Assessment of safety and efficacy of risdiplam treatment in adults with spinal muscular atrophy

Introduction: Risdiplam has been shown to be safe, well tolerated, and improves or stabilizes motor function in individuals with SMA, but limited published data exists for adults. The aim of this study was to assess the efficacy, safety, and tolerability of risdiplam treatment for adults with SMA. Methods: We conducted a retrospective chart review on adult patients with 5q-SMA who received risdiplam for a minimum of 6 months, including both treatment naïve and those who switched from nusinersen. Baseline demographic data was collected and outcomes included the Revised Upper Limb Module, Children's Hospital of Philadelphia Adult Test of Neuromuscular Disorders (CHOP-ATEND), six-minute walk test, Hammersmith Functional Motor Scale-Expanded, and forced vital capacity. Assessments were performed at baseline, 6, 12, and 24 months. Self-reported adverse effects were recorded. Linear mixed models were used for analysis. Results: = 0.042), while all other outcomes showed stability. The most common self-reported adverse effects were gastrointestinal issues. Serious adverse events included pneumonia, appendicitis, and femur and tibia/fibula fractures. The latter two were considered unlikely related to treatment. Discussion: Risdiplam is overall safe and well-tolerated up to 24 months in adults with SMA. The treatment resulted in improvement or stabilization of motor and respiratory function in non-ambulatory and ambulatory patients. Improvement on the CHOP-ATEND suggests it may be a sensitive marker of change. Longer-term follow-up is needed to understand the impact of risdiplam in adults with SMA.