Galidesivir (BCX4430) hydrochloride, an adenosine analog and a direct-acting antiviral agent, disrupts viral RNA-dependent RNA polymerase (RdRp) activity. Galidesivir hydrochloride is active in vitro against many RNA viral pathogens, including the filoviruses and emerging infectious agents such as MERS-CoV, SARS-CoV , and SARS-CoV-2. Galidesivir hydrochloride inhibits some negative-sense RNA viruses with EC 50 s ranging from ~3 to ~68 μM.