Roche Holding AG announced new longer-term efficacy and safety data for ENSPRYNG® (satralizumab). The data show ENSPRYNG has a favourable benefit:risk profile and is effective in reducing relapses over four years of treatment in people with anti-aquaporin-4 antibody (AQP4-IgG) seropositive neuromyelitis optica spectrum disorder (NMOSD), a rare debilitating disease that affects the central nervous system. Efficacy and safety results from the open-label extension (OLE) periods of the SAkuraStar and SAkuraSky studies, in addition to the design of SAkuraBONSAI, a new study in people with AQP4-IgG seropositive NMOSD who are treatment naïve, or where prior rituximab (or biosimilar) treatment has failed, will be presented at the 37th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS). The pivotal SAkuraStar and SAkuraSky four year OLE data found that 73% and 71% of people with AQP4-IgG seropositive NMOSD treated with ENSPRYNG remained relapse-free after 192 weeks (3.7 years), respectively, and 90% and 91% remained free from severe relapse*. These results demonstrate that the robust efficacy observed in the studies' double-blind periods is sustained longer-term for ENSPRYNG as both a monotherapy and in combination with immunosuppressive therapy. The data also demonstrate a favourable safety and tolerability profile for ENSPRYNG in the overall ENSPRYNG treatment period of up to seven years, comparable to the double-blind treatment periods in both SAkuraStar and SAkuraSky studies. Rates of adverse events and serious adverse events during the overall treatment periods were consistent with ENSPRYNG and placebo in the double-blind periods.