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News Article

Human antiviral shows promise against feline infectious peritonitis

GS-441524 is the second targeted antiviral drug (after GC376) to be evaluated for the treatment of cats with FIP

Feline infectious peritonitis (FIP) is a chronic viral infection of cats. The infectious agent, a mutant coronavirus - Feline infectious peritonitis virus (FIPV) – is notoriously difficult to control. FIPV infection is considered to be a good candidate for antiviral drug development as vaccines are ineffective.

In humans, among the most promising treatments against emerging viruses is 'GS-5734', one of the small-molecule antivirals targeting specific proteins involved in RNA virus replication. In studies, it has proven effective in preventing Ebola in rhesus monkeys and inhibiting coronaviruses both in tissue culture and in mouse infection models. It was these findings that brought it to the attention of a team of veterinary researchers in the USA, led by Professor Niels Pedersen of the University of California, Davis. Their own initial studies involving experimental FIP showed that the less chemically complex 'GS-441524', the parent nucleoside of GS-5734, was highly effective, opening the way for a field trial in cats with naturally occurring FIP. The results are published in the Journal of Feline Medicine and Surgery.

Thirty-one cats, ranging in age from 3-73 months, were enrolled in the study, and 26 completed the planned 12 weeks or more of treatment; the remainder died or were euthanized due to their severe disease. For these 26 cats, the clinical response was dramatic: fever usually resolved within 12-36 h, concurrent with a marked improvement in appetite, activity levels and weight gain. In cats with the more common effusive or 'wet' form of FIP, abdominal effusions rapidly disappeared, starting at around 10-14 days after commencing treatment. Encouragingly, and somewhat unexpectedly, cats with non-effusive ('dry') FIP and older cats responded as well to GS-441524 treatment as did cats with effusive FIP and young cats. The safety profile of GS-441524 was likewise impressive.

Currently, 24 of the 26 cats remain healthy, with one having succumbed to FIP disease and one to unrelated heart disease. Eighteen of these cats underwent just one round of treatment; the remaining eight suffered disease relapses, but these were successfully treated with a further (in two cases, a third) round of treatment at a higher dose.

GS-441524 is the second targeted antiviral drug after GC376 to be evaluated for the treatment of cats with FIP in the past two to three years (see Further reading). These two drugs inhibit viral replication in two very different manners; GS-441524 is a nucleoside analogue and GC376 is a viral protease inhibitor.

Read article: Efficacy and safety of the nucleoside analog GS-441524 for treatment of cats with naturally occurring feline infectious peritonitis by Niels C Pedersen, Michel Perron, Michael Bannasch, Elizabeth Montgomery, Eisuke Murakami, Molly Liepnieks and Hongwei Liu, published in Journal of Feline Medicine and Surgery, online 13 February 2019, doi: 10.1177/1098612X19825701

Article details

  • Date
  • 14 February 2019
  • Source
  • SAGE
  • Subject(s)
  • Dogs, Cats, and other Companion Animals