Structural Basis of the SARS-CoV-2/SARS-CoV Receptor Binding and Small-Molecule Blockers as Potential Therapeutics.

Abstract: Over the past two decades, deadly coronaviruses have caused major challenges to public health, with the most recent being the severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2, 2019) pandemic. The path for virus invasion into humans and other hosts is mediated by "host-pathogen" interactions, specifically, virus-receptor binding. An in-depth understanding of the virus-receptor binding mechanism is a prerequisite for the discovery of vaccines, antibodies, and/or small-molecule inhibitors that can interrupt this interaction and prevent or cure infection. In this review, we discuss the viral entry mechanism, the known structural aspects of virus-receptor interactions (SARS-CoV-2 S/humanACE2, SARS-CoV S/humanACE2, and MERS-CoV S/humanDPP4), the key protein domains and amino acid residues involved in binding, and the small-molecule inhibitors and other drugs that have (as of June, 2020) exhibited therapeutic potential. Specifically, we review the potential clinical utility of two transmembrane serine protease 2 (TMPRSS2)-targeting protease inhibitors, nafamostat mesylate and camostat mesylate, as well as two novel potent fusion inhibitors and the repurposed Ebola drug, remdesivir, which is specific to RdRp, against human coronaviruses, including SARS-CoV-2. This article has been accepted for publication on June 23, 2020. Changes may still occur before final publication. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 61 is January 8, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


Therapeutic dilemma in the repression of severe acute respiratory syndrome coronavirus-2 proteome.

Abstract: Currently, the pandemic coronavirus disease 2019 (COVID-19) has unprecedentedly captivated its human hosts by causing respiratory illnesses because of evolution of the genetic makeup of novel coronavirus (CoV) known as severe acute respiratory syndrome coronavirus-2 (SARS CoV-2). As much as the researchers are inundated for the quest of effective treatments from available drugs, the discovery and trials of new experimental drugs are also at a threshold for clinical trials. There has been much concern regarding the new and targeted drugs considering the comprehensive ambiguity regarding the mechanism and pathway of the drug action with respect to the new and unpredictable structural and nonstructural proteins (NSPs) of SARS CoV-2. This study was aimed to discuss functional pathways related to NSPs in CoVs with updated knowledge regarding SARS CoV-2, mechanisms of action of certain approved and investigational drugs for correct orientation regarding the treatment strategies, including nucleotide analog mechanism, receptor analog mechanism, and peptide-peptide interactions, along with the impact of COVID-19 on a global scale. Although there is a dire need for targeted drugs against SARS CoV-2, the practical achievement of its cure is possible by only using effective drugs with appropriate mechanisms to eliminate the disease.


Coronavirus puts drug repurposing on the fast track.


Use of the informational spectrum methodology for rapid biological analysis of the novel coronavirus 2019-nCoV: prediction of potential receptor, natural reservoir, tropism and therapeutic/vaccine target.

Abstract: A novel coronavirus recently identified in Wuhan, China (2019-nCoV) has expanded the number of highly pathogenic coronaviruses affecting humans. The 2019-nCoV represents a potential epidemic or pandemic threat, which requires a quick response for preparedness against this infection. The present report uses the informational spectrum methodology to identify the possible origin and natural host of the new virus, as well as putative therapeutic and vaccine targets. The performed in silico analysis indicates that the newly emerging 2019-nCoV is closely related to severe acute respiratory syndrome (SARS)-CoV and, to a lesser degree, Middle East respiratory syndrome (MERS)-CoV. Moreover, the well-known SARS-CoV receptor (ACE2) might be a putative receptor for the novel virus as well. Actin protein was also suggested as a host factor that participates in cell entry and pathogenesis of 2019-nCoV; therefore, drugs modulating biological activity of this protein (e.g. ibuprofen) were suggested as potential candidates for treatment of this viral infection. Additional results indicated that civets and poultry are potential candidates for the natural reservoir of the 2019-nCoV, and that domain 288-330 of S1 protein from the 2019-nCoV represents promising therapeutic and/or vaccine target.


Biophysical modeling of the SARS-CoV-2 viral cycle reveals ideal antiviral targets

Abstract: Effective therapies for COVID-19 are urgently needed. Presently there are more than 800 COVID-19 clinical trials globally, many with drug combinations, resulting in an empirical process with an enormous number of possible combinations. To identify the most promising potential therapies, we developed a biophysical model for the SARS-CoV-2 viral cycle and performed a sensitivity analysis for individual model parameters and all possible pairwise parameter changes (162 = 256 possibilities). We found that model-predicted virion production is fairly insensitive to changes in most viral entry, assembly, and release parameters, but highly sensitive to some viral transcription and translation parameters. Furthermore, we found a cooperative benefit to pairwise targeting of transcription and translation, predicting that combined targeting of these processes will be especially effective in inhibiting viral production.


Lessons learned from SARS-CoV and MERS-CoV: FDA-approved Abelson tyrosine-protein kinase 2 inhibitors may help us combat SARS-CoV-2


Glycoinformatics approach for identifying target positions to inhibit initial binding of SARS-CoV-2 S1 protein to the host cell

Abstract: COVID-19 outbreak is still threatening the public health. Therefore, in the middle of the pandemic, all kind of knowledge on SARS-CoV-2 may help us to find the solution. Determining the 3D structures of the proteins involved in host-pathogen interactions are of great importance in the fight against infection. Besides, post-translational modifications of the protein on 3D structure should be revealed in order to understand the protein function since these modifications are responsible for the host-pathogen interaction. Based on these, we predicted O-glycosylation and phosphorylation positions using full amino acid sequence of S1 protein. Candidate positions were further analyzed with enzyme binding activity, solvent accessibility, surface area parameters and the positions determined with high accuracy rate were used to design full 3D glycoprotein structure of the S1 protein using carbohydrate force field. In addition, the interaction between the C-type lectin CD209L and α-mannose residues was examined and carbohydrate recognition positions were predicted. We suggest these positions as a potential target for the inhibition of the initial binding of SARS-CoV-2 S1 protein to the host cell.


Identifying SARS-CoV-2 entry inhibitors through drug repurposing screens of SARS- S and MERS-S pseudotyped particles

Abstract: While vaccine development will hopefully quell the global pandemic of COVID-19 caused by SARS-CoV-2, small molecule drugs that can effectively control SARS-CoV-2 infection are urgently needed. Here inhibitors of two coronavirus spike proteins (S) were identified by screening a library of approved drugs with SARS-S and MERS-S pseudotyped particle entry assays. Using high-throughput screening technology, we discovered three compounds (cepharanthine, abemaciclib and trimipramine) to be broad spectrum inhibitors for spike-mediated entry. This work should contribute to the development of effective treatments against the initial stage of viral infection, thus reducing viral burden in COVID-19 patients.


Network pharmacology studies on the effect of Chai-Ling decoction in coronavirus disease 2019

Abstract: Background: Chai-Ling decoction (CLD), derived from a modification of Xiao-Chai-Hu (XCH) decoction and Wu-Ling-San (WLS) decoction, has been used to treat the early-stage of coronavirus disease 2019 (COVID-19). However, the mechanisms of CLD in COVID-19 remain unknown. In this study, the potential mechanisms of CLD in COVID-19 were preliminarily investigated based on network pharmacology and molecular docking method. Methods: Initially, the active components and targets of CLD were screened based on Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform and PharmMapper database. The targets of COVID-19 were obtained from GeneCards database. The protein-protein interaction network was established using STRING database to analyze the key targets. Gene Oncology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes analysis were also conducted to evaluate the pathways related to the targets of CLD on COVID-19. Moreover, the compound-target-pathway network was established using Cytoscape 3.2.7. Subsequently, the molecular docking method was performed to select the active compounds with high binding affinity on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and angiotensin-converting enzyme 2 (ACE2), which is the key target of SARS-CoV-2 in entering target cells. The possible binding sites were also visualized by a three-dimensional graph. Results: Network pharmacology analysis showed that there were 106 active components and 160 targets of CLD. Additionally, 251 targets related to COVID-19 were identified, and 24 candidates of CLD on COVID-19 were selected. A total of 283 GO terms of CLD on COVID-19 were identified, and 181 pathways were screened based on GO and Kyoto Encyclopedia of Genes and Genomes analyses. CLD might alleviate the inflammatory response and improve lung injury to treat COVID-19 through interleukin 17 signaling, T helper cell 17 differentiation, tumor necrosis factor signaling, and hypoxia inducible factor-1 signaling. Besides, molecular docking indicated that beta-sitosterol, kaempferol, and stigmasterol were the top three candidates in CLD with the highest affinity to SARS-CoV-2 and ACE2. Conclusion: Our study identifies the potential mechanisms of CLD on COVID-19 and beta-sitosterol, kaempferol, and stigmasterol may be the key compounds that exert antiviral effects against SARS-CoV-2.


An update on therapeutic repurposing strategies for COVID-19

Abstract: The severe acute respiratory syndrome coronavirus 2, well known as COVID-19 has become the current health distress to the entire world. In the pandemic scenario the research on the rapid development of new drug molecules is highly risky and tedious process. The current COVID-19 emergency demands an urgent development of possible strategies to protect people at high risk of infection and hence the drug repurposing became an emerging approach to fight COVID-19. This review summarizes an update on various therapeutic strategies with special attention on repurposing of drugs to fight against SARS-CoV-2 worldwide. The investigation of existing drugs for new therapeutic purposes is one line of scientific research followed to develop safe and effective COVID-19 treatments. Broad-spectrum antiviral agents (BSAAs) that have been believed to be safe through testing on early phase clinical trials have been hyped as good drug repurposing candidates. Broad-spectrum antiviral drugs such as Ribavirin, Umifenovir were advised for COVID-19 treatment. Some antibiotics may be repurposed as COVID-19 treatments such as teicoplanin, oritavancin, dalbavancin, monensin and azithromycin. Ivermectin an antiparasitic is recently repurposed. Hydroxychloroquine and chloroquine, having immunomodulating effect on humans, have been shown to have antiviral activity at starting and post-entry stages of the SARS-CoV-2 infection. There is a need for global health emergency to call for a courageous, global response at the political and governmental levels. Therefore, the regulatory agencies must act swiftly to lessen any financial obstacles involving private companies and update guidelines for drug licenses by repurposing if necessary.


