The basis for the approval was data from the phase 3 SAkuraSky and SAkuraStar studies, which combined included more than 170 patients who were treated with either satralizumab or placebo.
Satralizumab (Enspryng; Chugai/Roche), a pH-dependent binding humanized anti-interleukin (IL)-6 receptor monoclonal antibody, recently was granted marketing authorization from the European Commission as the first at-home subcutaneous treatment for patients with neuromyelitis optica spectrum disorder (NMOSD).1
Indicated for those living with anti-aquaporin-4 antibody (AQP4-IgG) seropositive NMOSD, the approval was based on the results from 2 global phase 3 clinical studies in people with NMOSD: SAkuraSky study (NCT02028884) and SAkuraStar study (NCT02073279). The treatment is now currently approved in 54 countries including Japan, the United States, and EU countries. Satralizumab recieved FDA approval in August 2020,2 joining Alexion’s eculizumab (Soliris) and Viela Bio’s inebilizumab (Uplinza), which were approved for the same indication on June 27, 2019, and June 11, 2020, respectively.
"We are very pleased that Enspryng is now approved in the EU as the first subcutaneous treatment for people with AQP4-IgG seropositive NMOSD, with the option to be treated at home,” Osamu Okuda, president and chief executive officer, Chugai, said in a statement.1 “Enspryng is the first approved therapeutic antibody for which our proprietary recycling antibody technology was applied. We are confident that Enspryng will meaningfully contribute to improving the treatment of people with NMOSD, by fitting into their day-to-day lives.”
The SAkura studies combined included more than 170 patients randomly assigned to receive satralizumab 120 mg or placebo. Both studies utilized time to protocol-defined relapse as the primary end point and included a population of patients who were APQ4-IgG antibody positive and negative to accurately reflect clinical practice.
In SAkuraStar (NCT02073279), 30% of patients treated with satralizumab monotherapy experienced relapse compared with 50% of those who received placebo (HR 0.45; 95% CI, 0.23—0.89; P =.018).3 Among those who were AQP4-IgG antibody positive, a 74% reduction in relapse risk was observed. In the overall satralizumab-treated population, 76.1% and 72.1% were relapse-free at 48 and 96 weeks, respectively, compared with 61.9% and 51.2% with placebo. Data from the AQP4-IgG seropositive subgroup showed that 82.9% and 76.5% were relapse-free at 48 and 96 weeks compared with 55.4% and 41.1% with placebo, respectively.
In total, 92% (n = 58) of those in the satralizumab group experienced an adverse event compared with 75% (n = 24) of the placebo group. Serious AEs were similar between groups; only 1 event led to study drug discontinuation in the treatment group.
In SAkuraSky (NCT02028884), the overall study population saw a 62% reduction in the risk of relapse (HR 0.38, 95% CI, 0.16-0.88; P =.0184), while the group of AQP4-IgG seropositive patients experienced a 79% reduction in relapse risk (HR 0.21, 95% CI, 0.06-0.75; P =.0086).4 Results showed 88.9% and 77.6% of patients in the total population were relapse-free at 48 and 96 weeks, respectively, compared with 66% and 58.7% of patients in the placebo group. Among AQP4-IgG seropositive patients, 91.5% treated with satralizumab were relapse-free at 48 and 96 weeks compared with 59.9% and 53.3% of patients in the placebo group. The most common AEs observed were upper respiratory tract infection, nasopharyngitis, and headache.