GS-441524-d is the deuterium labeled GS-441524 (HY-103586). GS-441524, predominant metabolite of Remdesivir and superior to Remdesivir against Covid-19 , shows comparable efficacy in cell-based models of primary human lung and cat cells infected with coronavirus. GS-441524 could strongly inhibits feline infectious peritonitis virus (FIPV), with an EC50 of 0.78 µM[1][2][3].