Multi-level proteomics reveals host-perturbation strategies of SARS-CoV-2 and SARS-CoV

Abstract: The sudden global emergence of SARS-CoV-2 urgently requires an in-depth understanding of molecular functions of viral proteins and their interactions with the host proteome. Several omics studies have extended our knowledge of COVID-19 pathophysiology, including some focused on proteomic aspects1–3. To understand how SARS-CoV-2 and related coronaviruses manipulate the host we here characterized interactome, proteome and signaling processes in a systems-wide manner. This identified connections between the corresponding cellular events, revealed functional effects of the individual viral proteins and put these findings into the context of host signaling pathways. We investigated the closely related SARS-CoV-2 and SARS-CoV viruses as well as the influence of SARS-CoV-2 on transcriptome, proteome, ubiquitinome and phosphoproteome of a lung-derived human cell line. Projecting these data onto the global network of cellular interactions revealed relationships between the perturbations taking place upon SARS-CoV-2 infection at different layers and identified unique and common molecular mechanisms of SARS coronaviruses. The results highlight the functionality of individual proteins as well as vulnerability hotspots of SARS-CoV-2, which we targeted with clinically approved drugs. We exemplify this by identification of kinase inhibitors as well as MMPase inhibitors with significant antiviral effects against SARS-CoV-2.


Targeted Oxidation Strategy (TOS) for Potential Inhibition of Coronaviruses by Disulfiram — a 70-Year Old Anti-Alcoholism Drug

Abstract: In the new millennium, the outbreak of new coronavirus has happened three times: SARS-CoV, MERS-CoV, and 2019-nCoV Unfortunately, we still have no pharmaceutical weapons against the diseases caused by these viruses The pandemic of 2019-nCoV reminds us of the urgency to search new drugs with totally different mechanism that may target the weaknesses specific to coronaviruses Herein, we disclose a new targeted oxidation strategy (TOS II) leveraging non-covalent interactions potentially to oxidize and inhibit the activities of cytosolic thiol proteins via thiol/thiolate oxidation to disulfide (TOD) Quantum mechanical calculations show encouraging results supporting the feasibility to selectively oxidize thiol of targeted proteins via TOS II even in relatively reducing cytosolic microenvironments Molecular docking against the two thiol proteases Mpro and PLpro of 2019-nCoV provide evidence to support a TOS II mechanism for two experimentally identified anti-2019-nCoV disulfide oxidants: disulfiram and PX-12 Remarkably, disulfiram is an anti-alcoholism drug approved by FDA 70 years ago, thus it can be immediately used in phase III clinical trial for anti-2019-nCoV treatment Finally, a preliminary list of promising TOS II drug candidates targeting the two thiol proteases of 2019-nCoV are proposed upon virtual screening of 32143 disulfides


COVID-19: Living through Another Pandemic

Abstract: Novel beta-coronavirus SARS-CoV-2 is the pathogenic agent responsible for coronavirus disease-2019 (COVID-19), a globally pandemic infectious disease. Due to its high virulence and the absence of immunity among the general population, SARS-CoV-2 has quickly spread to all countries. This pandemic highlights the urgent unmet need to expand and focus our research tools on what are considered "neglected infectious diseases" and to prepare for future inevitable pandemics. This global emergency has generated unprecedented momentum and scientific efforts around the globe unifying scientists from academia, government and the pharmaceutical industry to accelerate the discovery of vaccines and treatments. Herein, we shed light on the virus structure and life cycle and the potential therapeutic targets in SARS-CoV-2 and briefly refer to both active and passive immunization modalities, drug repurposing focused on speed to market, and novel agents against specific viral targets as therapeutic interventions for COVID-19.


The lysosome: A potential juncture between SARS-CoV-2 infectivity and Niemann-Pick disease type C, with therapeutic implications

Abstract: Drug repurposing is potentially the fastest available option in the race to identify safe and efficacious drugs that can be used to prevent and/or treat COVID-19. By describing the life cycle of the newly emergent coronavirus, SARS-CoV-2, in light of emerging data on the therapeutic efficacy of various repurposed antimicrobials undergoing testing against the virus, we highlight in this review a possible mechanistic convergence between some of these tested compounds. Specifically, we propose that the lysosomotropic effects of hydroxychloroquine and several other drugs undergoing testing may be responsible for their demonstrated in vitro antiviral activities against COVID-19. Moreover, we propose that Niemann-Pick disease type C (NPC), a lysosomal storage disorder, may provide new insights into potential future therapeutic targets for SARS-CoV-2, by highlighting key established features of the disorder that together result in an "unfavorable" host cellular environment that may interfere with viral propagation. Our reasoning evolves from previous biochemical and cell biology findings related to NPC, coupled with the rapidly evolving data on COVID-19. Our overall aim is to suggest that pharmacological interventions targeting lysosomal function in general, and those particularly capable of reversibly inducing transient NPC-like cellular and biochemical phenotypes, constitute plausible mechanisms that could be used to therapeutically target COVID-19.


The Landscape of Human Cancer Proteins Targeted by SARS-CoV-2

Abstract: The mapping of SARS-CoV-2 human protein-protein interactions by Gordon and colleagues revealed druggable targets that are hijacked by the virus. Here, we highlight several oncogenic pathways identified at the host-virus interface of SARS-CoV-2 to enable cancer biologists to apply their knowledge for rapid drug repurposing to treat COVID-19, and help inform the response to potential long-term complications of the disease.


Repurposing cefuroxime for treatment of COVID-19: a scoping review of in silico studies

Abstract: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of Coronavirus disease 19 (COVID-19), is a novel human Coronavirus that is responsible for about 300,000 deaths worldwide. To date, there is no confirmed treatment or vaccine prevention strategy against COVID-19. Due to the urgent need for effective treatment, drug repurposing is regarded as the immediate option. Potential drugs can often be identified via in silico drug screening experiments. Consequently, there has been an explosion of in silico experiments to find drug candidates or investigate anecdotal claims. One drug with several anecdotal accounts of benefit is Cefuroxime. The aim of this study was to identify and summarize in silico evidence for possible activity of Cefuroxime against SARS-CoV-2.To this end, we performed a scoping review of literature of in silico drug repurposing experiments for SARS-CoV-2 using PRISMA-ScR. We searched Medline, Embase, Scopus, Web of Knowledge, and Google Scholar for original studies published between 1st Feb, 2020 and 15th May, 2020 that screened drug libraries, and identified Cefuroxime as a top-ranked potential inhibitor drug against SARS-CoV-2 proteins. Six studies were identified. These studies reported Cefuroxime as a potential inhibitor of 3 key SARS-CoV-2 proteins; main protease, RNA dependent RNA polymerase, and ACE2-Spike complex. We provided a summary of the methodology and findings of the identified studies. Our scoping review identified significant in silico evidence that Cefuroxime may be a potential multi-target inhibitor of SARS-CoV-2. Further in vitro and in vivo studies are required to evaluate the potential of Cefuroxime for COVID-19.Communicated by Ramaswamy H. Sarma.


The pharmacological development of direct acting agents for emerging needed therapy against SARS-CoV-2

Abstract: Recently, the SARS-CoV-2 was quickly identified as the causal pathogen leading to the outbreak of severe acute respiratory syndrome-like illness all over the world. As the SARS-CoV-2 infection pandemic proceeds, many efforts are being dedicated to the development of diverse treatment strategies. Increasing evidence showed potential therapeutic agents directly acting against SARS-CoV-2 virus, such as interferon, RNA-dependent RNA polymerase inhibitors, protease inhibitors, viral entry blockers, neuraminidase inhibitor, vaccine, antibody agent targeting the SARS-CoV-2 RNA genome, natural killer cells and nucleocytoplasmic trafficking inhibitor. To date, several direct anti-SARS-CoV-2 agents have demonstrated promising in vitro and clinical efficacy. This article reviews the current and future development of direct acting agents against SARS-CoV-2.


Network Medicine Framework for Identifying Drug Repurposing Opportunities for COVID-19

Abstract: The COVID-19 pandemic demands the rapid identification of drug-repurpusing candidates. In the past decade, network medicine had developed a framework consisting of a series of quantitative approaches and predictive tools to study host-pathogen interactions, unveil the molecular mechanisms of the infection, identify comorbidities as well as rapidly detect drug repurpusing candidates. Here, we adapt the network-based toolset to COVID-19, recovering the primary pulmonary manifestations of the virus in the lung as well as observed comorbidities associated with cardiovascular diseases. We predict that the virus can manifest itself in other tissues, such as the reproductive system, and brain regions, moreover we predict neurological comorbidities. We build on these findings to deploy three network-based drug repurposing strategies, relying on network proximity, diffusion, and AI-based metrics, allowing to rank all approved drugs based on their likely efficacy for COVID-19 patients, aggregate all predictions, and, thereby to arrive at 81 promising repurposing candidates. We validate the accuracy of our predictions using drugs currently in clinical trials, and an expression-based validation of selected candidates suggests that these drugs, with known toxicities and side effects, could be moved to clinical trials rapidly.


In silico screening of Chinese herbal medicines with the potential to directly inhibit 2019 novel coronavirus

Abstract: OBJECTIVE: In this study we execute a rational screen to identify Chinese medical herbs that are commonly used in treating viral respiratory infections and also contain compounds that might directly inhibit 2019 novel coronavirus (2019-nCoV), an ongoing novel coronavirus that causes pneumonia. METHODS: There were two main steps in the screening process. In the first step we conducted a literature search for natural compounds that had been biologically confirmed as against sever acute respiratory syndrome coronavirus or Middle East respiratory syndrome coronavirus. Resulting compounds were cross-checked for listing in the Traditional Chinese Medicine Systems Pharmacology Database. Compounds meeting both requirements were subjected to absorption, distribution, metabolism and excretion (ADME) evaluation to verify that oral administration would be effective. Next, a docking analysis was used to test whether the compound had the potential for direct 2019-nCoV protein interaction. In the second step we searched Chinese herbal databases to identify plants containing the selected compounds. Plants containing 2 or more of the compounds identified in our screen were then checked against the catalogue for classic herbal usage. Finally, network pharmacology analysis was used to predict the general in vivo effects of each selected herb. RESULTS: Of the natural compounds screened, 13 that exist in traditional Chinese medicines were also found to have potential anti-2019-nCoV activity. Further, 125 Chinese herbs were found to contain 2 or more of these 13 compounds. Of these 125 herbs, 26 are classically catalogued as treating viral respiratory infections. Network pharmacology analysis predicted that the general in vivo roles of these 26 herbal plants were related to regulating viral infection, immune/inflammation reactions and hypoxia response. CONCLUSION: Chinese herbal treatments classically used for treating viral respiratory infection might contain direct anti-2019-nCoV compounds.


