CTSC | Stenoparib and COVID-19

  • Publication in mBio Journal

    Stenoparib, an inhibitor of cellular poly (ADP-ribose) polymerase (PARP), blocks replication of the SARS-CoV-2 and HCoV-NL63 human coronaviruses in vitro.

    Read mBio Journal

Senior Scientists

Experienced COVID-9 researchers testing coronavirus inhibitors.

Christopher T. French

Christopher T. French

Director of CTSC
An expert in host-pathogen interactions, Dr. French oversees the in vitro testing of COVID-19 at the CTSC. His independent research focuses on pathogenic mechanisms, ecology and developing new therapeutics for infectious diseases.

Paul S. Keim

Paul S. Keim

Executive Director of PMI
With research centered on genomic analysis, Dr. Keim is the Cowden Endowed Chair of Microbiology at Northern Arizona University (NAU), the Director of Pathogen Genomics at the Translational Genomics Research Institute (TGen).

Nathan Stone

Nathan Stone

Research Project Coordinator
Molecular and microbiologist interested in the genetics and ecology of infectious diseases, the population genetics of disease vectors, in relation to public health. He coordinates the laboratory processes for the CTSC.

Steen Knudsen

Steen Knudsen

CSO of Allarity Therapeutics
A 30-year career in bioinformatics combined with lab work (primarily gene expression) and clinical trials (primarily cancer). More recently, focus on regulatory process (FDA), business development and global patenting as well.

Abstract

Stenoparib, an inhibitor of cellular poly (ADP-ribose) polymerase (PARP), blocks replication of the SARS-CoV-2 coronaviruses in vitro.

By late 2020, the coronavirus disease (COVID-19) pandemic, caused by SARS-CoV-2 has caused tens of millions of infections and over 1 million deaths worldwide. A protective vaccine and more effective therapeutics are urgently needed. We evaluated a new PARP inhibitor, stenoparib, that recently advanced to Phase II clinical trials for treatment of ovarian cancer, for activity against human respiratory coronaviruses, including SARS-CoV-2, in vitro. Stenoparib exhibits dose-dependent suppression of SARS-CoV-2 multiplication and spread in Vero E6 monkey kidney and Calu-3 human lung adenocarcinoma cells. Stenoparib was also strongly inhibitory to the HCoV-NL63 human seasonal respiratory coronavirus. Compared to remdesivir, which inhibits viral replication downstream of cell entry, stenoparib impedes entry and post-entry processes as determined by time-of-addition (TOA) experiments. Moreover, a 10 mM dosage of stenoparib – below the approximated 25.5 mM half-maximally effective concentration (EC50), combined with 0.5 mM remdesivir suppressed coronavirus growth by more than 90%, indicating a potentially synergistic effect for this drug combination. Stenoparib as a standalone or as part of combinatorial therapy with remdesivir should be a valuable addition to the arsenal against COVID-19.

Fig. S1. Stenoparib inhibits plaque formation in Calu-3 cells.

Abstract Importance

Stenoparib impedes virus entry and post-entry processes, an advantage over drugs that have a narrower target range.

New therapeutics are urgently needed in the fight against COVID-19. Repurposing drugs that are either already approved for human use or are in advanced stages of the approval process can facilitate more rapid advances toward this goal. The PARP inhibitor stenoparib may be such a drug, as it is currently in Phase II clinical trials for the treatment of ovarian cancer and its safety and dosage in humans has already been established. Our results indicate that stenoparib possesses strong antiviral activity against SARS-CoV-2 and other coronaviruses in vitro. This activity appears to be based on multiple modes of action, where both pre-entry and post-entry viral replication processes are impeded. This may provide a therapeutic advantage over many current options that have a narrower target range. Moreover, our results suggest that stenoparib and remdesivir in combination may be especially potent against coronavirus infection.

Figures

Our data definitively shows that Stenoparib effectively inhibits SARS-CoV-2 in vitro.

Fig. 1. Stenoparib exhibits dose-dependent inhibition of SARS-CoV-2 as measured by RT-qPCR.

Fig. 2. Stenoparib is cytotoxic in Vero E6 cells at concentrations greater than 30 µM, but not in Calu-3 cells.

Fig. 3. Stenoparib exhibits dose-dependent inhibition of SARS-CoV-2 in Calu-3 cells.

Fig. 4. Stenoparib exhibits dose-dependent inhibition of HCoV-NL63 in LLC-MK2 cells.

Fig. 5. Stenoparib inhibits HCoV-NL63 entry and post entry events while remdesivir inhibits post-entry.

Fig. 6. Stenoparib and remdesivir in combination is a potent inhibitor of NL63.

Co-Authors

Technical researchers focused on in vitro testing.

Sierra A. Jaramillo

Sierra A. Jaramillo

Research Assistant

Ashley N. Jones

Ashley N. Jones

Research Technician

Adam J. Vazquez

Adam J. Vazquez

Research Specialist

Lora M. Versluis

Lora M. Versluis

Research Assistant

Madison Martz

Madison Martz

Research Technician

Marlee O. Raniere

Marlee O. Raniere

Research Assistant

Haley O. Nunnally

Haley O. Nunnally

Research Assistant

Katherine E. Zarn

Katherine E. Zarn

Research Assistant

Roxanne Nottingham

Roxanne Nottingham

Research Technician

Dr. Jason W. Sahl

Dr. Jason W. Sahl

Assistant Professor of Biology

Dr. David M. Wagner

Dr. David M. Wagner

Director Biodefense and Disease Ecology Center

Dr. Erik W. Settles

Dr. Erik W. Settles

Assistant Research Director

You may also like