Ledipasvir/Sofosbuvir: A Review in Chronic Hepatitis C

Electrochemical Lactonization Enabled by Unusual Shono-Type Oxidation from Functionalized Benzoic Acids

A novel method for electrochemical lactonization via C(sp3)-H functionalization was developed. This metal- and oxidant-free strategy enabled the efficient synthesis of various lactones. Gram-scale reaction and derivatization of the lactone product demonstrated the synthetic utility of this methodology. Mechanistic studies using control experiments and CV curves elucidated the proposed intramolecular HAT and the oxidative cyclization pathway. An unusual Shono-type oxidation was realized through this electrochemical approach, proceeding without a traditional nucleophilic addition process.

Anti HCV activity and expression inhibition of HCC markers by protein extract from Iberis gibraltarica

Abstract Hepatitis C virus infection (HCV) is the foremost reason of progressive hepatic fibrosis and cirrhosis, with an elevated risk of hepatocellular carcinoma (HCC) development. Medicinal plants have been used for human health benefits for several years, but their therapeutic potential needs to be explored. The main objective of this study was to figure out the in vitro antiviral and anticancer characteristics of total crude protein of Iberis gibraltarica against HCV and HCC. Total crude protein of Iberis gibraltarica was isolated and quantified. The level of cytotoxicity was measured against the HepG2 cell line and it shows no significant cytotoxicity at the concentration of 504µg/ml. The anti-HCV effect was determined by absolute quantification via real time RT-PCR method and viral titer was reduced up to 66% in a dose dependent manner against the total protein of Iberis gibraltarica. The anticancer potential of Iberis gibraltarica was also examined through mRNA expression studies of AFP and GPC3 genes against the total protein of Iberis gibraltarica-treated HepG2 cells. The results show up to 90% of the down-regulation expression of AFP and GPC3. The obtained results indicate the therapeutic potential of total protein of Iberis gibraltarica against HCV and hepatocellular carcinoma in vitro.

The Functional Implications of Broad Spectrum Bioactive Compounds Targeting RNA-Dependent RNA Polymerase (RdRp) in the Context of the COVID-19 Pandemic

BACKGROUND

As long as COVID-19 endures, viral surface proteins will keep changing and new viral strains will emerge, rendering prior vaccines and treatments decreasingly effective. To provide durable targets for preventive and therapeutic agents, there is increasing interest in slowly mutating viral proteins, including non-surface proteins like RdRp.

METHODS

A scoping review of studies was conducted describing RdRp in the context of COVID-19 through MEDLINE/PubMed and EMBASE. An iterative approach was used with input from content experts and three independent reviewers, focused on studies related to either RdRp activity inhibition or RdRp mechanisms against SARS-CoV-2.

RESULTS

Of the 205 records screened, 43 studies were included in the review. Twenty-five evaluated RdRp activity inhibition, and eighteen described RdRp mechanisms of existing drugs or compounds against SARS-CoV-2. In silico experiments suggested that RdRp inhibitors developed for other RNA viruses may be effective in disrupting SARS-CoV-2 replication, indicating a possible reduction of disease progression from current and future variants. In vitro, in vivo, and human clinical trial studies were largely consistent with these findings.

CONCLUSIONS

Future risk mitigation and treatment strategies against forthcoming SARS-CoV-2 variants should consider targeting RdRp proteins instead of surface proteins.

Modulation of the replication of positive-sense RNA viruses by the natural plant metabolite xanthohumol and its derivatives

The COVID-19 pandemic has highlighted the importance of identifying new potent antiviral agents. Nutrients as well as plant-derived substances are promising candidates because they are usually well tolerated by the human body and readily available in nature, and consequently mostly cheap to produce. A variety of antiviral effects have recently been described for the hop chalcone xanthohumol (XN), and to a lesser extent for its derivatives, making these hop compounds particularly attractive for further investigation. Noteworthy, mounting evidence indicated that XN can suppress a wide range of viruses belonging to several virus families, all of which share a common reproductive cycle. As a result, the purpose of this review is to summarize the most recent research on the antiviral properties of XN and its derivatives, with a particular emphasis on the positive-sense RNA viruses human hepatitis C virus (HCV), porcine reproductive and respiratory syndrome virus (PRRSV), and severe acute respiratory syndrome corona virus (SARS-CoV-2).

