Nusinersen does not improve lung function in a cohort of children with spinal muscular atrophy - A single-center retrospective study.

Objective: To examine the effect of intrathecal application of nusinersen on the respiratory function in terms of vital capacity in pediatric patients with spinal muscular atrophy (SMA). SMA is characterized by on-going muscular atrophy and weakness that lead to respiratory insufficiency. In recent years therapy with nusinersen has been shown to improve motor function in patients with SMA.

Methods: We retrospectively analyzed data from 12 pediatric patients (aged 4-12 years) with SMA II or III (7 walkers, 5 sitters) treated with nusinersen. We examined forced vital capacity (FVC) at baseline (i.e., before treatment) and 180 and 300 days after initiation of treatment.

Results: No significant difference in the ranks of FVC of patients with SMA at baseline and day 300 was found and, thus, stable FVCs are implied (n = 6; Z = - 0.105, p = 1.000; Median = 96.0%, 95%-CI [86.5, 110.5]; Median = 96.0%, 95%-CI [92.0, 109.5]; s. Table 1). This also applied to the comparison between baseline and day 180 (n = 7; Z = 0.00, p = 1.00; Median = 93.0%, 95%-CI [85.0, 110.0]; Median = 91.0%, 95%-CI [72.0, 118.0]) and day 180 and 300 (n = 9; Z = - 0.533, p = .652; Median = 95.0%, 95%-CI [72.0, 118.0]; Median = 90.0%, 95%-CI [74.0, 105.0]).

Conclusion: Nusinersen therapy alone may not improve lung function of pediatric patients with SMA type II or III.