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Coronavirus disease COVID-19, caused by the SARS-CoV-2 virus, is highly contagious and has a severe morbidity. Providing care to patients with COVID-19 requires the development of new types of antiviral drugs. The aim of this work is to develop a prodrug for the treatment of coronavirus disease using the antibiotic Amicoumacin A (Ami), the mechanism of action of which is based on translation inhibition. Enzymatic hydrolysis of an inactivated prodrug by the SARS-CoV-2 main protease can lead to the release of the active Ami molecule and, as a consequence, the suppression of protein biosynthesis in infected cells. To test the proposed hypothesis, a five-stage synthesis of an inactivated analogue of Amicoumacin A was carried out. Its in vitro testing with the SARS-CoV-2 recombinant protease MPro showed a low percentage of hydrolysis. Further optimization of the peptide fragment of the inactivated analog recognized by the SARS-CoV-2 MPro protease may lead to an increase in proteolysis and the release of Amicoumacin A.
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SARS-CoV-2 protease Nsp3 is a therapeutic target for developing anti-SARS-CoV-2 drugs. Nsp3 is a large multi-spanning membrane protein, and its characterization in vitro has been challenging. Here we describe an in vitro assay to characterize the biochemical activity of full-length Nsp3 isolated from cells. The assay can be used to evaluate Nsp3 inhibitors. © 2023, The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.
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The COVID-19 virus has caused a global emergency and has attracted the attention of healthcare professionals and the public around the world. The significant increase in the number of new cases of infection with this virus demonstrates the relevance of the search for drugs that are effective against this pathogen. The aim of this work was to evaluate the antiviral efficacy of Mefloquin® against COVID-19. The antiviral efficacy of Mefloquin® against the new pandemic virus SARS-CoV-2 was studied in in vitro experiments in Vero C1008 cell culture and in vivo on Syrian golden hamsters. The results of the study revealed that the drug Mefloquine® at a concentration of 2.0 µg ml-1, when applied after infection of cells, suppresses the reproduction of the SARS-CoV-2 virus by 1.7-1.9 lg, the inhibition rate is about 99%. When using Mefloquine, pathological changes in the lung tissue were less pronounced than in the control group. 6 days after infection, it was shown that when using Mefloquine, there was a statistically significant decrease in viral load in the lungs of infected Syrian golden hamsters, with an inhibition rate of 95.5%.
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Interferons (IFN) have antiviral activity against many viruses, including SARS-CoV-2. A combination of IFN-a2b and the antioxidant taurine is widely used in the Russian Federation, and its antiviral activity has not been studied before. The aim of this study was to determine the antiviral activity of interferon drugs, in combination with taurine and without it. The study included cytotoxicity and antiviral activity assays of IFN-a2b preparations, when stored according to the instructions at 2-8°C, and after 1 month storage at the temperature of 20-26°C in a pre-opened state. The combination of IFN alpha-2b with taurine has a higher antiviral activity compared to IFN alpha-2b mono-preparation by more than 25% at a «low» and 85% at a «high» multiplicity of infection. Selectivity index for combinations of IFN-a2b (50,000 IU/dose) + taurine (1 mg/ml) and IFN-a2b (10,000 IU/ml) + taurine (0.8 mg/ml) was more than 600 units, whereas for the IFN-a2b (10,000 IU/ml) it was 200 units. Antiviral activity does not change after one month at room temperature. The combination of interferon with taurine at high concentrations was less toxic than interferon. The results obtained demonstrate practicability of interferon alpha-2b and taurine combination use for treatment and prevention of COVID-19.
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Lectins are a group of highly specific carbohydrate-binding proteins with a wide spectrum of action, involved in the so-called «first line» of body defense. These unique biomolecules show high specificity for various mono- and oligosaccharides, primarily for viral and bacterial glycoconjugates. Cyanobacteria lectins are effective against enveloped viruses and are an appealing alternative to existing synthetic drugs. Virtually complete absence of resistance formation in viruses to these compounds is known. The purpose of this review is to analyze, summarize, and discuss the results of experimental studies in vivo and in vitro, illustrating the mechanisms of action and antiviral effects of lectins obtained from cyanobacteria in relation to the most dangerous and socially significant viruses: SARS-Cov-2, HIV, Ebola viruses, influenza, and hepatitis C. In addition, the article outlines some of the challenges that must be overcome in order to obtain effective antiviral drugs in the future.