Synthetic Routes to Approved Drugs Containing a Spirocycle

The use of spirocycles in drug discovery and medicinal chemistry has been booming in the last two decades. This has clearly translated into the landscape of approved drugs. Among two dozen clinically used medicines containing a spirocycle, 50% have been approved in the 21st century. The present review focuses on the notable synthetic routes to such drugs invented in industry and academia, and is intended to serve as a useful reference source of synthetic as well as general drug information for researchers engaging in the design of new spirocyclic scaffolds for medicinal use or embarking upon analog syntheses inspired by the existing approved drugs.

Transcriptional Inhibition of MicroRNA miR-122 by Small Molecules Reduces Hepatitis C Virus Replication in Liver Cells

MicroRNAs (miRNAs) are noncoding RNA molecules of 22-24 nucleotides that are estimated to regulate thousands of genes in humans, and their dysregulation has been implicated in many diseases. MicroRNA-122 (miR-122) is the most abundant miRNA in the liver and has been linked to the development of hepatocellular carcinoma and hepatitis C virus (HCV) infection. Its role in these diseases renders miR-122 a potential target for small-molecule therapeutics. Here, we report the discovery of a new sulfonamide class of small-molecule miR-122 inhibitors from a high-throughput screen using a luciferase-based reporter assay. Structure-activity relationship (SAR) studies and secondary assays led to the development of potent and selective miR-122 inhibitors. Preliminary mechanism-of-action studies suggest a role in the promoter-specific transcriptional inhibition of miR-122 expression through direct binding to the liver-enriched transcription factor hepatocyte nuclear factor 4α. Importantly, the developed inhibitors significantly reduce HCV replication in human liver cells.

Revolution in the diagnosis and management of hepatitis C virus infection in current era

Chronic hepatitis C virus (HCV) infection is a major global public health problem, particularly in developing part of the world. Significant advances have been made in the early diagnosis and treatment of the disease. Its management has been particularly revolutionized during the past two decades. In this review, we summarize the major advances in the diagnostic and management armamentarium for chronic HCV infection. The focus of the present review is on the newer directly acting anti-viral agents, which have revolutionized the management of chronic HCV infection. Management of uncomplicated chronic HCV infection and of specific complications and special at-risk populations of patients will be covered in detail. Despite the advent and approval of highly effective and well tolerable oral agents, still many challenges remain, particularly the affordability, the equitable distribution and access to later drugs. The World Health Organization aims to eliminate viral hepatitis including HCV by 2030 since its poses a major public health threat. There is an urgent need to ensure uniform and early access to diagnostic and therapeutic facilities throughout the world if the later goal has to be realized.

Real-world effectiveness of direct-acting antivirals in people living with human immunodeficiency virus and hepatitis C virus genotype 6 infections

BACKGROUND

Hepatitis C virus (HCV) genotype 6 (HCV-6) infection is prevalent predominantly in Southeast Asia, and the data on the virologic response of HCV-6 to direct-acting antivirals (DAAs) are sparse in people living with human immunodeficiency virus (HIV) (PLWH).

AIM

To assess the virologic response of HCV-6 to DAAs in PLWH.

METHODS

From September 2016 to July 2019, PLWH coinfected with HCV-6 initiating DAAs were included. Laboratory investigations were performed at baseline, the end of treatment, and 12 wk off-therapy.

