GS-441524 er et antiviralt stof, der blev udviklet af Gilead Sciences. It is the main plasma metabolite of the antiviral prodrugremdesivir, which has a half-life of around 24 hours in human patients. Remdesivir and GS-441524 were both tested against feline infectious peritonitis (FIP) in cell culture and found to be equivalent. Remdesivir was never tested in cats but GS-441524 has been found to be effective treatment for FIP, a lethal coronavirus disease which affects domestic cats and is widely used despite no official FDA approval due to Gilead's refusal to license this drug for veterinary use.[1][2][3][4]