Researchers make breakthrough in fatal cat disease

A new clinical trial has resulted in a critical veterinary breakthrough - cats with feline infectious peritonitis (FIP) in remission following treatment with a novel antiviral drug. This fatal viral disease previously had no effective treatment or cure. Researchers from Kansas State University and the University of California, Davis, published their study results in the Journal of Feline Medicine and Surgery.

Morris Animal Foundation, which funded the research, is committed to saving cats from FIP by funding a cluster of studies that has the potential to help animal health scientists better understand, treat and even develop cures for the disease. One of these studies, launched in March 2016 by Dr. Yunjeong Kim at Kansas State University and Dr. Niels Pedersen at University of California, Davis, was a small clinical trial to investigate whether a novel antiviral drug could cure or greatly extend the lifespan and quality of life for cats with FIP.

"This research is the first attempt to use modern antiviral strategies to cure a fatal, systemic viral disease of any veterinary species," said Dr. Pedersen. "Our task was to identify the best candidates for antiviral treatment, and the best dose and duration of treatment. Saving or improving the lives of even a few cats is a huge win for FIP research."

The team conducted a clinical trial with 20 client-owned cats that presented with various forms and stages of FIP, treating them with the antiviral drug. At the time of publication, seven cats were still in disease remission, a positive step forward for a historically untreatable disease.

"We found that most of cats, except for those with neurological disease, can be put into clinical remission quickly with antiviral treatment, but achieving long-term remission is challenging with chronic cases. These findings give us more insight into FIP pathogenesis and also underscores the importance of early diagnosis and early treatment" said Dr. Kim.

The best long-term treatment response was seen in kittens under 16 to 18 weeks of age with a particular form of FIP, and that were at certain stages in the disease's progression. Unfortunately, cats with neurological disease associated with FIP did not respond as well to the drug and did not achieve disease remission.

"Dr. Kim and I have been collaborating for over two years on an antiviral drug that proved highly active against the FIP virus in tissue culture and in a mouse model. The positive results of these studies convinced us to test the drug against naturally occurring FIP in cats," said Dr. Pedersen.

Feline infectious peritonitis is caused by a mutated coronavirus, and targets kittens and young cats under 2 years of age. At highest risk are cats that live in close proximity to each other, such as cats that live in shelters, where FIP is five to 10 times more prevalent. FIP is challenging to diagnose as early symptoms can resemble other diseases and, while there are supportive treatments if caught early, FIP is 100 percent fatal.

Although FIP affects only a small percentage of cats, (an estimated 1 percent to 5 percent of shelter cats die of FIP), the disease is devastating. Better diagnostic tools and development of an effective treatment are desperately needed. The virus that causes FIP also is similar to the coronaviruses responsible for Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS), often fatal diseases in humans. Research done in coronaviruses to advance feline health may have the added benefit of helping people, too.

"Too many people have adopted a kitten from their local shelter, only to have their hearts broken when that precious life is taken away by this terrible disease. It is greatly rewarding to see that our investment, and the hard work of the research team, is paying off in the promise of a life-saving treatment for our feline companions," said Dr. John Reddington, President and CEO of Morris Animal Foundation. "Many felt finding a cure for FIP was too daunting or impossible. However we were determined to change the outcome for cats."

The drug needs to be commercialized which is a complex process that involves identifying potential companies interested in taking a drug through FDA approval and licensing. This task could take several years before the drug is approved and made available for use by licensed veterinarians.