Sofosbuvir, Velpatasvir, and Voxilaprevir for Previously Treated HCV Infection

Retreatment of Hepatitis C Virus Among People Who Inject Drugs

BACKGROUND

Hepatitis C virus (HCV) is a leading cause of infectious disease death in the United States. Although highly effective direct-acting antiviral (DAA) regimens are well established, retreatment among people who inject drugs (PWID) has not been sufficiently studied. This study assessed DAA retreatment outcomes and associated factors.

METHODS

We performed analyses of longitudinal data from the HERO Study, a US-based multi-site pragmatic randomized trial conducted in 8 states to evaluate effectiveness of 2 HCV care models among DAA treatment-naïve PWID in opioid treatment programs and community clinics. After initial HERO Study sofosbuvir/velpatasvir (SOF/VEL) treatment, participants eligible for retreatment were identified, from 15 September 2016 to 13 September 2021. This analysis characterizes participants who either did not achieve sustained virologic response (SVR) or were reinfected with HCV post-SVR. We compared categorical variables using Fisher exact test and continuous variables using the Welch 2 sample t test for means and an asymptotic 2-sample Mood median test.

RESULTS

One hundred four participants were identified as eligible for retreatment. Less than half, 43 (41.3%), initiated retreatment. Among the 25 who initiated retreatment and for whom SVR results were available, 24 achieved SVR (96%). Participants who did not achieve SVR initiated retreatment more promptly than participants reinfected post-SVR (respectively, 471 vs 784 days on average, P < .001).

CONCLUSIONS

After reinfection or not achieving SVR with the first DAA regimen, retreated PWID achieved higher SVR rates than with initial DAA treatment. To attain HCV elimination and benefit individual and public health, assisting PWID with accessing prompt retreatment is crucial.

Retreatment of patients with chronic hepatitis C, subtype 3a, and cirrhosis, who previously failed a regimen containing second-generation NS5A inhibitors with sofosbuvir + glecaprevir/pibrentasvir and ribavirin for 16-24 weeks

The outcomes of retreatment patients infected with hepatitis C virus genotype 3, cirrhosis, with velpatasvir may be affected by treatment failure with velpatasvir. The efficacy of SOF+GLE/PIB+RIB 16-24 weeks of treatment has been shown. The presence of NS5A resistance-associated substitution mutations, including Y93H, and the number and regimens of the past failed therapy do not influence the likelihood of achieving sustained virological response. When velpatasvir treatment fails, pibrentasvir should be used as the first choice for retreatment.

Clinical- and Cost-Effectiveness of Liver Disease Staging in Hepatitis C Virus Infection: A Microsimulation Study

BACKGROUND

Liver disease assessment is a key aspect of chronic hepatitis C virus (HCV) infection pre-treatment evaluation but guidelines differ on the optimal testing modality given trade-offs in availability and accuracy. We compared clinical outcomes and cost-effectiveness of common fibrosis staging strategies.

METHODS

We simulated adults with chronic HCV receiving care at US health centers through a lifetime microsimulation across five strategies: (1) no staging or treatment (comparator), (2) indirect serum biomarker testing (Fibrosis-4 index [FIB-4]) only, (3) transient elastography (TE) only, (4) staged approach: FIB-4 for all, TE only for intermediate FIB-4 scores (1.45-3.25), and (5) both tests for all. Outcomes included infections cured, cirrhosis cases, liver-related deaths, costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs). We used literature-informed loss to follow-up (LTFU) rates and 2021 Medicaid perspective and costs.

RESULTS

FIB-4 alone generated the best clinical outcomes: 87.7% cured, 8.7% developed cirrhosis, and 4.6% had liver-related deaths. TE strategies cured 58.5%-76.6%, 16.8%-29.4% developed cirrhosis, and 11.6%-22.6% had liver-related deaths. All TE strategies yielded worse clinical outcomes at higher costs per QALY than FIB-4 only, which had an ICER of $12 869 per QALY gained compared with no staging or treatment. LTFU drove these findings: TE strategies were only cost-effective with no LTFU. In a point-of-care HCV test-and-treat scenario, treatment without any staging was most clinically and cost-effective.

CONCLUSIONS

FIB-4 staging alone resulted in optimal clinical outcomes and was cost-effective. Treatment for chronic HCV should not be delayed while awaiting fibrosis staging with TE.

Remdesivir is active in vitro against tick-borne encephalitis virus and selects for resistance mutations in the viral RNA-dependent RNA polymerase

BACKGROUND

Tick-borne encephalitis (TBE) is a neurological disease caused by the tick-borne encephalitis virus (TBEV). Despite available vaccines, breakthrough infections occur, some fatal.

OBJECTIVES

As no antiviral therapy for TBE is currently approved, this study evaluated the in vitro activity of already licenced remdesivir (RDV) and sofosbuvir (SOF) for possible drug repurposing against TBEV.

METHODS

TBEV was cultured in A549 cells, and the inhibitory effects of RDV (GS-5734), its parent nucleotide GS-441524, and SOF (GS-7977) were assessed.

RESULTS

After 78 h, RDV demonstrated significantly lower EC50 values than SOF (0.14 vs. 11 µM) based on TBEV RNA levels measured by RT-qPCR. RDV also had a lower mean EC50 (0.55 µM) compared to GS-441524 and SOF (>8.9 and 13.1 µM, respectively) using crystal violet staining after 5 days. After 11 passages of TBEV in the presence of RDV, emergence of virus with a higher EC50 (1.32 vs. 0.55 µM) was detected with two mutations (L3122F and Y3278F) in NS5, the viral RNA-dependent RNA polymerase (RdRp), and one substitution in envelope (E) protein (E402G). Similarly, SOF resistance appeared after 20 passages, increasing EC50 values (35.5 vs. 10 µM).

CONCLUSION

RDV exhibits potent in vitro antiviral activity against TBEV via specific targeting of the viral RdRp as confirmed by the emergence of resistance-associated double NS5 substitutions in vitro in the presence of RDV. While the potential in vivo implications of the observed RDV resistance remain to be determined, these in vitro data support further assessment of RDV for the treatment of TBEV infection.

Introducing Sofosbuvir/Velpatasvir + Ribavirin as a Generic Retreatment Regimen for Hepatitis C: Evaluation of a Government Program in Rwanda

Sofosbuvir/velpatasvir/voxilaprevir is recommended for hepatitis C virus (HCV) retreatment in those who fail initial treatment but is unavailable in resource-limited settings. We describe a government sofosbuvir/velpatasvir + ribavirin (SOF/VEL + RBV) × 24 weeks retreatment program in Rwanda (November 2021-October 2022). Of 231 participants, 174 were cured (75.3% intention-to-treat analysis). SOF/VEL + RBV may be considered for HCV retreatment in resource-limited settings.

Changes in Serum Rheumatoid Factor Following Eradication of Hepatitis C Virus Infection With Interferon or Direct Antiviral Therapy

Hepatitis C virus (HCV) infection is associated with a myriad of extrahepatic manifestations (EHM), as well as the production of autoantibodies, including rheumatoid factor (RF). This study aims to elucidate whether serum levels of RF change before and after HCV eradication, and whether these changes differ according to the type of therapy used. This is a retrospective cohort study of adults with chronic HCV infection treated with interferon-free or interferon-based regimens. All patients had HCV viremia at baseline and documented sustained virological response (SVR) 12 or 24 weeks after completing treatment. We measured the serum levels of RF at baseline and at SVR-12 or -24 to analyse the changes after eradication. This study enrolled 297 patients (median age, 59 years; female, 48.5%; cirrhosis, 16.8%). Among them, 78 (26.3%) were RF-positive by qualitative serology at baseline. This number decreased to 49 (16.5%) at SVR-12 or -24 (p < 0.001). Quantitatively, the median RF also decreased from 1.6 IU/mL (interquartile range [IQR], undetectable-15.8) to undetectable (IQR, undetectable-6.6 IU/mL) (p < 0.001). Significant reductions were observed in both groups. The proportion with RF seropositivity decreased from 24.3% to 15.4% (p = 0.001) in patients treated with interferon-free agents (n = 214) and from 31.3% to 19.3% (p = 0.006) in patients treated with interferon-based regimens (n = 83), without significant difference between two groups (p = 0.40). Serum RF decreased after HCV eradication, regardless of treatment regimen. Our findings suggest that HCV eradication may attenuate HCV-related autoimmunity.