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Background: Coronavirus disease 2019 (COVID-19) is an emerging respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARSCoV- 2). Recent studies have suggested numerous hypotheses that may explain multi-organ dysfunction during a COVID-19 infection. One possible hypothesis posits that the renin-angiotensin system dysregulation before SARS-CoV-2 infection could exacerbate disease symptoms and severity, especially in COVID-19 patients with underlying comorbidities. Objective: This study sought to investigate the effect of exogenous angiotensin II (Ang II) on peripheral blood mononuclear cells (PBMCs) stimulated with SARSCoV- 2 peptide pool. Methods: PBMCs from recovered COVID-19 patients (n = 18) were used in this study. SARS-CoV-2 specific t-cell responses were measured using activation induced cell marker assay and intracellular cytokine staining (ICS) assay, while enzyme-linked immunosorbent assay (ELISA) and ICS assays determined functional capability and polarization. Additionally, the relative level of protein phosphorylation in PBMCs was measured using a phosphokinase array. Results: Our results showed that in vitro Ang II treatment significantly increased the magnitude of SARS-CoV-2 specific t-cell response in stimulated PBMCs with SARS-CoV-2 peptide pool. Moreover, the phosphorylation level of numerous proteins implicated in cardiovascular diseases, inflammation, and viral infection showed significant increase in the presence of Ang II. Mitogenic stimulation of PBMCs after Ang II and SARS-CoV-2 peptide pool stimulation showed functional polarization of CD4+ and CD8+ t-cells toward Th1/Th17 and Th17 phenotypes, respectively. Meanwhile, ELISA showed an increased production of IL-1b and IL-6 in Ang II-stimulated PBMCs without affecting the reduction of IL-10 level resulting from SARS-CoV-2 peptide pool stimulation. Conclusion: To our knowledge, the present study is the first to demonstrate that Ang II exaggerates SARS-CoV-2 specific t-cells response. Therefore, during COVID-19 infection Ang II may aggravate the inflammatory response and change the immune response toward a more inflammatory profile against SARS-CoV-2 infection, leading to serious complications and worse outcomes during COVID-19 infection.
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Aim is to discuss diagnostic and therapeutic difficulties in COVID-19 related postoperative outcomes. A 5-year-old boy operated for jejunal atresia in neonatal period admitted with recurrent bilious vomiting. The upper GI series revealed dilated jejunum and absence of mechanical obstruction. The dilated jejunal segment was excised and anastomosis was performed. Later, he developed peritonitis without signs of anastomotic leaks. The second surgical exploration revealed diffuse peritonitis causing thickened and fibrous bowel loops causing hardly lysable adhesions. Then, his grandmother was learned to be COVID-PCR positive. Therefore, patients with atypical postoperative course should be investigated for possible COVID-19 during pandemics. Copyright © 2022 Ankara Pediatric Hematology Oncology Training and Research Hospital. All rights reserved.
