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Development and optimization of a high-throughput screening assay for in vitro anti-SARS-CoV-2 activity: Evaluation
Winston Chiu1, Lore Verschueren2, Christel Van den Eynde2
1KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory of Virology and Chemotherapy, Leuven, Belgium.
Abstract:
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 African green monkey kidney epithelial cells expressing a stable enhanced green fluorescent protein (VeroE6-eGFP cells) and was used to screen a library of 5676 compounds that passed Phase 1 clinical trials. Eight drugs (nelfinavir, RG-12915, itraconazole, chloroquine, hydroxychloroquine, sematilide, remdesivir, and doxorubicin) were identified as inhibitors of in vitro anti-SARS-CoV-2 activity in VeroE6-eGFP and/or Caco-2 cell lines. However, apart from remdesivir, toxicity and pharmacokinetic data did not support further clinical development of these compounds for COVID-19 treatment.
Insights
Researchers screened 5,676 drugs to find treatments for coronavirus disease 2019 (COVID-19). While eight drugs showed in vitro antiviral activity, only remdesivir demonstrated potential for further clinical development against SARS-CoV-2.
Area of Science:
- Virology
- Drug Discovery
- Infectious Diseases
Background:
- Vaccines are primary tools against COVID-19, but effective treatments are crucial for unvaccinated individuals and future viral threats.
- Existing antiviral options for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are limited.
- There is an urgent need for novel therapeutic strategies to combat COVID-19 and emerging coronavirus strains.
Purpose of the Study:
- To identify existing drugs with potential anti-SARS-CoV-2 activity.
- To screen a large library of clinically evaluated compounds for efficacy against SARS-CoV-2.
- To assess the suitability of identified compounds for clinical development as COVID-19 treatments.
Main Methods:
- Development of a high-throughput, high-content imaging-based SARS-CoV-2 infection assay using VeroE6-eGFP cells.
- Screening of a library comprising 5,676 compounds that had passed Phase 1 clinical trials.
- Evaluation of antiviral activity in VeroE6-eGFP and Caco-2 cell lines.
Main Results:
- Eight compounds exhibited in vitro inhibitory activity against SARS-CoV-2.
- The identified compounds included nelfinavir, RG-12915, itraconazole, chloroquine, hydroxychloroquine, sematilide, remdesivir, and doxorubicin.
- Except for remdesivir, toxicity and pharmacokinetic profiles precluded further clinical investigation for COVID-19.
Conclusions:
- The study identified several compounds with in vitro anti-SARS-CoV-2 potential.
- Remdesivir emerged as the most promising candidate for further clinical evaluation among the tested drugs.
- The findings highlight the challenges in repurposing existing drugs for COVID-19 treatment due to safety and efficacy considerations.
