Combination of vemurafenib, pleconaril, and AG7404 attenuates enterovirus replication in vitro and in vivo.

Enteroviruses infect multiple human tissues and cause diseases including meningitis, the common cold, myocarditis, pancreatitis, hepatitis, poliomyelitis, sepsis, type 1 diabetes, hand, foot, and mouth disease. Despite this burden, no antiviral therapy has been approved to date. Progress has been limited by the structural and topical diversity of enteroviruses because many variants are intrinsically insensitive to candidate agents and sensitive strains develop resistance rapidly. Here, we report that the approved anticancer drug vemurafenib inhibited replication of some tested enteroviruses in cell cultures. Passage of echovirus EV1 and coxsackievirus CVB5 for six cycles in cell culture yielded vemurafenib-resistant virus variants harboring mainly missense mutations in the viral 3A and VP1 proteins, underscoring the need for combination therapy. We therefore evaluated cocktails, combining vemurafenib with the VP1 inhibitor pleconaril and the 3C protease inhibitor AG7404. In cell culture, the cocktails suppressed replication of all seven tested enteroviruses. The combination was also effective in human pancreatic, retinal, and brain organoids. In infected mice, the triple regimen reduced viral titers in the pancreas. These findings support multi-stage targeting of the enterovirus life cycle as a promising path toward broadly active therapeutic cocktails.