UNASSIGNED: Respiratory viruses are responsible for significant worldwide morbidity and mortality. While vaccines are highly effective at reducing the morbidity and mortality associated with viral infections, this protection is incomplete. It requires a high degree of compliance, which is hindered by vaccine hesitancy. To address these gaps, antiviral agents and therapeutics are crucial in combating diseases caused by respiratory viruses. Antiviral agents are broadly classified into two groups: 1) direct-acting antivirals (DAA) and 2) host-directed antivirals (HDA).
UNASSIGNED: This review comprehensively examines Phase II FDA-approved antiviral drugs for influenza virus, SARS-CoV-2, and RSV as published in clinicaltrials.gov. It focuses on DAAs and various monoclonal antibodies (mAbs) that have been approved for the prevention and treatment of viral respiratory tract infections.
UNASSIGNED: Antiviral drugs being developed assess different mechanisms of action to combat viruses and other delivery routes (i.e. oral, inhalation, or parenteral). The associated clinical trials address the impact on disease while determining the appropriate dosage levels for further investigation in Phase III. A robust pipeline of agents is necessary to meet the global need for effective antiviral therapeutics.

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.

OBJECTIVE: Chronic hepatitis C-related decompensated cirrhosis is associated with lower sustained virologic response (SVR)-12 rates and variable regression of disease severity after direct-acting antiviral agents. We assessed rates of SVR-12, recompensation (Baveno VII criteria), and survival in such patients.
METHODS: Between July 2018 and July 2023, patients with decompensated chronic hepatitis C-related cirrhosis after direct-acting antiviral agents treatment were evaluated for SVR-12 and then had 6-monthly follow-up.
RESULTS: Of 6516 patients with cirrhosis, 1152 with decompensated cirrhosis (age 53.2 ± 11.5 years; 63% men; Model for End-stage Liver Disease-Sodium [MELD-Na]: 16.5 ± 4.6; 87% genotype 3) were enrolled. SVR-12 was 81.8% after 1 course; ultimately SVR was 90.8% after additional treatment. Decompensation events included ascites (1098; 95.3%), hepatic encephalopathy (191; 16.6%), and variceal bleeding (284; 24.7%). Ascites resolved in 86% (diuretic withdrawal achieved in 24% patients). Recompensation occurred in 284 (24.7%) at a median time of 16.5 (interquartile range, 14.5-20.5) months. On multivariable Cox proportional hazards analysis, low bilirubin (aHR, 0.6; 95% confidence interval [CI], 0.5-0.8; P < 0.001), INR (aHR, 0.2; 95% CI, 0.1-0.3; P < 0.001), absence of large esophageal varices (aHR, 0.4; 95% CI, 0.2-0.9; P = 0.048), or gastric varices (aHR, 0.5; 95% CI, 0.3-0.7; P = 0.022) predicted recompensation. Portal hypertension progressed in 158 (13.7%) patients, with rebleed in 4%. Prior decompensation with variceal bleeding (aHR, 1.6; 95% CI, 1.2-2.8; P = 0.042), and presence of large varices (aHR, 2.9; 95% CI, 1.3-6.5; P < 0.001) were associated with portal hypertension progression. Further decompensation was seen in 221 (19%); 145 patients died and 6 underwent liver transplantation. A decrease in MELDNa of ≥3 was seen in 409 (35.5%) and a final MELDNa score of <10 was seen in 335 (29%), but 2.9% developed hepatocellular carcinoma despite SVR-12.
CONCLUSIONS: SVR-12 in hepatitis C virus-related decompensated cirrhosis in a predominant genotype 3 population led to recompensation in 24.7% of patients over a follow-up of 4 years in a public health setting. Despite SVR-12, new hepatic decompensation evolved in 19% and hepatocellular carcinoma developed in 2.9% of patients. (ClinicalTrials.gov, Number: NCT03488485).

