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

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.

GS-441524tris-isobutyryl ester is a prodrug form of the antiviral nucleoside analog and remdesivir metabolite GS-441524 .1It reduces the cytopathic effect of respiratory syncytial virus (RSV) in infected HEp-2 cells with an EC50value of 0.26 μM. 1.Mackman, R.L., Hui, H.C., Perron, M., et al.Prodrugs of a 1’-CN-4-aza-7,9-dideazaadenosine C-nucleoside leading to the discovery of remdesivir (GS-5734) as a potent inhibitor of respiratory syncytial virus with efficacy in the african green monkey model of RSVJ. Med. Chem.64(8)5001-5017(2021)

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-621763, a prodrug of GS-441524, exhibits antiviral activity against SARS-CoV-2 pathogenesis.

E197 is a DOCK5 inhibitor. E197 can inhibit both mouse and human osteoclast activity. In particular, E197 prevented pathological bone loss in mice. Most interestingly, treatment with E197 did not affect osteoclast and osteoblast numbers and hence did not impair bone formation. E197 could represent a lead molecule to develop new antiosteoporotic drugs targeting the mechanism of osteoclast adhesion onto the bone.

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