GS-704277 is an alanine metabolite of Remdesivir. GS-704277 is further hydrolyzed to GA-441524 (HY-103586) with antiviral activity. Remdesivir, a nucleoside analogue with effective antiviral activity, is highly effective in the control of SARS-CoV-2 (COVID-19) infection[1][2][3][4][5].