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.