Available Evidence and Ongoing Clinical Trials of Remdesivir: Could It Be a Promising Therapeutic Option for COVID-19?

Repurposing Polyether Ionophores as a New-Class of Anti-SARS-Cov-2 Agents as Adjunct Therapy

The emergence of SARS-CoV-2 and its variants have posed a significant threat to humankind in tackling the viral spread. Furthermore, currently repurposed drugs and frontline antiviral agents have failed to cure severe ongoing infections effectively. This insufficiency has fuelled research for potent and safe therapeutic agents to treat COVID-19. Nonetheless, various vaccine candidates have displayed a differential efficacy and need for repetitive dosing. The FDA-approved polyether ionophore veterinary antibiotic for treating coccidiosis has been repurposed for treating SARS-CoV-2 infection (as shown by both in vitro and in vivo studies) and other deadly human viruses. Based on selectivity index values, ionophores display therapeutic effects at sub-nanomolar concentrations and exhibit selective killing ability. They act on different viral targets (structural and non-structural proteins), host-cell components leading to SARS-CoV-2 inhibition, and their activity is further enhanced by Zn²⁺ supplementation. This review summarizes the anti-SARS-CoV-2 potential and molecular viral targets of selective ionophores like monensin, salinomycin, maduramicin, CP-80,219, nanchangmycin, narasin, X-206 and valinomycin. Ionophore combinations with Zn²⁺ are a new therapeutic strategy that warrants further investigation for possible human benefits.

A Review on SARS-CoV-2 Genome in the Aquatic Environment of Africa: Prevalence, Persistence and the Future Prospects

The COVID-19 pandemic (Coronavirus disease 2019) remains problematic in all its manifestations on the global stage where countless events of human-to-human exposure have led to fatal cases; thus, the aftermath being an unprecedented public health concern, with inaccessible health care and the instability of economies and financial institutions. These pose massive obstacles that can insatiably devour existing human resources causing negative impacts, especially in developing countries. Tracking the origin, dissemination and mutating strains of the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) on population-wide scales is a somewhat overwhelming task, with the urgent need to map the dissemination and magnitude of SARS-CoV-2 in near real-time. This review paper focuses on the poor sanitation of some waterbodies and wastewater management policies in low-income African countries, highlighting how these contribute to the COVID-19 pandemic on the continent. Since the outbreak of the novel coronavirus pandemic, there has been an upsurge in scientific literature and studies concerning SARS-CoV-2 with different opinions and findings. The current paper highlights the challenges and also summarizes the environmental aspects related to the monitoring and fate of the SARS-CoV-2 genomes in the aquatic milieu of Sub-Saharan Africa.

AVIFAVIR for Treatment of Patients With Moderate Coronavirus Disease 2019 (COVID-19): Interim Results of a Phase II/III Multicenter Randomized Clinical Trial

In May 2020 the Russian Ministry of Health granted fast-track marketing authorization to RNA polymerase inhibitor AVIFAVIR (favipiravir) for the treatment of COVID-19 patients. In the pilot stage of Phase II/III clinical trial, AVIFAVIR enabled SARS-CoV-2 viral clearance in 62.5% of patients within 4 days, and was safe and well-tolerated.

Clinical Trials Registration. NCT04434248.

Drug repurposing for identification of potential inhibitors against SARS-CoV-2 spike receptor-binding domain: An in silico approach

Background & objectives

The world is currently under the threat of coronavirus disease 2019 (COVID-19) infection, caused by SARS-CoV-2. The objective of the present investigation was to repurpose the drugs with potential antiviral activity against receptor-binding domain (RBD) of SARS-CoV-2 spike (S) protein among 56 commercially available drugs. Therefore, an integrative computational approach, using molecular docking, quantum chemical calculation and molecular dynamics, was performed to unzip the effective drug-target interactions between RBD and 56 commercially available drugs.

Methods

The present in silico approach was based on information of drugs and experimentally derived crystal structure of RBD of SARS-CoV-2 S protein. Molecular docking analysis was performed for RBD against all 56 reported drugs using AutoDock 4.2 tool to screen the drugs with better potential antiviral activity which were further analysed by other computational tools for repurposing potential drug or drugs for COVID-19 therapeutics.

Results

Drugs such as chalcone, grazoprevir, enzaplatovir, dolutegravir, daclatasvir, tideglusib, presatovir, remdesivir and simeprevir were predicted to be potentially effective antiviral drugs against RBD and could have good COVID-19 therapeutic efficacy. Simeprevir displayed the highest binding affinity and reactivity against RBD with the values of -8.52 kcal/mol (binding energy) and 9.254 kcal/mol (band energy gap) among all the 56 drugs under investigation.

Interpretation & conclusions

In the current investigation, simeprevir was identified as the potential antiviral drug based on the in silico findings in comparison to remdesivir, favipiravir and other 53 drugs. Further, laboratory and clinical investigations are needed to be carried out which will aid in the development of quick therapeutics designed for COVID-19.