Characteristics and Outcomes of Direct-Acting Antiviral Experienced Patients with Hepatitis C Undergoing Retreatment at an Essential Hospital in the United States

Background

Hepatitis C virus (HCV) guidelines recommend direct-acting antiviral (DAA) rescue regimens in cases of treatment failure, and first-line regimens for reinfection. In patients with barriers to follow-up after treatment, it is difficult to determine if HCV viremia represents failure or reinfection. Patients are often retreated with rescue regimens despite higher costs. We compared the outcome of first-line vs rescue therapy in DAA experienced patients whose prior outcome was indeterminate.

Methods

This retrospective cohort study included DAA experienced adults undergoing retreatment at a hospital in Massachusetts between January 2016 and May 2022. We used descriptive statistics to characterize the population. For patients with an indeterminate prior HCV treatment outcome, we compared the groups' characteristics and outcomes.

Results

We included 112 patients. The mean age was 52 years (SD: 12.2), 80.4% were male, and 42.9% were White. Nearly 1 in 4 (25%) reported active substance use. Outcomes of prior DAA treatment included sustained virologic response at 12 weeks in 39.3% (n = 44) and treatment failure in 27.7% (n = 31). The prior treatment outcome was indeterminate in 33% (n = 37). We compared the outcomes of patients with an indeterminate treatment outcome retreated with first-line vs rescue therapy. Sustained virologic response at 12 weeks (66.7 vs 52.7%), treatment failure (0% vs 10.5%), and indeterminate outcome (33.3% vs 36.8%) were similar between the groups (P = .502).

Conclusions

Outcomes with first-line DAAs were comparable to rescue medications for retreatment of patients with DAA experience and an indeterminate prior treatment outcome. Our findings can help decrease treatment-level barriers for HCV treatment.

Cost-effectiveness analysis of emergency department-based hepatitis C screening and linkage-to-care program

BACKGROUND

In the United States (US), hepatitis C virus (HCV) screening is not covered by payers in settings outside of primary care. A non-traditional, emergency department (ED)-based HCV screening program can be cost-effective and identify infection in vulnerable populations with a high HCV risk. This study examined the long-term cost-effectiveness of routine HCV screening and linkage-to-care for high-risk patients in the ED from the payer's perspective.

METHODS

The University of Illinois Hospital and Health Sciences System (UIH) implemented Project HEAL (HIV & HCV Screening, Education, Awareness, Linkage-to-Care). Under this initiative, patients who presented to the ED received opt-out HCV screening if they were at high risk for HCV infection (birth cohort between 1945 and 1964, persons who inject drugs, and HIV infection) with subsequent linkage-to-care if infected. Using the summary data from Project HEAL, a hybrid decision-analytic Markov model was developed based on the HCV screening procedure in the ED and the natural history of HCV. A 30-year time horizon and 1-year cycle length were used. All patients who received the ED-based HCV screening were referred for treatment with direct-acting antiviral (DAA) regardless of their fibrosis stage.

RESULTS

When unscreened/untreated patients received DAA treatment at F1, F2, F3, and compensated cirrhosis stages, the incremental cost-effectiveness ratio (ICER) ranged from $6,084 to $77,063 per quality-adjusted life year (QALY) gained. When unscreened/untreated patients received DAA treatment at the decompensated cirrhosis stage, no HCV screening was dominated.

CONCLUSION

ED-based HCV screening and linkage-to-care was cost-effective at the willingness-to-pay (WTP) threshold of $100,000/QALY in all scenarios. A reduction in infected persons in the community may provide additional benefits not evaluated in this study.

Progress in the Stereoselective Synthesis Methods of Pyrrolidine-Containing Drugs and Their Precursors

The presented review systematizes and summarizes the data on the synthesis of pyrrolidine derivatives, which are precursors for obtaining drugs. Based on the analysis of published data, the most promising directions in the synthesis of biologically active compounds containing a pyrrolidine ring are identified. Stereoselective synthesis methods are classified based on the source of the pyrrolidine ring. The first group includes methods that use a pyrrolidine ring as the starting compound. The second group combines stereoselective methods of cyclization of acyclic starting compounds, which lead to optically pure pyrrolidine derivatives.

QSPR analysis of drugs used for treatment of hepatitis via reduced reverse degree-based topological descriptors

Topological indices refer to numerical values that are structure-invariant and are used to quantify the bonding topology of a molecular graph. The primary objective of studying topological indices is to acquire and modify chemical structure data, thereby establishing a mathematical correlation between structures and physico-chemical properties, bio-activities, and other experimental attributes. Several studies show a high intrinsic correlation between the molecular architectures of pharmaceuticals and their boiling and melting temperatures, as well as other chemical properties. Researchers can discover more about the physical characteristics, chemical stability, and bioactivities of these chemical molecular structures by using topological indices. To compensate for the lack of chemical experiments and to give a theoretical foundation for the production of pharmaceuticals and chemical materials, topological indices on the molecular structure of chemicals/drugs are studied. This study evaluates the chemical structures of medications used to treat hepatitis (A, B, C, D, E and G) based on reduced reverse degree-based topological indices. The success of drug design is influenced by factors such as solubility, metabolic stability, toxicity, permeability, and transporter effects, which are contingent upon the physical and chemical characteristics of the medication. In recent times, computational techniques have gained prominence in the field of hepatitis medication discovery and development. Machine learning is employed by certain systems to assess the effectiveness and adverse effects of medications. The primary focus of this article is to examine the chemical applicability of ten reduced reverse degree-based descriptors in predicting the ten physico-chemical properties for the 16 drugs employed in the treatment of hepatitis.

A systematic review of sofosbuvir/velpatasvir/voxilaprevir in HCV patients previously treated with direct-acting antivirals

The importance of sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) remains crucial in managing chronic HCV infection among patients who have experienced treatment failure and relapse after prior use of direct-acting antivirals (DAAs), as evidenced by high SVR12. However, limited real-world data exists on safety and efficacy. Therefore, the study’s goal was to conduct a qualitative systematic review to assess SOF/VEL/VOX’s effectiveness and safety. Thorough searches spanned PubMed, Embase, and Scopus, from 2015 to August 1st, 2023. The outcomes assessed were SVR12 and treatment-related adverse events (AEs). We identified and analyzed 12 studies in which SVR12 of the per-protocol (PP) population was 96.7% and of the intention-to-treat (ITT) population was 92.6% showing excellent efficacy of SOF/VEL/VOX. SVR12 rates notably differed among patients: those without GT3 infection (94.20%) and without cirrhosis (97.60%) experienced higher rates compared to patients having GT3 infection (87.40%) and cirrhotic patients (94.20%). Treatment-related AEs were also recorded. To summarize, our study presents evidence that SOF/VEL/VOX serves as an extremely safe and efficacious therapy for HCV-infected patients, previously treated with DAAs.

Impact of multiple comorbidities on long-term mortality in older patients following transcatheter aortic valve replacement

Background

Older candidates for transcatheter aortic valve replacement (TAVR) frequently present with both cardiac and noncardiac comorbidities. There are few risk scores that evaluate a wide range of comorbidities.

Methods

Patients who underwent TAVR for severe aortic stenosis were retrospectively evaluated. A new prediction model (Cardiac and nonCardiac Comorbidities risk score: 3C score) was determined based on coefficient in the multivariate Cox regression analysis for two-year all-cause mortality. C-statistics were assessed to compare the predictive abilities of the 3C score, the Charlson Comorbidities Index (CCI) score, the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II, and the Model for End-stage Liver Disease eXcluding International normalized ratio (MELD-XI) score.

Results

The present study included 226 patients (age, 86 ± 5 years; males, 38 %). The values of the CCI score, EuroSCORE II, and MELD-XI score were 2 (1-3), 3.36 (2.12-4.58), and 5.35 (3.05-8.55), respectively. Multivariate Cox regression analysis identified two cardiac (left ventricular ejection fraction [LVEF] <40 % [2 points]; pulmonary hypertension [1 point]) and three noncardiac comorbidities (hepatobiliary system impairment [3 points]; estimated glomerular filtration rate <30 ml/min/1.73 m2 [1 point]; cachexia [1 point]). The C-statistics of the 3C score, EuroSCORE II, MELD-XI score, and CCI score were 0.767 (0.666-0.867), 0.610 (0.491-0.729), 0.580 (0.465-0.696), and 0.476 (0.356-0.596), respectively (p < 0.001).