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The past two decades have witnessed a proliferation of commercially available molecular assays for commonly-encountered human parasites.1,2 Some assays are authorized for in vitro diagnostic use by national accrediting bodies, whereas many more are available as non-authorized kits that must be thoroughly evaluated by the clinical laboratory prior to clinical use. Likewise, some assays are available in convenient, easy-to-use, cartridge based formats, while others are available as individual reagents that must be assembled for use in the laboratory. This session will discuss the range of currently available commercial molecular assays and discuss their pros and cons. References 1. Ryan U, Paparini A, Oskam C. New technologies for detection of enteric parasites. Trends Parasitol 2017;33: 532-546. 2. Chandra Parija S, Poddar A. Molecular diagnosis of infectious parasites in the post-COVID-19 era. Trop Parasitol 2021;11: 3-10. Copyright © 2021
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Incidences and mortality from cardiovascular illnesses have grown during the last few decades. In patients with pre-existing cardiac disease, the COVID-19 pandemic has exacerbated cardiovascular problems. Researchers observed that rates of many conditions, comprising coronary heart failure and stroke, had been drastically higher in those who had recovered from COVID-19 as compared to those who did not have the disease. Herbal medicine is becoming more and more popular due to its relatively high safety and low toxicity. Shilajit has several beneficial properties because it primarily comprises fulvic acid and more than 84 minerals. It demonstrates antioxidant activity, which is a key factor in cardioprotection. Shilajit is appropriately referred to as "Rasayana/ Rasayanam";it translates as "rejuvenator" in Ayurvedic and Siddha scriptures since it prevents illnesses and improves the quality of life. The current study involved the collection, authentication, purification, and use of several extractive solvents to achieve high yield, then the extract was enriched by using organic solvents. UV-Vis spectroscopy was performed on each of the enriched samples, and the results showed that the enriched samples had increased fulvic acid concentrations. Fulvic acid was used as a standard in thin-layer chromatography. The extract's in-vitro antioxidant activity was assessed using the DPPH assay, and the results indicated good antioxidant activity. phytosomes were formulated by rapid injection methods for extract and enriched extract, and they were characterized using several spectroscopic techniques. According to the study's findings, combining novel formulation with conventional drug may improve its therapeutic potential and bioavailability.
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Introduction: COVID-19 is an acute respiratory tract disease caused by the emerging coronavirus SARS-CoV-2. Although several options for che-moprophylaxis are under development, effective treatment for COVID-19 is not yet available. Objective(s): To investigate the antiviral properties of synthesized silver na-noparticles (AgNPs) against SARS-CoV-2 using in vitro models. Material(s) and Method(s): This work synthesized AgNPs using an electrochemical method and characterized them using physico-chemical techniques (ICP-OES, ultraviolet-visible spectroscopy, and transmission electron microscopy). AgNPs with diameter sizes ranging between 2.6 to 30 nm and an average size of 6.2 nm were obtained by the electrochemical method. The cytotoxic effect and the antiviral activity of prepared AgNPs against SARS-CoV-2 were evaluated in vitro using Vero E6 cells. Cell viability was evaluated by MTT assay in the presence of serial dilutions of AgNPs. The antiviral effect of AgNPs was evaluated before and after the infection of Vero E6 cells by plaque assay. Result(s): Cytotoxic effect was observed at concentrations above 0.07 ppm. AgNPs exhibit a significant reduction of SARS-CoV-2 viral titer after a pre-post treatment strategy with inhibition of 96.5%, 64.13%, and 74.72% at 0.03, 0.017, and 0.008 ppm, respectively. Conclusion(s): Our results suggest that AgNPs could reduce SARS-CoV-2 replication with a low cytotoxic effect. Still, additional in vitro and in vivo studies are required to define its potential therapeutic application in humans. Copyright © 2023 Universidad de Antioquia.
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The outbreak of COVID-19 has become a public health emergency of international concern;thus, it is important to not only develop drugs for treating COVID-19 but also develop a method for evaluating the therapeutic effect based on the characteristics of SARS-CoV-2 and its variants. To test the antiviral activity of a drug against COVID-19, in this study, we established and compared experimental conditions, such as the treatment time and mode of action (dose) of the therapeutic substance, and a test method to evaluate its effectiveness. We optimized an assay for testing antiviral activity by plaque reduction, tissue culture infectious dose 50, and quantitative RT-PCR. These methods were applied to test the antiviral efficacy of the therapeutic against SARS-CoV-2. Antiviral activity testing using in vitro assays against SARS-CoV-2 and its variants was assessed by measuring plaque-reducing or cytopathic effects in Vero-E6 cells. The in vitro assay was validated by evaluating the antiviral activity of remdesivir. Remdesivir reduced SARS-CoV-2 titer without detectable cytotoxicity and successfully inhibited viral replication in a dose-dependent manner. Therefore, we suggest this in vitro assay as an effective method for testing the antiviral activity for a potential repurposed drug against COVID-19 or rapid screening of therapeutic candidates. Copyright © 2022 Journal of Bacteriology and Virology.