Potential therapeutic targets and promising drugs for combating SARS-CoV-2

Abstract: As of April 9, 2020, a novel coronavirus (SARS-CoV-2) had caused 89,931 deaths and 1,503,900 confirmed cases worldwide, which indicates an increasingly severe and uncontrollable situation. Initially, little was known about the virus. As research continues, we now know the genome structure, epidemiological and clinical characteristics, and pathogenic mechanisms of SARS-CoV-2. Based on this knowledge, potential targets involved in the processes of virus pathogenesis need to be identified, and the discovery or development of drugs based on these potential targets is the most pressing need. Here, we have summarized the potential therapeutic targets involved in virus pathogenesis and discuss the advances, possibilities, and significance of drugs based on these targets for treating SARS-CoV-2. This review will facilitate the identification of potential targets and provide clues for drug development that can be translated into clinical applications for combating SARS-CoV-2.


Novel Drugs Targeting the SARS-CoV-2/COVID-19 Machinery

Abstract: Like other human pathogenic viruses, coronavirus SARS-CoV-2 employs sophisticated macromolecular machines for viral host cell entry, genome replication and protein processing. Such machinery encompasses SARS-CoV-2 envelope spike (S) glycoprotein required for host cell entry by binding to the ACE2 receptor, viral RNA-dependent RNA polymerase (RdRp) and 3-chymotrypsin-like main protease (3Clpro/Mpro). Under the pressure of the accelerating COVID-19 pandemic caused by the outbreak of SARSCoV- 2 in Wuhan, China in December 2019, novel and repurposed drugs were recently designed and identified for targeting the SARS-CoV-2 reproduction machinery, with the aim to limit spread of SARS-CoV-2 and morbidity and mortality of the COVID-19 pandemic.


Perspectives for repurposing drugs for the coronavirus disease 2019

Abstract: The newly emerged 2019 novel coronavirus (CoV), named as severe acute respiratory syndrome CoV-2 (SARS-CoV-2), like SARS-CoV (now, SARS-CoV-1) and Middle East respiratory syndrome CoV (MERS-CoV), has been associated with high infection rates with over 36,405 deaths. In the absence of approved marketed drugs against coronaviruses, the treatment and management of this novel CoV disease (COVID-19) worldwide is a challenge. Drug repurposing that has emerged as an effective drug discovery approach from earlier approved drugs could reduce the time and cost compared to de novo drug discovery. Direct virus-targeted antiviral agents target specific nucleic acid or proteins of the virus while host-based antivirals target either the host innate immune responses or the cellular machineries that are crucial for viral infection. Both the approaches necessarily interfere with viral pathogenesis. Here we summarize the present status of both virus-based and host-based drug repurposing perspectives for coronaviruses in general and the SARS-CoV-2 in particular.


Therapeutic strategies in an outbreak scenario to treat the novel coronavirus originating in Wuhan, China

Abstract: A novel coronavirus (2019-nCoV) originating in Wuhan, China presents a potential respiratory viral pandemic to the world population. Current efforts are focused on containment and quarantine of infected individuals. Ultimately, the outbreak could be controlled with a protective vaccine to prevent 2019-nCoV infection. While vaccine research should be pursued intensely, there exists today no therapy to treat 2019-nCoV upon infection, despite an urgent need to find options to help these patients and preclude potential death. Herein, I review the potential options to treat 2019-nCoV in patients, with an emphasis on the necessity for speed and timeliness in developing new and effective therapies in this outbreak. I consider the options of drug repurposing, developing neutralizing monoclonal antibody therapy, and an oligonucleotide strategy targeting the viral RNA genome, emphasizing the promise and pitfalls of these approaches. Finally, I advocate for the fastest strategy to develop a treatment now, which could be resistant to any mutations the virus may have in the future. The proposal is a biologic that blocks 2019-nCoV entry using a soluble version of the viral receptor, angiotensin-converting enzyme 2 (ACE2), fused to an immunoglobulin Fc domain, providing a neutralizing antibody with maximal breath to avoid any viral escape, while also helping to recruit the immune system to build lasting immunity. The sequence of the ACE2-Fc protein is provided to investigators, allowing its possible use in recombinant protein expression systems to start producing drug today to treat patients under compassionate use, while formal clinical trials are later undertaken. Such a treatment could help infected patients before a protective vaccine is developed and widely available in the coming months to year(s).


COVID-19 Drug Discovery Using Intensive Approaches

Abstract: Since the infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in China during December 2019, the coronavirus disease 2019 (COVID-19) has spread on a global scale, causing the World Health Organization (WHO) to issue a warning. While novel vaccines and drugs that target SARS-CoV-2 are under development, this review provides information on therapeutics which are under clinical trials or are proposed to antagonize SARS-CoV-2. Based on the information gained from the responses to other RNA coronaviruses, including the strains that cause severe acute respiratory syndrome (SARS)-coronaviruses and Middle East respiratory syndrome (MERS), drug repurposing might be a viable strategy. Since several antiviral therapies can inhibit viral replication cycles or relieve symptoms, mechanisms unique to RNA viruses will be important for the clinical development of antivirals against SARS-CoV-2. Given that several currently marketed drugs may be efficient therapeutic agents for severe COVID-19 cases, they may be beneficial for future viral pandemics and other infections caused by RNA viruses when standard treatments are unavailable.


Predicting potential drug targets and repurposable drugs for COVID-19 via a deep generative model for graphs

Abstract: Coronavirus Disease 2019 (COVID-19) has been creating a worldwide pandemic situation. Repurposing drugs, already shown to be free of harmful side effects, for the treatment of COVID-19 patients is an important option in launching novel therapeutic strategies. Therefore, reliable molecule interaction data are a crucial basis, where drug-/protein-protein interaction networks establish invaluable, year-long carefully curated data resources. However, these resources have not yet been systematically exploited using high-performance artificial intelligence approaches. Here, we combine three networks, two of which are year-long curated, and one of which, on SARS-CoV-2-human host-virus protein interactions, was published only most recently (30th of April 2020), raising a novel network that puts drugs, human and virus proteins into mutual context. We apply Variational Graph AutoEncoders (VGAEs), representing most advanced deep learning based methodology for the analysis of data that are subject to network constraints. Reliable simulations confirm that we operate at utmost accuracy in terms of predicting missing links. We then predict hitherto unknown links between drugs and human proteins against which virus proteins preferably bind. The corresponding therapeutic agents present splendid starting points for exploring novel host-directed therapy (HDT) options.


Structural Basis of the SARS-CoV-2/SARS-CoV Receptor Binding and Small-Molecule Blockers as Potential Therapeutics

Abstract: Over the past two decades, deadly coronaviruses have caused major challenges to public health, with the most recent being the severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2, 2019) pandemic. The path for virus invasion into humans and other hosts is mediated by "host-pathogen" interactions, specifically, virus-receptor binding. An in-depth understanding of the virus-receptor binding mechanism is a prerequisite for the discovery of vaccines, antibodies, and/or small-molecule inhibitors that can interrupt this interaction and prevent or cure infection. In this review, we discuss the viral entry mechanism, the known structural aspects of virus-receptor interactions (SARS-CoV-2 S/humanACE2, SARS-CoV S/humanACE2, and MERS-CoV S/humanDPP4), the key protein domains and amino acid residues involved in binding, and the small-molecule inhibitors and other drugs that have (as of June, 2020) exhibited therapeutic potential. Specifically, we review the potential clinical utility of two transmembrane serine protease 2 (TMPRSS2)-targeting protease inhibitors, nafamostat mesylate and camostat mesylate, as well as two novel potent fusion inhibitors and the repurposed Ebola drug, remdesivir, which is specific to RdRp, against human coronaviruses, including SARS-CoV-2. This article has been accepted for publication on June 23, 2020. Changes may still occur before final publication. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 61 is January 8, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


Protein-ligand interaction study to identify potential dietary compounds binding at the active site of therapeutic target proteins of SARS-CoV-2

Abstract: Objective: Total 186 biologically important phenylpropanoids and polyketides compounds from different Indian medicinal plants and dietary sources were screened to filter potential compounds that bind at the active site of the therapeutic target proteins of SARS-CoV-2. Method: The molecular docking studies were carried out by using the Autodock Vina. The in silico ADMET and drug-likeness properties of the compounds were predicted from SwissADME server. Result: The molecular docking study of the 186 compounds with the therapeutic target proteins (Mpro, PLpro, RdRp, SGp and ACE2) of SARS-CoV-2 resulted 40 compounds that bind at the active site with dock score above -8.0 kcal/mol. Conclusion: Based on the in silico ADMET study and drug-likeness prediction of 40 compounds, we proposed petunidin, baicalein, cyanidin, 7-hydroxy-3',4'-methylenedioxyflavan, quercetin and ellagic acid among the 186 biologically important phenylpropanoids and polyketides as potential lead compounds, which can further be investigated pharmacologically and clinically to formulate therapeutic approaches for the COVID-19.


A review on the cleavage priming of the spike protein on coronavirus by angiotensin-converting enzyme-2 and furin

Abstract: The widespread antigenic changes lead to the emergence of a new type of coronavirus (CoV) called as severe acute respiratory syndrome (SARS)-CoV-2 that is immunologically different from the previous circulating species. Angiotensin-converting enzyme-2 (ACE-2) is one of the most important receptors on the cell membrane of the host cells (HCs) which its interaction with spike protein (SP) with a furin-cleavage site results in the SARS-CoV-2 invasion. Hence, in this review, we presented an overview on the interaction of ACE-2 and furin with SP. As several kinds of CoVs, from various genera, have at their S1/S2 binding site a preserved site, we further surveyed the role of furin cleavage site (FCS) on the life cycle of the CoV. Furthermore, we discussed that the small molecular inhibitors can limit the interaction of ACE-2 and furin with SP and can be used as potential therapeutic platforms to combat the spreading CoV epidemic. Finally, some ongoing challenges and future prospects for the development of potential drugs to promote targeting specific activities of the CoV were reviewed. In conclusion, this review may pave the way for providing useful information about different compounds involved in improving the effectiveness of CoV vaccine or drugs with minimum toxicity against human health.Communicated by Ramaswamy H. Sarma.


Molecular Investigation of SARS-CoV-2 Proteins and Their Interactions with Antiviral Drugs

Abstract: A new Coronavirus strain, named SARS-CoV-2, suddenly emerged in early December 2019. SARS-CoV-2 resulted in being dramatically infectious, with thousands of people infected. In this scenario, and without effective vaccines available, the importance of an immediate tool to support patients and against viral diffusion becomes evident. In this study, we exploit the molecular docking approach to analyze the affinity between different viral proteins and several inhibitors, originally developed for other viral infections. Our data show that, in some cases, a relevant binding can be detected. These findings support the hypothesis to develop new antiviral agents against COVID-19, on the basis of already established therapies.