Conclusions

Among cardiac and noncardiac comorbidities, special attention should be given to hepatobiliary system impairment and reduced LVEF in older patients following TAVR. The 3C score may contribute to the risk stratification.

Rationale for Hepatitis C Virus Treatment During Hematopoietic Stem Cell Transplant in the Era of Novel Direct-Acting Antivirals

BACKGROUND AND AIMS

Untreated hepatitis C (HCV) infection in patients undergoing hematopoietic stem cell transplantation (HSCT) can lead to worse outcomes. Traditionally, HSCT patients infected with HCV would wait until after immune reconstitution to receive HCV therapy, as the oncologic urgency of transplant would not allow time for a full preceding treatment course of HCV therapy. However, in the era of newer direct-acting antivirals (DAAs), we propose that concomitant treatment of HCV while undergoing HSCT is safe and feasible, while keeping in mind potential drug-drug interactions.

METHODS

A literature review was performed to summarize the available data on the impact of HCV on patients undergoing HSCT. Drug-drug interactions for DAA's and pertinent HSCT drugs were evaluated using Lexicomp online® and http://hep-druginteractions.org .

RESULTS

During HSCT, HCV appears to be a conditional risk factor for sinusoidal obstruction syndrome and a potential risk factor for graft versus host disease, both of which are associated with increased mortality. HCV reactivation and exacerbation may impact the use of chemotherapeutics, but available studies haven't shown impact specifically on HSCT. Limited case reports exist but demonstrate safe and effective use DAAs during HSCT. These, along with a drug-drug interaction review demonstrate agents such as sofosbuvir/velpatasvir and glecaprevir/pibrentasvir are promising DAAs for use in HSCT.

CONCLUSION

HCV infection may worsen outcomes for patients undergoing HSCT. Concomitant treatment of HCV during HSCT using newer DAAs appears feasible and may improve patient morbidity and mortality, however large-scale studies are needed to further support this practice.

The Role of Tripartite Motif Family Proteins in Chronic Liver Diseases: Molecular Mechanisms and Therapeutic Potential

The worldwide impact of liver diseases is increasing steadily, with a consistent upswing evidenced in incidence and mortality rates. Chronic liver diseases (CLDs) refer to the liver function's progressive deterioration exceeding six months, which includes abnormal clotting factors, detoxification failure, and hepatic cholestasis. The most common etiologies of CLDs are mainly composed of chronic viral hepatitis, MAFLD/MASH, alcoholic liver disease, and genetic factors, which induce inflammation and harm to the liver, ultimately resulting in cirrhosis, the irreversible final stage of CLDs. The latest research has shown that tripartite motif family proteins (TRIMs) function as E3 ligases, which participate in the progression of CLDs by regulating gene and protein expression levels through post-translational modification. In this review, our objective is to clarify the molecular mechanisms and potential therapeutic targets of TRIMs in CLDs and provide insights for therapy guidelines and future research.

Distrust in the Health Care System and Adherence to Direct-Acting Antiviral Therapy among People with Hepatitis C Virus Who Inject Drugs

This study is a secondary analysis of a randomized clinical trial (October 2013-April 2017) involving 150 People Who Inject Drugs (PWIDs) with hepatitis C virus (HCV) seen in opioid agonist treatment programs in the Bronx, New York, and investigates the impact of distrust in the healthcare system on adherence to Direct-Acting Antivirals (DAAs) HCV treatment therapy among PWIDs. The distrust was scaled on a 9-item instrument and the adherence to DAA medications was measured using electronic blister packs. This study demonstrated a significant inverse relationship between levels of distrust and medication adherence: 71.8 ± 2.2% (se) vs. 77.9 ± 1.8%, p = 0.024 between participants with higher and lower distrust levels. Despite the absence of significant association of distrust with sociodemographic or substance use characteristics, these findings suggest that building trust within the healthcare system is paramount for improving adherence to DAAs among PWIDs. The results call for a healthcare approach that emphasizes trust-building through patient-centered care, sensitivity training, peer support, and health system reform to effectively address the treatment needs of this marginalized population.

Cu-Electrocatalysis Enables Vicinal Bis(difluoromethylation) of Alkenes: Unraveling Dichotomous Role of Zn(CF2H)2(DMPU)2 as Both Radical and Anion Source

The difluoromethyl group (CF2H) serves as an essential bioisostere in drug discovery campaigns according to Lipinski's Rule of 5 due to its advantageous combination of lipophilicity and hydrogen bonding ability, thereby improving the ADME properties. However, despite the high prevalence and importance of vicinal hydrogen bond donors in pharmaceutical agents, a general synthetic method for doubly difluoromethylated compounds in the vicinal position is absent. Here we describe a copper-electrocatalyzed strategy that enables the vicinal bis(difluoromethylation) of alkenes. By leveraging electrochemistry to oxidize Zn(CF2H)2(DMPU)2-a conventionally utilized anionic transmetalating source, we paved a way to utilize it as a CF2H radical source to deliver the CF2H group in the terminal position of alkenes. Mechanistic studies revealed that the interception of the resultant secondary radical by a copper catalyst and subsequent reductive elimination is facilitated by invoking the Cu(III) intermediate, enabling the second installation of the CF2H group in the internal position. The utility of this electrocatalytic 1,2-bis(difluoromethylation) strategy has been highlighted through the late-stage bioisosteric replacement of pharmaceutical agents such as sotalol and dipivefrine.

'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.

Feasibility of hepatitis C elimination by screening and treatment alone in high-income countries

BACKGROUND AND AIMS

Despite the availability of highly effective direct-acting antiviral therapy, chronic hepatitis C (CHC) continues to cause a major public health burden. In many high-income countries, treatment rates have been declining, which was exacerbated by the impact of the COVID-19 pandemic, threatening the ability to meet the World Health Organization (WHO)'s targets for eliminating HCV as a public health threat by 2030. We sought to model the impact of CHC in Canada, a resource-rich country with ongoing immigration from HCV-endemic regions; which relies exclusively on risk-based screening for case identification.

APPROACH AND RESULTS

We developed an agent-based model to characterize the HCV epidemic in a high-income country with ongoing immigration. Combinations of prevention such as harm reduction, screening, and treatment strategies were considered. Model parameters were estimated from the literature and calibrated against historical HCV data. Sensitivity analyses were performed to assess uncertainty. Under the current status quo of risk-based screening, we predict the incidence of CHC-induced decompensated cirrhosis, HCC, and liver-related deaths would decrease by 79.4%, 76.1%, and 62.1%, respectively, between 2015 and 2030, but CHC incidence would only decrease by 11.1%. The results were sensitive to HCV transmission rate and an annual number of people initiating treatment.

CONCLUSIONS

Current risk-based screening, and subsequent treatment, will be inadequate to achieve WHO goals. With extensive scale-up in screening, and treatment, the mortality target may be achievable, but the target for preventing new CHC cases is unlikely reachable, highlighting the importance of developing enhanced harm-reduction strategies for HCV elimination.

Cutting-edge pharmacotherapy for hepatitis C virus infection: a comprehensive review

INTRODUCTION

Pharmacotherapy against hepatitis C virus (HCV) infection has tremendously improved since the advent of interferon (IFN)-free direct-acting antivirals (DAAs). Additionally, fixed-dose pangenotypic DAAs, which are safe, potent, easy for use, and can cover a wide spectrum of patients, have been recommended by professional guidelines for DAA-naïve and DAA-experienced patients with HCV.

AREAS COVERED

We review the pharmacokinetics, pharmacodynamics, and potential drug-drug interactions (DDIs) of fixed-dose pangenotypic DAA regimens, including glecaprevir/pibrentasvir (GLE/PIB), sofosbuvir/velpatasvir (SOF/VEL), and sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX). Additionally, we summarize the efficacy and safety of these regimens in clinical trials as well as real-world studies for treating different populations. Lastly, we discuss unmet medical needs in managing HCV in the era of fixed-dose pangenotypic DAAs.

EXPERT OPINION

Protease inhibitors (PIs), including GLE and VOX, are prone to have more frequent DDIs, compared to the non-structural (NS) 5A and 5B inhibitors. These regimens are generally well tolerated and can be applied to different populations, except for the contraindicated use of PI-containing DAA regimens in decompensated cirrhosis. Using the first-line GLE/PIB and SOF/VEL can eradicate HCV in more than 95% of DAA-naïve patients across different populations. The viral cure usually exceeds 95% when using the rescue SOF/VEL/VOX regimen for prior DAA failures.

