REGN-EB3 (INMAZEB®, Regeneron Pharmaceuticals) is a combination of three fully-human monoclonal antibodies-atoltivimab (REGN3470), maftivimab (REGN3479), and odesivimab (REGN3471) -that target Ebola virus glycoprotein. Based on the results of the PALM study conducted during an Ebola outbreak in the Democratic Republic of Congo, REGN-EB3 was recently approved by the US FDA as a treatment for Ebola virus infection. This article summarizes the milestones in the development of REGN-EB3 leading to this first approval for the treatment of infection caused by Zaire ebolavirus (Ebola virus) in adult and paediatric patients.