The Impact of Nusinersen and Risdiplam on Motor Function for Spinal Muscular Atrophy Type 2 and 3: A Meta-Analysis

Spinal muscular atrophy (SMA) is a prevalent paediatric neuromuscular disorder characterised by muscle weakness and atrophy resulting from degeneration of spinal cord anterior horn alpha motor neurons. Gene therapy formulations exhibit varying benefits and limitations, driving the need for patient-friendly treatment options tailored to specific populations. The objective of this meta-analysis was to assess the effectiveness of gene therapy for motor function in children with SMA. The analysis encompassed a total of 719 participants from six randomised controlled trials (RCTs) conducted between 2017 and 2023. Among the studies, one demonstrated a significant and large standardised effect size (Cohen's d) favouring nusinersen in terms of Hammersmith Functional Motor Scale - Expanded (HFMSE) (d = 0.97) and revised upper limb module (RULM) (d = 0.96). Additionally, another study showed a moderate standardised effect size (Cohen's d) in favour of nusinersen concerning Hammersmith Infant Neurological Examination-Section 2 (HINE-2) (d = 0.48). However, it is important to note that further research with a longer duration of observation is required to strengthen the evidence.