[Hepatitis C: From diagnosis to global virus elimination]

Chronic infection with hepatitis C virus (HCV) is a common cause of complications such as liver cirrhosis and hepatocellular carcinoma (HCC). It is one of the most significant infectious diseases worldwide, posing a substantial health burden. Since the introduction of direct-acting antiviral agents (DAAs), the treatment landscape has undergone a revolution. HCV infection is curable, and the treatment is safe and well tolerated. Due to the availability of this effective therapeutic option, the World Health Organization (WHO) set an ambitious goal in 2015 to eliminate Hepatitis C by 2030, a goal that the German government also embraced in 2016. The key tasks involve identifying previously undiagnosed cases and ensuring they receive antiviral treatment. Addressing at-risk populations through specific measures, including micro-elimination projects and population-wide campaigns, is essential to achieving the WHO's target both in Germany and globally.

Real-life effectiveness of sofosbuvir/velpatasvir/voxilaprevir in hepatitis C patients previously treated with sofosbuvir/velpatasvir or glecaprevir/pibrentasvir

BACKGROUND

Sofosbuvir, velpatasvir and voxilaprevir (SOF/VEL/VOX) is the recommended rescue therapy for patients with chronic hepatitis C infection who fail direct-acting antivirals (DAAs). Data are limited on the effectiveness of this treatment after the current first-line therapies. Our aim was to analyse the effectiveness and safety of SOF/VEL/VOX among patients failing sofosbuvir/velpatasvir (SOF/VEL) or glecaprevir/pibrentasvir (GLE/PIB).

METHODS

Retrospective multicentre study (26 Spanish hospitals), including chronic hepatitis C patients unsuccessfully treated with SOF/VEL or GLE/PIB, and retreated with SOF/VEL/VOX ± ribavirin for 12 weeks between December 2017 and December 2022.

RESULTS

In total, 142 patients included: 100 (70.4%) had failed SOF/VEL and 42 (29.6%) GLE/PIB. Patients were mainly men (84.5%), White (93.9%), with hepatitis C virus genotype (GT) 3 (49.6%) and 47.2% had liver cirrhosis. Sustained virological response (SVR) was evaluated in 132 patients who completed SOF/VEL/VOX and were followed 12 weeks after end of treatment; 117 (88.6%) achieved SVR. There were no significant differences in SVR rates according to initial DAA treatment (SOF/VEL 87.9% vs. GLE/PIB 90.2%, p = 0.8), cirrhosis (no cirrhosis 90% vs. cirrhosis 87.1%, p = 0.6) or GT3 infection (non-GT3 91.9% vs. GT3 85.5%, p = 0.3). However, when considering the concurrent presence of SOF/VEL treatment, cirrhosis and GT3 infection, SVR rates dropped to 82.8%. Ribavirin was added in 8 (6%) patients, all achieved SVR.

CONCLUSION

SOF/VEL/VOX is an effective rescue therapy for failures to SOF/VEL or GLE/PIB, with an SVR of 88.6%. Factors previously linked to lower SVR rates, such as GT3 infection, cirrhosis and first-line therapy with SOF/VEL were not associated with lower SVRs.

Changes in clinical outcomes in Japanese patients with hepatocellular carcinoma due to hepatitis C virus following the development of direct-acting antiviral agents

BACKGROUND AND AIM

Direct-acting antivirals (DAAs) have been accessible in Japan since 2014. The aim of this study is to compare how the prognosis of patients with hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCV-HCC) changed before and after DAA development.

METHODS

A retrospective analysis of 1949 Japanese HCV-HCC patients from January 2000 to January 2023 categorized them into pre-DAA (before 2013, n = 1169) and post-DAA (after 2014, n = 780) groups. Changes in clinical features and prognosis were assessed.

RESULTS

Despite no significant differences in BCLC stage between groups, the post-DAA group exhibited higher rates of sustained virological response (SVR) (45.6% vs. 9.8%), older age (73 vs 69 years), lower levels of AST (40 vs 56 IU/L), ALT (31 vs 46 IU/L), and AFP (11.7 vs 23.6 ng/mL), higher platelet count (13.5 vs 10.8 × 104/μL), better prothrombin time (88.0% vs 81.9%), and better ALBI score (-2.54 vs -2.36) (all P < 0.001). The post-DAA group also showed higher rates of curative treatments (74.1% vs 65.2%) and significantly improved recurrence-free survival (median 2.8 vs 2.1 years). Adjusted for inverse probability weighting, overall survival was superior in the post-DAA group (median 7.4 vs 5.6 years, P < 0.001). Subanalysis within the post-DAA group revealed significantly shorter overall survival for patients without SVR (median 4.8 years vs NA vs NA) compared to pre-SVR or post-SVR patients (both P < 0.001). No significant difference in OS was observed between the pre-SVR and post-SVR groups (P = 1.0).

CONCLUSION

The development of DAA therapy has dramatically improved the prognosis of HCV-HCC patients.

Computational Study on the Wealth Conformations of Hepatitis C Virus Envelope Glycoprotein 2 and Role of Its Glycan Coat

Hepatitis C virus (HCV) is a major cause of chronic liver disease and hepatocellular carcinoma. Antibody development efforts mainly revolve around HCV envelope glycoprotein 2 (E2), which mediates host cell entry by interacting with several cell surface receptors, including CD81. We still have limited knowledge about the structural ensembles and the dynamic behavior of both the CD81 binding sites and the glycans on E2. Here, multiple microsecond-long, all-atom molecular dynamics (MD) simulations, as well as a Markov state model (MSM), were performed to provide an atomistic perspective on the dynamic nature of E2 and its glycans. End-to-end accessibility analyses outline a complete overview of the vulnerabilities of the glycan shield of E2, which may be exploited in therapeutic efforts. Additionally, the Markov state model built from the simulation maps four metastable states for AS412 and three metastable states for the front layer in CD81 binding sites, while binding with HEPC3 would induce a conformation selection for both of them. Overall, this work presents hitherto unseen functional and structural insights into E2 and its glycan coat, providing a new theoretical foundation to control the conformational plasticity of E2 that could be harnessed for vaccine development.

Revolutionizing hepatitis C treatment: next-gen direct-acting antivirals

INTRODUCTION

With the introduction of highly effective and safe therapies with next-generation direct-acting antivirals (DAAs), that act without interferon, hepatitis C virus (HCV) infection remains the only treatable chronic infectious disease.

AREAS COVERED

The review aims to provide an overview of the therapy revolution with a description of specific DAAs, their mechanisms of action, a summary of the safety and efficacy of specific regimens, and a discussion of populations requiring special therapeutic approaches.

EXPERT OPINION

DAAs are highly effective, safe, and easy to use. However, challenges such as access to health services and loss of patients from the cascade of care, especially in groups disproportionately affected by HCV infection, such as substance abusers, make it difficult to achieve the WHO's goal of HCV elimination. The proposed strategy to combat these difficulties involves a one-step approach to diagnosing and treating the infection, the availability of long-lasting forms of medication, and the development of an effective vaccine. The aforementioned opportunities are all the more important as the world is facing an opioid epidemic that is translating into an increase in HCV prevalence. This phenomenon is of greatest concern in women of childbearing age and in those already pregnant due to treatment limitations.

Four weeks of off-treatment follow-up is sufficient to determine virologic responses at off-treatment week 12 in patients with hepatitis C virus infection receiving fixed-dose pangenotypic direct-acting antivirals

Early confirmation of sustained virologic response (SVR) or viral relapse after direct-acting antivirals (DAAs) for hepatitis C virus (HCV) infection is essential based on public health perspectives, particularly for patients with high risk of nonadherence to posttreatment follow-ups. A total of 1011 patients who achieved end-of-treatment virologic response, including 526 receiving fixed-dose pangenotypic DAAs, and 485 receiving other types of DAAs, who had available off-treatment weeks 4 and 12 serum HCV RNA data to confirm SVR at off-treatment week 12 (SVR12) or viral relapse were included. The positive predictive value (PPV) and negative predictive value (NPV) of SVR4 to predict patients with SVR12 or viral relapse were reported. Furthermore, we analyzed the proportion of concordance between SVR12 and SVR24 in 943 patients with available SVR24 data. The PPV and NPV of SVR4 to predict SVR12 were 98.5% (95% confidence interval [CI]: 98.0-98.9) and 100% (95% CI: 66.4-100) in the entire population. The PPV of SVR4 to predict SVR12 in patients receiving fixed-dose pangenotypic DAAs was higher than those receiving other types of DAAs (99.8% [95% CI: 98.9-100] vs. 97.1% [95% CI: 96.2-97.8], p < 0.001). The NPVs of SVR4 to predict viral relapse were 100%, regardless of the type of DAAs. Moreover, the concordance between SVR12 and SVR24 was 100%. In conclusion, an off-treatment week 4 serum HCV RNA testing is sufficient to provide an excellent prediction power of SVR or viral relapse at off-treatment week 12 among patients with HCV who are treated with fixed-dose pangenotypic DAAs.

