Effectiveness and safety of risdiplam in Chinese adolescents and adults with spinal muscular atrophy: a prospective real-world study

Abstract Background Evidence for the efficacy of risdiplam in adolescents and adults with 5q spinal muscular atrophy (SMA) has been demonstrated in clinical trials, but its sustained effectiveness and safety in real-world settings, particularly in Chinese adults, are still limited. We evaluated the effectiveness and safety of risdiplam in this population in a real-world setting. Methods This prospective observational study included adolescent and adult patients with genetically confirmed 5q SMA under standard clinical care (January 2023 to December 2024). Patients received risdiplam monotherapy with a maintenance dose of 5 mg daily. Primary outcomes were changes in Hammersmith Functional Motor Scale Expanded (HFMSE), Revised Upper Limb Module (RULM) scores, and 6-min walk test (6MWT). Results Fifteen patients (8 male, 7 female) were included, with a median effectiveness assessment time of 1.38 years (IQR, 1.30–1.56). The median RULM score significantly improved from 18.00 (IQR, 10.00-25.50) at baseline to 21.00 (IQR, 12.00-26.50) at final follow-up ( P = 0.043). The median HFMSE score showed a non-significant increase [9.00 (IQR, 1.50–14.50) vs. 9.00 (IQR, 3.50–15.50), P = 0.159]. The 6-minute walk test remained stable, with improvement observed in two patients. The median ALSFRS-R scores remained stable [33.00 (IQR, 26.00–35.00) vs. 32.00 (IQR, 26.50–36.00), P = 0.936]. No adverse events were reported, indicating good tolerability. Conclusions In this exploratory real-world study, our findings provide evidence supporting the potential effectiveness and safety of risdiplam in managing SMA in adolescent and adult patients. Longer-term and larger-scale studies remain warranted to further characterize its clinical durability.