Antiviral proves effective at preventing, treating COVID-19 in lab


Date:
February 9, 2021
Source:
University of North Carolina Health Care
Summary:
Using a new research model containing human lung tissue, scientists
showed that the broad spectrum, experimental drug EIDD-2801 proved
effective at preventing and treating SARS-CoV-2 infection.



FULL STORY ========================================================================== Publishing their work in Nature, scientists at the UNC School of Medicine
and UNC Gillings School of Global Public Health found that the orally administered experimental drug EIDD-2801 halts SARS-CoV-2 replication and prevents infection of human cells in a new in vivo lab model containing
human lung tissue.


========================================================================== Separate phase 2 and 3 clinical trials are ongoing to evaluate EIDD-2801
safety in humans and its effect on viral shedding in COVID-19 patients.

The number of new COVID-19 cases continues to rise in many parts of the
world, with the highest incidence in the United States. Although some
highly efficacious vaccines have been authorized for emergency use, it
may take considerable time to reach target vaccination levels needed for
herd immunity due to the logistics of vaccine manufacturing, shipping,
storage, and distribution as well as public acceptance.

Also, SARS-CoV-2 variants have emerged which appear to have increased transmissibility and have added more challenges to ensure vaccine
viability.

Therefore, alternative treatments and preventive approaches that can be
widely and rapidly implemented are urgently needed to curb the risk for COVID-19 related hospitalization and death in multiple settings including nursing homes and long-term care facilities.

Mouse models can be useful in studying highly pathogenic human
coronaviruses including SARS-CoV-2 and compounds that might control
infection. But human coronaviruses do not replicate in mice unless
researchers alter the virus, genetically modify the mice, or introduce
the individual human receptor genes into mice so the virus can infect
cells. Such mouse models have added to the scientific community's
understanding of coronavirus infection and disease progression, but none
of these models possess the diverse human cells found in human lungs
where viral infection can cause severe disease. UNC scientists created
a solution to this problem -- a line of mice with human lung tissue that includes all the primary human cells infected when individuals fall ill
with COVID-19.

Immune-deficient mice implanted with human lung tissue (LoM) allowed for replication of SARS-CoV-2, which resulted in infection that recapitulates several features of early diffuse lung damage seen in COVID-19
patients. In addition, acute SARS-CoV-2 infection induced a robust and sustained Type I interferon and inflammatory cytokine/chemokine response.



==========================================================================
To evaluate the therapeutic efficacy of EIDD-2801 for COVID-19, the
researchers administered EIDD-2801 to LoM starting 24 hours or 48 hours
post SARS-CoV- 2 exposure and every 12 hours thereafter.

"We found that EIDD-2801 had a remarkable effect on virus replication
after only two days of treatment -- a dramatic, more than 25,000-fold
reduction in the number of infectious particles in human lung tissue
when treatment was initiated 24 hours post-exposure," said senior
author J. Victor Garcia, PhD, professor of medicine and director of the International Center for the Advancement of Translational Science. "Virus titers were significantly reduced by 96% when treatment was started
48 hours post-exposure." Next, the researchers tested the ability of
EIDD-2801 to prevent SARS-CoV- 2 infection by administering the drug 12
hours prior to SARS-CoV-2 exposure and every 12 hours thereafter.

"Remarkably, we found that EIDD-2801 pre-exposure prophylaxis
significantly inhibited SARS-CoV-2 replication -- reducing virus titers
in the human lung tissues of LoM by over 100,000 fold in two independent experiments," said co- first author Angela Wahl, PhD, assistant professor
of medicine and assistant director of the International Center for the Advancement of Translational Science.

Bats are the presumed source of SARS-CoV-2 and the highly pathogenic
human coronaviruses SARS-CoV and MERS-CoV, all of which emerged into
the human population within the past two decades.



==========================================================================
"We show that LoM allow for the in vivo study of all recently emerged
human coronaviruses in a single platform," said co-first author Lisa
Gralinski, PhD, assistant professor of epidemiology. "Our model allows researchers to directly compare infection between human coronaviruses
and the effectiveness of potential preventative and therapeutic
approaches." Gralinski, added, "We also show efficient replication
of endogenous bat coronaviruses in LoM human lung tissue without the
need for prior adaptation of the viruses, confirming that bats harbor
viruses that are capable of directly infecting humans without the need
for further adaptation." "Previously, we demonstrated that EIDD-2801
is also efficacious against SARS- CoV and MERS-CoV infection in vivo
and in primary human airway epithelial cultures," said Ralph Baric,
PhD, the William Kenan Distinguished Professor of Epidemiology at
the UNC Gillings School of Global Public Health and the UNC School of
Medicine. "Overall, these results indicate that EIDD-2801 may not only
be efficacious in treating and preventing COVID-19, it could also prove
to be highly effective against future coronavirus outbreaks as well."
Clinical trials for EIDD-2801 are ongoing, and the first results could
be released as early as March.

Other authors are Claire Johnson, Wenbo Yao, Martina Kovarova, Kenneth
Dinnon III, Hongwei Liu, Victoria Madden, Halina Krzystek, Chandrav
De, Kristen White, Kendra Gully, Alexandra Scha"fer, Tanzila Zaman,
Sarah Leist, Paul Grant, Frederic Askin, Edward Browne, Corbin Jones,
and Raymond Pickles, all from UNC- Chapel Hill, and Gregory Bluemling, Alexander Kolykhaloy, Michael Natchus, George Painter from Emory
University.

This work was supported through grants from the National Institutes of
Health and the North Carolina Coronavirus Relief Fund.


========================================================================== Story Source: Materials provided by
University_of_North_Carolina_Health_Care. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Angela Wahl, Lisa E. Gralinski, Claire E. Johnson, Wenbo Yao,
Martina
Kovarova, Kenneth H. Dinnon III, Hongwei Liu, Victoria J. Madden,
Halina M. Krzystek, Chandrav De, Kristen K. White, Kendra Gully,
Alexandra Scha"fer, Tanzila Zaman, Sarah R. Leist, Paul O. Grant,
Gregory R.

Bluemling, Alexander A. Kolykhalov, Michael G. Natchus, Frederic B.

Askin, George Painter, Edward P. Browne, Corbin D. Jones, Raymond J.

Pickles, Ralph S. Baric, J. Victor Garcia. SARS-CoV-2 infection
is effectively treated and prevented by EIDD-2801. Nature, Feb. 9,
2021; DOI: 10.1038/s41586-021-03312-w ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/02/210209121042.htm

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