatitis C virus nonstructural protein 5A inhibitors

Berberis lyceum and Fumaria indica are two Pakistani indigenous herbal medicines used to treat liver infections, including hepatitis C virus (HCV). This study aimed to evaluate the cytotoxicity, and antioxidant activity of these plant extracts and computationally screen their selected phytoconstituents as HCV NS5A inhibitors. The viability of HepG2 cells was assessed 24 h and 48 h post-treatment using colorimetric and dye exclusion methods. Antioxidant properties were examined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power, and total antioxidant capacity assays. Seventeen known phytochemicals identified from each plant were docked into the active binding site of HCV NS5A protein. The top hit ligands were analyzed for their druglikeness properties and the indices of absorption, distribution, metabolism, elimination, and toxicity (ADMET). The results showed that both plant extracts were non-toxic (CC50 > 200 µg/ml). The IC50 values of DPPH-radical scavenging activity were 51.02 ± 0.94 and 62.91 ± 1.85 µg/ml for B. lyceum and F. indica, respectively. They also exhibited reducing power and total antioxidant capacity.The phytochemicals were identified as potent HCV NS5A inhibitors with good druglikeness and ADMET properties. Six of the docked phytochemicals exhibited higher binding scores (-17.9 to −19.2 kcal/mol) with HCV NS5A protein than the standard drug, daclatasvir (-17.2 kcal/mol). Molecular dynamics (MD) simulation confirmed the stability of two compounds, berbamine and paprafumine at 100 ns with active site of HCV NS5A protein. The identified compounds through molecular docking and MD simulation could have potential as HCV NS5A inhibitor after further validation. Communicated by Ramaswamy H. Sarma

Population Pharmacokinetic Analysis of Yimitasvir in Chinese Healthy Volunteers and Patients With Chronic Hepatitis C Virus Infection.

Yimitasvir is a novel, oral hepatitis C virus (HCV) non-structural protein 5A inhibitor for the treatment of chronic HCV genotype 1 infection. The objective of this analysis was to develop a population pharmacokinetic model of yimitasvir in Chinese healthy volunteers and HCV infection patients. The model was performed using data from 219 subjects across six studies. Nonlinear mixed effects models were developed using Phoenix NLME software. The covariates were evaluated using a stepwise forward inclusion (p < 0.01) and then a backward exclusion procedure (p < 0.001). A two-compartment model with sequential zero-first order absorption and first-order elimination reasonably described yimitasvir pharmacokinetics (PK). The apparent oral clearance and central volume of distribution were 13.8 l·h−1 and 188 l, respectively. The bioavailability (F) of yimitasvir decreased 12.9% for each 100 mg dose increase. Food was found to affect absorption rate (Ka) and F. High-fat meal decreased Ka and F by 90.9% and 38.5%, respectively. Gender and alanine aminotransferase were identified as significant covariates on apparent oral clearance. Female subjects had lower clearance than male subjects. Zero-order absorption duration was longer in healthy volunteers (2.17 h) than that in patients (1.43 h). The population pharmacokinetic model described yimitasvir PK profile well. Food decreased Ka and F significantly, so it was recommended to take yimitasvir at least 2 h before or after a meal. Other significant covariates were not clinically important.

Dimer Organization of Membrane‐Associated NS5A of Hepatitis C Virus as Determined by Highly Sensitive 1H‐Detected Solid‐State NMR

AbstractThe Hepatitis C virus nonstructural protein 5A (NS5A) is a membrane‐associated protein involved in multiple steps of the viral life cycle. Direct‐acting antivirals (DAAs) targeting NS5A are a cornerstone of antiviral therapy, but the mode‐of‐action of these drugs is poorly understood. This is due to the lack of information on the membrane‐bound NS5A structure. Herein, we present the structural model of an NS5A AH‐linker‐D1 protein reconstituted as proteoliposomes. We use highly sensitive proton‐detected solid‐state NMR methods suitable to study samples generated through synthetic biology approaches. Spectra analyses disclose that both the AH membrane anchor and the linker are highly flexible. Paramagnetic relaxation enhancements (PRE) reveal that the dimer organization in lipids requires a new type of NS5A self‐interaction not reflected in previous crystal structures. In conclusion, we provide the first characterization of NS5A AH‐linker‐D1 in a lipidic environment shedding light onto the mode‐of‐action of clinically used NS5A inhibitors.

Dimer Organization of Membrane-Associated NS5A of Hepatitis C Virus as Determined by Highly Sensitive 1 H-Detected Solid-State NMR.