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Natural products, such as botanical dietary supplements, are used globally and in some regions growing in their popularity and use, especially in the current COVID-19 pandemic. Ensuring the safety of these products is an important public health priority. Botanicals are naturally complex, with varying chemical compositions due to factors such as differences in growing conditions, extraction processes, and/or changes to the finished product. Globally, conventional in vivo and in vitro testing schemes are built on single chemicals, not on complex mixtures such as botanical products. Because of the chemical variability and a reliance on history of use data, toxicity data for many botanical mixtures are lacking and few tools have been tested for their suitability for these complex mixtures. A cross-sector collaboration between scientists in industry, government, and academia for botanical safety has been initiated with the goal of providing a sound scientific basis for integrating existing data with new approach methodologies to evaluate botanical safety. Thirteen botanicals with existing toxicity and/or clinical information available were chosen as initial candidates to evaluate various in silico and in vitro assays for their suitability to detect toxicological endpoints. Characterization of all thirteen botanicals was completed in early 2022, with quantification information obtained for selected individual constituents. Using this information as well as already available constituent details in the literature, the suitability of various in silico models and their use in various aspects of botanical safety evaluation were explored;as a screening step in an overall safety assessment for specific toxicological endpoints (e.g., genotoxicity, DART), to predict pharmacokinetic properties for use in PBPK modeling, and to predict formation of potentially toxic metabolites. Planned in vitro studies targeting specific endpoints of interest (hepatotoxicity, genotoxicity, developmental and reproductive toxicity, neurotoxicity, cardiotoxicity, and systemic toxicity) will be initiated mid-2022. This presentation will provide an overview of work completed to-date as well as a summary of the test materials, planned assays, and learnings to-date regarding advancements available for botanical safety assessment. Copyright © 2022 Elsevier B.V.
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Introduction: Risk of congenital heart disease (CHD) for in vitro fertilization (IVF) pregnancies is higher than the general population, though other factors may be involved. IVF is an indication for fetal echocardiogram (FE), however there is center variation to perform FE without a secondary indication if the anatomy ultrasound (AU) is normal. We aim to assess the number of new CHD diagnoses following normal AU in IVF-only pregnancies. Hypothesis: We hypothesize that there is minimal benefit to a FE in IVF-only pregnancies with a normal AU and may result in overutilization of resources. Method(s): Retrospective chart review from 2016-2021 of all IVF pregnancies with and without a secondary indication for FE at our center. Those without FE during the COVID-19 pandemic were included to assess postnatal CHD detection. Patients were classified as IVF-only if they had a normal AU and no secondary indication for FE;all others classified as IVF+other. Maternal and fetal demographics, AU, FE, and postnatal echo (post-echo) data was obtained. Result(s): A total of 556 maternal and 628 fetal patients from IVF pregnancies were included;401 fetuses were IVF-only with a FE, 116 were IVF-only with no FE, the remaining were IVF+other. There was no complex CHD (CCHD) in either IVF-only groups, the FE group detected several minor findings, and the no FE group detected three small septal defects on post-echo (Table 1). The probability of a normal postnatal evaluation in IVF-only with a normal FE was 94% and with no FE was 96%. Minor variations found on FE triggered additional testing (71 total FE in 43 fetuses) and detected a few minor CHD, none requiring intervention. Conclusion(s): Given low-risk for CCHD in IVF-only pregnancies, there is minimal benefit to a FE in the setting of a normal comprehensive AU and raises questions of cost vs. benefit of FE. This may impact future recommendations for indications for FE in the setting of IVF-only without added risk factors for CHD.