SARS-CoV-2 resistance to monoclonal antibodies and small-molecule drugs

Over four years have passed since the beginning of the COVID-19 pandemic. The scientific response has been rapid and effective, with many therapeutic monoclonal antibodies and small molecules developed for clinical use. However, given the ability for viruses to become resistant to antivirals, it is perhaps no surprise that the field has identified resistance to nearly all of these compounds. Here, we provide a comprehensive review of the resistance profile for each of these therapeutics. We hope that this resource provides an atlas for mutations to be aware of for each agent, particularly as a springboard for considerations for the next generation of antivirals. Finally, we discuss the outlook and thoughts for moving forward in how we continue to manage this, and the next, pandemic.

Personalized care approaches to hepatitis C therapy: recent advances and future directions

INTRODUCTION

The introduction of direct-acting antivirals (DAAs) has significantly transformed the therapeutic landscape for chronic C hepatitis virus (HCV) infection. However, there is still room for further improvement in optimizing therapy efficacy and minimizing adverse effects.

AREAS COVERED

This review is devoted to the rationale for adopting a personalized approach to HCV therapy. Specifically, we explore the role of host-related factors, such as sex or the presence of comorbidities. We thoroughly examine the implications of commonly encountered comorbidities, including HIV infection, chronic renal disease, liver cirrhosis, and other chronic viral hepatitis infections. Additionally, we discuss the prevalent drug-to-drug interactions between DAAs and other medications, while providing guidance on their management. Finally, we investigate viral-related issues that can influence treatment outcomes, such as viral genotype, quasi-species, and the presence of resistance-associated mutations.

EXPERT OPINION

Despite pivotal trials demonstrating efficacy rates exceeding 90% for currently available DAA regimens, there are still opportunities to optimize therapy outcomes and tailor treatment to each patient. This can be achieved through a meticulous evaluation of the patient's specific clinical conditions and comorbidities, a vigilant approach to manage potential drug interactions, and diligent patient follow-up.

Hepatitis C Virus Antiviral Drug Resistance and Salvage Therapy Outcomes Across Australia

Background

Hepatitis C virus (HCV) infection can now be cured with well-tolerated direct-acting antiviral (DAA) therapy. However, a potential barrier to HCV elimination is the emergence of resistance-associated substitutions (RASs) that reduce the efficacy of antiviral drugs, but real-world studies assessing the clinical impact of RASs are limited. Here, an analysis of the impact of RASs on retreatment outcomes for different salvage regimens in patients nationally who failed first-line DAA therapy is reported.

Methods

We collected data from 363 Australian patients who failed first-line DAA therapy, including: age, sex, fibrosis stage, HCV genotype, NS3/NS5A/NS5B RASs, details of failed first-line regimen, subsequent salvage regimens, and treatment outcome.

Results

Of 240 patients who were initially retreated as per protocol, 210 (87.5%) achieved sustained virologic response (SVR) and 30 (12.5%) relapsed or did not respond. The SVR rate for salvage regimens that included sofosbuvir/velpatasvir/voxilaprevir was 94.3% (n = 140), sofosbuvir/velpatasvir 75.0% (n = 52), elbasvir/grazoprevir 81.6% (n = 38), and glecaprevir/pibrentasvir 84.6% (n = 13). NS5A RASs were present in 71.0% (n = 210) of patients who achieved SVR and in 66.7% (n = 30) of patients who subsequently relapsed. NS3 RASs were detected in 20 patients (20%) in the SVR group and 1 patient in the relapse group. NS5B RASs were observed in only 3 patients. Cirrhosis was a predictor of relapse after retreatment, as was previous treatment with sofosbuvir/velpatasvir.

Conclusions

In our cohort, the SVR rate for sofosbuvir/velpatasvir/voxilaprevir was higher than with other salvage regimens. The presence of NS5A, NS5B, or NS3 RASs did not appear to negatively influence retreatment outcomes.

Utilising organs from hepatitis C virus PCR-positive donors in Western Australia

We transplanted six solid organs from three hepatitis C virus (HCV) polymerase chain reaction (PCR)-positive donors during 2018-2023. Recipients were treated with glecaprevir/pibrentasvir or sofosbuvir/velpatasvir for 4-12 weeks, with all six achieving sustained virological response without significant adverse events. As occurs in other jurisdictions, solid organ transplants from HCR PCR-positive donors can be safely utilised in Australia.

Real-world effectiveness of voxilaprevir/velpatasvir/sofosbuvir in patients following DAA failure

Background & Aims

Voxilaprevir/velpatasvir/sofosbuvir (VOX/VEL/SOF) is highly effective for re-treatment of direct-acting antiviral (DAA)-experienced patients with chronic HCV infection. In the present study, predictors of virologic treatment response were analyzed in an integrative analysis of three large real-world cohorts.

Methods

Consecutive patients re-treated with VOX/VEL/SOF after DAA failure were enrolled between 2016 and 2021 in Austria, Belgium, Germany, Italy, Spain and Switzerland.

Results

A total of 746 patients were included: median age was 56 (16-88) years and 77% were male. Most patients were infected with HCV genotype 1 (56%) and 3 (32%). 86% of patients carried resistance-associated substitutions in the NS3, NS5A or NS5B regions. Overall, 95.4% (683/716) of patients achieved a sustained virologic response. Treatment effectiveness was significantly affected by advanced liver disease (p <0.001), hepatocellular carcinoma (p <0.001), higher baseline ALT levels (p = 0.02), HCV genotype 3 (p <0.001), and prior VEL/SOF treatment (p = 0.01). In a multivariate analysis, only HCV genotype 3, hepatocellular carcinoma and cirrhosis turned out to be independent predictors of treatment failure. Resistance-associated substitutions, as well as the presence of rare genotypes, did not impact treatment outcome. The effectiveness of rescue therapy with glecaprevir/pibrentasvir and SOF, with or without ribavirin, for 12 to 24 weeks was found to be high (100%).

Conclusions

Infection with HCV genotype 3, the presence of liver cancer and cirrhosis are independently associated with failure of VOX/VEL/SOF re-treatment. It is unclear whether the addition of ribavirin and/or extension of treatment duration may be effective to avoid virologic relapse on VOX/VEL/SOF. However, rescue treatment with glecaprevir/pibrentasvir+SOF seems to be effective.

Impact and implications

Representative data on the effectiveness of voxilaprevir/velpatasvir/sofosbuvir (VOX/VEL/SOF) in clinical practice are still scarce and the collection of a larger number of patients with difficult-to-treat cofactors including the assessment of resistance-associated substitution profiles is required before more specific recommendations for optimal re-treatment in these patients can be given. Thus, we aimed to analyze treatment effectiveness and predictors of virologic response to VOX/VEL/SOF in an integrative analysis of three large real-word cohorts. The study results, derived from a multicenter cohort consisting of 746 patients, demonstrated that re-treatment with VOX/VEL/SOF is an effective salvage therapy associated with an overall per protocol sustained virologic response rate of 95%. Hepatocellular carcinoma onset, cirrhosis and HCV genotype 3 were identified as independent negative predictors of treatment response, whereas resistance-associated substitutions, as well as rare genotypes and chimera, did not impact sustained virologic response rates following re-treatment with VOX/VEL/SOF.

Is it time for China to prioritize pan-genotypic regimens for treating patients with hepatitis C?

INTRODUCTION

The treatment of hepatitis C has entered the pan-genotypic era, but the effectiveness is not good for the genotype 3b patients who have a large proportion in China. The guidelines for hepatitis C recommend the use of gene-specific regimens when the regional 3b prevalence rate greater than 5%. This study is to explore rationality of this proportion and the cost-effectiveness to implement pan-genotypic regimens in China.