Coronavirus membrane fusion mechanism offers a potential target for antiviral development

Abstract: The coronavirus disease 2019 (COVID-19) pandemic has focused attention on the need to develop effective therapies against the causative agent, SARS-CoV-2, and also against other pathogenic coronaviruses (CoV) that have emerged in the past or might appear in future. Researchers are therefore focusing on steps in the CoV replication cycle that may be vulnerable to inhibition by broad-spectrum or specific antiviral agents. The conserved nature of the fusion domain and mechanism across the CoV family make it a valuable target to elucidate and develop pan-CoV therapeutics. In this article, we review the role of the CoV spike protein in mediating fusion of the viral and host cell membranes, summarizing the results of research on SARS-CoV, MERS-CoV, and recent peer-reviewed studies of SARS-CoV-2, and suggest that the fusion mechanism be investigated as a potential antiviral target. We also provide a supplemental file containing background information on the biology, epidemiology, and clinical features of all human-infecting coronaviruses, along with a phylogenetic tree of these coronaviruses.


Identification of a druggable binding pocket in the spike protein reveals a key site for existing drugs potentially capable of combating Covid-19 infectivity

Abstract: BACKGROUND: Following the recent outbreak of the new coronavirus pandemic (Covid-19), the rapid determination of the structure of the homo-trimeric spike glycoprotein has prompted the study reported here. The aims were to identify potential "druggable" binding pockets in the protein and, if located, to virtual screen pharmaceutical agents currently in use for predicted affinity to these pockets which might be useful to restrict, reduce, or inhibit the infectivity of the virion. RESULTS: Our analyses of this structure have revealed a key potentially druggable pocket where it might be viable to bind pharmaceutical agents to inhibit its ability to infect human cells. This pocket is found at the inter-chain interface that exists between two domains prior to the virion binding to human Angiotensin Converting Enzyme 2 (ACE2) protein. One of these domains is the highly mobile receptor binding domain, which must move into position to interact with ACE2, which is an essential feature for viral entry to the host cell. Virtual screening with a library of purchasable drug molecules has identified pharmaceuticals currently in use as prescription and over the counter medications that, in silico, readily bind into this pocket. CONCLUSIONS: This study highlights possible drugs already in use as pharmaceuticals that may act as agents to interfere with the movements of the domains within this protein essential for the infectivity processes and hence might slow, or even halt, the infection of host cells by this new coronavirus. As these are existing pharmaceuticals already approved for use in humans, this knowledge could accelerate their roll-out, through repurposing, for affected individuals and help guide the efforts of other researchers in finding effective treatments for the disease.


Attacking COVID-19 Progression using Multi-Drug Therapy for Synergetic Target Engagement

Abstract: COVID-19 is a devastating respiratory and inflammatory illness caused by a new coronavirus that is rapidly spreading throughout the human population. Over the past 6 months, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19, has already infected over 11.6 million (25% located in United States) and killed more than 540K people around the world. As we face one of the most challenging times in our recent history, there is an urgent need to identify drug candidates that can attack SARS-CoV-2 on multiple fronts. We have therefore initiated a computational dynamics drug pipeline using molecular modeling, structure simulation, docking and machine learning models to predict the inhibitory activity of several million compounds against two essential SARS-CoV-2 viral proteins and their host protein interactors; S/Ace2, Tmprss2, Cathepsins L and K, and Mpro to prevent binding, membrane fusion and replication of the virus, respectively. All together we generated an ensemble of structural conformations that increase high quality docking outcomes to screen over>6 million compounds including all FDA-approved drugs, drugs under clinical trial (>3000) and an additional>30 million selected chemotypes from fragment libraries. Our results yielded an initial set of 350 high value compounds from both new and FDA-approved compounds that can now be tested experimentally in appropriate biological model systems. We anticipate that our results will initiate screening campaigns and accelerate the discovery of COVID-19 treatments.


COVID-19: Drug Targets and Potential Treatments

Abstract: Currently, humans are immersed in a pandemic caused by the emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which threatens public health worldwide. To date, no drug or vaccine has been approved to treat the severe disease caused by this coronavirus, COVID-19. In this paper, we will focus on the main virus-based and host-based targets that can guide efforts in medicinal chemistry to discover new drugs for this devastating disease. In principle, all CoV enzymes and proteins involved in viral replication and the control of host cellular machineries are potentially druggable targets in the search for therapeutic options for SARS-CoV-2. This Perspective provides an overview of the main targets from a structural point of view, together with reported therapeutic compounds with activity against SARS-CoV-2 and/or other CoVs. Also, the role of innate immune response to coronavirus infection and the related therapeutic options will be presented.


Tackling SARS-CoV-2: proposed targets and repurposed drugs

Abstract: The SARS-CoV-2 pandemic, declared as a global health emergency by the WHO in February 2020, has currently infected more than 6 million people with fatalities near 371,000 and increasing exponentially, in absence of vaccines and drugs. The pathogenesis of SARS-CoV-2 is still being elucidated. Identifying potential targets and repurposing drugs as therapeutic options is the need of the hour. In this review, we focus on potential druggable targets and suitable therapeutics, currently being explored in clinical trials, to treat SARS-CoV-2 infection. A brief understanding of the complex interactions of both viral as well as host targets, and the possible repurposed drug candidates are described with an emphasis on understanding the mechanisms at the molecular level.


Drug repurposing for coronavirus (COVID-19): in silico screening of known drugs against coronavirus 3CL hydrolase and protease enzymes

Abstract: In December 2019, COVID-19 epidemic was described in Wuhan, China, and the infection has spread widely affecting hundreds of thousands. Herein, an effort was made to identify commercially available drugs in order to repurpose them against coronavirus by the means of structure-based virtual screening. In addition, ZINC15 library was used to identify novel leads against main proteases. Human TMPRSS2 3D structure was first generated using homology modeling approach. Our molecular docking study showed four potential inhibitors against Mpro enzyme, two available drugs (Talampicillin and Lurasidone) and two novel drug-like compounds (ZINC000000702323 and ZINC000012481889). Moreover, four promising inhibitors were identified against TMPRSS2; Rubitecan and Loprazolam drugs, and compounds ZINC000015988935 and ZINC000103558522. ADMET profile showed that the hits from our study are safe and drug-like compounds. Furthermore, molecular dynamic (MD) simulation and binding free energy calculation using the MM-PBSA method was performed to calculate the interaction energy of the top-ranked drugs.Communicated by Ramaswamy H. Sarma.


Targeting the entry step of SARS-CoV-2: a promising therapeutic approach


Plausible mechanisms of Niclosamide as an antiviral agent against COVID-19

Abstract: Abstract Corona virus disease 2019 (COVID-19) pandemic caused 18 440 deaths world wide as of 25 March 2020 and posing a serious threat to public health. There is a need, therefore, for effective therapeutic strategies to cure this disease. However, high attrition rates, substantial costs and slow pace are the major limitations of novel drug discovery. Drug repurposing, by employing ‘old’ drugs to treat ‘new’ diseases is an attractive approach in drug discovery. Niclosamide (NIC) is an approved anti-helminthic drug with diverse antiviral mechanisms. In this work we hypothesize, the potential antiviral mechanisms of NIC against COVID-19.


Pulmonary delivery of nanostructured lipid carriers for effective repurposing of salinomycin as an antiviral agent

Abstract: Coronavirus disease outbreak caused a severe public health burden all over the world. Salinomycin (SAL) is a broad-spectrum antibiotic that had drawn attention in selective targeting of cancer and viral infections. Recent drug screen identified SAL as a potent antiviral agent against SARS-CoV-2. In this review we discuss the potential of pulmonary delivery of SAL using nanostructured lipid carriers (NLCs) against SARS-CoV-2.


SARS-CoV-2 infection of kidney organoids prevented with soluble human ACE2


The SARS coronavirus nucleocapsid protein – Forms and functions

Abstract: Abstract The nucleocapsid phosphoprotein of the severe acute respiratory syndrome coronavirus (SARS-CoV N protein) packages the viral genome into a helical ribonucleocapsid (RNP) and plays a fundamental role during viral self-assembly. It is a protein with multifarious activities. In this article we will review our current understanding of the N protein structure and its interaction with nucleic acid. Highlights of the progresses include uncovering the modular organization, determining the structures of the structural domains, realizing the roles of protein disorder in protein–protein and protein–nucleic acid interactions, and visualizing the ribonucleoprotein (RNP) structure inside the virions. It was also demonstrated that N-protein binds to nucleic acid at multiple sites with a coupled-allostery manner. We propose a SARS-CoV RNP model that conforms to existing data and bears resemblance to the existing RNP structures of RNA viruses. The model highlights the critical role of modular organization and intrinsic disorder of the N protein in the formation and functions of the dynamic RNP capsid in RNA viruses. This paper forms part of a symposium in Antiviral Research on “From SARS to MERS: 10years of research on highly pathogenic human coronaviruses.”


Fusion mechanism of 2019-nCoV and fusion inhibitors targeting HR1 domain in spike protein


The signal peptide as a new target for drug design

Abstract: Abstract Many current and potential drug targets are membrane-bound or secreted proteins that are expressed and transported via the Sec61 secretory pathway. They are targeted to translocon channels across the membrane of the endoplasmic reticulum (ER) by signal peptides (SPs), which are temporary structures on the N-termini of their nascent chains. During translation, such proteins enter the lumen and membrane of the ER by a process known as co-translational translocation. Small molecules have been found that interfere with this process, decreasing protein expression by recognizing the unique structures of the SPs of particular proteins. The SP may thus become a validated target for designing drugs for numerous disorders, including certain hereditary diseases.


Adamantanes might be protective from COVID-19 in patients with neurological diseases: multiple sclerosis, parkinsonism and cognitive impairment

Abstract: Abstract Facing the outbreak of coronavirus disease 2019 (COVID-19) pandemic, there is an urgent need to find protective or curable drugs to prevent or to stop the course of the coronavirus SARS-CoV-2 infection. Recent evidence accumulates that adamantanes, widely used in different neurological diseases, could be repurposed for COVID-19. We hereby report on a questionnaire-based study performed to assess severity of COVID-19 in patients suffering from multiple sclerosis (n=10), Parkinson's disease (n=5) or cognitive impairment (n=7). In all patients infection with SARS-CoV-2 was confirmed by rtPCR of nasopharyngeal swabs. They were receiving treatment with either amantadine (n=15) or memantine (n=7) in stable registered doses. All of them had two-week quarantine since documented exposure and none of them developed clinical manifestations of infectious disease. They also did not report any significant changes in neurological status in the course of primary nervous system disease. Above results warrant further studies on protective effects of adamantanes against COVID-19 manifestation, especially in subjects suffering from neurological disease.


Can beta-adrenergic blockers be used in the treatment of COVID-19?


