Published by: Ingrid King. Last Updated on: November 1, 2022 by Crystal Uys


Guest post by Ingrid R. Niesman, MS PhD

Unprecedented circumstances provide opportunities when you least expect them. In our current crisis, cats may hold the key to beating back the SARS-CoV-2 virus.

The link between FIP and COVID-19 

While we were blindsided by this baffling new illness, in retrospect, we shouldn’t have been so unprepared for a novel coronavirus to emerge. Feline enteric coronavirus (FECV), the virus responsible for development of Feline Infectious Peritonitis (FIP) in young cats, emerged out of nowhere in the 1960’s. We’re still not clear about the origins. Does this sound familiar?

The speed of COVID-19 infections worldwide, combined with the multitude of clinical symptoms, has confounded our understanding of SARS-CoV-2, the virus that causes COVID-19. Yet, veterinarians have been seeing these clinical signs for years in FIP-affected kittens and cats. Most cats have no symptoms or only mild symptoms when infected with FECV. They shed the virus for a short time and recover. A small subset of infected cats proceeds to full-blown FIP, including cytokine storms and overactive immune systems.

Clinical data from FIP trials are a valuable resource

Because the FDA maintains separate tracks for animal and human health, therapies that can treat animal viruses as well as human viruses have been kept separate. Physicians and veterinarians aren’t always up to date on new drugs that could benefit humans and companion animals.

One company is using their expertise in FIP antiviral therapies to repurpose their drug, and their data, in our battle to save cats and human lives.  Anivive Lifesciences, based in Long Beach, CA, has recently filed a pre-Investigational New Drug (pre-IND) to begin preclinical studies for their FIP candidate drug GC376 for treatment of COVID-19.

At the same time, Anivive is not giving up on FIP cats. “Our focus is still on cats,” says Chief Medical Officer David Bruyette, DVM, DACVIM. “We are taking a parallel path for human approval. We are sitting on a wealth of animal clinical data.” This means that Anivive has a head start on understanding the value of GC376’s antiviral properties when used as a human therapy.

Other companies are using genetically modified mice, ferrets or even hamsters as human surrogates, but these animals do not mirror human disease. They don’t die. They recover. “The difficulty in transitioning to humans is a lack of a model recapitulating all clinical features of the disease,” says Dr. Bruyette. Having what appears to be a spontaneous model of a COVID-19-like illness, namely FIP, will benefit development of GC376 for humans. Just to be clear, Anivive is not infecting cats with either SARS-CoV-2 or FECV in their research. Their current FIP data will be used to understand clinical comparisons during human trials, such as windows for optimal treatment or dosing during different disease stages. No one else has this treasure-trove of information to mine.

GC376 inhibits coronaviruses by blocking the action of a protein that the virus needs to replicate itself. This, in turn, stops a cell from producing virus particles, effectively putting the brakes on further spread of the infection through a host, be it a cat or a human.

GC376 has shown effectiveness in treating FIP. In a 2017 publication from UC Davis, GC376 saved seven cats, the first real promising clinical treatment for FIP known at the time. Since GC376 has broad-spectrum efficacy against other coronaviruses, the idea of repurposing it to humans has gained momentum.

Good news for humans is even better news for cats

The FDA is streamlining the usual path for drug approvals in response to COVID-19. Dr. Bruyette explains the new streamlined process, “We will be receiving feedback from the FDA about our plans to move the drug toward human trials. With that feedback we can work towards meeting all the requirements to safely move into humans.” This acceleration will benefits cats. Because the amount of drug needed for a human is considerably greater than a cat, Anivive is ramping up manufacturing capabilities and moving ahead more quickly on formulation and stability studies.

Keeping GC376 affordable for veterinary clients 

When asked about commercialization of GC376 for veterinary use, Chief Commercial Officer, Chad Dodd, DVM was empathic about Anivive’s strategy to keep this drug affordable for veterinary clients. “At the end of the day, we are committed to veterinary medicine first,” said Dr. Dodd. “Given the current pandemic and scarcity of effective therapies, we are also exploring the use of GC376 in humans to help combat COVD-19.”

The future of One Health 

One Health, a worldwide initiative studying the interconnections between animal and human health, is a crucial element in disease prevention and surveillance. Without this work, we would have little knowledge of the pool of potential disease-causing viruses existing in farm animals or wildlife. Yet enthusiasm for funding animal medicine lags behind human medicine.

Dr. Bruyette expects that the funding disparity between human-related medicine and animal-related medicine should shrink now that this connection is more widely publicized. Therapies for a feline disease discovered 50 years ago could have provided antiviral drugs at the beginning of this outbreak if there had been more funding for this kind work.

Right now, we are playing catch-up. Fortunately for us, Anivive is one of the companies leading that charge.

Ingrid R. Niesman MS PhD is the Director of the SDSU Electron Microscope Imaging Facility at San Diego State University. She graduated from Utah State University and received her MS from the University of Illinois-Urbana-Champaign. After 30 years of technical electron microscopy, cell biology, neuroscience and infectious disease research, Dr. Niesman completed her PhD in the UK at the University of Sunderland. Her work experience includes time at LSU Medical School, Washington University, UAMS in Little Rock, UCSD, TSRI and a postdoctoral year at CALIBR in La Jolla, CA. She has worked for at least two National Academy of Science members and is credited with over 50 publications. She can be reached at [email protected]

About the author