METHODS

A decision Markov model was developed from the health system perspective to evaluate the effectiveness and cost-effectiveness between pan-genotypic and gene-specific treatment regimens for hepatitis C patients. Additionally, we set a regional genotype 3b patient proportion of 0-100% to explore at which proportion it is necessary to perform genotype identification and typing therapy on patients. Model parameters were derived from published literature and public databases. Effectiveness was measured by cured patient numbers, newly diagnosed cases of decompensated cirrhosis, hepatocellular carcinoma, need for liver transplantation, and quality-adjusted life years (QALYs). Cost-effectiveness outcomes included costs and the incremental cost-effectiveness ratio (ICER). The 1-3 times 2022 Chinese per capita gross domestic product was used as the willingness-to-pay threshold. One-way and probabilistic sensitivity analyses were performed to assess the uncertainty of the model parameters.

RESULTS

Compared with gene-specific regimens, pan-genotypic regimens resulted in an additional 0.13 QALYs and an incremental cost of $165, the ICER was $1,268/QALY. From the view of efficacy, the pan-genotypic regimens cured 5,868 more people per 100,000 patients than gene-specific regimens, avoiding 86.5% of DC cases, 64.6% of HCC cases, and 78.2% of liver transplant needs. Identifying 3b patients before treatment was definitely cost-effectiveness when their prevalence was 12% or higher. The results remained robust in sensitivity analyses.

CONCLUSIONS

In China, the prioritized recommendation of pan-genotypic therapeutics proves to be both cost-effective and efficacious. But, in regions where the prevalence of genotype 3b exceeds 12%, it is necessary to identify them to provision of more suitable therapies.

Recent Methods for the Synthesis of Quinoxaline Derivatives and their Biological Activities

Quinoxaline derivatives have been incorporated into numerous marketed drugs used for the treatment of various diseases. Examples include glecaprevir (Mavyret), voxilaprevir (Vosevi), Balversa (L01EX16) (erdafitinib), carbadox, XK469R (NSC698215), and becampanel (AMP397). These quinoxaline derivatives exhibit a diverse range of pharmacological activities, including antibacterial, antitubercular, antiviral, anti-HIV, anti-inflammatory, antifungal, anticancer, antiproliferative, antitumor, kinase inhibition, antimicrobial, antioxidant, and analgesic effects. Recognizing the significance of these bioactive quinoxaline derivatives, researchers have dedicated their efforts to developing various synthetic methods for their production. This review aimed to compile the most recent findings on the synthesis and biological properties of quinoxaline derivatives from 2015 to 2023.

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.

Temporal trends in HCV treatment uptake and success among people who inject drugs in Baltimore, MD since the introduction of direct acting antivirals

Background

Although hepatitis C virus (HCV) can be cured by direct acting antivirals (DAA), uptake is not well characterized for people who inject drugs (PWID).

Methods

Among 1,130 participants of a community-based cohort of PWID with chronic HCV, we longitudinally characterized HCV treatment uptake and cure early (2014-2016) and later (2017-2020).

Results

Cumulative HCV treatment uptake increased from 4% in 2014 to 68% in 2020 and the percent with HCV viremia declined from nearly 100% to 33%. Predictors of treatment uptake varied across periods. Age (incidence rate ratio [IRR] per 5-year increase: 1.28; 95% confidence interval [CI]: 1.15, 1.42), educational attainment (IRR for ≥ high school diploma: 1.31; 95% CI: 1.04, 1.66), HIV coinfection with suppressed viral load (IRR vs. HIV negative: 2.08; 95% CI: 1.63, 2.66) and alcohol dependence (IRR vs. no alcohol use: 0.63; 95% CI: 0.43, 0.91) were associated with treatment uptake in the early period, but not later. HIV coinfection with a detectable viral load (IRR vs. HIV negative: 0.46; 95% CI: 0.23, 0.95) and daily injecting (IRR: 0.46 vs. no injection; 95% CI: 0.27, 0.79) were significantly associated with lower treatment uptake later. Homelessness was associated with significantly reduced likelihood of viral clearance in the late DAA era (IRR: 0.51; 95% CI: 0.30, 0.88).

Conclusion

Treatment uptake improved substantially in this cohort of PWID in the first five years of DAA availability with commensurate declines in viremia. Additional efforts are needed to treat those actively injecting and unstably housed in order to realize elimination goals.

The impact of sofosbuvir/velpatasvir/voxilaprevir treatment on serum hyperglycemia in hepatitis C virus infections: a systematic review and meta-analysis

BACKGROUND

The combination of Sofosbuvir (SOF), velpatasvir (VEL), and voxilaprevir (VOX) is an effective, safe rescue therapy for patients with previous treatment failure. Direct-acting antiviral (DAA) treatment for hepatitis C virus (HCV) infection in diabetics with a history of hypoglycemia could improve insulin resistance due to HCV clearance. However, some studies have shown that SOF/VEL/VOX causes grade 3 hyperglycemia and other adverse events, which contradicts the findings of other DAA studies.

AIM

To analyze the incidence of grade 3 hyperglycemia of SOF/VEL/VOX for chronic HCV infection.

METHODS

We searched electronic databases from the inception of each database until October 2021. A random-effects model was employed to pool data. The study was conducted according to the PRISMA guidelines, and quality assessment was performed by using the Cochrane risk-of-bias tool for randomized controlled trials (RCTs). The study protocol was registered on the INPLASY database (Registration No. 2021120109).

RESULTS

Five RCTs were included in this review. Overall, 49 of 2315 patients had grade 3 hyperglycemia with a risk ratio of 0.015 (95% confidence interval, 0.010-0.020; p < .001), and the incidence risk ratio (IRR) for cirrhosis compared to without cirrhosis was 12.000 (95% confidence interval: 0.727-198.160), the HCV genotype 3-genotype 1 IRR was 4.13 (95% confidence interval: 1.52-11.22) in subgroup analysis. No significant differences were found within the other subgroups, in prior DAA treatment experience, and in treatment duration.

CONCLUSION

Although the incidence of hyperglycemia was rare in diabetic patients with HCV, it is recommended that glucose levels be closely monitored during the first 3 months of therapy and that diabetes medication be modified if necessary.

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.

Direct-acting antiviral resistance of Hepatitis C virus is promoted by epistasis

Direct-acting antiviral agents (DAAs) provide efficacious therapeutic treatments for chronic Hepatitis C virus (HCV) infection. However, emergence of drug resistance mutations (DRMs) can greatly affect treatment outcomes and impede virological cure. While multiple DRMs have been observed for all currently used DAAs, the evolutionary determinants of such mutations are not currently well understood. Here, by considering DAAs targeting the nonstructural 3 (NS3) protein of HCV, we present results suggesting that epistasis plays an important role in the evolution of DRMs. Employing a sequence-based fitness landscape model whose predictions correlate highly with experimental data, we identify specific DRMs that are associated with strong epistatic interactions, and these are found to be enriched in multiple NS3-specific DAAs. Evolutionary modelling further supports that the identified DRMs involve compensatory mutational interactions that facilitate relatively easy escape from drug-induced selection pressures. Our results indicate that accounting for epistasis is important for designing future HCV NS3-targeting DAAs.

Dismal prognosis for cirrhotic patients with hepatitis C after initial failure of direct acting anti-virals, but salvage therapy may be life-saving

BACKGROUND

Effective direct-acting antiviral treatment against hepatitis C virus infection is available in many countries worldwide. Despite good treatment results, a proportion of patients does not respond to treatment. The aim of this study was to investigate the long-term prognosis and the outcome of salvage therapy, after an initial treatment failure, in a nation-wide real-life setting.

METHOD

Data from all adult patients registered in the national Swedish hepatitis C treatment register who did not achieve sustained virological response after initial antiviral treatment, was retrieved from 2014 through 2018.

RESULTS

In total, 288 patients with primary treatment failure were included, of whom 236 underwent a second treatment course as salvage therapy after a median delay of 353 (IQR: 215-650) days. Fifteen patients received a third treatment course as second salvage treatment after a further median delay of 193 (IQR: 160-378) days. One-hundred-eleven out of 124 (90%) non-cirrhotic and 62/79 (78%) cirrhotic patients achieved sustained virological response following the first salvage treatment. Sustained virological response was achieved by 108/112 (96%) patients who received a triple antiviral regimen. In total 69 patients were lost to follow-up or died waiting for salvage treatment. Baseline cirrhosis was associated with poor long-term survival.

CONCLUSION

Our study indicates that salvage therapy was effective in most patients with primary treatment failure, in particular when a triple direct acting antiviral regimen was given. To avoid the risk of death or complications, patients with primary treatment failure should be offered salvage therapy with a triple regimen, as soon as possible.

