Nusinersen for adults with spinal muscular atrophy

Introduction: Nusinersen was effective in improving motor function and survival in infantile and childhood-onset spinal muscular atrophy (SMA), and the value of real-world experiences in adult SMA patients increase gradually. Here, we present our clinical experience in adult SMA patients treated with nusinersen according to CHERISH study.

Material and methods: Thirty-two SMA patients treated with nusinersen were included in the study.

Results: Median age at nusinersen initiation was 33.5 (20.0-60.0) years and 23 of SMA patients were male. Six (18.8%) patients had SMA type 2, and 26 (81.2%) had SMA type 3. Median follow-up period of patients under nusinersen treatment was 17 months (9-21). Twenty-three patients improved by at least 3 Hammersmith Functional Motor Scale Expanded (HFMSE) points after loading doses. There was significant HFMSE score increase in type 3 patients at each time point, whereas type 2 patients seem to benefit from nusinersen loading doses, subsequently stayed stable. Motor improvement was positively correlated with baseline HFMSE scores in patients whose baseline HFMSE scores were ≤47. There was a correlation between the changes in Amyotrophic Lateral Sclerosis Functional Rating Scale Revised (ALSFRS-R) score and HFMSE scores. Ambulatory patients who could not show clinically meaningful increase in HFMSE scores improved at least 30 m by 6-min walk test (6MWT).

Conclusion: Overall, 78% of patients have responded to treatment according to HFMSE or 6MWT. ALSFRS-R and 6MWT may be alternative tools to monitor nusinersen effect.