RESULTS

Of the 349 PLWH included (mean age 48.9 years, 82.5% men), 80.5% comprised people who inject drugs, 18.1% men who have sex with men, and 1.4% heterosexuals. Coexistent hepatitis B virus infection was present in 12.3% of the included PLWH, liver cirrhosis 10.9%, hepatocellular carcinoma 0.9%, and previous HCV treatment experience 10.9%. The mean baseline plasma HCV RNA was 6.2 log₁₀ IU/mL. Treatment with glecaprevir/pibrentasvir was initiated in 51.9%, sofosbuvir/ledipasvir 41.5%, sofosbuvir/velpatasvir 6.3%, and sofosbuvir/daclatasvir 0.3%. At DAA initiation, antiretroviral therapy containing tenofovir alafenamide was given in 26.4%, tenofovir disoproxil fumarate 34.4%, non-tenofovir alafenamide/tenofovir disoproxil fumarate 39.3%, non-nucleoside reverse-transcriptase inhibitors 30.4%, protease inhibitors 4.0%, and integrase strand transfer inhibitors 66.8%; 94.8% of the included patients had CD4 counts ≥ 200 cells/mm³ and 96.0% had plasma HIV RNA < 50 copies/mL. Overall, 96.8% achieved undetectable plasma HCV RNA (< 30 IU/mL) at end of treatment; and 92.3% achieved sustained virologic response 12 wk off-therapy in the intention-to-treat analysis (93.5% in patients receiving sofosbuvir-based DAAs and 91.2% in those receiving glecaprevir/pibrentasvir).

CONCLUSION

Similar to the observation made in HIV-negative patients, sustained virologic response 12 wk off-therapy with DAAs is high in PLWH coinfected with HCV-6.

Efficacy and safety of ledipasvir/sofosbuvir for hepatitis C among drug users: a systematic review and meta-analysis

BACKGROUND AND AIMS

Limited data is available on the efficacy of direct acting anti-viral drugs on hepatitis C in drug users. The aim of this meta-analysis was to comprehensively analyze the efficacy and safety of LDV/SOF in drug users infected with the hepatitis C virus (HCV).

METHODS

The PubMed, Cochrane library, Embase and Web of Science databases were searched for articles published till April 2021 on HCV-positive drug users who were treated with ledipasvir/sofosbuvir (LDV/SOF). The primary endpoint was pooled sustained virological response at 12 weeks (SVR12) with 95% confidence interval (95% CI). Funnel plots and Egger's test were used to assess the publication bias.

RESULTS

A total of 12 studies and 711 subjects treated with LDV/SOF-based regimen for HCV were included, and the pooled SVR12 rate was 89.8% (95% CI 85.9-92.7). The pooled SVR12 rate of genotype 1 drug users was 92.4% (95% CI 88.6-95.0). Subgroup analysis showed that pooled SVR12 rates of patients treated with LDV/SOF and LDV/SOF ± RBV were 89.2% (95% CI 83.4-93.1), 90.4% (95% CI 83.6-94.5) respectively. In addition, the SVR12 rates were 88% (95% CI 70.7-95.7) for 8 weeks, 89.9% (95% CI 81.0-94.9) for 12 weeks and 82.2% (95% CI 24.9-98.5) for 24 weeks of treatment.

CONCLUSION

LDV/SOF is a safe and relatively effective treatment for hepatitis C in drug users.

Remdesivir and Ledipasvir among the FDA-Approved Antiviral Drugs Have Potential to Inhibit SARS-CoV-2 Replication

The rapid spread of the virus, the surge in the number of deaths, and the unavailability of specific SARS-CoV-2 drugs thus far necessitate the identification of drugs with anti-COVID-19 activity. SARS-CoV-2 enters the host cell and assembles a multisubunit RNA-dependent RNA polymerase (RdRp) complex of viral nonstructural proteins that plays a substantial role in the transcription and replication of the viral genome. Therefore, RdRp is among the most suitable targets in RNA viruses. Our aim was to investigate the FDA approved antiviral drugs having potential to inhibit the viral replication. The methodology adopted was virtual screening and docking of FDA-approved antiviral drugs into the RdRp protein. Top hits were selected and subjected to molecular dynamics simulations to understand the dynamics of RdRp in complex with these drugs. The antiviral activity of the drugs against SARS-CoV-2 was assessed in Vero E6 cells. Notably, both remdesivir (half-maximal effective concentration (EC50) 6.6 μM, 50% cytotoxicity concentration (CC50) > 100 µM, selectivity index (SI) = 15) and ledipasvir (EC50 34.6 μM, CC50 > 100 µM, SI > 2.9) exerted antiviral action. This study highlights the use of direct-acting antiviral drugs, alone or in combination, for better treatments of COVID-19.

