Effectiveness and Safety of Risdiplam in Chinese Adolescents and Adults with Spinal Muscular Atrophy: A Prospective Real-World Study

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 populations, remains to be demonstrated. We evaluated the efficacy 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 (5 mg daily), with dosing adjusted based on clinical condition and tolerability. 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 mean (SD) efficacy assessment time of 1.45 (0.38) years. The mean (SD) RULM score significantly improved from 17.60 (10.87) at baseline to 19.33 (11.11) at final follow-up (P = 0.043). The mean (SD) HFMSE score showed a non-significant increase (13.00 (16.21) to 13.60 (16.26), P = 0.159). The 6-minute walk test remained stable, with improvement observed in two patients. The mean (SD) ALSFRS-R scores were unchanged (31.47 (7.61) vs. 31.80 (7.59), P = 0.936). No adverse events were reported, indicating good tolerability. Conclusions Our real-world findings provide evidence supporting the sustained efficacy 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 sustainability.