Is HCV elimination among persons living with HIV feasible? Data from the NoCo study in the setting of the ICONA cohort

BACKGROUND AND AIMS

Whether the HCV test-and-treat strategy impacted on the rate of new HCV infections among PLWH in Italy is unknown.

METHODS

Prospective study of PLWH in the ICONA network. At baseline, PLWH were tested for HCV-Ab; HCV-RNA (if HCV-Ab positive) and, if positive, treated with DAA. SVR12 indicated eradication. Seroconversions and re-infections were evaluated yearly in HCV-Ab neg and HCV-RNA neg at first screening. We estimated the following: HCV seroconversions, incidence of HCV reinfections, and access to DAA and SVR12 rates tighter with factors associated with each outcome. Data were analysed by Cox regression, Poisson regression and logistic regression models.

RESULTS

Sixteen thousand seven hundred and forty-three PLWH were included; 27.3% HCV-Ab positive; of these, 39.3% HCV-RNA positive. HCV seroconversion incidence: .48/100 PYFU (95% CI: .36-.65); re-infections incidence: 1.40/100 PYFU (95% CI: .91-2.04). The risk factor for HCV re-infection was young age: aIRR 1.85, 95% CI: 1.17-2.95) per 10 years younger. 86.4% of HCV viremic in follow-up started DAA. PWID vs. heterosexuals (aHR .75, 95% CI .62-.90), HIV-RNA >50 copies/mL (aHR .70, 95% CI .56-.87), HCV genotype other than G1, G2, G3, G4 or with multiple/missing HCV genotype and post-COVID-19 calendar periods were associated with lower DAA access. 922/965 (95.5%) PLWH achieved SVR12. We estimated 72% reduction of chance to achieve SVR12 in PLWH with a CD4 count <200/mm3 (vs. CD4 ≥200/mm3 aOR .18, 95% CI: .07-.46). 95.5% of DAA-treated individuals eradicated HCV, but they represent only 53.2% of HCV viremic PLWH and 66.4% of those in follow-up. HCV-RNA positivity by year decreased from 41.7% in 2017 to 11.7% in 2022.

CONCLUSIONS

The screening-and-treat campaign implemented in Italy, even if only partially effective, resulted in a dramatic drop in HCV circulation in our cohort.

Glecaprevir-pibrentasvir for 4 weeks among people with recent HCV infection: The TARGET3D study

Background & Aims

Short duration treatment may aid HCV elimination among key populations. This study evaluated the efficacy of glecaprevir-pibrentasvir for 4 weeks among people with recent HCV infection.

Methods

In this single-arm multicentre international trial, adults with recent HCV (duration of infection <12 months) received glecaprevir-pibrentasvir 300 mg-120 mg daily for 4 weeks. Primary infection was defined as a first positive anti-HCV antibody and/or HCV RNA measurement within 6 months of enrolment and either acute clinical hepatitis within 12 months (symptomatic illness or alanine aminotransferase >10x the upper limit of normal) or antibody seroconversion within 18 months. Reinfection was defined as new positive HCV RNA within 6 months and prior clearance (spontaneous or treatment). The primary endpoint was sustained virological response at 12 weeks post-treatment (SVR12) in the intention-to-treat (ITT) and per-protocol (PP) populations.

Results

Twenty-three participants (96% men, 70% HIV, 57% ever injected drugs) received treatment, of whom 74% had genotype 1a infection and 35% recent reinfection. At baseline, median duration of infection was 17 weeks (IQR 11-29) and HCV RNA was 5.8 log10IU/ml (IQR 5.2-6.9). SVR12 was achieved by 78% (18/23; 95% CI 56-93%) and 82% (18/22; 95% CI 60-95%) of the ITT and PP populations, respectively, and in 100% (12/12; 95% CI 74-100%) of participants with baseline HCV RNA ≤6 log10. There were four cases of virological failure (relapse); three received retreatment with 12 weeks sofosbuvir-velpatasvir or grazoprevir-elbasvir (SVR, n = 2; loss to follow-up, n = 1). No serious adverse events were reported.

Conclusion

While most achieved SVR, the efficacy of a 4-week regimen of glecaprevir-pibrentasvir was lower than observed with longer treatment durations (≥6 weeks) among people with recent HCV.

Trial Registration

Clinicaltrials.gov Identifier: NCT02634008.

Impact and implications

Short duration treatment may aid HCV elimination among key populations. This investigator-initiated single-arm multicentre international pilot trial demonstrated that efficacy of glecaprevir-pibrentasvir for 4 weeks among people with recent HCV infection was sub-optimal (SVR12 78% ITT, 82% PP). Baseline HCV RNA appeared to impact response, with higher efficacy among participants with lower baseline HCV RNA (≤6 log10; SVR12 100% ITT, 12/12). While most achieved SVR, the efficacy of 4 weeks of glecaprevir-pibrentasvir was below that seen with longer treatment durations (≥6 weeks).

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.

Alcohol Use and Sustained Virologic Response to Hepatitis C Virus Direct-Acting Antiviral Therapy

Importance

Some payers and clinicians require alcohol abstinence to receive direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) infection.

Objective

To evaluate whether alcohol use at DAA treatment initiation is associated with decreased likelihood of sustained virologic response (SVR).

Design, Setting, and Participants

This retrospective cohort study used electronic health records from the US Department of Veterans Affairs (VA), the largest integrated national health care system that provides unrestricted access to HCV treatment. Participants included all patients born between 1945 and 1965 who were dispensed DAA therapy between January 1, 2014, and June 30, 2018. Data analysis was completed in November 2020 with updated sensitivity analyses performed in 2023.

Exposure

Alcohol use categories were generated using responses to the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) questionnaire and International Classification of Diseases, Ninth Revision and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnoses for alcohol use disorder (AUD): abstinent without history of AUD, abstinent with history of AUD, lower-risk consumption, moderate-risk consumption, and high-risk consumption or AUD.

Main Outcomes and Measures

The primary outcome was SVR, which was defined as undetectable HCV RNA for 12 weeks or longer after completion of DAA therapy. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% CIs of SVR associated with alcohol category.

Results

Among 69 229 patients who initiated DAA therapy (mean [SD] age, 62.6 [4.5] years; 67 150 men [97.0%]; 34 655 non-Hispanic White individuals [50.1%]; 28 094 non-Hispanic Black individuals [40.6%]; 58 477 individuals [84.5%] with HCV genotype 1), 65 355 (94.4%) achieved SVR. A total of 32 290 individuals (46.6%) were abstinent without AUD, 9192 (13.3%) were abstinent with AUD, 13 415 (19.4%) had lower-risk consumption, 3117 (4.5%) had moderate-risk consumption, and 11 215 (16.2%) had high-risk consumption or AUD. After adjustment for potential confounding variables, there was no difference in SVR across alcohol use categories, even for patients with high-risk consumption or AUD (OR, 0.95; 95% CI, 0.85-1.07). There was no evidence of interaction by stage of hepatic fibrosis measured by fibrosis-4 score (P for interaction = .30).

Conclusions and Relevance

In this cohort study, alcohol use and AUD were not associated with lower odds of SVR. Restricting access to DAA therapy according to alcohol use creates an unnecessary barrier to patients and challenges HCV elimination goals.

IFNL4 Genotype Frequencies in Asian Populations Support Shorter Duration Therapy with Sofosbuvir-Based Hepatitis C Virus Regimens to Increase the Number Cured

Globally, ∼56.8 million people are chronically infected with hepatitis C virus (HCV), with about half residing in Asia. The cost and efficiency of delivering regimens based on direct-acting antiviral agents for HCV are important considerations in implementing these curative treatments. For sofosbuvir-based regimens, most patients are treated for 12 weeks; however, treatment for 8 weeks has been shown to cure HCV infection in 95% of patients without cirrhosis. Furthermore, virological failure after 8-week treatment occurs in only 1%-2% of individuals without cirrhosis, who have a favorable IFNL4 genotype, which is present in >50% of South Asians and >80% of East Asians. We propose that sofosbuvir-based treatment for 8 weeks, or perhaps shorter, would yield high response rate regimens in Asian countries and markedly increase the number of patients who could be cured for a given cost of the medication. We propose that a noninferiority trial in an East Asian population be conducted to test this hypothesis.

