Therapeutic agents for the treatment of human mpox

The aim of this study was to summarize the current knowledge of therapeutic options for mpox (formerly known as monkeypox) in the context of recent outbreaks and the ongoing evolution of the virus.

Multiple therapeutic agents, including tecovirimat, cidofovir, brincidofovir, and vaccinia immune globulin, have been used during the multicountry outbreak of mpox caused by Clade 2b monkeypox virus that began in 2022. Tecovirimat has been most extensively used, based on efficacy against mpox lethal challenge in animal models, and human safety data. Real-world observational evidence has further supported safety with minimal adverse events in large cohorts and mixed reports of reductions in time to lesion resolution. Several prospective randomized controlled trials using tecovirimat are underway with headline results from a study in the Democratic Republic of the Congo showing no difference in lesion resolution compared to placebo. Other studies including in outpatient settings are underway in Europe and the Americas. Cidofovir and brincidofovir, limited by adverse event profiles, have been less extensively studied. Vaccinia immune globulin has been used predominantly in salvage therapy for severe mpox, with no large observational series available.

The 2022 multicountry outbreak of mpox marked a public health emergency. Agents approved for smallpox management were widely used for mpox, supported by animal and in-vitro evidence, and human safety data. The large number of human cases has allowed retrospective observational study of these agents and facilitated recruitment in prospective trials. The ongoing evolution of the virus may pose challenges for therapeutic interventions, necessitating rigorous randomized controlled trials to guide clinical use.