Genentech and Chugai Pharmaceuticals presented full results from the pivotal Phase III SAkuraStar study which evaluated satralizumab as monotherapy for neuromyelitis optica spectrum disorder (NMOSD), a rare, debilitating central nervous system disease. Results from the study were presented at the 35th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS).
SAkuraStar is a multicenter, randomized, double-blind, placebo-controlled study conducted in 95 patients 20-70 years of age. The patients were randomized to either of the following two treatment groups in a 2:1 ratio: satralizumab (120 mg) or placebo. Both treatments were administered subcutaneously at Week 0, 2, and 4. The subsequent treatment was continued at 4-week intervals. The double-blind treatment period ended when the total number of protocol-defined relapse (PDRs) had reached 44 or at 1.5 years after the enrollment of the last patient, whichever occurred first. The primary endpoint was the time to first protocol-defined relapse (PDR), adjudicated by an independent review committee in the double-blind period. Data showed that satralizumab monotherapy achieved a 55% reduction in the risk of relapses compared to placebo in the overall population, representative of NMOSD patient). In the large (~67%) subgroup of patients seropositive for AQP4-IgG antibodies, the effect was higher with a 74% reduction in risk of relapses. AQP4-IgG seropositive patients tend to experience a more severe disease course. In the overall satralizumab-treated population, 76.1% were relapse-free at 48 weeks, and 72.1% relapse-free at 96 weeks, compared to 61.9% and 51.2% with placebo, respectively. Data from the AQP4-IgG seropositive subgroup showed that 82.9% were relapse-free at 48 weeks and 76.5% relapse-free at 96 weeks when treated with satralizumab, compared to 55.4% and 41.1% with placebo, respectively. The most common adverse events were urinary tract infections and upper respiratory tract infections.
About Neuromyelitis Optica Spectrum Disorder (NMOSD)
NMOSD is a rare, lifelong and debilitating autoimmune disease of the central nervous system that primarily damages the optic nerve(s) and spinal cord, causing blindness, muscle weakness, and paralysis. People with NMOSD experience unpredictable, severe relapses directly causing cumulative, permanent, neurological damage and disability.
NMOSD is commonly associated with pathogenic antibodies (AQP4-IgG) that target and damage a specific cell type, called astrocytes, resulting in inflammatory lesions of the optic nerve(s), spinal cord and brain. AQP4-IgG antibodies are detectable in the blood serum of around two-thirds of NMOSD patients.
Satralizumab is a humanized monoclonal antibody that targets the IL-6 receptor. The cytokine IL-6 is thought to be a key driver in NMOSD, triggering the inflammation cascade and leading to damage and disability.Source: Genetech