Virtual screening indicates potential inhibitors of the P2X7 receptor

Anti-inflammatory agents can be synthetic or natural compounds and are often used to attenuate different levels of inflammation. Inflammatory diseases, due to the involvement of multiple systems, are becoming difficult to treat, involve long durations of therapy where applicable, have a high cost of management and have a deleterious impact on public health. The search for natural and synthetic compounds with anti-inflammatory activity is an important strategy in drug design. Bioactive synthetic drugs may be repurposed for other pharmacological applications, and natural product chemical structures offer unlimited opportunities for new drug discoveries due to the unparalleled availability of chemical diversity. Virtual screening of 2774 molecules on the mouse P2X7 protein showed that potential ligands are composed of five flavonoids (narirutin, diosmin, complanatuside, hesperidin, and oroxin B) and other drugs such as velpatasvir, itacitinib and lifitegrast. In vitro studies in mouse cells confirmed the inhibitory activity of the indicated ligands on the P2X7 receptor by applying virtual screening. The behavior of protein bonded to the ligands was verified by analysis of the molecular dynamic simulation trajectories for four of the most potent inhibitor compounds, indicating that the ligands velpatasvir, itacitinib, lithospermic acid and narirutin remained in the binding site indicated by molecular docking.

Direct-Acting Antiviral Therapy for Treatment of Acute and Recent Hepatitis C Virus Infection: A Narrative Review

Following the discovery of hepatitis C virus (HCV) in 1989, 3 decades of basic, translational, and clinical research culminated in the development of direct-acting antiviral (DAA) therapy-curative oral treatment for HCV infection. The availability of DAA therapy revolutionized HCV clinical management, including acute (duration of infection <6 mo) and recent (duration of infection <12 mo) infection. Several DAA regimens, including the contemporary pan-genotypic combinations of sofosbuvir-velpatasvir and glecaprevir-pibrentasvir, have been shown to be safe and effective among people with acute and recent HCV infection, highlighting their potential in an HCV controlled human infection model. This article describes the natural history and management of acute and recent HCV infection in the era of DAA therapy and outlines a strategy for use of DAA therapies in the setting of an HCV controlled human infection model.

Controlled Human Infection Model for Hepatitis C Virus Vaccine Development: Trial Design Considerations

The design of a clinical trial for a controlled human infection model (CHIM) to accelerate hepatitis C virus (HCV) vaccine development requires careful consideration. The design of a potential approach to HCV CHIM is outlined, involving initial sentinel cohorts to establish the safety and curability of the viral inoculum followed by larger cohorts to establish the spontaneous clearance rate for each inoculum. The primary endpoint would be HCV clearance by 24 weeks post-inoculation, recognizing that the prevention of chronic infection would be the primary goal of HCV vaccine candidates. Additional considerations are discussed, including the populations to be enrolled, the required monitoring approach, indications for antiviral therapy, and the required sample size for different CHIM approaches. Finally, safety considerations for CHIM participants are discussed.

A randomized-controlled trial of SOF/VEL/VOX with or without ribavirin for retreatment of chronic hepatitis C

BACKGROUND & AIMS

The combination of sofosbuvir, velpatasvir and voxilaprevir (SOF/VEL/VOX) is recommended for the retreatment of patients with HCV infection in whom previous direct-acting antiviral (DAA) treatment failed. However, whether ribavirin further increases the therapeutic efficacy of SOF/VEL/VOX retreatment remains unclear. We aimed to test this hypothesis in a randomized-controlled trial.

METHODS

We randomly assigned 315 patients with DAA treatment failure from five Egyptian sites into two groups. Group A (n = 158) received SOF/VEL/VOX for 12 weeks, and group B (n = 157) received SOF/VEL/VOX + weight-based ribavirin for 12 weeks. Therapeutic efficacy was defined as SVR12 (sustained virologic response 12 weeks after treatment end). Safety and tolerability were evaluated by monitoring treatment-related adverse events (AEs) and laboratory abnormalities.

RESULTS

Males comprised 53.9% of group A and 57.1% of group B (p = 0.58); mean ages were 51.8 and 47.3 years in group A and B, respectively. Seventeen patients in each group were lost to follow-up. SVR12 rates were 87.3% (138/158) by intention-to-treat analysis and 97.8% (138/141) by per-protocol analysis in group A; and 87.9% (138/157) and 98.5% (138/140), respectively, in group B (p = n.s. for intention-to-treat and per-protocol analyses). Both regimens were well-tolerated, with no deaths and only one serious AE (anemia) in group B, which required ribavirin discontinuation. Fifty-five patients in group A vs. 77 in group B experienced any AE (p = 0.002).

CONCLUSION

This randomized-controlled trial showed equal, high efficacy of both regimens for the retreatment of previous DAA failures, although ribavirin was associated with more AEs. Therefore SOF/VEL/VOX monotherapy should be the preferred retreatment strategy. CLINCIALTRIALS.

GOV NUMBER

NCT04695769.

IMPACT AND IMPLICATIONS

HCV treatment guidelines recommend retreatment of direct-acting antiviral (DAA) treatment failures with the combination of sofosbuvir, velpatasvir and voxilaprevir (SOF/VEL/VOX) for 12 weeks. However, whether ribavirin exerts an additional/synergistic effect remains unclear. The present study confirmed that SOF/VEL/VOX without ribavirin is the best regimen for retreatment of DAA treatment failures, and thus will help guide clinicians caring for patients who are not cured with a first course of DAA therapy.

Therapeutic potential of salicylamide derivatives for combating viral infections

Since time immemorial human beings have constantly been fighting against viral infections. The ongoing and devastating coronavirus disease 2019 pandemic represents one of the most severe and most significant public health emergencies in human history, highlighting an urgent need to develop broad-spectrum antiviral agents. Salicylamide (2-hydroxybenzamide) derivatives, represented by niclosamide and nitazoxanide, inhibit the replication of a broad range of RNA and DNA viruses such as flavivirus, influenza A virus, and coronavirus. Moreover, nitazoxanide was effective in clinical trials against different viral infections including diarrhea caused by rotavirus and norovirus, uncomplicated influenza A and B, hepatitis B, and hepatitis C. In this review, we summarize the broad antiviral activities of salicylamide derivatives, the clinical progress, and the potential targets or mechanisms against different viral infections and highlight their therapeutic potential in combating the circulating and emerging viral infections in the future.

Efficacy and safety of sofosbuvir-velpatasvir and sofosbuvir-velpatasvir-voxilaprevir for hepatitis C in Korea: a Phase 3b study

BACKGROUND/AIMS

Despite the availability of direct-acting antivirals (DAAs) for chronic hepatitis C virus (HCV) infection in Korea, need remains for pangenotypic regimens that can be used in the presence of hepatic impairment, comorbidities, or prior treatment failure. We investigated the efficacy and safety of sofosbuvir-velpatasvir and sofosbuvir-velpatasvir-voxilaprevir for 12 weeks in HCV-infected Korean adults.

METHODS

This Phase 3b, multicenter, open-label study included 2 cohorts. In Cohort 1, participants with HCV genotype 1 or 2 and who were treatment-naive or treatment-experienced with interferon-based treatments, received sofosbuvir-velpatasvir 400/100 mg/day. In Cohort 2, HCV genotype 1 infected individuals who previously received an NS5A inhibitor-containing regimen ≥ 4 weeks received sofosbuvir-velpatasvir-voxilaprevir 400/100/100 mg/day. Decompensated cirrhosis was an exclusion criterion. The primary endpoint was SVR12, defined as HCV RNA < 15 IU/mL 12 weeks following treatment.

RESULTS

Of 53 participants receiving sofosbuvir-velpatasvir, 52 (98.1%) achieved SVR12. The single participant who did not achieve SVR12 experienced an asymptomatic Grade 3 ASL/ALT elevation on day 15 and discontinued treatment. The event resolved without intervention. All 33 participants (100%) treated with sofosbuvir-velpatasvir-voxilaprevir achieved SVR 12. Overall, sofosbuvir-velpatasvir and sofosbuvir-velpatasvir-voxilaprevir were safe and well tolerated. Three participants (5.6%) in Cohort 1 and 1 participant (3.0%) in Cohort 2 had serious adverse events, but none were considered treatment-related. No deaths or grade 4 laboratory abnormalities were reported.

CONCLUSION

Treatment with sofosbuvir-velpatasvir or sofosbuvir-velpatasvir-voxilaprevir was safe and resulted in high SVR12 rates in Korean HCV patients.