The Hepatitis C virus nonstructural protein 5A (NS5A) is a membrane‐associated protein involved in multiple steps of the viral life cycle. Direct‐acting antivirals (DAAs) targeting NS5A are a cornerstone of antiviral therapy, but the mode‐of‐action of these drugs is poorly understood. This is due to the lack of information on the membrane‐bound NS5A structure. Herein, we present the structural model of an NS5A AH‐linker‐D1 protein reconstituted as proteoliposomes. We use highly sensitive proton‐detected solid‐state NMR methods suitable to study samples generated through synthetic biology approaches. Spectra analyses disclose that both the AH membrane anchor and the linker are highly flexible. Paramagnetic relaxation enhancements (PRE) reveal that the dimer organization in lipids requires a new type of NS5A self‐interaction not reflected in previous crystal structures. In conclusion, we provide the first characterization of NS5A AH‐linker‐D1 in a lipidic environment shedding light onto the mode‐of‐action of clinically used NS5A inhibitors.

Daclatasvir Plus Sofosbuvir With and Without Ribavirin for Previously Treated or Untreated Chronic HCV Infection Genotype 1, 2 and 4 in Togo

Background: Daclatasvir (DCV) is a potent, pangenotypic nonstructural protein 5A inhibitor with demonstrated antiviral efficacy when combined with sofosbuvir (SOF) with or without ribavirin (RBV) in patients with chronic hepatitis C virus (HCV) infection. We are using SOF-DCV combination for large scale treatment. Objectives: The aim of the current study was designed to investigate the efficacy and safety of sofosbuvir/daclatasvir, with or without ribavirin for previously treated or untreated in treatment of HCV genotype 1, 2 and 4, as well as their effect on the liver fibrosis. Methods: One hundred twenty-seven patients with chronic HCV infection were categorized into 2 groups. The group 1 comprised treatment naïve patients, with total serum bilirubin ≤ 1.2mg/10-1L, serum albumin ≥ 3,5g/10-1L, ALAT ≥ 3N, ASAT≤ 2N and platelets count 150 x 109 /L. The group 2 included Peg-INF-alpha or sofosbuvir treatment-experienced patients or patients having at least 2 of the following characteristics: total bilirubin ≤ 1.2mg/10-1L, serum albumin ≥ 3,5g/10-1L, ALAT ≥ 3N, ASAT ≤ 2N and platelets count 150 x 109 /L. The first group was treated with sofosbuvir/daclatasvir for 12 weeks except sofosbuvir treatment experienced patients, who were treated with sofosbuvir/daclatasvir + ribavirin for 24 weeks, with generic medications: DCV 60 mg plus SOF 400 mg ± ribavirin (RBV) within the treatment of hepatitis C virus infection. Efficacy and safety were assessed, and baseline factors associated with sustained virological response at post-treatment week 12 (SVR12) were explored. Results: Sustained virological response (SVR12), was 95,8% in group 1 and 93,8% in group 2. Such high efficacy was accompanied with tolerable adverse effects as well as with significant improvement in liver fibrosis. Conclusion: SOF plus DCV with or without ribavirin achieved high efficacy and safety in HCV genotypes 1,2 and 4 patients. Their effect was accompanied with attenuation of liver fibrosis. Further wider-scale studies are needed to evaluate the actual role of IL 18 polymorphism in treatment response with Sofosbuvir/Daclatasvir.

Efficacy and Safety of All-oral Emitasvir and Sofosbuvir in Patients with Genotype 1b HCV Infections without Cirrhosis

Background and Aims: Emitasvir is a new type of hepatitis C virus (HCV) nonstructural protein 5A (NS5A) inhibitor, and the data of phase 2 trial has shown emitasvir-sofosbuvir to have good safety and tolerance. We conducted this phase 3 trial to further verify the efficacy and safety.Methods: We evaluated the antiviral activity and safety of a 12-week regimen of emitasvir phosphate (100 mg) combined with sofosbuvir (400 mg) once daily in non-cirrhotic patients with genotype 1 HCV infection. The primary endpoint was a sustained virological response at 12 weeks (SVR12) after the end of treatment.Results: Of the 362 patients enrolled in the trial, 39.8% were male, 99.2% had HCV genotype 1b, 0.8% had genotype 1a and 79.8% were treatment-naïve. The average age was 47.2 years. All patients completed the treatment and follow-up. All 3 patients with genotype 1a achieved SVR. Two genotype 1b treatment-naïve patients experienced virologic relapse. The rate of SVR12 was 99.7% (358/359), and SVR24 was 99.4% (357/359) in genotype 1b. Overall, 36.2% had resistance-associated substitutions (RASs) in NS5A and 98.3% had RASs in NS5B at baseline. The RASs at baseline had no effect on the rates of response. Serious adverse events were reported in 16 patients and were not related to emitasvir-sofosbuvir. Most adverse events did not require therapy.Conclusions: The 12 weeks of treatment with emitasvir-sofosbuvir was a highly efficient and safe treatment for a wide range of patients with HCV genotype 1b infection without cirrhosis, who had not been treated or who had been treated with interferon-based regimen previously.

