Infectious Diseases

Updated 03 September 2020

From a deadly disease in cats, to Covid-19 in humans: A treatment researchers have high hopes for

Scientists hope that a drug used to cure a disease caused by a coronavirus in cats, will be effective in humans, with clinical trials the next step.

  • In the search for a Covid-19 treatment, researchers are turning towards treatment for other diseases caused by coronaviruses
  • Protease has an antiviral effect on a coronavirus that causes a fatal disease in cats
  • As it has already been proved safe in animals, researchers are ready to continue with clinical trials

With drugs such as remdesivir and the corticosteroid dexamethasone showing promise in trials, researchers are investigating several other options to treat Covid-19.

Now, researchers at the University of Alberta are about to proceed with clinical trials of a drug used to cure another deadly disease caused by a coronavirus. The twist? This disease occurs in cats.

"In just two months, our results have shown that the drug is effective at inhibiting viral replication in cells with SARS-CoV-2," said Joanne Lemieux, a professor of biochemistry in the Faculty of Medicine & Dentistry in a press release.

Protease inhibitor as antiviral treatment

The drug being investigated is a type of protease inhibitor which slows down the ability of a virus to replicate inside the body, which then stops infection.

Proteases are enzymes which are able to break down proteins and peptides. These enzymes are found throughout the body and are used to treat a wide array of diseases, including high blood pressure, cancer and HIV.

Because of this, researchers are sure that a protease known to halt replication of a type of coronavirus in felines will be well-tolerated in humans as well.

"This drug is very likely to work in humans, so we're encouraged that it will be an effective antiviral treatment for COVID-19 patients," said Lemieux.

The possibility of using this drug in humans was first studied after the 2003 outbreak of severe acute respiratory syndrome (SARS). It was then developed by veterinary researchers to cure a disease that is fatal in cats.  

The findings were published in the peer-reviewed journal Nature Communications after first being posted on BioRxIV, a research website.

"There's a rule with Covid-19 research that all results need to be made public immediately," Lemieux said, which is why they were posted before being peer-reviewed.

What must happen before the drug is approved for humans?

The compounds of the drug were synthesised and then tested against SARS-CoV-2 in test tubes and in human cell lines.

"We determined the three-dimensional shape of the protease with the drug in the active site pocket, showing the mechanism of inhibition," said Lemieux. "This will allow us to develop even more effective drugs."

The team will then test modifications of the drug to make it work even better against SARS-CoV-2, even though there is enough antiviral response against the novel coronavirus to justify proceeding to clinical trials.

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