Duration of antibiotic therapy in critically ill patients: a randomized controlled trial of a clinical and C-reactive protein-based protocol versus an evidence-based best practice strategy without biomarkers

Abstract: BACKGROUND: The rational use of antibiotics is one of the main strategies to limit the development of bacterial resistance. We therefore sought to evaluate the effectiveness of a C-reactive protein-based protocol in reducing antibiotic treatment time in critically ill patients. METHODS: A randomized, open-label, controlled clinical trial conducted in two intensive care units of a university hospital in Brazil. Critically ill infected adult patients were randomly allocated to (i) intervention to receive antibiotics guided by daily monitoring of CRP levels and (ii) control to receive antibiotics according to the best practices for rational use of antibiotics. RESULTS: One hundred thirty patients were included in the CRP (n = 64) and control (n = 66) groups. In the intention-to-treat analysis, the median duration of antibiotic therapy for the index infectious episode was 7.0 (5.0–8.8) days in the CRP and 7.0 (7.0–11.3) days in the control (p = 0.011) groups. A significant difference in the treatment time between the two groups was identified in the curve of cumulative suspension of antibiotics, with less exposure in the CRP group only for the index infection episode (p = 0.007). In the per protocol analysis, involving 59 patients in each group, the median duration of antibiotic treatment was 6.0 (5.0–8.0) days for the CRP and 7.0 (7.0–10.0) days for the control (p = 0.011) groups. There was no between-group difference regarding the total days of antibiotic exposure and antibiotic-free days. CONCLUSIONS: Daily monitoring of CRP levels may allow early interruption of antibiotic therapy in a higher proportion of patients, without an effect on total antibiotic consumption. The clinical and microbiological relevance of this finding remains to be demonstrated. TRIAL REGISTRY: ClinicalTrials.gov Identifier: NCT02987790. Registered 09 December 2016.


Benefit-risk assessment for remdesivir in COVID-19


Recommandations EMA sur l’usage compassionnel du remdesivir


Brèves : En savoir plus sur le remdesivir


Advantages of the Parent Nucleoside GS-441524 over Remdesivir for Covid-19 Treatment

Abstract: [Image: see text] While remdesivir has garnered much hope for its moderate anti-Covid-19 effects, its parent nucleoside, GS-441524, has been overlooked. Pharmacokinetic analysis of remdesivir evidences premature serum hydrolysis to GS-441524; GS-441524 is the predominant metabolite reaching the lungs. With its synthetic simplicity and in vivo efficacy in the veterinary setting, we contend that GS-441524 is superior to remdesivir for Covid-19 treatment.


Remdesivir: Various toxicities: 4 case reports


Five reasons why data on compassionate use of remdesivir deserved publication (and are worth reading).


Quantification of plasma remdesivir and its metabolite GS-441524 using liquid chromatography coupled to tandem mass spectrometry. Application to a Covid-19 treated patient.

Abstract: Objectives A method based on liquid chromatography coupled to triple quadrupole mass spectrometry detection using 50 µL of plasma was developed and fully validated for quantification of remdesivir and its active metabolites GS-441524. Methods A simple protein precipitation was carried out using 75 µL of methanol containing the internal standard (IS) remdesivir-13C6 and 5 µL ZnSO4 1 M. After separation on Kinetex® 2.6 µm Polar C18 100A LC column (100 × 2.1 mm i.d.), both compounds were detected by a mass spectrometer with electrospray ionization in positive mode. The ion transitions used were m/z 603.3 → m/z 200.0 and m/z 229.0 for remdesivir, m/z 292.2 → m/z 173.1 and m/z 147.1 for GS-441524 and m/z 609.3 → m/z 206.0 for remdesivir-13C6. Results Calibration curves were linear in the 1-5000 μg/L range for remdesivir and 5-2500 for GS-441524, with limit of detection set at 0.5 and 2 μg/L and limit of quantification at 1 and 5 μg/L, respectively. Precisions evaluated at 2.5, 400 and 4000 μg/L for remdesivir and 12.5, 125, 2000 μg/L for GS-441524 were lower than 14.7% and accuracy was in the [89.6-110.2%] range. A slight matrix effect was observed, compensated by IS. Higher stability of remdesivir and metabolite was observed on NaF-plasma. After 200 mg IV single administration, remdesivir concentration decrease rapidly with a half-life less than 1 h while GS-441524 appeared rapidly and decreased slowly until H24 with a half-life around 12 h. Conclusions This method would be useful for therapeutic drug monitoring of these compounds in Covid-19 pandemic.


Remdesivir for the Treatment of Covid-19 - Preliminary Report.


Hopes rise on coronavirus drug remdesivir.


The role of remdesivir in South Africa: preventing COVID-19 deaths through increasing ICU capacity.

Abstract: Countries such as South Africa have limited intensive care unit (ICU) capacity to handle the expected number of COVID-19 patients requiring ICU care. Remdesivir can prevent deaths in countries such as South Africa by decreasing the number of days people spend in ICU, therefore freeing up ICU bed capacity.


Repurposing Therapeutics for Potential Treatment of SARS-CoV-2: A Review.

Abstract: The need for proven disease-specific treatments for the novel pandemic coronavirus SARS-CoV-2 necessitates a worldwide search for therapeutic options. Since the SARS-CoV-2 virus shares extensive homology with SARS-CoV and MERS-CoV, effective therapies for SARS-CoV and MERS-CoV may also have therapeutic potential for the current COVID-19 outbreak. To identify therapeutics that might be repositioned for treatment of the SARS-CoV-2 disease COVID-19, we strategically reviewed the literature to identify existing therapeutics with evidence of efficacy for the treatment of the three coronaviruses that cause severe respiratory illness (SARS-CoV, MERS-CoV, and SARS-CoV-2). Mechanistic and in vitro analyses suggest multiple promising therapeutic options with potential for repurposing to treat patients with COVID-19. Therapeutics with particularly high potential efficacy for repurposing include camostat mesylate, remdesivir, favipiravir, tocilizumab, baricitinib, convalescent plasma, and humanized monoclonal antibodies. Camostat mesylate has shown therapeutic potential, likely by preventing viral entry into epithelial cells. In early research, the targeted antivirals remdesivir and favipiravir appear to benefit patients by decreasing viral replication; clinical trials suggest that remdesivir speeds recovery from COVID-19. Tocilizumab and baricitinib appear to improve mortality by preventing a severe cytokine storm. Convalescent plasma and humanized monoclonal antibodies offer passive immunity and decreased recovery time. This review highlights potential therapeutic options that may be repurposed to treat COVID-19 and suggests opportunities for further research.


Antivirals for COVID-19.

Abstract: Drugs targeting RNA respiratory viruses has resulted in few effective therapies, highlighting challenges for antivirals to treat COVID-19. Several antivirals are being investigated for symptomatic COVID-19 but no definitive data support their clinical use. Remdesivir, with good in vitro activity against SARS-CoV2, appeared to result in favorable outcomes for hospitalized patients in a compassionate use series with shortened time to recovery and a modest decrease in mortality. Currently, remdesivir is available in phase III clinical trials, the compassionate use program, and eventually through the emergency use authorization. A randomized controlled trial of lopinavir/ritonavir demonstrated no apparent clinical or virologic benefit and drug-drug interactions and side effects further limit its utility. Antivirals to treat influenza (oseltamivir) have limited activity against SARS-CoV-2, but favipiravir and umifenovir, influenza antivirals available internationally, have distinct viral targets and require further investigation. Antivirals with evidence of clinical activity must be studied as treatment and prophylaxis for those at high risk for severe COVID-19.


A promising antiviral candidate drug for the COVID-19 pandemic: A mini-review of remdesivir.

Abstract: Remdesivir (GS-5734), a viral RNA-dependent RNA polymerase (RdRP) inhibitor that can be used to treat a variety of RNA virus infections, is expected to be an effective treatment for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. On May 1, 2020, The U.S. Food and Drug Administration (FDA) has granted Emergency Use Authorization (EUA) for remdesivir to treat COVID-19 patients. In light of the COVID-19 pandemic, this review presents comprehensive information on remdesivir, including information regarding the milestones, intellectual properties, anti-coronavirus mechanisms, preclinical research and clinical trials, and in particular, the chemical synthesis, pharmacology, toxicology, pharmacodynamics and pharmacokinetics of remdesivir. Furthermore, perspectives regarding the use of remdesivir for the treatment of COVID-19 are also discussed.


Remdesivir for 5 or 10 Days in Patients with Severe Covid-19.

Abstract: BACKGROUND Remdesivir is an RNA polymerase inhibitor with potent antiviral activity in vitro and efficacy in animal models of coronavirus disease 2019 (Covid-19). METHODS We conducted a randomized, open-label, phase 3 trial involving hospitalized patients with confirmed SARS-CoV-2 infection, oxygen saturation of 94% or less while they were breathing ambient air, and radiologic evidence of pneumonia. Patients were randomly assigned in a 1:1 ratio to receive intravenous remdesivir for either 5 days or 10 days. All patients received 200 mg of remdesivir on day 1 and 100 mg once daily on subsequent days. The primary end point was clinical status on day 14, assessed on a 7-point ordinal scale. RESULTS In total, 397 patients underwent randomization and began treatment (200 patients for 5 days and 197 for 10 days). The median duration of treatment was 5 days (interquartile range, 5 to 5) in the 5-day group and 9 days (interquartile range, 5 to 10) in the 10-day group. At baseline, patients randomly assigned to the 10-day group had significantly worse clinical status than those assigned to the 5-day group (P = 0.02). By day 14, a clinical improvement of 2 points or more on the ordinal scale occurred in 64% of patients in the 5-day group and in 54% in the 10-day group. After adjustment for baseline clinical status, patients in the 10-day group had a distribution in clinical status at day 14 that was similar to that among patients in the 5-day group (P = 0.14). The most common adverse events were nausea (9% of patients), worsening respiratory failure (8%), elevated alanine aminotransferase level (7%), and constipation (7%). CONCLUSIONS In patients with severe Covid-19 not requiring mechanical ventilation, our trial did not show a significant difference between a 5-day course and a 10-day course of remdesivir. With no placebo control, however, the magnitude of benefit cannot be determined. (Funded by Gilead Sciences; GS-US-540-5773 ClinicalTrials.gov number, NCT04292899.).


Hints of hope with remdesivir.


Remdesivir in covid-19.


Tocilizumab and Remdesivir in a Pregnant Patient With Coronavirus Disease 2019 (COVID-19).