Treatment of viral hepatitis C genotypes 1 and 2 by sofosbuvir and ledipasvir with or without ribavirin combination: A possible alternative to pangenotypic treatment in a low-income country?

OBJECTIVES

The aim of this study was to evaluate the efficacy and safety of sofosbuvir/ledipasvir ± ribavirin in Malagasy patients with hepatitis C virus genotypes 1 and 2, in real conditions.

PATIENTS AND METHODS

This was a retrospective monocentric clinical study, carried out over a period of 3 years from March 1, 2017 to February 28, 2020, in a hospital hepato-gastroenterology department.

RESULTS

In total, 26 patients (M/F: 11/15) with hepatitis C virus genotype 1 (n = 13) or genotype 2 (n = 13), were treated with sofosbuvir/ledipasvir without (n = 21) or with (n = 5) ribavirin for 12 weeks. The mean age was 61.38 ± 7.09 years. Seventeen patients (65.4%) had cirrhosis. The overall sustained virological response was 96.2% (95% CI = 80.4-99.9%). There was no significant difference between the sustained virological responses of genotypes 1 and 2 (92.3% vs 100%; p = 0.31) or those of cirrhotic or non-cirrhotic patients (94.1% vs 100%; p = 0.46). A relapse was observed in one patient (5.9%) - cirrhotic and genotype 1b - under sofosbuvir/ledipasvir with ribavirin. Seven patients (26.9%) experienced mild adverse reactions, including asthenia (57.1%) and insomnia (42.9%).

CONCLUSION

Treatment with sofosbuvir/ledipasvir ± ribavirin for infection with hepatitis C virus genotype 1 has been shown to be safe and effective, even in the presence of cirrhosis. The sofosbuvir/ledipasvir combination is a good option for genotype 2 non-cirrhotic patients.

Treatment of chronic hepatitis C virus infection with crushed ledipasvir/sofosbuvir administered through a percutaneous endoscopic gastrostomy tube in a patient with HIV coinfection

PURPOSE

Ledipasvir/sofosbuvir is an oral combination therapy containing fixed doses of direct-acting antiviral agents indicated for the treatment of hepatitis C virus (HCV) infection. Currently there are limited data on the clinical efficacy of crushed ledipasvir/sofosbuvir administered via feeding tube.

SUMMARY

This case report discusses the successful treatment of chronic HCV genotype 1b infection with crushed ledipasvir/sofosbuvir administered through a percutaneous endoscopic gastrostomy (PEG) tube in a patient with human immunodeficiency virus (HIV) coinfection and high-grade sarcoma who had severe swallowing difficulties. The patient received crushed ledipasvir/sofosbuvir daily for a total of 12 weeks. At 12 weeks the patient had achieved a sustained virologic response.

CONCLUSION

Currently, ledipasvir/sofosbuvir is available only as a tablet, with limited pharmacokinetic data available to guide clinicians on use of the fixed-dose combination medication in crushed form. This case report highlights our experience treating a patient with HCV/HIV coinfection through administration of crushed ledipasvir/sofosbuvir via PEG tube, which we found to be a safe and effective therapeutic option.

Study Design Characteristics and Pharmacological Mechanisms in International Clinical Trials Registry Platform: Registered Clinical Trials on Antiviral Drugs for COVID-19

OBJECTIVE

This study aimed to evaluate the pharmacological mechanisms of antiviral drugs against the novel coronavirus disease (COVID-19) and the study designs in clinical trials registered with the International Clinical Trials Registry Platform (ICTRP).

METHODS

Clinical trials involving antiviral drugs for treating COVID-19 were retrieved from the ICTRP database. For each trial, the study design, number of participants, primary endpoints, source register, antiviral mechanism, and results were evaluated.

