Abstract| Volume 37, 101578, January 2020

Efficacy of Satralizumab (SA237) As Add-on Therapy in Pre-Specified Additional Analyses of Sakurasky, a Double-Blind Placebo-Controlled Phase 3 Study in Patients with Neuromyelitis Optica Spectrum Disorders (NMOSD)

      A central role of interleukin-6 (IL-6) as key player in the pathophysiology of NMOSD, is strongly supported by the significant reduction in risk of relapse as previously demonstrated in the SAkuraSky study of the IL-6R inhibitor satralizumab for treatment of NMOSD as an add-on therapy. Here, we report the results of additional analyses ( number, NCT020728884).
      83 patients meeting NMOSD diagnostic criteria with/without AQP4-Ab and at least two relapses in the last 2 years were randomly assigned to receive satralizumab 120 mg subcutaneously or placebo at week 0, 2 and 4 and every 4 weeks thereafter, added to stable immunosuppressant treatment. The primary endpoint was time to first protocol-defined relapse. Pre-specified additional analyses included efficacy in AQP4-Ab positive vs. negative subgroups, and effect on annualized relapse rate (ARR). Hazard ratios (HRs) were based on Cox proportional hazards model.
      Satralizumab added to baseline treatment significantly reduced risk of protocol-defined relapse by 62% vs placebo; HR, 0.38; 95% confidence interval (CI), 0.16 to 0.88; P=0.0184. Pre-specified additional analyses showed a 79% relapse risk reduction with satralizumab vs placebo in AQP4-Ab(+) patients (n=55; HR, 0.21; 95% CI, 0.06 to 0.75) and 34% in AQP4-Ab(-) patients (HR 0.66; 95% CI, 0.20 to 2.24). In the overall study population, ARR was 0.11 (95% CI, 0.05 to 0.21) when treated with satralizumab vs 0.32 (95% CI, 0.19 to 0.51) with placebo.
      Treatment with satralizumab as add-on to baseline immunosuppressant therapy significantly reduced relapse risk, particularly in AQP4-Ab(+) NMOSD patients.