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Background. The COVID-19 pandemic has demonstrated the importance of pathogen genomic surveillance. At RKI, the German National Institute of Public Health, we established the Integrated Molecular Surveillance for SARS-CoV-2 (IMS-SC2) network to perform SARS-CoV-2 genomic surveillance. Methods. SARS-CoV-2 positive samples from laboratories distributed across Germany regularly undergo whole-genome sequencing at RKI. This surveillance instrument enables (i) almost-real-time monitoring of SARS-CoV-2 genomic diversity and evolution, (ii) in vitro assessment of vaccine coverage against emerging variants and (iii) genome-based estimates of SARS-CoV-2-incidences. Results. We report the results of our analyses of 3623 SARS-CoV-2 genomes collected between 12/1/2020 and 12/31/2021. All variants of concern were identified, at ratios equivalent to those in the 100-fold larger German GISAID sequence dataset from the same time period. Lineage distributions fluctuated over time, covering the rise of the Alpha and Delta, as well as the emergence of Omicron. Phylogenetic analysis confirmed variant assignments. Multiple mutations of concern emerged during the observation period. To model vaccine effectiveness in vitro, we employed authentic-virus neutralization assays, confirming that both the Beta and Zeta variants are capable of immune evasion. The IMS-SC2 sequence dataset facilitated an estimate of the SARS-CoV-2 incidence based on genetic evolution rates. Together with modelled vaccine efficacies, Delta-specific incidence estimation indicated that the German vaccination campaign contributed substantially to a deceleration of the nascent German Delta wave. Conclusion. This example illustrates that pathogen genomics enables a proactive approach to controlling a pandemic as the virus evolves. Molecular and genomic SARS-CoV-2 surveillance will be crucial during the post-pandemic future, informing public health policies including vaccination strategies. Of note, the IMS-SC2 infrastructure can be adapted to many other pathogens, serving as a blueprint for future efforts to increase genomic pathogen surveillance.
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Background. Sotrovimab (VIR-7831) is an engineered human monoclonal antibody targeting a conserved region of the SARS-CoV-2 spike protein;it has been shown to have a favorable safety profile and be effective for early treatment of highrisk COVID-19 patients. The COMET-TAIL phase 3 study evaluated sotrovimab administered intravenously (IV) or intramuscularly (IM) for the treatment of participants with mild to moderate COVID-19 who are at high risk of disease progression. Methods. Between June to August 2021, 973 participants were randomized and received sotrovimab by 500 mg IV infusion or by 500 or 250 mg IM injection. Deep sequencing of the spike gene was performed on nasopharyngeal samples. Baseline (BL;Day 1 or Day 3), post-BL (Day 5 or later), treatment-emergent (TE) substitutions at sotrovimab epitope positions, and presence of variants of concern/interest (VOC/ VOI), were evaluated at a >=5% allelic frequency. Phenotypic analyses were conducted using a pseudotyped virus assay. Results. Sequences were available from 764 participants (500 mg IV: 314/393;500 mg IM: 302/387;250 mg IM: 148/193). Consistent with VOC circulation during enrollment, the Delta variant was detected in 88.2% (674/764) of participants. Alpha and Mu variants were also seen at >2% prevalence. Of the 764 participants, 26 met the primary endpoint for clinical progression to hospitalization >24 hours or death due to any cause through day 29 and were infected with Delta (500 mg IV: 4;500 mg IM: 9;250 mg IM: 11), Alpha (500 mg IM: 1), or Mu (500 mg IV: 1) variants. Substitutions at sotrovimab epitope positions were similar across arms and were detected in 82/764 (10.7%) participants at any visit (500 mg IV: 42/314;500 mg IM: 27/302;250 mg IM: 13/148). Of these, 2 participants experienced clinical progression: 1 participant infected with the Mu variant (500 mg IV) carried the characteristic R346K substitution at BL;1 participant infected with the Delta variant (500 mg IM) had P337L and E340K substitutions detected at Day 3 and P337L was enriched at Day 8. The predominant TE epitope substitutions included P337L and E340A/K/V, which confer reduced susceptibility to sotrovimab in vitro. Conclusion. Overall, TE epitope substitutions were not associated with clinical progression.