RESULTS

On June 10, 2020, 145 eligible clinical trials were retrieved from the ICTRP, of which 99 (68.3%) were randomized trials, 109 (75.2%) were parallel assignment trials, 38 (26.2%) were double or single blinded, 130 (89.7%) involved two groups, and 75 (51.6%) included more than 100 participants; and clinical improvement or recovery and virus-negative conversion were the two most common endpoints, accounting for 40.7% and 18.6%, respectively. The drugs were divided according to the antiviral mechanism into HIV reverse transcriptase inhibitors, RNA-dependent RNA polymerase inhibitors, HIV protease inhibitors (PIs), hepatitis C virus NS3 PIs, and anti-influenza drugs.

CONCLUSION

The design characteristics of clinical trials of antiviral drugs for treating COVID-19 as well as the mechanism of action and antiviral efficacy of the drugs were evaluated in this study. The results of these trials could constitute a reference for future clinical trials to be executed on COVID-19 treatment and prevention.

Cyclic tailor-made amino acids in the design of modern pharmaceuticals

Tailor-made AAs are indispensable components of modern medicinal chemistry and are becoming increasingly prominent in new drugs. In fact, about 30% of small-molecule pharmaceuticals contain residues of tailor-made AAs or structurally related diamines and amino-alcohols. Cyclic tailor-made AAs present a particular value to rational structural design by virtue of their local conformational constraints and are widely used in lead optimization programs. The present review article highlights 34 compounds, all of which are derived from cyclic AAs, representing recently-approved, small-molecule pharmaceuticals as well as promising drug candidates currently in various phases of clinical study. For each compound, the discussion includes the discovery, therapeutic profile and optimized synthesis, with a focus on the preparation of cyclic tailor-made AA as the principal structural feature. The present review article is intended to serve as a reference source for organic, medicinal and process chemists along with other professionals working in the fields of drug design and pharmaceutical discovery.

Tailor-Made Amino Acids and Fluorinated Motifs as Prominent Traits in Modern Pharmaceuticals

Structural analysis of modern pharmaceutical practices allows for the identification of two rapidly growing trends: the introduction of tailor-made amino acids and the exploitation of fluorinated motifs. Curiously, the former represents one of the most ubiquitous classes of naturally occurring compounds, whereas the latter is the most xenobiotic and comprised virtually entirely of man-made derivatives. Herein, 39 selected compounds, featuring both of these traits in the same molecule, are profiled. The total synthesis, source of the corresponding amino acids and fluorinated residues, and medicinal chemistry aspects and biological properties of the molecules are discussed.

Effectiveness and safety of sofosbuvir/velpatasvir/voxilaprevir in patients with chronic hepatitis C previously treated with DAAs

BACKGROUND & AIMS

Around 5% of patients with chronic hepatitis C virus (HCV) infection treated with direct-acting antiviral (DAA) agents do not achieve sustained virological response (SVR). The currently approved retreatment regimen for prior DAA failure is a combination of sofosbuvir, velpatasvir, and voxilaprevir (SOF/VEL/VOX), although there is little data on its use in clinical practice. The aim of this study was to analyse the effectiveness and safety of SOF/VEL/VOX in the real-world setting.

METHODS

This was a prospective multicentre study assessing the efficacy of retreatment with SOF/VEL/VOX in patients who had experienced a prior DAA treatment failure. The primary endpoint was SVR 12 weeks after the completion of treatment (SVR12). Data on safety and tolerability were also recorded.

RESULTS

A total of 137 patients were included: 75% men, 35% with liver cirrhosis. Most were infected with HCV genotype (GT) 1 or 3. The most common prior DAA combinations were sofosbuvir plus an NS5A inhibitor or ombitasvir/paritaprevir/r+dasabuvir. A total of 136 (99%) patients achieved undetectable HCV RNA at the end of treatment. Overall SVR12 was 95% in the 135 patients reaching this point. SVR12 was lower in patients with cirrhosis (89%, p = 0.05) and those with GT3 infection (80%, p <0.001). Patients with GT3 infection and cirrhosis had the lowest SVR12 rate (69%). Of the patients who did not achieve SVR12, 1 was reinfected and 7 experienced treatment failure (6 GT3, 1 GT1a). The presence of resistance-associated substitutions did not impact SVR12. Adverse effects were mild and non-specific.

