Medically reviewed by Dr. Kimberly Langdon Cull, M.D. on August 25, 2023
This randomized controlled trial demonstrated that satralizumab has long-term efficacy in treating AQP4-IgG+ NMOSD with a consistently low annualized relapse rate.
Satralizumab is an interleukin 6 (IL-6) receptor inhibitor that works by decreasing protocol-defined relapse (PDR) risk in patients diagnosed with neuromyelitis optica spectrum disorder (NMOSD). This randomized controlled trial assessed the efficacy of satralizumab in the treatment of patients suffering from aquaporin-4-immunoglobulin G seropositive (AQP4-IgG+) NMOSD. The findings of this trial, published in the journal Neurology, Neuroimmunology, and Neuroinflammation, indicate the long-term efficacy of satralizumab in AQP4-IgG+ NMOSD patients over 3.5 years of treatment.
A total of 119 patients diagnosed with AQP4-IgG+ NMOSD were included in the double-blind study, out of which 44 and 57 patients enrolled in the SAkuraSky and SAkuraStar open-label extension trials, respectively.
Relapse Risk and Annualized Relapse Rate
During the double-blind period, satralizumab decreased PDR risk compared to placebo. During the total satralizumab treatment period, 12 and 17 patients experienced an investigator-reported PDR (iPDR) in the SAkuraSky and SAkuraStar groups, respectively. The overall adjusted annualized relapse rate (ARR) was 0.12 in the SAkuraSky and 0.08 in the SAkuraStar group.
Satralizumab and Relapse Severity
In the double-blind period, there was a significant reduction in the risk of severe PDR with satralizumab treatment compared to placebo in both the SAkuraSky and SAkuraStar groups. In the total satralizumab treatment period, severe iPDR was experienced by three patients in the SAkuraSky group and six patients in the SAkuraStar groups.
Rescue Therapy Use of Satralizumab
A total of 56 AQP4-IgG+ NMOSD patients were administered acute relapse rescue therapy during the double-blind periods of the SAkuraSky and SAkuraStar trials. In the total satralizumab treatment period, 20 patients in the SAkuraSky and 19 patients in the SAkuraStar groups were administered acute relapse rescue therapy.
Safety Profile of Satralizumab
There was consistency across double-blind and total satralizumab treatment periods for the rates of adverse events, infections, serious infections, and serious adverse events. The majority of the adverse events were of mild-to-moderate severity.
The study concluded that satralizumab has long-term efficacy in treating AQP4-IgG+ NMOSD with consistently low ARR. A large number of participants remained free from worsening disease, relapse, or severe relapse.
Kleiter, I., Traboulsee, A., Palace, J., Yamamura, T., Fujihara, K., Saiz, A., Javed, A., Mayes, D. G., Von Büdingen, H., Klingelschmitt, G., Stokmaier, D., & Bennett, J. L. (2023). Long-term efficacy of satralizumab in AQP4-IGG-Seropositive Neuromyelitis Optica Spectrum Disorder from SAkuraSky and SAkuraStar. Neuroimmunology and Neuroinflammation, 10(1). https://doi.org/10.1212/nxi.0000000000200071