Clinical Experience of Nusinersen in a Broad Spectrum of Spinal Muscular Atrophy: A Retrospective Study

BACKGROUND: Nusinersen has recently been approved and more widely used as first-line treatment of spinal muscular atrophy (SMA). This study aimed to evaluate the real-world experience of nusinersen use for patients with a broad spectrum of SMA. METHODS: We reviewed consecutive patients with SMA treated with nusinersen from April 2018 to April 2020. Data collected included clinical and diagnostic characteristics, molecular genetics, functional motor outcomes, and adverse events. RESULTS: Seven patients including four with SMA type 1 and three with SMA type 2 were treated with nusinersen. The median disease duration at the time of the first dose and the median follow-up duration were 37 months (range: 0.5–254 months) and 6.1 months (range: 2.1–22.1 months), respectively. Of the 41 lumbar punctures (LPs), seven fluoroscopy-guided LPs were successfully performed for two patients without sedation. All patients showed improvement in motor function even though the current tools for motor assessment seemed unable to detect subtle subjective improvement. All patients maintained a stable respiratory status. No patient has experienced a severe adverse event or discontinued treatment so far. CONCLUSION: Although the number of patients in this study was small, our results suggest that nusinersen is effective even in patients with a later stage of the disease. Additional long-term prospective studies with more number of patients having a broad spectrum of diseases are needed to identify meaningful improvement in the motor function and quality of life after nusinersen treatment.