Phase III SAkuraSky study results for SA 237 shows reduction in relapses in neuromyelitis optica spectrum disorder

Roche presented today full pivotal Phase III study results for SA 237 (satralizumab) as a monotherapy for neuromyelitis optica spectrum disorder (NMOSD), a rare, debilitating central nervous system disease. Results from the SAkuraStar study show that satralizumab monotherapy achieved a 55% reduction in the risk of relapses compared to placebo in the overall population, representative of NMOSD patients (Hazard Ratio [HR]=0.45, 95% Confidence Interval [CI]: 0.23-0.89; p=0.0184). In the large (~67%) subgroup of patients seropositive for AQP4-IgG antibodies, the effect was higher with a 74% reduction in risk of relapses (HR=0.26, 95% CI: 0.11-0.63; p=0.0014). People who are AQP4-IgG seropositive 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.

Overall, the proportion of patients with serious adverse events was similar between the satralizumab monotherapy and placebo treatment groups in the SAkuraStar study; and between the satralizumab added to baseline therapy and placebo added to baseline therapy treatment groups in the SAkuraSky study. A lower rate of infections (including serious infections) was observed in patients treated with satralizumab compared with the placebo group. Data were presented at the 35th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS).

Comment: Satralizumab inhibits IL-6 signaling, which is believed to play a key role in the inflammation that occurs in people with NMOSD, leading to damage and disability. People with NMOSD experience unpredictable, severe relapses that directly cause cumulative, permanent neurological damage.