Patient-specific genetic factors predict treatment failure in sofosbuvir-treated patients with chronic hepatitis C

Pharmacokinetic evaluation of sofosbuvir/velpatasvir for the treatment of Chronic Hepatitis C in pediatrics aged 3 and older

INTRODUCTION

The World Health Organization proposed targets to eliminate hepatitis C virus (HCV) by 2030, aiming to treat ≥80% of people with HCV, decreasing new chronic infections by 90% and liver-related mortality by 65%. While children/adolescents represent a minority of cases, the true burden is underestimated. Advances in drug development have resulted in simplified treatments that are well-tolerated, effective, and pangenotypic in activity. Sofosbuvir/velpatasvir, a combined nucleotide analog NS5B polymerase inhibitor and NS5A inhibitor, respectively, is approved for HCV treatment for individuals ≥3 years, supported by safety data using lower-dose, novel formulations.

AREAS COVERED

This review discusses chemistry, pharmacokinetics/pharmacodynamics, dosing, efficacy, and safety of sofosbuvir/velpatasvir highlighting pediatric data. Literature review included publications/conference abstracts from PubMed, Google, and Google Scholar. Information from key clinical trials/regulatory approvals is reviewed.

EXPERT OPINION

Sofosbuvir/velpatasvir is a safe and effective therapy for the treatment of pangenotypic chronic HCV infection with limited cases of virologic relapse and adverse events among pediatric populations aged 3 years and older. However, the tolerability among children less than 6 years could be improved by alternative formulations, if not, shorter treatment durations. An aspirational role of direct-acting antivirals (DAAs) that should be explored is for the prevention of infection in exposed and at-risk pediatric populations.

A Synopsis of Hepatitis C Virus Treatments and Future Perspectives

Hepatitis C virus (HCV) infection is a worldwide public health problem. Chronic infection with HCV can lead to liver cirrhosis or cancer. Although some immune-competent individuals can clear the virus, others develop chronic HCV disease due to viral mutations or an impaired immune response. IFNs type I and III and the signal transduction induced by them are essential for a proper antiviral effect. Research on the viral cycle and immune escape mechanisms has formed the basis of therapeutic strategies to achieve a sustained virological response (SVR). The first therapies were based on IFNα; then, IFNα plus ribavirin (IFN-RBV); and then, pegylated-IFNα-RBV (PEGIFNα-RIV) to improve cytokine pharmacokinetics. However, the maximum SVR was 60%, and several significant side effects were observed, decreasing patients' treatment adherence. The development of direct-acting antivirals (DAAs) significantly enhanced the SVR (>90%), and the compounds were able to inhibit HCV replication without significant side effects, even in paediatric populations. The management of coinfected HBV-HCV and HCV-HIV patients has also improved based on DAA and PEG-IFNα-RBV (HBV-HCV). CD4 cells are crucial for an effective antiviral response. The IFNλ3, IL28B, TNF-α, IL-10, TLR-3, and TLR-9 gene polymorphisms are involved in viral clearance, therapeutic responses, and hepatic pathologies. Future research should focus on searching for strategies to circumvent resistance-associated substitution (RAS) to DAAs, develop new therapeutic schemes for different medical conditions, including organ transplant, and develop vaccines for long-lasting cellular and humoral responses with cross-protection against different HCV genotypes. The goal is to minimise the probability of HCV infection, HCV chronicity and hepatic carcinoma.