Brincidofovir in the era of Mpox

Mpox (formerly monkeypox), a systemic infection caused by the mpox virus (MPXV), has become a global problem of increasing concern. There are currently no antiviral treatments that have been shown to be safe and effective for the treatment of mpox. Brincidofovir is a lipid-modified acyclic nucleotide with in vitro and in vivo activity against multiple DNA viruses, including MPXV. It is licensed in the US and Canada for the treatment of human smallpox disease in adults and children, including neonates. It has been used under FDA-authorized emergency use for patients in the US with severe mpox. The authors review the antiviral activity, clinical development, pharmacokinetics, safety and efficacy of brincidofovir and its potential as an mpox treatment. A comprehensive review was conducted in PubMed, Science Direct, Embase and Google Scholar. Research is needed to better understand mpox epidemiology, natural history, antiviral therapy and vaccines. Brincidofovir is being evaluated in a randomized, double-blind, placebo-controlled trial under the Mpox Study in Africa (MOSA) protocol. Additional studies will assist in clarification of single vs. combination therapy, safety and populations most likely to benefit, as well as the management of treatment complications such as immune reconstitution inflammatory syndrome (IRIS).