N-[(2S)-butan-2-yl]-6-[(3R)-3-{[4-(trifluoromethoxy)benzyl]carbamoyl}-4-{[4-(trifluoromethoxy)phenyl]sulfonyl}piperazin-1-yl]pyridazine-3-carboxamide

B1PBP5 — RNA-directed RNA polymerase