Abstract: BACKGROUND There are limited data regarding treatment options for pregnant women with severe coronavirus disease 2019 (COVID-19). CASE A 35-year-old primigravid patient at 22 weeks of gestation presented with 7 days of fever, cough, anosmia, and dyspnea. Nasopharyngeal swab was positive for the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and a chest X-ray demonstrated bilateral patchy infiltrates. Laboratory evaluation was notable for marked elevation of interleukin-6 and C-reactive protein concentrations. On hospital day 3, owing to increased dyspnea and oxygen requirement, the patient was treated with tocilizumab followed by 5 days of remdesivir. She responded well, recovered to room air, and was discharged home after a 9-day hospitalization. CONCLUSION Tocilizumab and remdesivir may be effective for treatment of severe COVID-19 in pregnancy, but additional data are needed to guide risk-benefit considerations.


Successful treatment of patients severely ill with COVID-19.


Efficacy of remdesivir in a rhesus macaque model of MERS-CoV infection.


Covid-19: Remdesivir is helpful but not a wonder drug, say researchers.


Efficacy of remdesivir in COVID-19 patients with a simulated two-arm controlled study

Abstract: While the recent study on the compassionate use of remdesivir for COVID-19 patients has shown a 68% clinical improvement7 it is a one-arm study that renders the evaluation of the efficacy in reducing death and the length of stay of hospitalization intractable due to a lacking of the control group. We came up with a two-arm controlled study design to simulate the treated and the untreated (control group) group by applying two respective transition models to the empirical data on dynamics of the disease severity (Figure 2 of the original article7) that are classified into low- (no and low oxygen supplement), medium- (non-invasive ventilator and high oxygen supplement), and high-(ECMO and invasive ventilator) from enrolment until discharge, death or the end of follow-up. By using a simulated two-arm controlled study, the remdesivir treatment group as opposed to the control group led to a statistically significantly 29% (95% CI: 22-35%) reduction of death from COVID-19. The treated group also revealed a 33% (95% CI 28-38%) significantly higher odds of discharge than the control group. The median time to discharge for the treated group (5.5 days, 16.5 days, and 29.5 days for low-, medium-, and high-risk state, respectively) was around half of those of the control arm. Our results with a simulated two-arm controlled study have not only corroborated the efficacy of remdesivir but also made great contribution to designing a further large-scale randomized controlled trial. They have significant implications for reducing transmission probability and infectious time of COVID-19 patients when contacting with susceptible health care workers during hospitalization.


The role of remdesivir in South Africa: preventing COVID-19 deaths through increasing ICU capacity


Impacts of remdesivir on dynamics and efficacy stratified by the severity of COVID-19: a simulated two-arm controlled study

Abstract: Background: The impact of remdesivir on length of stay of hospitalization, high-risk state, and death stratified by the severity of COVID-19 at enrollment is controversial. Methods: We applied a simulated two-arm controlled study design to the data on compassionate use of remdesivir as a secondary analysis. Dynamics of risk states and death from COVID-19 patients defined by the six-point disease severity recommended by the WHO R&D and the time to discharge from hospital were used to evaluate the efficacy of remdesivir treatment compared with standard care. Results: Stratified by the risk state at enrollment, low-risk patients exhibited the highest efficacy of remdesivir in reducing subsequent progression to high-risk state by 67% (relative risk (RR)=0.33,95% CI: 0.30-0.35) and further to death by 55% (RR=0.45, 95%CI: 0.39-0.50). For the medium-risk patients, less but still statistically significant efficacy results were noted in reducing progression to high-risk state by 52% (RR=0.48, 95% CI: 0.45-0.51) and further to death by 40% (RR=0.60, 95% CI:0.54-0.66). High-risk state patients treated with remdesivir led to a 25% statistically significant reduction in death (RR=0.75, 95% CI: 0.69-0.82). Regarding the outcome of discharge, remdesivir treatment was most effective for medium-risk patients at enrollment (RR: 1.41, 95% CI: 1.35-1.47) followed by high- (RR=1.34, 95% CI: 1.27-1.42) and low-risk patients (RR=1.28, 95% CI: 1.25-1.31). Conclusion: Our results with a simulated two-arm controlled study have provided a new insight into the precision treatment of remdesivir for COVID-19 patients based on risk-stratified efficacy.


What could remdesivir data tell us about tackling COVID-19?

Abstract: In the coming weeks, the world will get a sense of whether Gilead Sciences’ remdesivir, an antiviral developed for Ebola, is useful against the novel coronavirus With the coronavirus pandemic spiraling—during the week of March 30, worldwide infections crossed 900,000 and deaths exceeded 45,000—initial results emerging from several late-stage studies will be under the microscope But infectious disease experts on the front lines warn that the data are unlikely to clearly answer the question of whether remdesivir works in COVID-19, the respiratory illness caused by the SARS-CoV-2 virus Those first tests are in the sickest, hardest-to-treat patients Moreover, antivirals don’t have a great track record at taking down coronaviruses, which can be a little more sophisticated than your average RNA virus Still, some industry watchers hope the studies signal enough success to convince the US Food and Drug Administration to approve Gilead’s experimental drug When a new infectious disease threatens


Foundational research and NIH funding enabling Emergency Use Authorization of remdesivir for COVID-19

Abstract: Emergency Use Authorization for remdesivir months after discovery of COVID19 is unprecedented. Typically, decades of research and public sector funding are required to establish the mature body of foundational research requisite for efficient, targeted drug discovery and development. This work quantifies the body of research related to the biological target of remdesivir, RNA-dependent RNA polymerase (RdRp), or parent chemical structure, nucleoside analogs (NcAn), through 2019, as well as NIH funding for this research from 2000 to 2019. There were 6,567 RdRp related publications in PubMed, including 1,263 with NIH support, and 11,073 NcAn-related publications, including 2,319 with NIH support. NIH support for RdRp research comprised 2,203 Project Years with Costs of $1,875 million. NIH support for NcAn research comprised 4,607 Project Years with Costs of $4,612 million. Research Project grants accounted for 63% and 48% of Project Years for RdRp and NcAn respectively, but only 19% and 12% of Project Costs. Analytical modeling of research maturation estimates that RdRp and NcAn research passed an established maturity threshold in 2008 and 1994 respectively. Of 97 investigational compounds targeting RdRp since 1989, the three authorized for use entered clinical trials after both thresholds. This work demonstrates the scale of foundational research on the biological target and parent chemical structure of remdesivir that supported its discovery and development for COVID19. This work identifies $6.5 billion in NIH funding for research leading to remdesivir, underscoring the role of public sector investments in basic research and research infrastructure that underlie new drugs and the response to emergent disease.


Use of Remdesivir in the Management of COVID-19: A Systematic Review on Current Evidences.

Abstract: The rapid progression of corona virus disease in 2019 (COVID-19) pandemic has become an unprecedented global concern. This systemic review aimed at evaluating the available evidence on efficacy, safety to identify any promising role for compassionate use of remdesivir in patient suffered for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) as re-purposeful use. We searched PubMed, EMBASE, Cochrane Library for randomized controlled trials (RCTs), prospective case series studies and case reports that evaluated use of remdesivir in COVID-19. The outcomes were mortality, recovery rate, length of hospital stay and clinical outcome. Though the drug remdesivir (RDV) is not approved by the FDA, still the "Emergency Use Authorization" (EUA) for compassionate use in severe cases is endorsed. After vigorous searching, screening and sorting of completed and published scientific evidences in electronic database, there were only 2 randomized control trial (RCT), 2 uncontrolled trials found until April 2020. We also included 3 published case reports to analyze the validity use of RDV because of the scarcity of evidence based reports. Remdesivir was thought to be one of the promising options for treating the patients of COVID-19 based on few laboratory experiments and reports from some compassionate use and case reports. The safety and efficacy of this drug in COVID-19 cases require high-quality evidence from well-designed and adequately-powered clinical trials with proper sample size for precise decision.


Remdesivir for the Treatment of Covid-19 - Preliminary Report


Remdesivir as a possible therapeutic option for the COVID-19


Compassionate Use of Remdesivir in Covid-19


Hopes rise for coronavirus drug remdesivir


Compassionate Use of Remdesivir for Patients with Severe Covid-19

Abstract: BACKGROUND: Remdesivir, a nucleotide analogue prodrug that inhibits viral RNA polymerases, has shown in vitro activity against SARS-CoV-2. METHODS: We provided remdesivir on a compassionate-use basis to patients hospitalized with Covid-19, the illness caused by infection with SARS-CoV-2. Patients were those with confirmed SARS-CoV-2 infection who had an oxygen saturation of 94% or less while they were breathing ambient air or who were receiving oxygen support. Patients received a 10-day course of remdesivir, consisting of 200 mg administered intravenously on day 1, followed by 100 mg daily for the remaining 9 days of treatment. This report is based on data from patients who received remdesivir during the period from January 25, 2020, through March 7, 2020, and have clinical data for at least 1 subsequent day. RESULTS: Of the 61 patients who received at least one dose of remdesivir, data from 8 could not be analyzed (including 7 patients with no post-treatment data and 1 with a dosing error). Of the 53 patients whose data were analyzed, 22 were in the United States, 22 in Europe or Canada, and 9 in Japan. At baseline, 30 patients (57%) were receiving mechanical ventilation and 4 (8%) were receiving extracorporeal membrane oxygenation. During a median follow-up of 18 days, 36 patients (68%) had an improvement in oxygen-support class, including 17 of 30 patients (57%) receiving mechanical ventilation who were extubated. A total of 25 patients (47%) were discharged, and 7 patients (13%) died; mortality was 18% (6 of 34) among patients receiving invasive ventilation and 5% (1 of 19) among those not receiving invasive ventilation. CONCLUSIONS: In this cohort of patients hospitalized for severe Covid-19 who were treated with compassionate-use remdesivir, clinical improvement was observed in 36 of 53 patients (68%). Measurement of efficacy will require ongoing randomized, placebo-controlled trials of remdesivir therapy. (Funded by Gilead Sciences.).


Remdesivir for Treatment of COVID-19: Combination of Pulmonary and IV Administration May Offer Aditional Benefit

Abstract: Remdesivir is one of the most promising drugs to treat COVID-19 based on the following facts: remdesivir has a broad-spectrum antiviral mechanism of action; it demonstrated in vitro activity against SARS-CoV-2 and in vivo efficacy in animal models against the similar coronavirus MERS-CoV; its safety profile has been tested in Ebola patients and in compassionate use in COVID-19 patients. Currently, remdesivir is being investigated in ten randomized controlled trials against COVID-19. The dose regimen of remdesivir is an IV loading dose of 200 mg on day 1 followed by daily IV maintenance doses of 100 mg for 5-9 days. Based on our data analysis, however, remdesivir with IV administration alone is unlikely to achieve excellent clinical efficacy. This analysis is based on the following observations: plasma exposures of remdesivir and its active metabolite are unlikely to be correlated with its clinical efficacy; remdesivir and its active metabolites are unlikely to be adequate in the lung to kill the SARS-CoV-2 virus. Even if remdesivir demonstrates benefits in the current randomized controlled trials, its efficacy may be limited. We suggest that a combination of an IV and pulmonary delivery dose regimen should be studied immediately to realize a potentially more effective antiviral therapy against COVID-19. Graphical abstract.


