Efficacy and safety of a fixed dose combination tablet of asunaprevir + beclabuvir + daclatasvir for the treatment of Hepatitis C

Therapeutic Intervention of Serine Protease Inhibitors against Hepatitis C Virus

Hepatitis C virus (HCV) is a globally prevalent and hazardous disorder that is responsible for inducing several persistent and potentially fatal liver diseases. Current treatment strategies offer limited efficacy, often accompanied by severe and debilitating adverse effects. Consequently, there is an urgent and compelling need to develop novel therapeutic interventions that can provide maximum efficacy in combating HCV while minimizing the burden of adverse effects on patients. One promising target against HCV is the NS3-4A serine protease, a complex composed of two HCV-encoded proteins. This non-covalent heterodimer is crucial in the viral life cycle and has become a primary focus for therapeutic interventions. Although peginterferon, combined with ribavirin, is commonly employed for HCV treatment, its efficacy is hampered by significant adverse effects that can profoundly impact patients' quality of life. In recent years, the development of direct-acting antiviral agents (DAAs) has emerged as a breakthrough in HCV therapy. These agents exhibit remarkable potency against the virus and have demonstrated fewer adverse effects when combined with other DAAs. However, it is important to note that there is a potential for developing resistance to DAAs due to alterations in the amino acid position of the NS3-4A protease. This emphasizes the need for ongoing research to identify strategies that can minimize the emergence of resistance and ensure long-term effectiveness. While the combination of DAAs holds promise for HCV treatment, it is crucial to consider the possibility of drug-drug interactions. These interactions may occur when different DAAs are used concurrently, potentially compromising their therapeutic efficacy. Therefore, carefully evaluating and monitoring potential drug interactions are vital to optimize treatment outcomes. In the pursuit of novel therapeutic interventions for HCV, the field of computational biology and bioinformatics has emerged as a valuable tool. These advanced technologies and methodologies enable the development and design of new drugs and therapeutic agents that exhibit maximum efficacy, reduced risk of resistance, and minimal adverse effects. By leveraging computational approaches, researchers can efficiently screen and optimize potential candidates, accelerating the discovery and development of highly effective treatments for HCV, treatments.

Mechanisms and Clinical Significance of Pharmacokinetic Drug Interactions Mediated by FDA and EMA-approved Hepatitis C Direct-Acting Antiviral Agents

The treatment of patients infected with the hepatitis C virus (HCV) has been revolutionised by the development of direct-acting antiviral agents (DAAs) that target specific HCV proteins involved in viral replication. The first DAAs were associated with clinical problems such as adverse drug reactions and pharmacokinetic drug-drug interactions (DDIs). Current FDA/EMA-approved treatments are combinations of DAAs that simultaneously target the HCV N5A-protein, the HCV N5B-polymerase and the HCV NS3/4A-protease. Adverse events and DDIs are less likely with these DAA combinations but several DDIs of potential clinical significance remain. Much of the available information on the interaction of DAAs with CYP drug-metabolising enzymes and influx and efflux transporters is contained in regulatory summaries and is focused on DDIs of likely clinical importance. Important DDIs perpetrated by current DAAs include increases in the pharmacokinetic exposure to statins and dabigatran. Some mechanistic information can be deduced. Although the free concentrations of DAAs in serum are very low, a number of these DDIs are likely mediated by the inhibition of systemic influx transporters, especially OATP1B1/1B3. Other DDIs may arise by DAA-mediated inhibition of intestinal efflux transporters, which increases the systemic concentrations of some coadministered drugs. Conversely, DAAs are victims of DDIs mediated by cyclosporin, ketoconazole, omeprazole and HIV antiretroviral drug combinations, especially when boosted by ritonavir and, to a lesser extent, cobicistat. In addition, concurrent administration of inducers, such as rifampicin, carbamazepine and efavirenz, decreases exposure to some DAAs. Drug-drug interactions that increase the accumulation of HCV N3/4A-protease inhibitors like grazoprevir may exacerbate hepatic injury in HCV patients.

Effect of Direct Antiviral Therapy Against HCV on CD4+ T Cell Count in Patients with HIV-HCV Coinfection

Background

HCV-related liver disease is an important cause of morbidity and mortality in patients with HIV infection. It is well known that the response rates to HCV therapy are similar between HCV-monoinfected patients and HIV-HV coinfected ones. The aim of this study was to evaluate the impact of HCV eradication on CD4 + T cell count in a population of HIV-HCV coinfected patients.

Materials and Methods

We enrolled patients with HIV-HCV coinfection attending the Infectious Diseases Unit of the A.O.U. Federico II of Naples, from January 2016 to February 2019, treated with ART (AntiRetroviral Therapy) and DAAs (Direct Antiviral Agents). For each patient, we evaluated HIV and HCV viral load and CD4+ T cell count before starting therapy with DAAs, by SVR12 time and by SVR48 time. Fibrosis was evaluated by the mean of Fibroscan^®.

Results

Fifty-two patients were enrolled, 40 males. Fibrosis score was F0-F3 in 15 patients and cirrhosis in the remaining 11 (all in Child-Pugh class A). All had been receiving ART, and all were treated with DAAs. Only patient who had not achieved HIV viral suppression for non-compliance also experienced a relapse of HCV infection after the end of DAAs. In all patients, we observed that the CD4+ T cell count at baseline did not show significant variations compared to SVR12 and SVR48 time. We also assessed CD4 count in relation to HIV categories and stage of liver disease, see Table 1. Also, based on the assessments of the subclasses considered, there were no significant changes in the CD4 + T cell count.

Conclusion

Our study shows that HCV viral eradication obtained with DAAs in patients with HIV-HCV coinfection is not associated with significant changes in the CD4 + T cell count, regardless of CDC category and stage of liver disease.

