Satralizumab (Enspryng®), a humanized anti-interleukin-6 (IL-6) receptor monoclonal recycling antibody, has been developed by Chugai Pharmaceutical and Roche for the treatment of neuromyelitis optica spectrum disorder (NMOSD). In June 2020, based on positive results from two pivotal phase III trials, subcutaneous satralizumab received its first global approval in Canada for the treatment of NMOSD in adults and children aged ≥ 12 years who are aquaporin 4 water channel autoantibody (AQP4-IgG) seropositive. Satralizumab was subsequently approved in Japan, Switzerland and the USA. Satralizumab is under regulatory review in the EU, and is undergoing clinical development in several countries worldwide. This article summarizes the milestones in the development of satralizumab leading to this first approval for the treatment of NMOSD.