Rapid review for the anti-coronavirus effect of remdesivir

Abstract: The outbreak of SARS-CoV-2 rapidly spread across China and worldwide. Remdesivir had been proposed as a promising option for treating coronavirus disease 2019 (COVID-19). We provided a rapid review to critically assess the potential anti-coronavirus effect of remdesivir on COVID-19 and other coronaviruses based on the most up-to-date evidence. Even though remdesivir was proposed as a promising option for treating COVID-19 based on laboratory experiments and reports from compassionate use, its safety and effect in humans requires high-quality evidence from well-designed and adequately-powered clinical trials for further clarification.


Repurposing Therapeutics for Potential Treatment of SARS-CoV-2: A Review


Efficacy of remdesivir in patients with COVID-19: a protocol for systematic review and meta-analysis of randomised controlled trials

Abstract: BACKGROUND: Despite global containment measures to fight the coronavirus disease 2019 (COVID-19), the pandemic continued to rise, rapidly spread across the world, and resulting in 2.6 million confirmed cases and 185 061 deaths worldwide as of 23 April 2020. Yet, there are no approved vaccines or drugs to make the disease less deadly, while efforts are underway. Remdesivir, a nucleotide-analogue antiviral drug developed for Ebola, is determined to prevent and stop infections with COVID-19, while results are yet controversial. Here, we aim to conduct a systematic review and meta-analysis of randomised controlled trials (RCTs) to evaluate the efficacy of remdesivir in patients with COVID-19. METHOD AND ANALYSIS: We will search MEDLINE-PubMed, Embase, Cochrane Library, ClinicalTrials.gov and Google scholar databases for articles published as of 30 June 2020 and we will complete the study on 30 August 2020. We will follow the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015 guidelines for the design and reporting of the results. We will include RCTs that assessed the efficacy of remdesivir versus placebo or standard of care. The primary endpoint will be time to clinical recovery. The secondary endpoints will be proportion of participants relieved from clinical symptoms defined at the time (in hours) from initiation of the study treatment, all-cause mortality, discharged date, frequency of respiratory progression and treatment-emergent adverse events. RevMan V.5.3 software will be used for statistical analysis. Random effects model will be carried out to calculate mean differences for continuous outcome data and risk ratio for dichotomous outcome data between remdesivir and placebo or standard of care. ETHICS AND DISSEMINATION: There are no ethical considerations associated with this study as we will use publicly available data from previously published studies. We plan to publish results in open-access peer-reviewed journals and present at international and national conferences. PROSPERO REGISTRATION NUMBER: CRD42020177953.


What Do We Know About Remdesivir Drug Interactions?


The use of convalescent plasma therapy and remdesivir in the successful management of a critically ill obstetric patient with novel coronavirus 2019 infection: A case report

Abstract: Remdesivir is a novel therapeutic with known activity against SARS CoV-2 and related coronaviruses. Remdesivir, as well as convalescent plasma therapy, are currently under investigation as potential therapies for patients with Coronavirus Disease 19 (COVID-19). In this case report we summarize the use of convalescent plasma therapy and then remdesivir as a late addition in the treatment of a critically ill obstetric patient with COVID-19. The patient subsequently improved, was extubated 5â¯days after initiation of remdesivir, was transitioned to room air 24â¯h later, and discharged at the completion of remdesivir therapy.


Statistical Issues and Lessons Learned from COVID-19 Clinical Trials with Lopinavir-Ritonavir and Remdesivir

Abstract: BACKGROUND: Recently, three randomized clinical trials on COVID-19 treatments were completed, one for lopinavir-ritonavir and two for remdesivir. One trial reported that remdesivir was superior to placebo in shortening the time to recovery, while the other two showed no benefit of the treatment under investigation. OBJECTIVE: From statistical perspectives, we identify several key issues in the design and analysis of three COVID-19 trials and reanalyze the data from the cumulative incidence curves in the three trials using more appropriate statistical methods. METHODS: The lopinavir-ritonavir trial enrolled 39 additional patients due to insignificant results after the sample size reached the planned number, which led to inflation of the type I error rate. The remdesivir trial of Wang et al. failed to reach the planned sample size due to a lack of eligible patients, while the bootstrap method was used to predict the quantity of clinical interest conditionally and unconditionally if the trial had continued to reach the originally planned sample size. Moreover, we used a terminal (or cure) rate model and a model-free metric known as the restricted mean survival time or the restricted mean time to improvement (RMTI) to analyze the reconstructed data. The remdesivir trial of Beigel et al. reported the median recovery time of the remdesivir and placebo groups and the rate ratio for recovery, while both quantities depend on a particular time point representing local information. We use the restricted mean time to recovery (RMTR) as a global and robust measure for efficacy. RESULTS: For the lopinavir-ritonavir trial, with the increase of sample size from 160 to 199, the type I error rate was inflated from 0.05 to 0.071. The difference of RMTIs between the two groups evaluated at day 28 was -1.67 days (95% CI [-3.62, 0.28]; P=.09) in favor of lopinavir-ritonavir but not statistically significant. For the remdesivir trial of Wang et al., the difference of RMTIs at day 28 was -0.89 day (95% CI [-2.84, 1.06]; P=.37). The planned sample size was 453, yet only 236 patients were enrolled. The conditional prediction shows that the HR estimates would reach statistical significance if the target sample size had been maintained. For the remdesivir trial of Beigel et al., the difference of RMTRs between the remdesivir and placebo groups at day 30 was -2.7 days (95% CI [-4.0, -1.2]; P<.001), confirming the superiority of remdesivir. The difference in the recovery time at the 25th percentile (95% CI [-3, 0]; P=.65) was insignificant, while the differences manifested to be statistically significant at larger percentiles. CONCLUSIONS: Based on the statistical issues and lessons learned from the recent three clinical trials on COVID-19 treatments, we suggest more appropriate approaches for the design and analysis for ongoing and future COVID-19 trials.


Probable Molecular Mechanism of Remdesivir for the Treatment of COVID-19: Need to Know More

Abstract: COVID-19 is now pandemic throughout the world. Scientist, doctors are searching for effective therapy of this diseases. The remdesivir, an antiviral drug, is appeared as 'molecule of hope' for the treatment of this disease. USFDA gave emergency approval to this drug for the treatment of COVID-19. The molecular mechanism is unknown. In this paper, we tried to describe the probable molecular mechanism of remdesivir to inhibit the RNA synthesis of SARS-CoV-2. However, more detail mechanism is needed to understand mechanism of action of remdesivir.


A promising antiviral candidate drug for the COVID-19 pandemic: A mini-review of remdesivir


Early experience with remdesivir in SARS-CoV-2 pneumonia

Abstract: At present, there is no definitive antiviral treatment for coronavirus disease 2019 (COVID-19). We describe our early experience with remdesivir in four critically ill COVID-19 patients. Patients received a 200 mg loading dose, followed by 100 mg daily intravenously for up to 10 days. All patients had been previously treated with other antivirals before remdesivir initiation. One patient experienced a torsade de pointes requiring cardiac resuscitation and one died due to multiple organ failure. Three patients showed biochemical signs of liver injury. Lymphocyte count increased in all patients soon after remdesivir initiation. Nasal swab SARS-CoV-2 RNA became negative in three of four patients after 3 days of therapy. We observed an in vivo virological effect of remdesivir in four critically ill, COVID-19 patients, coupled with a significant burden of adverse events. Although limited by the low number of subjects studied, our preliminary experience may be relevant for clinicians treating COVID-19.


Remdesivir for 5 or 10 Days in Patients with Severe Covid-19

Abstract: BACKGROUND: Remdesivir is an RNA polymerase inhibitor with potent antiviral activity in vitro and efficacy in animal models of coronavirus disease 2019 (Covid-19). METHODS: We conducted a randomized, open-label, phase 3 trial involving hospitalized patients with confirmed SARS-CoV-2 infection, oxygen saturation of 94% or less while they were breathing ambient air, and radiologic evidence of pneumonia. Patients were randomly assigned in a 1:1 ratio to receive intravenous remdesivir for either 5 days or 10 days. All patients received 200 mg of remdesivir on day 1 and 100 mg once daily on subsequent days. The primary end point was clinical status on day 14, assessed on a 7-point ordinal scale. RESULTS: In total, 397 patients underwent randomization and began treatment (200 patients for 5 days and 197 for 10 days). The median duration of treatment was 5 days (interquartile range, 5 to 5) in the 5-day group and 9 days (interquartile range, 5 to 10) in the 10-day group. At baseline, patients randomly assigned to the 10-day group had significantly worse clinical status than those assigned to the 5-day group (P = 0.02). By day 14, a clinical improvement of 2 points or more on the ordinal scale occurred in 64% of patients in the 5-day group and in 54% in the 10-day group. After adjustment for baseline clinical status, patients in the 10-day group had a distribution in clinical status at day 14 that was similar to that among patients in the 5-day group (P = 0.14). The most common adverse events were nausea (9% of patients), worsening respiratory failure (8%), elevated alanine aminotransferase level (7%), and constipation (7%). CONCLUSIONS: In patients with severe Covid-19 not requiring mechanical ventilation, our trial did not show a significant difference between a 5-day course and a 10-day course of remdesivir. With no placebo control, however, the magnitude of benefit cannot be determined. (Funded by Gilead Sciences; GS-US-540-5773 ClinicalTrials.gov number, NCT04292899.).


Arguments in favour of remdesivir for treating SARS-CoV-2 infections


Hints of hope with remdesivir


Remdesivir in covid-19


That Escalated Quickly: Remdesivir's Place in Therapy for COVID-19

Abstract: Remdesivir is a nucleoside antiviral recently studied in several randomized trials for treatment of COVID-19. The available observational and prospective data are conflicting, requiring clinicians to critically evaluate and reconcile results to determine patient populations that may optimally benefit from remdesivir therapy, especially while drug supply is scarce. In this review, we analyze pertinent clinical remdesivir data for patients with COVID-19 from January 1, 2020, through May 31, 2020.