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Background. Remdesivir (RDV) is a broad-spectrum nucleotide analog prodrug approved for the treatment of COVID-19 in non-hospitalized and hospitalized adult as well as pediatric patients with clinical benefit demonstrated in multiple Phase 3 trials. Here we present SARS-CoV-2 resistance analyses from the Phase 3 ACTT-1 placebo-controlled clinical trial in hospitalized adults. Methods. Oro- or nasopharyngeal swab samples in ACTT-1 study were collected on Day 1, 3, 5, 8, 11, 15, and 29. All participants with >80th and 50% of participants with < 20th percentile of cumulative viral shedding underwent resistance analysis in both the RDV and placebo arm. The SARS-CoV-2 genome was sequenced using next generation sequencing. Phenotyping was conducted using virus isolation from clinical samples or generation of select site-directed mutants (SDMs) in a SARS-CoV-2 replicon system. Results. The majority of the sequencing data were obtained from participants with 80th percentile of cumulative viral shedding from the RDV and placebo arms as shown in Table 1. Among participants with both baseline and postbaseline sequencing data, emergent substitutions in nsp12 were observed in 12 of 31 participants (38.7%) treated with RDV and 12 of 30 participants (40.0%) in the placebo arm. The nsp12 substitutions that emerged in the RDV arm were only observed in one participant each, and the majority were present as mixtures with wildtype sequence. The following nsp12 mutations emerged in the RDV treatment group and were successfully phenotyped as clinical isolates or SDMs with low to no fold change in RDV susceptibility: A16V (0.8-fold), P323L+V792I (2.2-fold), C799F (2.5-fold), K59N (1.0-fold), and K59N+V792I (3.4-fold). V792I and C799F were identified previously in vitro in resistance selection experiments (Stevens Sci Transl Med 2022). In addition, for D684N and V764L identified in the RDV arm, the recovery of neither clinical isolates nor SDMs for phenotypic analysis were successful. Conclusion. The similar rate of emerging nsp12 substitutions in participants treated with RDV compared to placebo and the minimal to no change in RDV susceptibility among the treatment-emergent nsp12 substitutions support a high barrier to RDV resistance development in COVID-19 patients.
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Background. Ensitrelvir is a novel oral SARS-CoV-2 3C-like protease inhibitor, and under late clinical development stage for COVID-19 diseases. Ensitrelvir exhibited an inhibition potency for organic cation transporter 1 (OCT1) and multidrug and toxin extrusion protein 1 (MATE1) in in vitro study and clinical drug-drug interaction (DDI) study is required judging fromDDI guidance.Metformin is widely used for treatment of diabetes, and is a sensitive substrate for OCT1 and MATE1. We evaluated the effect of ensitrelvir on the pharmacokinetics (PK) ofmetformin with physiologically-based pharmacokinetic (PBPK) modeling and simulation and clinical DDI study. Methods. The PBPK model of ensitrelvir was developed based on the physicochemical parameters, in vitro transporter inhibition parameters, and estimated PK parameters for human. DDI simulations between ensitrelvir and metformin were performed. Simcyp PBPK Simulator (Version 20, Certara UK Limited, UK) was used to develop PBPK model and simulate the DDIs. The in vitro 50% inhibitory concentration (IC50) values of each transporter were used as inhibition constant (Ki) for DDI simulations. Based on the PBPK analysis, the clinical DDI study planed. Results. PBPK analysis: As the result of DDI simulation, ensitrelvir increased the area under the curve (AUC) of metformin by 12%. The result suggests that in vivo DDI potency of ensitrelvir via inhibition of OCT1 or MATE1 would be low at a single dose of ensitrelvir 1000 mg. Clinical DDI study: The plasma concentration-time profile of metformin and ensitrelvir were monitored after 96 hours from a single dose of metformin with or without ensitrelvir. Ensitrelvir does not have effect on the PK of metformin (a geometric mean of AUC ratio was 1.02, Japanese healthy subjects, N=14), suggesting no MATE1 and OCT1 inhibition by ensitrelvir at a clinical dose. The PBPK analysis could well predict the clinical DDI study result. Conclusion. The results of PBPK analysis and the clinical DDI study suggest that no OCT1 and MATE1 inhibition by ensitrelvir is in the clinical dose. Therefore, ensitrelvir does not have a clinically meaningful effect on the pharmacokinetic profile of OCT1 and/or MATE1 substrates including metformin.
