Van Damme, E. | Search bioRxiv

bioRxiv2022

Development and optimisation of a high-throughput screening assay for in vitro anti-SARS-CoV-2 activity: evaluation of 5676 phase 1 passed structures

Although vaccines are currently used to control the coronavirus disease 2019 (COVID-19) pandemic, treatment options are urgently needed for those who cannot be vaccinated and for future outbreaks involving new severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) strains or coronaviruses not covered by current vaccines. Thus far, few existing antivirals are known to be effective against SARS-CoV-2 and clinically successful against COVID-19. As part of an immediate response to the COVID-19 pandemic, a high-throughput, high content imaging-based SARS-CoV-2 infection assay was developed in VeroE6-eGFP cells and was used to screen a library of 5676 compounds that passed phase 1 clinical trials. Eight candidates (nelfinavir, RG-12915, itraconazole, chloroquine, hydroxychloroquine, sematilide, remdesivir, and doxorubicin) with in vitro anti-SARS-CoV-2 activity in VeroE6-eGFP and/or Caco-2 cell lines were identified. However, apart from remdesivir, toxicity and pharmacokinetic data did not support further clinical development of these compounds for COVID-19 treatment.

immunology↗

bioRxiv2020

In Vitro Activity of Itraconazole Against SARS-CoV-2

BackgroundAs long as there is no vaccine available, having access to inhibitors of SARS-CoV-2 will be of utmost importance. Antivirals against coronaviruses do not exist, hence global drug re-purposing efforts have been carried out to identify agents that may provide clinical benefit to patients with COVID-19. Itraconazole, an antifungal agent, has been reported to have potential activity against animal coronaviruses. MethodsUsing cell-based phenotypic assays, the in vitro antiviral activity of itraconazole and 17-OH itraconazole was assessed against clinical isolates from a German and Belgian patient infected with SARS-CoV-2. ResultsItraconazole demonstrated antiviral activity in human Caco-2 cells (EC50 = 2.3 M; MTT assay). Similarly, its primary metabolite, 17-OH itraconazole, showed inhibition of SARS-CoV-2 activity (EC50 = 3.6 M). Remdesivir inhibited viral replication with an EC50 = 0.4 M. Itraconazole and 17-OH itraconazole resulted in a viral yield reduction in vitro of approximately 2-log10 and approximately 1-log10, as measured in both Caco-2 cells and VeroE6-eGFP cells, respectively. The viral yield reduction brought about by remdesivir or GS-441524 (parent nucleoside of the antiviral prodrug remdesivir; positive control) was more pronounced, with an approximately 3 log10 drop and >4 log10 drop in Caco-2 cells and VeroE6-eGFP cells, respectively. DiscussionItraconazole and 17-OH itraconazole exert in vitro low micromolar activity against SARS-CoV-2. Despite the in vitro antiviral activity, itraconazole did not result in a beneficial effect in hospitalized COVID-19 patients in a clinical study (EudraCT Number: 2020-001243-15). HighlightsO_LIItraconazole exerted in vitro low micromolar activity against SARS-CoV-2 (EC50 = 2.3 M) C_LIO_LIRemdesivir demonstrated potent antiviral activity, confirming validity of the assay C_LIO_LIItraconazole has since shown no efficacy in a clinical study in hospitalized COVID-19 patients C_LI

pharmacology and toxicology↗