Boceprevir-d9 is the deuterium labeled Boceprevir. Boceprevir (EBP 520) is a potent, highly selective, orally bioavailable HCV NS3 protease inhibitor with a Ki of 14 nM in both enzyme assay and an EC90 of 350 nM in cell-based replicon assay[1][2][3][4][5]. Boceprevir inhibits SARS-CoV-2 3CLpro activity[6].