While COVID-19 may not affect cats much, felines are known to contract another kind of coronavirus that can sometimes be fatal. Now, early research has shown that the same drugs that can be used on cats to treat this disease may also help people suffering from COVID-19.
The virus they treat in cats, known as ‘feline enteric coronavirus’ (FeCV) affects the gastrointestinal tract. While it rarely causes symptoms, in about one in 10% of cats, it mutates after infection and begins to infiltrate immune cells where it then causes havoc in the body and sets off severe inflammation. At this point, the infection is called ‘feline infectious peritonitis virus’ and is often fatal if left untreated.
In lab experiments, researchers found that one drug, known as GC376, disables an enzyme that some coronaviruses use to replicate- including SARS-CoV-2. Based on these findings, and the fact that the drug has already been shown as safe and effective in cats, the company behind the drug, Anivive Lifesciences, is now working to develop clinical trials in people.
Meanwhile, the other drug known to be effective in cats, called GS-441524, is an antiviral cousin of remdesivir, a drug known to accelerate recovery times in people suffering from COVID-19. Similar in structure, remdesivir differs from GS-441524 as it has an extra part that better enables it to enter cells.
In a study in 2018, researchers demonstrated that GS-441524 not only inhibited viral replication in lab-grown cells but also successfully treated 10 out of 10 cats with feline infectious peritonitis virus. In a separate study from 2019, researchers then showed that treatment with the drug for at least 12 weeks left 25 out of 26 cats surviving the disease.
In July this year, a study also found the same drug was able to inhibit SARS-CoV-2 replication in lab-grown monkey and human cells. However, while remdesivir is already on its way to full FDA approval, GS-441524 has yet to be trialed in humans. Nevertheless, Gilead, the company behind both this drug and remdesivir has said it has begun preclinical studies to compare the drugs.
Although it is still unknown whether GS-441524 or GC376 will be effective in humans against COVID-19, the drugs exemplify the connections between animal and human health, and how knowledge of both, could accelerate the finding of treatments in either species.