GS-441524 treatment of cats with naturally occurring feline infectious peritonitis.

GS-443902 trisodium (GS-441524 triphosphate trisodium), the active triphosphate metabolite of Remdesivir (GS-5734), serves as a potent inhibitor of viral RNA-dependent RNA-polymerases (RdRp), displaying inhibitory concentrations (IC50) of 1.1 μM and 5 μM for RSV RdRp and HCV RdRp, respectively.

GS-441524 was shown to be a safe and effective treatment for feline infectious peritonitis (FIP). The optimum dosage was found to be 4.0 mg/kg SC q24h for at least 12 weeks

GS-441524 is a potent inhibitor of feline infectious peritonitis (FIP) virus with an EC50 of 0.78 μM.. GS-441524 strongly inhibits feline infectious peritonitis (FIP) virus in tissue culture and experimental cat infection studies. GS-441524 is a molecular precursor to a pharmacologically active nucleoside triphosphate molecule. These analogs act as an alternative substrate and RNA-chain terminator of viral RNA dependent RNA polymerase. GS-441524 was non-toxic in feline cells at concentrations as high as 100 uM and effectively inhibited FIPV replication in cultured CRFK cells and in naturally infected feline peritoneal macrophages at concentrations as low as 1 uM. Note: GS-441524 is an active metabolite of Remdesivir.