The oral protease inhibitor (PF-07321332) protects Syrian hamsters against infection with SARS-CoV-2 variants of concern

  1. Rana Abdelnabi
  2. Caroline S. Foo
  3. Dirk Jochmans
  4. Laura Vangeel
  5. Steven De Jonghe
  6. Patrick Augustijns
  7. Raf Mols
  8. Birgit Weynand
  9. Thanaporn Wattanakul
  10. Richard M. Hoglund
  11. Joel Tarning
  12. Charles E. Mowbray
  13. Peter Sjö
  14. Fanny Escudié
  15. Ivan Scandale
  16. Eric Chatelain
  17. Johan Neyts

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Abstract

There is an urgent need for potent and selective antivirals against SARS-CoV-2. Pfizer developed PF-07321332 (PF-332), a potent inhibitor of the viral main protease (Mpro, 3CLpro) that can be dosed orally and that is in clinical development. We here report that PF-332 exerts equipotent in vitro activity against the four SARS-CoV-2 variants of concerns (VoC) and that it can completely arrest replication of the alpha variant in primary human airway epithelial cells grown at the air-liquid interface. Treatment of Syrian Golden hamsters with PF-332 (250 mg/kg, twice daily) completely protected the animals against intranasal infection with the beta (B.1.351) and delta (B.1.617.2) SARS-CoV-2 variants. Moreover, treatment of SARS-CoV-2 (B.1.617.2) infected animals with PF-332 completely prevented transmission to untreated co-housed sentinels.

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  1. Version published to 10.1038/s41467-022-28354-0
  2. ScreenIT

    SciScore for 10.1101/2021.11.04.467077: (What is this?)

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

    Table 1: Rigor

    EthicsIRB: Housing conditions and experimental procedures were approved by the ethics committee of animal experimentation of KU Leuven (license P065-2020).
    Euthanasia Agents: On day 4 pi, animals were euthanized for sampling of the lungs and further analysis by i.p. injection of 500 μL Dolethal (200 mg/mL sodium pentobarbital, Vétoquinol SA).
    Sex as a biological variableFemale Syrian hamsters (Mesocricetus auratus) were purchased from Janvier Laboratories and kept per two in individually ventilated isolator cages (IsoCage N Bio-containment System, Tecniplast) at 21°C, 55% humidity and 12:12 day/night cycles.
    Randomizationnot detected.
    BlindingAll caretakers and technicians were blinded to group allocation in the animal facility.
    Power AnalysisGroup size was calculated on the independent t-test with an effect size of 2.0 and a power of 80% (effect size = deltamean/SD = 1 log10 decrease in viral RNA/0.5 log10), resulting in 5-6 animals/group.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Experimental Models: Cell Lines
    SentencesResources
    Virus stocks were then grown on Vero E6 cells in (DMEM 2% FBS medium) and passaged two times.
    Vero E6
    suggested: RRID:CVCL_XD71)
    Diluted compounds were then mixed with Vero E6-eGFP cells corresponding to a final density of 25,000 cells/well in 96-well blackview plates (Greiner Bio-One, Vilvoorde, Belgium; Catalog 655090).
    Vero E6-eGFP
    suggested: None
    A549-Dual™ hACE2-TMPRSS2 cells obtained by Invitrogen (Cat. a549d-cov2r) were cultured in DMEM 10% FCS (Hyclone) supplemented with 10 μg/ml blasticidin (Invivigen, ant-bl-05), 100
    A549-Dual™ hACE2-TMPRSS2
    suggested: RRID:CVCL_A7ZQ)
    The simulation results were overlaid with the in vitro EC50 reported in Vero E6 cells and A549-ACE2TMPRSS2 cells.
    A549-ACE2TMPRSS2
    suggested: None
    Experimental Models: Organisms/Strains
    SentencesResources
    Microsomal metabolic stability: Mouse liver microsomes (CD-1 male strain) were purchased from GIBCO.
    CD-1
    suggested: RRID:MGI:2686808)
    Software and Algorithms
    SentencesResources
    The four variants were originally isolated in-house from nasopharyngeal swabs taken from travellers returning to Belgium (baseline surveillance) and were subjected to sequencing on a MinION platform (Oxford Nanopore) directly from the nasopharyngeal swabs 16.
    MinION
    suggested: (MinION, RRID:SCR_017985)
    All statistical analyses were performed using GraphPad Prism 9 software (GraphPad, San Diego, CA, USA).
    GraphPad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)
    GraphPad
    suggested: (GraphPad Prism, RRID:SCR_002798)
    The data from the two studies were modelled simultaneously using nonlinear mixed-effects approach in NONMEM, v7.4
    NONMEM
    suggested: (NONMEM, RRID:SCR_016986)

    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: We found the following clinical trial numbers in your paper:

    IdentifierStatusTitle
    NCT05047601RecruitingA Post-Exposure Prophylaxis Study of PF-07321332/Ritonavir i…
    NCT04575597Active, not recruitingEfficacy and Safety of Molnupiravir (MK-4482) in Non-Hospita…

    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.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  3. Version published to 10.1101/2021.11.04.467077v1 on bioRxiv