People living with HIV-HCV co-infection comprise a target group for HCV-micro-elimination. We conducted an HCV cascade of care (CoC) for HIV-HCV co-infected individuals living in Greece and investigated factors associated with different HCV-CoC stages. We analyzed data from 1213 participants from the Athens Multicenter AIDS Cohort Study. A seven-stage CoC, overall and by subgroup (people who inject drugs (PWID), men having sex with men (MSM), men having sex with women (MSW), and migrants], was constructed, spanning from HCV diagnosis to sustained virologic response (SVR). Logistic/Cox regression models were employed to identify factors associated with passing through each CoC step. Among 1213 anti-HCV-positive individuals, 9.2% died before direct-acting antiviral (DAA) availability. PWID exhibited higher mortality rates than MSM. Of 1101 survivors, 72.2% remained in care and underwent HCV-RNA testing. Migrants and PWID showed the lowest retention rates. HCV-RNA was available for 79.2% of those in care, with 77.8% diagnosed with chronic HCV. Subsequently, 71% initiated DAAs, with individuals with very low CD4 counts (<100 cells/μL) exhibiting lower odds of DAA initiation. SVR testing was available for 203 individuals, with 85.7% achieving SVR. The SVR rates did not differ across risk groups. In 2023, significant gaps and between-group differences persisted in HCV-CoC among HIV-HCV co-infected individuals in Greece.

OBJECTIVE: Direct-acting antivirals for the treatment of hepatitis C virus (HCV) represented a paradigm shift. In 2017, sofosbuvir/velpatasvir (SOF/VEL-Epclusa®) was approved, which showed a high cure rate in all patient, contributing to HCV elimination. The analysis aimed to quantify the clinical and economic value of SOF/VEL in HCV chronic patients since its approval in Spain.
METHODS: An economic evaluation was elaborated adapting a Markov model that simulated the lifetime disease progression in of all HCV chronic patients treated with SOF/VEL (30,488 patients) since its launch (5-years), compared to previous therapies. Patients entered the model and were distributed between the fibrosis states (F0-to-F4) in treated and untreated. All patients (100%) were treated with SOF/VEL regardless of their fibrosis, and 49% with previous therapies in ≥F2. The average sustained viral response (SVR) rates 98.9% SOF/VEL versus 61.0% previous therapies. All parameters for the analysis were obtained from real-life data and literature. Only direct healthcare costs associated with disease management were included. The SOF/VEL value was measured as the number of hepatic complications avoided and their associated cost, and hepatic mortality compared to previous therapies. National Health System perspective and a 3% discount rate was applied.
RESULTS: SOF/VEL decreased the number of liver complications, avoiding 92% decompensated cirrhosis, 80% hepatocellular carcinomas, and 87% liver transplants, as well as 85% liver-related mortality. Their cost associated was reduced, amounting to savings of 197M€.
CONCLUSIONS: SOF/VEL adds relevant value to the HCV treatment, reducing the clinical and economic disease burden and contributing to HCV elimination in Spain.

Current management of HCV infection is based on Direct-Acting Antiviral Drugs (DAAs). However, resistance-associated mutations, especially in the NS3 and NS5B regions are gradually decreasing the efficacy of DAAs. Among the most effective HCV NS3/4A protease drugs, Sofosbuvir also develops resistance due to mutations in the NS3 and NS5B regions. Four mutations at positions A156Y, L36P, Q41H, and Q80K are classified as high-level resistance mutations. The resistance mechanism of HCV NS3/4A protease toward Sofosbuvir caused by these mutations is still unclear, as there is less information available regarding the structural and functional effects of the mutations against Sofosbuvir. In this work, we combined molecular dynamics simulation, molecular mechanics/Generalized-Born surface area calculation, principal component analysis, and free energy landscape analysis to explore the resistance mechanism of HCV NS3/4A protease due to these mutations, as well as compare interaction changes in wild-type. Subsequently, we identified that the mutant form of HCV NS3/4A protease affects the activity of Sofosbuvir. In this study, the resistance mechanism of Sofosbuvir at the atomic level is proposed. The proposed drug-resistance mechanism will provide valuable guidance for the design of HCV drugs.