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Background. AZD7442 is a combination of extended-half-life SARS-CoV-2- neutralizing monoclonal antibodies (tixagevimab/cilgavimab) that bind to distinct epitopes on the SARS-CoV-2 spike protein. In the PROVENT study, a single 300 mg intramuscular dose of AZD7442 demonstrated 77% efficacy for prevention of COVID-19 vs placebo at primary analysis, with 83% efficacy through 6-months follow-up, and was well-tolerated. We report conservation of AZD7442 binding sites and neutralizing activity against pseudotyped virus-like particles (VLPs) harboring spike substitutions identified in surveillance, and clinical SARS-CoV-2 isolates from the PROVENT study. Methods. Consensus SARS-CoV-2 whole genome sequences were analyzed from open source databases to identify prevalent spike substitutions within the AZD7442 binding site. Phenotypic analyses determined neutralization susceptibility of pseudotyped VLPs with identified spike substitutions. Genotypic analyses were also performed on SARS-CoV-2 spike sequences from PROVENT study (NCT04625725) participants with RT-PCR-positive symptomatic illness. Results. Most residues in tixagevimab (13/17) and cilgavimab (13/19) binding sites were >99% conserved among global SARS-CoV-2 isolates (N=8,373,740 through Apr 19, 2022). In 2021, AZD7442 binding site polymorphisms emerged among circulating strains (prevalence: R346K, 11%;N440K, 22%;G446S, 15%;S477N, 28%;L452R, 43%;T478K, 70%;E484A, 27%;E484K, 3%;Q493R, 27%), but these did not affect AZD7442 in vitro neutralization potency. AZD7442 retained neutralization activity against variants of concern or interest tested, including Omicron BA.2, with moderate reduction observed for Omicron BA.1. By median 6-months follow-up (Aug 29, 2021, data cut-off) in the PROVENT study, there were no AZD7442-resistant substitutions observed in breakthrough SARS-CoV-2 illness visits. Conclusion. AZD7442 retained neutralization activity against all SARS-CoV-2 variants of concern or interest evaluated. Binding site substitutions identified in circulation, and in breakthrough SARS-CoV-2 infections following a single 300 mg dose of AZD7442 in the PROVENT study, were not associated with AZD7442 escape.
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Background. Acinetobacter baumannii typically causes infections in debilitated, hospitalized patients and is difficult to treat due to multiple virulence factors and the presence of intrinsic and acquired antibiotic resistance mechanisms leading to frequent isolation of multi-drug resistant (MDR) phenotypes. Due to problematic pharmacokinetics and/or dose-limiting toxicities of salvage agents, combination therapy with aminoglycosides, ampicillin/sulbactam, polymyxins, minocycline, or tigecycline, is often used. Eravacycline has demonstrated greater in-vitro potency against A. baumannii compared to other tetracycline derivatives making it potentially the more appealing option. However, its utility is hindered by a lack of data supporting pharmacodynamic targets and adequate dosing strategies for CRAB. The goal of this case series was to describe our experience with the use of combination eravacycline therapy for the treatment of CRAB pneumonia. Methods. This case series included all patients >= 18 years of age, diagnosed with SARS-CoV-2, >= 1 sputum culture positive for CRAB and a clinical diagnosis of new bacterial pneumonia, who received at least one dose of eravacycline between April 1st and October 1st, 2020. The primary outcome was clinical resolution of CRAB pneumonia. Secondary outcomes evaluated microbiological resolution, need for extended durations of therapy, and frequency of re-starting CRAB therapy within 48 hours of completion. Results. In total, 25 patients were included in this case series. The median duration of combination therapy was 10 days. Most patients (96%) received eravacycline + ampicillin/sulbactam, with 7 of those patients also receiving inhaled colistin (Table 2). In total, 17 (68%) patients achieved clinical resolution of CRAB pneumonia. Post-treatment sputum cultures were collected in 18 patients, of which 13 (72%) achieved microbiological resolution. One patient received > 14 days of therapy and no patients re-initiated therapy within 48 hours of eravacycline completion. Table 1: Baseline Characteristics Table 2: Study Outcomes Conclusion. In this small case series, eravacycline showed favorable clinical outcomes in patients with CRAB pneumonia. In light of limited treatment options, this agent can be considered for CRAB pneumonia salvage therapy.