Pharmacokinetic, Pharmacodynamic, and Drug-Interaction Profile of Remdesivir, a SARS-CoV-2 Replication Inhibitor

Remdesivir (RDV, Veklury^®) is a once-daily, nucleoside ribonucleic acid polymerase inhibitor of severe acute respiratory syndrome coronavirus 2 replication. Remdesivir has been granted approvals in several countries for use in adults and children hospitalized with severe coronavirus disease 2019 (COVID-19). Inside the cell, remdesivir undergoes metabolic activation to form the intracellular active triphosphate metabolite, GS-443902 (detected in peripheral blood mononuclear cells), and ultimately, the renally eliminated plasma metabolite GS-441524. This review discusses the pre-clinical pharmacology of RDV, clinical pharmacokinetics, pharmacodynamics/concentration-QT analysis, rationale for dose selection for treatment of patients with COVID-19, and drug–drug interaction potential based on available in vitro and clinical data in healthy volunteers. Following single-dose intravenous administration over 2 h of an RDV solution formulation across the dose range of 3–225 mg in healthy participants, RDV and its metabolites (GS-704277and GS-441524) exhibit linear pharmacokinetics. Following multiple doses of RDV 150 mg once daily for 7 or 14 days, major metabolite GS-441524 accumulates approximately 1.9-fold in plasma. Based on pharmacokinetic bridging from animal data and available human data in healthy volunteers, the RDV clinical dose regimen of a 200-mg loading dose on day 1 followed by 100-mg maintenance doses for 4 or 9 days was selected for further evaluation of pharmacokinetics and safety. Results showed high intracellular concentrations of GS-443902 suggestive of efficient conversion from RDV into the triphosphate form, and further supporting this clinical dosing regimen for the treatment of COVID-19. Mathematical drug–drug interaction liability predictions, based on in vitro and phase I data, suggest RDV has low potential for drug–drug interactions, as the impact of inducers or inhibitors on RDV disposition is minimized by the parenteral route of administration and extensive extraction. Using physiologically based pharmacokinetic modeling, RDV is not predicted to be a clinically significant inhibitor of drug-metabolizing enzymes or transporters in patients infected with COVID-19 at therapeutic RDV doses.

The mass production of systematic reviews about COVID-19: An analysis of PROSPERO records

OBJECTIVE

This study aimed to assess the characteristics of different designs of systematic reviews (SRs) registered in the International Prospective Register of Systematic Reviews (PROSPERO) about COVID-19.

METHODS

The search was performed in the PROSPERO database using the strategy proposed by the database and considered only human studies. The last date of the search was April 27, 2020. Full text of all records was accessed, and data were extracted by a single researcher, which was further double-checked by another researcher. A descriptive analysis was performed considering record characteristics using tables.

RESULTS

We included 564 records from which the vast majority were registered as SRs (n = 513, 91%). In general, we found poor reporting and missing or confusing information, since 84% of the records (n = 474) did not report the full search that would be adopted, 16% (n = 90) did not report clearly the databases that would be used, and 49.1% (n = 277) did not report the number of primary outcomes. The main focus of most of the records involved clinical, epidemiological, complication, and laboratory characteristics (n = 173, 30.7%) or the treatment of COVID-19 (n = 138, 24.5%).

CONCLUSION

A large number of SRs about COVID-19 have been conducted, and many of the assessed records were poorly reported and would be difficult to replicate. Besides, collected data points to an epidemic of redundant reviews on COVID-19.

Structural insights of key enzymes into therapeutic intervention against SARS-CoV-2

COVID-19 pandemic, caused by SARS-CoV-2, has drastically affected human health all over the world. After the emergence of the pandemic the major focus of efforts to attenuate the infection has been on repurposing the already approved drugs to treat COVID-19 adopting a fast-track strategy. However, to date a specific regimen to treat COVID-19 is not available. Over the last few months a substantial amount of data about the structures of various key proteins and their recognition partners involved in the SARS-CoV-2 pathogenesis has emerged. These studies have not only provided the molecular level descriptions ofthe viral pathogenesis but also laid the foundation for rational drug design and discovery. In this review, we have recapitulated the structural details of four key viral enzymes, RNA-dependent RNA polymerase, 3-chymotrypsin like protease, papain-like protease and helicase, and two host factors including angiotensin-converting enzyme 2 and transmembrane serine protease involved in the SARS-CoV-2 pathogenesis, and described the potential hotspots present on these structures which could be explored for therapeutic intervention. We have also discussed the significance of endoplasmic reticulum α-glucosidases as potential targets for anti-SARS-CoV-2 drug discovery.

Remdesivir use in the coronavirus disease 2019 pandemic: A mini-review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative viral pathogen of coronavirus disease 2019 (COVID-19), appears to have various clinical presentations and may result in severe respiratory failure. The global SARS-CoV-2-associated viral pneumonia pandemic was first reported in December 2019 in China. Based on known pharmacological mechanisms, many therapeutic drugs have been repurposed to target SARS-CoV-2. Among these drugs, remdesivir appears to be the currently most promising according to several clinical trials and reports of compassionate use. In this mini-review, we summarize the current evidence on the efficacy and challenges of remdesivir for the treatment of coronavirus disease 2019 (COVID-19).

The HMOX1 Pathway as a Promising Target for the Treatment and Prevention of SARS-CoV-2 of 2019 (COVID-19)

The coronavirus disease of 2019 (COVID-19) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a global pandemic with increasing incidence and mortality rates. Recent evidence based on the cytokine profiles of severe COVID-19 cases suggests an overstimulation of macrophages and monocytes associated with reduced T-cell abundance (lymphopenia) in patients infected with SARS-CoV-2. The SARS-CoV-2 open reading frame 3 a (ORF3a) protein was found to bind to the human HMOX1 protein at a high confidence through high-throughput screening experiments. The HMOX1 pathway can inhibit platelet aggregation, and can have anti-thrombotic and anti-inflammatory properties, amongst others, all of which are critical medical conditions observed in COVID-19 patients. Here, we review the potential of modulating the HMOX1-ORF3a nexus to regulate the innate immune response for therapeutic benefits in COVID-19 patients. We also review other potential treatment strategies and suggest novel synthetic and natural compounds that may have the potential for future development in clinic.