Data from the overall satralizumab treatment period, which expanded on the double-blind periods by adding new data from the ongoing open-label extension periods, were consistent with the double-blind period results.
Benjamin Greeberg, MD
Results from the combined double-blind and open-label extension periods of the SAkuraSky (NCT02028884) and SAkuraStar (NCT02073279) clinical trials demonstrated that treatment with satralizumab (SA237; Genentech) was well-tolerated and showed a favorable treatment profile in patients with neuromyelitis optica spectrum disorder (NMOSD).1
Research presented at the 2020 Consortium of Multiple Sclerosis Centers (CMSC) Virtual Annual Meeting revealed that rates of adverse events (AEs) and serious AEs were comparable between the satralizumab and placebo groups in the double blind period (AEs: 478.49 vs. 506.51 events per 100 patient years [PYs], respectively; serious AEs: 14.97 vs 17.98 events per 100 PYs, respectively). These results were also found to be consistent in the overall satralizumab treatment (OST) period, which was defined as the combined time between the double-blind and extension periods.
In total, 4 (3.8%) patients in the satralizumab group and 6 (8.1%) in the placebo group withdrew from the study during the double-blind period due to an AE. Additionally, researchers noted that lower rates of infection were found in satralizumab-treated patients compared with placebo (113.04 vs 154.85 events per 100 PYs).
The research, conducted by Benjamin M. Greenberg, MD, pediatric neurologist, University of Texas Southwestern Medical Center, and colleagues, showed that injection-related reaction rates were higher with satralizumab vs placebo in the double-blind period (17.03 vs 8.99 events per 100 PYs).
There were no reported treatment discontinuations from injection-related reactions, and most were found to be mild-to-moderate in severity. No deaths or anaphylactic reactions were reported in the study. In both the double-blind and OST periods, infection rates with satralizumab remained similar.
The pooled double-blind period contained 104 satralizumab-treated patients and 74 on placebo. A total of 166 patients were included in the open-label extension. In the OST period, the mean and median exposures to satralizumab were 133.3 and 128.6 weeks.
In both SAkuraSky and SAkuraStar, patients received either satralizumab 120 mg every 4 weeks or placebo in the double-blind period, followed up by a satralizumab only open-label extension. The main goal of this subset data was to evaluate the safety in the double-blind and OST periods and report as AE rates per 100 PYs.
Previous results reported showed 76.1% of patients assigned to satralizumab monotherapy in SAkuraStar were relapse-free at 48 weeks, compared to 61.9% who received placebo. Additionally, at 96 weeks, 72.1% of patients who received treatment with satralizumab were relapse-free, compared with 51.2% of patients in the placebo group.
Data from both SAkuraSky and SAkuraStar led to satralizumab’s biologics license application acceptance from the FDA in October 2019. The treatment was previously granted breakthrough therapy designation for the treatment of NMSOD in December 2018.2
Interleukin-6 (IL-6), an interleukin that acts as both a pro-inflammatory cytokine and an anti-inflammatory myokine, is implicated in the immunopathology of NMOSD. Kathleen Hawker, MD, Group Medical Director of Neuroscience, Genentech, told NeurologyLive earlier this month that “the positive phase III results for satralizumab, as both a monotherapy and in combination with baseline immunosuppressant therapy, reinforce that IL-6 inhibition may be an effective therapeutic approach for NMOSD. As an investigational monoclonal antibody that targets the IL-6 receptor, satralizumab may help block IL-6 signaling and therefore limit NMOSD disease activity.”
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1. Greenberg BM, de Seze J, Fox E, et al. Safety of satralizumab based on pooled data from phase 3 studies in patients with neuromyelitis optica spectrum disorder (NMOSD). Int J MS Care. 2020;22 (2 Suppl). RTH0
2. FDA Accepts Genentech’s Biologics License Application for Satralizumab for Neuromyelitis Optica Spectrum Disorder [news release]. San Francisco, CA: Genentech. Published October 29, 2019. Accessed May 27, 2020. biospace.com/article/releases/fda-accepts-genentech-s-biologics-license-application-for-satralizumab-for-neuromyelitis-optica-spectrum-disorder.