Discovery of a Silicon-Containing Pan-Genotype Hepatitis C Virus NS5A Inhibitor.

We describe a study leading to the discovery of compound 11, a pan-genotypic hepatitis C virus (HCV) nonstructural protein 5A (NS5A) inhibitor with excellent potency, metabolic stability, and pharmacokinetics (PK). Compound 11 incorporating a 4-silapiperidine group was discovered by further optimizing our previous lead with a triethylsilyl moiety. It displayed great potency against genotype 1 subtype a (GT1a), -1b, -2a, -3a, -4a, -5a, and -6a with an EC50 range of 0.33-17 pM and improved potency against the resistance-associated variant GT1a_M28T. Pharmacokinetics (PK) study indicated that compound 11 has reasonable PK exposures with a high liver distribution in preclinical animal species (mouse, rat, and dog). The results of a 14 day repeat-dose toxicity study identified the safety of compound 11.

GSK2818713, a Novel Biphenylene Scaffold-Based Hepatitis C NS5A Replication Complex Inhibitor with Broad Genotype Coverage.

Pan-genotype NS5A inhibitors underpin hugely successful hepatitis C virus (HCV) therapy. The discovery of GSK2818713 (13), a nonstructural protein 5A (NS5A) HCV inhibitor characterized by a significantly improved genotype coverage relative to first-generation NS5A inhibitor daclatasvir (DCV), is detailed herein. The SAR analysis revealed cooperative potency effects of the biphenylene, bicyclic pyrrolidine (Aoc), and methyl-threonine structural motifs. Relative to DCV, 13 improved activity against genotype 1a (gt1a) and gt1b NS5A variants as well as HCV chimeric replicons containing NS5A fragments from genotypes 2-6. Long-term treatment of subgenomic replicons with 13 potently and durably decreased HCV RNA levels for gt1a, gt2a, and gt3a. These properties, suitable pharmacokinetics, and the lack of cross-resistance resulted in the selection of 13 as a preclinical candidate.

Real-world effectiveness and safety of sofosbuvir and nonstructural protein 5A inhibitors for chronic hepatitis C genotype 1, 2, 3, 4, or 6: a multicentre cohort study

BackgroundWe investigated real-world effectiveness and safety of sofosbuvir and the nonstructural protein 5A inhibitors in the treatment of patients infected with hepatitis C virus (HCV) genotypes 1, 2, 3, 4, or 6.MethodsWe analyzed data from 1021 patients with HCV infection (506 with genotype 1; 16 with genotype 2; 314 with genotype 3; 13 with genotype 4; 166 with genotype 6) who received 12 to 24 weeks of daclatasvir plus sofosbuvir (n = 767), ledipasvir/sofosbuvir (n = 197), or sofosbuvir/velpatasvir (n = 57), with or without ribavirin in 12 centers across Thailand to estimate sustained virologic response at post-treatment week 12 (SVR12).ResultsOverall, SVR12 rate was 98.0% (95% confidence interval [CI], 96.7–98.8%) with daclatasvir plus sofosbuvir, 97.9% (95% CI, 94.8–99.2%) with ledipasvir/sofosbuvir, and 96.5% (95% CI, 88.1–99.0%) with sofosbuvir/velpatasvir. SVR12 was achieved by 99.2% (95% CI, 97.9–99.7%) of subjects with genotype 1 infection, 100% (95% CI, 78.5–100%) of those with genotype 2 infection, 96.7% (95% CI, 94.0–98.2%) of those with genotype 3 infection, 90.9% (95% CI, 62.3–98.4%) of those with genotype 4 infection, and 96.7% (95% CI 92.5–98.6%) of those with genotype 6 infection. Patients with advanced liver disease were at risk of treatment failure. Only four patients discontinued treatment before week 4 due to non-hepatic adverse events.ConclusionsIn this large cohort of patients with various HCV genotypes managed in the real-world practice setting, daclatasvir plus sofosbuvir, ledipasvir/sofosbuvir, and sofosbuvir/velpatasvir achieved high SVR rates with good safety profile, comparable to those observed in clinical trials.

