The drugs, dipeptide-based protein inhibitors, referred to as GC376 and GC373, are designed to treat cats with feline infectious peritonitis, a potentially fatal illness caused by another type of coronavirus, feline enteric coronavirus (FCoV), according to a press release about the study. The release explained that FCoV is a coronavirus that has traits similar to the SARS-CoV-2, the virus causing COVID-19.
“The main protease in feline form of coronavirus and the virus associated with feline infectious peritonitis is highly homologous compared to the SARS-CoV2 protease associated with COVID-19,” Joanne Lemieux, a professor in the department of biochemistry at the University of Alberta, stated in the release. The success in treating cats with the medication may carry over to helping humans infected with COVID-19, the researcher said.
“In cats, GC376 (the prodrug) converts to GC373 and was able to successfully treat cats with no toxicity. Of the 20 cats tested, 19 recovered,” Lemieux said in the release.
The researchers from the University of Alberta in Canada think the medication blocks an enzyme produced by the feline enteric coronavirus, preventing it from reproducing, hence stopping the feline infectious peritonitis. This may work in a similar way to fight the novel coronavirus in humans, they said.
“The studies found that GC376 and GC373 were effective in targeting the protease for both SARS-CoV and SARS-CoV-2,” the researchers stated in the study.
“GC373 and GC376 are potent inhibitors of SARS-CoV-2 replication in cell culture. They are strong drug candidates for the treatment of human coronavirus infections because they have already been successful in animals,” the authors stated.
“It is not surprising that a feline drug could be used to treat COVID-19, especially since this drug targets the main protease of the virus, which is highly conserved,” Lemieux said in the release.
Lemieux said these findings lay down the foundation for human trials, adding that researchers received a grant to start trials in Canada. The researchers are also pursuing clinical trials in the United States, according to a recent release.