Pharmacokinetics of remdesivir and GS-441524 in two critically ill patients who recovered from COVID-19

Abstract: BACKGROUND: Remdesivir is a prodrug of the nucleoside analogue GS-441524 and is under evaluation for treatment of SARS-CoV-2-infected patients. OBJECTIVES: To evaluate the pharmacokinetics of remdesivir and GS-441524 in plasma, bronchoalveolar aspirate (BAS) and CSF in two critically ill COVID-19 patients. METHODS: Remdesivir was administered at 200 mg loading dose on the first day followed by 12 days of 100 mg in two critically ill patients. Blood samples were collected immediately after (C0) and at 1 (C1) and 24 h (C24) after intravenous administration on day 3 until day 9. BAS samples were collected on Days 4, 7 and 9 from both patients while one CSF on Day 7 was obtained in one patient. Remdesivir and GS-441524 concentrations were measured in these samples using a validated UHPLC-MS/MS method. RESULTS: We observed higher concentrations of remdesivir at C0 (6- to 7-fold higher than EC50 from in vitro studies) and a notable decay at C1. GS-441524 plasma concentrations reached a peak at C1 and persisted until the next administration. Higher concentrations of GS-441524 were observed in the patient with mild renal dysfunction. Mean BAS/plasma concentration ratios of GS-441524 were 2.3% and 6.4% in Patient 1 and Patient 2, respectively. The CSF concentration found in Patient 2 was 25.7% with respect to plasma. GS-441524 levels in lung and CNS suggest compartmental differences in drug exposure. CONCLUSIONS: We report the first pharmacokinetic evaluation of remdesivir and GS-441524 in recovered COVID-19 patients. Further study of the pharmacokinetic profile of remdesivir, GS-441524 and the intracellular triphosphate form are required.


Tocilizumab and Remdesivir in a Pregnant Patient With Coronavirus Disease 2019 (COVID-19)

Abstract: BACKGROUND: There are limited data regarding treatment options for pregnant women with severe coronavirus disease 2019 (COVID-19). CASE: A 35-year-old primigravid patient at 22 weeks of gestation presented with 7 days of fever, cough, anosmia, and dyspnea. Nasopharyngeal swab was positive for the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and a chest X-ray demonstrated bilateral patchy infiltrates. Laboratory evaluation was notable for marked elevation of interleukin-6 and C-reactive protein concentrations. On hospital day 3, owing to increased dyspnea and oxygen requirement, the patient was treated with tocilizumab followed by 5 days of remdesivir. She responded well, recovered to room air, and was discharged home after a 9-day hospitalization. CONCLUSION: Tocilizumab and remdesivir may be effective for treatment of severe COVID-19 in pregnancy, but additional data are needed to guide risk-benefit considerations.


Comparative Antiviral Activity of Remdesivir and Anti-HIV Nucleoside Analogs Against Human Coronavirus 229E (HCoV-229E)

Abstract: Remdesivir is a nucleotide prodrug that is currently undergoing extensive clinical trials for the treatment of COVID-19. The prodrug is metabolized to its active triphosphate form and interferes with the action of RNA-dependent RNA polymerase of SARS-COV-2. Herein, we report the antiviral activity of remdesivir against human coronavirus 229E (HCoV-229E) compared to known anti-HIV agents. These agents included tenofovir (TFV), 4'-ethynyl-2-fluoro-2'-deoxyadenosine (EFdA), alovudine (FLT), lamivudine (3TC), and emtricitabine (FTC), known as nucleoside reverse-transcriptase inhibitors (NRTIs), and a number of 5'-O-fatty acylated anti-HIV nucleoside conjugates. The anti-HIV nucleosides interfere with HIV RNA-dependent DNA polymerase and/or act as chain terminators. Normal human fibroblast lung cells (MRC-5) were used to determine the cytotoxicity of the compounds. The study revealed that remdesivir exhibited an EC50 value of 0.07 µM against HCoV-229E with TC50 of > 2.00 µM against MRC-5 cells. Parent NRTIs were found to be inactive against (HCoV-229E) at tested concentrations. Among all the NRTIs and 5'-O-fatty acyl conjugates of NRTIs, 5'-O-tetradecanoyl ester conjugate of FTC showed modest activity with EC50 and TC50 values of 72.8 µM and 87.5 µM, respectively. These data can be used for the design of potential compounds against other coronaviruses.


COVID-19, a far cry from the influenza


Epidemiology and Clinical Symptoms Related to Seasonal Coronavirus Identified in Patients with Acute Respiratory Infections Consulting in Primary Care over Six Influenza Seasons (2014-2020) in France.

Abstract: There is currently debate about human coronavirus (HCoV) seasonality and pathogenicity, as epidemiological data are scarce. Here, we provide epidemiological and clinical features of HCoV patients with acute respiratory infection (ARI) examined in primary care general practice. We also describe HCoV seasonality over six influenza surveillance seasons (week 40 to 15 of each season) from the period 2014/2015 to 2019/2020 in Corsica (France). A sample of patients of all ages presenting for consultation for influenza-like illness (ILI) or ARI was included by physicians of the French Sentinelles Network during this period. Nasopharyngeal samples were tested for the presence of 21 respiratory pathogens by real-time RT-PCR. Among the 1389 ILI/ARI patients, 105 were positive for at least one HCoV (7.5%). On an annual basis, HCoVs circulated from week 48 (November) to weeks 14-15 (May) and peaked in week 6 (February). Overall, among the HCoV-positive patients detected in this study, HCoV-OC43 was the most commonly detected virus, followed by HCoV-NL63, HCoV-HKU1, and HCoV-229E. The HCoV detection rates varied significantly with age (p = 0.00005), with the age group 0-14 years accounting for 28.6% (n = 30) of HCoV-positive patients. Fever and malaise were less frequent in HCoV patients than in influenza patients, while sore throat, dyspnoea, rhinorrhoea, and conjunctivitis were more associated with HCoV positivity. In conclusion, this study demonstrates that HCoV subtypes appear in ARI/ILI patients seen in general practice, with characteristic outbreak patterns primarily in winter. This study also identified symptoms associated with HCoVs in patients with ARI/ILI. Further studies with representative samples should be conducted to provide additional insights into the epidemiology and clinical features of HCoVs.


Potential impact of seasonal forcing on a SARS-CoV-2 pandemic.

Abstract: A novel coronavirus (SARS-CoV-2) first detected in Wuhan, China, has spread rapidly since December 2019, causing more than 100,000 confirmed infections and 4000 fatalities (as of 10 March 2020). The outbreak has been declared a pandemic by the WHO on Mar 11, 2020. Here, we explore how seasonal variation in transmissibility could modulate a SARS-CoV-2 pandemic. Data from routine diagnostics show a strong and consistent seasonal variation of the four endemic coronaviruses (229E, HKU1, NL63, OC43) and we parameterise our model for SARS-CoV-2 using these data. The model allows for many subpopulations of different size with variable parameters. Simulations of different scenarios show that plausible parameters result in a small peak in early 2020 in temperate regions of the Northern Hemisphere and a larger peak in winter 2020/2021. Variation in transmission and migration rates can result in substantial variation in prevalence between regions. While the uncertainty in parameters is large, the scenarios we explore show that transient reductions in the incidence rate might be due to a combination of seasonal variation and infection control efforts but do not necessarily mean the epidemic is contained. Seasonal forcing on SARS-CoV-2 should thus be taken into account in the further monitoring of the global transmission. The likely aggregated effect of seasonal variation, infection control measures, and transmission rate variation is a prolonged pandemic wave with lower prevalence at any given time, thereby providing a window of opportunity for better preparation of health care systems.


INFECTIONS IN PREGNANCY WITH COVID-19 AND OTHER RESPIRATORY RNA VIRUS DISEASES ARE RARELY, IF EVER, TRANSMITTED TO THE FETUS: EXPERIENCES WITH CORONAVIRUSES, HPIV, hMPV RSV, AND INFLUENZA.

Abstract: SARS-CoV-2, the agent of COVID-19, is similar to two other coronaviruses, SARS-CoV and MERS-CoV, in causing life-threatening maternal respiratory infections and systemic complications. Because of global concern for potential intrauterine transmission of SARS-CoV-2 from pregnant women to their infants, this report analyzes the effects on pregnancy of infections caused by SARS-CoV-2 and other respiratory RNA viruses, and examines the frequency of maternal-fetal transmission with SARS-CoV-2, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), influenza, respiratory syncytial virus (RSV), parainfluenza (HPIV) and metapneumovirus (hMPV). There have been no confirmed cases of intrauterine transmission reported with COVID-19 or any other coronavirus infections. Influenza virus, despite causing approximately one billion annual infections globally, has only a few cases of confirmed or suspected intrauterine fetal infections reported. RSV is in an unusual cause of illness among pregnant women, and with the exception of one premature infant with congenital pneumonia, no other cases of maternal-fetal infection are described. Parainfluenza virus and human metapneumovirus can produce symptomatic maternal infections but do not cause intrauterine fetal infection. In summary, it appears that the absence thus far of maternal-fetal transmission of the SARS-CoV-2 virus during the COVID-19 pandemic is similar to other coronaviruses, and is also consistent with the extreme rarity of suggested or confirmed cases of intrauterine transmission of other respiratory RNA viruses. This observation has important consequences for pregnant women as it appears that if intrauterine transmission of SARSCoV-2 does eventually occur, it will be a rare event. Potential mechanisms of fetal protection from maternal viral infections are also discussed.


[Comparison of pathological changes and pathogenic mechanisms caused by H1N1 influenza virus, highly pathogenic H5N1 avian influenza virus, SARS-CoV, MERS-CoV and 2019-nCoV coronavirus].

Abstract: 我国武汉出现的新型冠状病毒肺炎疫情经过迅速发展已对全国造成严重影响，但到目前为止对新型冠状病毒肺炎病理变化和发病机制却知之甚少。本文总结重症流感病毒H1N1、高致病性禽流感病毒H5N1、SARS-CoV、MERS-CoV及2019-nCoV冠状病毒几种引起重大疫情病毒感染性疾病的病理改变，尸检肺组织均表现为弥漫性肺泡损伤（diffuse alveolar damage，DAD），但不同病毒引起的病理表现存在差异，重症流感病毒2009 H1N1病毒与受体α-2,6-SA及α-2,3-SA结合，除DAD病变外，常伴有上呼吸道、气管、支气管和细支气管的炎性病变，且较易合并细菌感染。高致病性禽流感病毒H5N1主要结合α-2,3-SA受体，主要累及肺泡上皮及细支气管，少见上呼吸道及气管、支气管病变，常伴局灶肺出血及肺组织坏死。机化及纤维化较少见。SARS-CoV通过结合血管紧张素转换酶2（ACE2）进入细胞，病变与病程相关，DAD渗出期一般见于病程10～14 d死亡患者。病程大于10 d患者表现为DAD机化期，并常伴有闭塞性细支气管炎伴机化性肺炎样改变及肺泡腔内显著多核巨细胞。SARS-CoV及H5N1感染患者肺外器官均可见脾和淋巴结内淋巴细胞耗竭、急性肾小管坏死、骨髓内噬血细胞现象。.