Real-world evidence in spinal muscular atrophy: addressing heterogeneity of populations and treatment comparisons.

In this short correspondence, we comment the recently published article "Efficacy and safety of gene therapy with onasemnogene abeparvovec in children with spinal muscular atrophy in the D-A-CH-region: a population-based observational study" (The Lancet-Global Health Europe, https://doi.org/10.1016/j.lanepe.2024.101092). We commend the authors for generating real-world evidence that highlights the importance of rapid access to disease modifying therapy (DMT) for newly diagnosed patients. However, we caution that confirmatory studies are required to better understand the impact of treatment sequences, particularly in the presence of prior DMT exposure. Addressing these issues will ensure that clinical decision-making is based on the most rigorous evidence available.