CONCLUSION

Real-world data show that SOF/VEL/VOX is an effective, safe rescue therapy for patients with prior DAA treatment failure despite the presence of resistance-associated substitutions. However, patients with liver cirrhosis infected by GT3 remain the most-difficult-to-treat group.

LAY SUMMARY

Treatment with sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) for 12 weeks is the current recommendation for the 5% of patients infected with HCV who do not achieve eradication of the virus under treatment with direct-acting antivirals. In a Spanish cohort of 137 patients who failed a previous combination of direct-acting antivirals, a cure rate of 95% was achieved with SOF/VEL/VOX. Genotypic characteristics of the virus (genotype 3) and the presence of cirrhosis were factors that decreased the rate of cure. Treatment with SOF/VEL/VOX is an effective and safe rescue therapy due to its high efficacy and very good safety profile.

Higher relapse rate among HIV/HCV-coinfected patients receiving sofosbuvir/ledipasvir for 8 vs 12 weeks

OBJECTIVES

To compare the efficacy of sofosbuvir/ledipasvir (SOF/LDV) for 8 weeks (SL8) versus a 12-week course of SOF/LDV (SL12) among HIV/HCV-coinfected patients in clinical practice. In addition we compared sustained virological response (SVR) rates achieved with SL8 in HCV-monoinfected and HIV/HCV-coinfected patients in a real life setting.

METHODS

HCV-infected patients were retrospectively selected from the HEPAVIR-DAA and GEHEP-MONO real-life prospective cohorts if they fulfilled the following criteria: 1) Infected with genotype 1; 2) Treatment with SL8 or SL12; 3) Treatment naïve prior to receiving SL8 or SL12; 4) Absence of cirrhosis; 5) Baseline HCV RNA<6 × 10⁶ IU/mL; 6) Reached the scheduled time-point for SVR (SVR12) assessment. SVR12 and relapse rates of HCV-monoinfected and HIV/HCV-coinfected patients were compared on an intention to treat basis. The responses with SL8 and SL12 were also compared.

RESULTS

In the SL8 group, 107 (51%) HCV-monoinfected and 102 (49%) HIV/HCV-coinfected patients were included. One hundred and sixty-four (43%) HCV-monoinfected subjects and 220 (57%) HIV/HCV-coinfected patients received SL12. SVR12 rates for HIV/HCV-coinfected patients treated with SL8 vs SL12 were SVR12 92.2% vs. 97.3% (p = 0.044) and the respective relapse rates were 4.9% vs. 0.5% (p = 0.013). SVR12 rates for SL8 among HCV-monoinfected and HIV/HCV-coinfected patients were: 96.3% vs. 92.2% (p = 0.243), respectively. The corresponding relapse rates were 0.9% vs. 4.9% (p = 0.112).

CONCLUSION

HIV/HCV-coinfected patients reach high rates of SVR12 with SL8, although lower than with SL12, mainly due to a higher probability of relapse. SVR12 rates with SL8 are numerically lower and the proportion of relapses higher in HIV/HCVcoinfected patients than in HCV-monoinfected subjects.

Clinical utility of ledipasvir/sofosbuvir in the treatment of adolescents and children with hepatitis C

Chronic infection with hepatitis C virus (HCV) affects an estimated 0.1%–2% of the pediatric population in the United States. While the clinical course in young children is indolent, adolescents who contract HCV have a disease course similar to adults, with a 26-fold increased risk of chronic liver disease-associated mortality, hepatocellular carcinoma, and need for curative liver transplantation. Furthermore, adolescent patients are entering childbearing age and carry a risk of passing HCV to their offspring via vertical transmission. Pegylated-interferon (PEG-IFN) with ribavirin was previously the only treatment option for pediatric patients with chronic hepatitis C (CHC), but the high likelihood of adverse reactions and subcutaneous route of administration limited its use and efficacy. Recently, the direct-acting antivirals (DAAs) ledipasvir (LDV) and sofosbuvir (SOF) were approved for adolescents with CHC. This review discusses the natural history of CHC in pediatric patients, data supporting LDV/SOF in adolescents, and ongoing studies evaluating DAAs in pediatric patients.