Retreatment of chronic hepatitis C virus genotype-4 patients after non-structural protein 5A inhibitors' failure: efficacy and safety of different regimens.

Nonstructural protein 5A (NS5A) is an important regimen for the treatment of chronic hepatitis C virus (HCV) genotype-4 infected patients. Retreatments for NS5A virologic failure are limited. The aim of this study is to provide real-life data regarding the effectiveness and safety of retreatment with different regimens after NS5A regimen virologic failure in GT4 patients. A total of 524 HCV patients (mean age 48 ± 11 years, 71% males), with virologic failure to sofosbuvir+daclatasvir, n = 450 and sofosbuvir/ledipasvir, n = 74 were included in this study. Patients were retreated with sofosbuvir + ombitasvir/paritaprevir/ritonavir + ribavirin, n = 278 and sofosbuvir + simeprevir + daclatasvir + ribavirin, n = 246. Response was evaluated 12 weeks after the end of treatment (SVR12). Overall, SVR12 was 95.2% [95% confidence interval (CI) 93.3%-97.1%]. In sofosbuvir + ombitasvir/paritaprevir/ritonavir + ribavirin and sofosbuvir + simeprevir + daclatasvir + ribavirin, SVR12s were 94.9% (95% CI 92.5%-97.4%) and 95.5% (95% CI 92.8%-98%), respectively. In liver cirrhosis patients, SVR12s were 96.4% (95% CI 90.7%-100%) and 98% (95% CI 94.9%-100%), respectively. Relapse in the sofosbuvir + ombitasvir/paritaprevir/ritonavir + ribavirin was n = 14 patients, and n = 11 patients in sofosbuvir + simeprevir + daclatasvir + ribavirin. Three patients developed hepatic encephalopathy, haematemesis, lower limb oedema, and one patient died in the SOF + OBV/PTV/RTV + RIB. In the sofosbuvir + simeprevir + daclatasvir + ribavirin, three patients developed hepatocellular carcinoma and one patient died. No treatment discontinuation due to anaemia. Salvage treatment for NS5A-treatment failure is effective and well tolerated in genotype-4 patients, in both noncirrhotic and compensated cirrhotic groups.

Cost-Effectiveness Analysis of Baseline Testing for Resistance-Associated Polymorphisms to Optimize Treatment Outcome in Genotype 1 Noncirrhotic Treatment-Naïve Patients With Chronic Hepatitis C Virus

ObjectivesDirect-acting antivirals containing nonstructural protein 5A (NS5A) inhibitors administered over 8 to 12 weeks are effective in ∼95% of patients with hepatitis C virus. Nevertheless, patients resistant to NS5A inhibitors have lower cure rates over 8 weeks (<85%); for these patients, 12 weeks of treatment produces cure rates greater than 95%. We evaluated the lifetime cost-effectiveness of testing for NS5A resistance at baseline and optimizing treatment duration accordingly in genotype 1 noncirrhotic treatment-naïve patients from the perspective of the UK National Health Service. MethodsA decision-analytic model compared (1) standard 12-week treatment (no testing), (2) shortened 8-week treatment (no testing), and (3) baseline testing with 12-/8-week treatment for those with/without NS5A polymorphisms. Patients who failed first-line therapy were retreated for 12 weeks. Model inputs were derived from published studies. Costs, quality-adjusted life-years, and the probability of cost-effectiveness were calculated. ResultsBaseline testing had an incremental net monetary benefit (INMB) of £11 838 versus standard 12 weeks of therapy (no testing) and low probability (31%) of being the most cost-effective, assuming £30 000 willingness to pay. Shortened 8 weeks of treatment (no testing) had an INMB of £12 294 and the highest probability (69%) of being most cost-effective. Scenario analyses showed baseline testing generally had the highest INMB and probability of being most cost-effective if first- and second-line drug prices were low (<£20k). ConclusionsOptimizing treatment duration based on NS5A polymorphisms for genotype 1 noncirrhotic treatment-naive patients in the United Kingdom is not cost-effective if the drug costs are high; the strategy is generally most cost-effective when drug prices are low (<£20k).