GS-443902 trisodium (GS-441524 triphosphate trisodium) is a potent viral RNA-dependent RNA-polymerases (RdRp) inhibitor with IC 50 s of 1.1 μM, 5 μM for RSV RdRp and HCV RdRp, respectively. GS-443902 trisodium is the active triphosphate metabolite of Remdesivir (GS-5734).