OBJECTIVE: Antiviral drugs are considered as potentially cardiotoxic, due to prolongation of QT interval which may affect incidence of severe ventricular arrhythmias. The main aim of this retrospective study was to assess the influence of treatment by three antiviral drugs on QT interval and to find patients who are at an increased risk of developing malignant ventricular arrhythmias.
METHODS: The study included 23 patients (14 men, 9 women) who were treated with a combination of interferon alpha, ribavirin, and an NS3/4A protease inhibitor. The parameters from the 12 leads electrocardiograms were evaluated before treatment, and then 3 ± 1 and 6 ± 1 months after treatment.
RESULTS: Heart rate (HR) 69 ± 12 / min and corrected QT interval (QTc) 412 ± 35 ms were obtained before the treatment and there was not observed a significant prolongation of intervals after 3 months (HR 72 ± 11 / min, QTc 412 ± 33 ms) and after 6 months (HR 64 ± 12 / min, QTc 405 ± 28 ms) respectively. In total QTc interval was prolonged from the baseline in 53% and in 43% of the patients 3 months respectively 6 months after treatment. A QTc prolongation over of 450 ms and new treatment-related repolarization change was noted in 1 (4%) patient.
CONCLUSIONS: The study demonstrates that a combination therapy of 3 antiviral drugs does not significantly prolong the QTc interval and does not cause severe pathological changes on the ECG. Patients undergoing this treatment are not at risk of developing heart disease as an undesirable side effect.

Directly acting antivirals (DAAs) are a breakthrough in the treatment of HCV. There are controversial reports on their tendency to induce hepatocellular carcinoma (HCC) in HCV patients. Numerous reports have concluded that the HCC is attributed to patient-related factors while others are inclined to attribute this as a DAA side-effect. This study aims to investigate the effect of polymerase inhibitor DAAs, especially daclatasivir (DLT) on cellular proliferation as compared to ribavirin (RBV). The interaction of DAAs with variable cell-cycle proteins was studied in silico. The binding affinities to multiple cellular targets were investigated and the molecular dynamics were assessed. The in vitro effect of the selected candidate DLT on cancer cell proliferation was determined and the CDK1 inhibitory potential in was evaluated. Finally, the cellular entrapment of the selected candidates was assessed by an in-house developed and validated LC-MS/MS method. The results indicated that polymerase inhibitor antiviral agents, especially DLT, may exert an anti-proliferative potential against variable cancer cell lines. The results showed that the effect may be achieved via potential interaction with the multiple cellular targets, including the CDK1, resulting in halting of the cellular proliferation. DLT exhibited a remarkable cell permeability in the liver cancer cell line which permits adequate interaction with the cellular targets. In conclusion, the results reveal that the polymerase inhibitor (DLT) may have an anti-proliferative potential against liver cancer cells. These results may pose DLT as a therapeutic choice for patients suffering from HCV and are liable to HCC development.

Children represent only a small proportion of those infected with the hepatitis C virus (HCV) compared to adults. Nevertheless, a substantial number of children have chronic HCV infection and are at risk of complications including cirrhosis, portal hypertension, hepatic decompensation with hepatic encephalopathy, and hepatocellular carcinoma in adulthood. The overall prevalence of the HCV in children was estimated to be 0.87% worldwide. The HCV spreads through the blood. Children born to women with chronic hepatitis C should be evaluated and tested for HCV due to the known risk of infection. The course of treatment for hepatitis C depends on the type of HCV. Currently, there are two pan-genotype HCV treatments (Glecaprevir/pibrentasvir and Sofosbuvir/velpatasvir) for children. We aim to review the updated clinical guidelines on the management of HCV infection in children, including screening, diagnosis, and long-term monitoring, as well as currently published clinical trials and ongoing research on direct acting antiviral hepatitis C treatment in children.

Hepatitis C virus (HCV) infection remains one of the leading causes of liver complications globally. Ubiquitin Specific Peptidase-18 (USP18) is a ubiquitin-specific protease that cleaves interferon-stimulated gene 15 (ISG15) from ISGylated protein complexes and is involved in regulating interferon responsiveness. To study the effect of direct-acting antivirals (DAAs) on the USP18 gene using qPCR, 132 participants were recruited and classified into different groups based on treatment duration. USP18 expression was raised compared to rapid virologic response (RVR) and early virologic response (EVR) groups with P = 0.0026 and P = 0.0016, respectively. USP18 was found to be 7.36 folds higher in naïve patients than those with RVR and sustained viral response (SVR). In RVR and SVR groups where patients had cleared HCV RNA after treatment with direct-acting antiviral agents (DAA) therapy, the expression of USP18 was found to be low, with a fold change of 1.3 and 1.4 folds, respectively. Expression of USP18 was significantly higher in the non-RVR group than in the RVR group. In the No EVR group, gene expression was significantly higher than in the EVR group. It is concluded that targeting HCV proteins using DAAs can cause USP18 expression to be normalized more effectively. Moreover, USP18 is a vital marker indicating treatment resistance and distinguishing responders from non-responders during DAA therapy.