AT-527 is a potent in vitro replication inhibitor of SARS-CoV-2, the virus responsible for the COVID-19 pandemic

  1. Steven S. Good
  2. Jonna Westover
  3. Kie Hoon Jung
  4. Paolo La Colla
  5. Gabriella Collu
  6. Adel Moussa
  7. Bruno Canard
  8. Jean-Pierre Sommadossi

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Abstract

AT-527, an orally administered double prodrug of a guanosine nucleotide analog, has been shown previously to be highly efficacious and well tolerated in HCV-infected subjects. Herein we report the potent in vitro activity of AT-511, the free base form of AT-527, against several coronaviruses, including SARS-CoV-2, the causative agent of COVID-19. In normal human airway epithelial (HAE) cell preparations, the average concentration of AT-511 required to inhibit replication of SARS-CoV-2 by 90% (EC 90 ) was 0.5 µM, very similar to the EC 90 for AT-511 against HCoV-229E, HCoV-OC43 and SARS-CoV in Huh-7 cells. No cytotoxicity was observed for AT-511 in any of the antiviral assays up to the highest concentration tested (100 µM). Surprisingly, AT-511 was 30-fold less active against MERS-CoV. This differential activity may provide a clue to the apparent unique mechanism of action of the guanosine triphosphate analog formed from AT-527.

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  1. ScreenIT

    SciScore for 10.1101/2020.08.11.242834: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Experimental Models: Cell Lines
    SentencesResources
    After BHK-21 cells were grown to confluency in 96-well plates, growth medium was replaced with fresh maintenance medium (growth medium with 1% inactivated FBS in place of 10% FBS) containing serially diluted test compound and HCoV-229E at a multiplicity of infection (MOI) of 0.01.
    BHK-21
    suggested: None
    Antiviral assays in Huh-7 and RD cells: The antiviral activities of test compounds were evaluated against human coronaviruses alpha (229E), beta (OC43), MERS (EMC) and SARS (Urbani) using a neutral red assay to determine inhibition of virus-induced and compound-induced CPE and using a virus yield reduction (VYR) assay as a second, independent determination of the inhibition of viral replication.
    Huh-7
    suggested: None

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

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  2. Version published to 10.1101/2020.08.11.242834v2 on bioRxiv
  3. Version published to 10.1101/2020.08.11.242834v1 on bioRxiv