Motor Function and Safety of Nusinersen and Risdiplam in Asian Patients with Types 2-4 Spinal Muscular Atrophy (SMA): A Systematic Review and Meta-Analysis.

INTRODUCTION

The aim of this study was to systematically appraise and synthesize real-world data of motor function and safety in Asian patients with spinal muscular atrophy (SMA) treated with nusinersen or risdiplam.

METHODS

This study systematically searched PubMed, Cochrane, Embase, CNKI, and Wanfang databases for real-world studies (RWS) published from January 2017 to January 2024. Based on the prespecified study selection and eligibility criteria, RWS evaluating motor function and/or safety outcomes in patients with types 2-4 SMA treated with nusinersen or risdiplam were included, while studies without Asian populations were excluded. The Newcastle-Ottawa Scale (NOS) was used to assess the risk of bias, and a meta-analysis was conducted for each motor function endpoint based on the extracted data.

RESULTS

A total of 26 RWS were included in this review, of which 17 reporting main motor function outcomes were included in the meta-analyses. Intervention in all 17 studies was nusinersen; none included risdiplam. Statistically significant improvement was observed in Revised Upper Limb Module (RULM) [Mean difference (MD) = 2.27 (0.84, 3.71)], Hammersmith Functional Motor Scale Expanded (HFMSE) [MD = 2.62 (1.79, 3.45)] and six-minute walk test (6MWT) [MD = 18.29 (9.12, 27.45)] when treated with nusinersen ≤ 6 months and > 6 months (HFMSE [MD = 4.34 (3.54, 5.14)]; 6MWT [MD = 45.59 (12.92, 78.27)]). Clinically meaningful responses of motor milestones were also observed when treating nusinersen over 6 months: 54.4% (0.305, 0.772) for RULM, 53.0% (0.273, 0.779) for HFMSE and 97.1% (0.819, 1.000) for 6MWT. A total of 19 studies addressed safety outcomes. Reported adverse events were consistent with the expected safety profile for nusinersen.

CONCLUSION

Our study suggests that nusinersen is associated with a statistically significant and clinically meaningful motor function improvement in Asian patients with types 2-4 SMA in the real-world setting. No unexpected safety concern was observed for nusinersen. Motor function and safety outcomes after risdiplam could not be evaluated in this patient population under real-world settings due to limited studies.