Long-term adherence, safety and effectiveness of nusinersen in spinal muscular atrophy patients: a population-based study

Nusinersen was the first disease modifying treatment approved for 5q spinal muscular atrophy (SMA). Long-term results of broad populations, particularly for adolescents and adults, remain limited. We conducted a population-based, ambispective observational study of all SMA patients living in the Valencian Community (Spain) between September 2017 and December 2022 and follow-up until December 2025. Demographic, clinical and motor outcomes using revised SMA Functional Composite Score (SMA-FCR) were collected. Patients were classified as responders or non-responders. The risk for nusinersen discontinuation was assessed with a Bayesian model, and SMA-FCR trajectories with mixed linear regression. Of 72 patients included, 18 were