HCV direct acting antiviral treatment leads to highly durable rates of ALT and AST lower than 30/19 criteria and improved APRI and FIB-4 scores

Direct acting antiviral treatment (DAA) has been the standard of care for hepatitis C virus (HCV) infection, but its long-term benefits in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) improvement and hepatic fibrosis assessed by aspartate aminotransferase-to-platelet ratio index (APRI) and Fibrosis-4 index (FIB-4) scores remain unknown. The purpose of the present study was to assess DAA's long-term benefits, including frequencies of posttreatment week 96 ALT/AST < 30 (males)/19 (females) (<30/19), improvement of APRI and FIB-4 scores, and the associated factors. This was a single-center, retrospective study on 157 patients with HCV with DAA-mediated sustained virological response (SVR) 12. At posttreatment week (post-Rx wk) 96, 75.4% had ALT < 30/19; 62.7%, AST < 30/19; and 60.1%, both ALT/AST < 30/19. ALT/AST < 30/19 at post-Rx wk 96 was associated with ALT/AST < 30/19 at post-Rx wk 12 (p = 0.026), independently of Child-Turcotte-Pugh < 6 (p = 0.862), platelets ≤ 120 × 10⁹ /L (p = 0.343). Improvement rates of APRI < 0.5 and FIB-4 < 1.45 from baseline to post-Rx wk 96 were from 30.9% to 80.5%, and from 23% to 37.8%, respectively. Both APRI and FIB-4 improvement was associated with both ALT/AST < 30 (males)/19 (females) at post-Rx wk 12 (p = 0.012 and 0.011, respectively). Conclusion: The present study showed that DAA-mediated SVR12 in patients with HCV resulted in (1) high and durable rates of ALT (75.4%), AST (62.7%), and both ALT/AST (60.1%) < 30/19, and (2) high rates of APRI < 0.5 (80.5%) and FIB-4 < 1.45 (37.8%) at post-Rx wk 96, demonstrated clinical value of ALT/AST < 30/19 and excellent long-term outcomes of DAA-mediated SVR12 in these patients.

Identification of Aloe-derived natural products as prospective lead scaffolds for SARS-CoV-2 main protease (Mpro) inhibitors

In the past two years, the COVID-19 pandemic has caused over 5 million deaths and 250 million infections worldwide. Despite successful vaccination efforts and emergency approval of small molecule therapies, a diverse range of antivirals is still needed to combat the inevitable resistance that will arise from new SARS-CoV-2 variants. The main protease of SARS-CoV-2 (M^pro) is an attractive drug target due to the clinical success of protease inhibitors against other viruses, such as HIV and HCV. However, in order to combat resistance, various chemical scaffolds need to be identified that have the potential to be developed into potent inhibitors. To this end, we screened a high-content protease inhibitor library against M^proin vitro, in order to identify structurally diverse compounds that could be further developed into antiviral leads. Our high-content screening efforts retrieved 27 hits each with > 50% inhibition in our M^pro FRET assay. Of these, four of the top inhibitor compounds were chosen for follow-up due to their potency and drugability (Lipinski's rules of five criteria): anacardic acid, aloesin, aloeresin D, and TCID. Further analysis via dose response curves revealed IC₅₀ values of 6.8 μM, 38.9 μM, 125.3 μM, and 138.0 μM for each compound, respectively. Molecular docking studies demonstrated that the four inhibitors bound at the catalytic active site of M^pro with varying binding energies (-7.5 to -5.6 kcal/mol). Furthermore, M^pro FRET assay kinetic studies demonstrated that M^pro catalysis is better represented by a sigmoidal Hill model than the standard Michaelis-Menten hyperbola, indicating substantial cooperativity of the active enzyme dimer. This result suggests that the dimerization interface could be an attractive target for allosteric inhibitors. In conclusion, we identified two closely-related natural product compounds from the Aloe plant (aloesin and aloeresin D) that may serve as novel scaffolds for M^pro inhibitor design and additionally confirmed the strongly cooperative kinetics of M^pro proteolysis. These results further advance our knowledge of structure-function relationships in M^pro and offer new molecular scaffolds for inhibitor design.

Comparative effectiveness of pharmacological interventions on mortality and the average length of hospital stay of patients with COVID-19: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Up to now, numerous randomized controlled trials (RCTs) have examined various drugs as possible treatments for Coronavirus Disease 2019 (COVID-19), but the results were diverse and occasionally even inconsistent with each other. To this point,we performed a systematic review and meta-analysis to assess the comparative effectiveness of pharmacological agents in published RCTs.

AREAS COVERED

A literature search was performed using PubMed, SCOPUS, EMBASE, and Web of Science databases. RCTs evaluating mortality and the average length of hospital stay to standard of care (SOC)/placebo/control were included. RCTs mainly were classified into five categories of drugs, including anti-inflammatory, antiviral, antiparasitic, antibody and antibiotics. Meta-analysis was done on 5 drugs classes and sub-group meta-analysis was done on single drugs and moderate or severe stage of disease.

EXPERT OPINION

Mortality and the average length of hospital stay of COVID-19 patients were significantly reduced with anti-inflammatory drugs (odds ratio [OR]: 0.77, 95% confidence interval [CI]: 0.69 to 0.85, P<0.00001, and mean difference [MD]: -1.41, CI:-1.75 to -1.07, P<0.00001, respectively) compared to SOC/control/placebo. Furthermore, antiparasitic was associated with reduced length of hospital stay (MD: -0.65, CI: -1.26 to -0.03, P<0.05) in comparison to SOC/placebo/control. However, no effectiveness was found in other pharmacological interventions.