Safety and efficacy of sofosbuvir-velpatasvir to treat chronic hepatitis C virus infection in treatment-naive patients in Rwanda (SHARED-3): a single-arm trial

'Unusual' HCV genotype subtypes: origin, distribution, sensitivity to direct-acting antiviral drugs and behaviour on antiviral treatment and retreatment

The high genetic diversity of hepatitis C virus (HCV) has led to the emergence of eight genotypes and a large number of subtypes in limited geographical areas. Currently approved pangenotypic DAA regimens have been designed and developed to be effective against the most common subtypes (1a, 1b, 2a, 2b, 2c, 3a, 4a, 5a and 6a). However, large populations living in Africa and Asia, or who have migrated from these regions to industrialised countries, are infected with 'unusual', non-epidemic HCV subtypes, including some that are inherently resistant to currently available direct-acting antiviral (DAA) drugs due to the presence of natural polymorphisms at resistance-associated substitution positions. In this review article, we describe the origin and subsequent global spread of HCV genotypes and subtypes, the current global distribution of common and unusual HCV subtypes, the polymorphisms naturally present in the genome sequences of unusual HCV subtypes that may confer inherently reduced susceptibility to DAA drugs and the available data on the response of unusual HCV subtypes to first-line HCV therapy and retreatment. We conclude that the problem of unusual HCV subtypes that are inherently resistant to DAAs and its threat to the global efforts to eliminate viral hepatitis are largely underestimated and warrant vigorous action.

The nucleoside analog 4'-fluorouridine suppresses the replication of multiple enteroviruses by targeting 3D polymerase

Human enteroviruses are the major pathogens causing hand-foot-and-mouth disease in infants and young children throughout the world, and infection with enterovirus is also associated with severe complications, such as aseptic meningitis and myocarditis. However, there are no antiviral drugs available to treat enteroviruses infection at present. In this study, we found that 4'-fluorouridine (4'-FlU), a nucleoside analog with low cytotoxicity, exhibited broad-spectrum activity against infections of multiple enteroviruses with EC50 values at low micromolar levels, including coxsackievirus A10 (CV-A10), CV-A16, CV-A6, CV-A7, CV-B3, enterovirus A71 (EV-A71), EV-A89, EV-D68, and echovirus 6. With further investigation, the results indicated that 4'-FlU directly interacted with the RNA-dependent RNA polymerase of enterovirus, the 3D pol, and impaired the polymerase activity of 3D pol, hence inhibiting viral RNA synthesis and significantly suppressing viral replication. Our findings suggest that 4'-FlU could be promisingly developed as a broad-spectrum direct-acting antiviral agent for anti-enteroviruses therapy.

SASLT guidelines: Update in treatment of hepatitis C virus infection, 2024

ABSTRACT

Hepatitis C virus (HCV) infection has been a major global health concern, with a significant impact on public health. In recent years, there have been remarkable advancements in our understanding of HCV and the development of novel therapeutic agents. The Saudi Society for the Study of Liver Disease and Transplantation formed a working group to develop HCV practice guidelines in Saudi Arabia. The methodology used to create these guidelines involved a comprehensive review of available evidence, local data, and major international practice guidelines regarding HCV management. This updated guideline encompasses critical aspects of HCV care, including screening and diagnosis, assessing the severity of liver disease, and treatment strategies. The aim of this updated guideline is to assist healthcare providers in the management of HCV in Saudi Arabia. It summarizes the latest local studies on HCV epidemiology, significant changes in virus prevalence, and the importance of universal screening, particularly among high-risk populations. Moreover, it discusses the promising potential for HCV elimination as a public health threat by 2030, driven by effective treatment and comprehensive prevention strategies. This guideline also highlights evolving recommendations for advancing disease management, including the treatment of HCV patients with decompensated cirrhosis, treatment of those who have previously failed treatment with the newer medications, management in the context of liver transplantation and hepatocellular carcinoma, and treatment for special populations.

Hepatitis C Virus Infection in the Elderly in the Era of Direct-Acting Antivirals: Evidence from Clinical Trials and Real Life

The introduction of direct-acting antiviral agents (DAAs) into clinical practice has revolutionized the therapeutic approach to patients with chronic hepatitis C virus (HCV) infection. According to the most recent guidelines, the first line of treatment for HCV infection involves the use of one of three pan-genotypic DAA combinations, sofosbuvir/velpatasvir (SOF/VEL), glecaprevir/pibrentasvir (GLE/PIB), and sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX). These drugs have been shown to be effective and safe in numerous clinical trials and real-world studies, but special populations have been neglected. Among the special populations to be treated are elderly patients, whose numbers are increasing in clinical practice. The management of these patients can be challenging, in particular due to multiple comorbidities, polypharmacotherapy, and potential drug-drug interactions. This narrative review aims to summarize the current scientific evidence on the efficacy and safety of DAAs in the elderly population, both in clinical trials and in real-life settings. Although there is still a paucity of real-world data and no clinical trials have yet been conducted in the population aged ≥ 75 years old, some considerations about the efficacy and safety of DAAs in the elderly can be made based on the results of these studies. The pan-genotypic associations of DAAs appear to be as efficacious and safe in the elderly population as in the general population; this is both in terms of similar sustained virologic response (SVR) rates and similar frequencies of adverse events (AEs). However, further studies specifically involving this patient population would be necessary to confirm this evidence.

Hepatitis C

Hepatitis C virus (HCV) is a hepatotropic RNA virus that can cause acute and chronic hepatitis, with progressive liver damage resulting in cirrhosis, decompensated liver disease, and hepatocellular carcinoma. In 2016, WHO called for the elimination of HCV infection as a public health threat by 2030. Despite some progress, an estimated 57 million people were living with HCV infection in 2020, and 300 000 HCV-related deaths occur per year. The development of direct-acting antiviral therapy has revolutionised clinical care and generated impetus for elimination, but simplified and broadened HCV screening, enhanced linkage to care, and higher coverage of treatment and primary prevention strategies are urgently required.

Small molecule NS5B RdRp non-nucleoside inhibitors for the treatment of HCV infection: A medicinal chemistry perspective

Hepatitis C virus (HCV) infection has become a global health problem with enormous risks. Nonstructural protein 5B (NS5B) RNA-dependent RNA polymerase (RdRp) is a component of HCV, which can promote the formation of the viral RNA replication complex and is also an essential part of the replication complex itself. It plays a vital role in the synthesis of the positive and negative strands of HCV RNA. Therefore, the development of small-molecule inhibitors targeting NS5B RdRp is of great value for treating HCV infection-related diseases. Compared with NS5B RdRp nucleoside inhibitors, non-nucleoside inhibitors have more flexible structures, simpler mechanisms of action, and more predictable efficacy and safety of drugs in humans. Technological advances over the past decade have led to remarkable achievements in developing NS5B RdRp inhibitors. This review will summarize the non-nucleoside inhibitors targeting NS5B RdRp developed in the past decade and describe their structure optimization process and structure-activity relationship.