It’s not news that cats commonly get their own strain of coronavirus (FCoV). According to Niels Pedersen, PhD, DVM and distinguished professor at the University of California, Davis, in about ten percent of cats infected with the ubiquitous and otherwise benign FCoV, it transforms into an immune-mediated disease called feline infectious peritonitis (FIP).
FIP had always been considered fatal until very recently. It turns out that treatment for FIP is nearly identical to Remdesivir, an anti-viral drug that President Donald Trump and U.S. Food and Drug Administration Commissioner Dr. Stephen Hahn have repeatedly mentioned, and is now approved for use to treat COVID-19. Remdesivir was created to treat Ebola by Gilead Sciences, but the results were mixed as other drugs proved better.
A few years back, Pedersen approached the non-profit funder of cat health studies, Winn Feline Foundation, as he sought to trial Remdesivir on cats with FIP. Winn’s scientific advisory board said, “Yes.” However, Gilead said, “Not so fast.”
Pedersen says, “We chose to use GS-441424 for treatment of the coronavirus disease FIP because it had identical antiviral properties to Remdesivir, and at the time was not under consideration by Gilead Sciences for use in humans. GS-441424 is also much cheaper to make than Remdesivir. Therefore, there was no apparent conflict with using one form for cats and another form for humans.”
The initial trials even blew Pedersen away. GS-441424 worked to cure cats with effusive or wet FIP. However, Gilead had a change of heart and refused to grant animal rights for the drug.
Back to the drawing board, Pedersen persevered. And with collaborators at Kansas State University, including Yunjeong Kim, PhD, DVM and associate professor in the department of pathobiology and diagnostics in the school’s College of Veterinary Medicine, they developed another nearly identical antiviral. This drug—known as GC376—also was trialled and had success in treating the wet form of FIP. Arguably, more success than the original Gilead drug. Currently, Anivive Lifescience is seeking FDA approval for this drug to treat cats with FIP, as announced at the Winn Feline Foundation symposium last November at U C Davis, Purrsuing FIP and Winning.
Chinese companies realized the opportunity, as people are, of course, desperate to help their kitties with FIP—and these kitty parents aren’t waiting a year or longer for even a rushed FDA approval. So, Chinese manufacturers began to offer compounds on the black market (presumably like GC376 and also GS-441424, and therefore similar to Remdesivir—but they don’t disclose exactly what their compounds are). At least the leading Chinese company has anecdotally seen great success in treating cats with FIP around the world, but the cost isn’t inexpensive. And that company confirmed that they are working with the Chinese government regarding potential use of their compounds to treat COVID-19. Also, that company wants their drug approved here in the U.S. so they will no longer need to force cat owners to deal with the so-called black market.
In the meantime, Anivive, while waiting for GC376 to be approved for cats, is now seeking approval to trial the compound to treat COVID-19 in humans. The compound Anivive is seeking to approve in GC376 is incredibly similar to Remdesivir, except their mechanism of action is significantly different: GC376 is a protease inhibitor and Remdesivir is a polymerase inhibitor, explains Dr. David Bruyette, chief medical officer at Anivive. Bruyette adds that he believes the two drugs may work together in tandem far more effectively than either can alone. The notion is similar to providing a cocktail when it comes to treating HIV-AIDS, as one drug alone just doesn’t do the trick.
Winn Feline Foundation president Dr. Drew Weigner says, “We hope that approved treatments for FIP will become available in the near future, and that greater efforts will be directed toward vaccination protocols, as this is the mainstay of controlling coronavirus infections in cats, and in all species.”
And no matter how all this plays out, veterinarians will no doubt be a part of this truly one health issue. +