Longitudinal efficacy of risdiplam treatment in Chinese children with spinal muscular atrophy

Area of Science:

• Neurology
• Pediatrics
• Pharmacology

Background:

• Spinal muscular atrophy (SMA) is a rare genetic disorder affecting motor neurons.
• Risdiplam is a recent therapeutic option for SMA, but real-world data are limited.
• This study addresses the need for real-world evidence on risdiplam's efficacy and safety in Chinese children with SMA.

Purpose of the Study:

• To evaluate the real-world effectiveness of risdiplam in pediatric SMA patients in China.
• To assess changes in motor function and safety outcomes in children treated with risdiplam.
• To explore factors influencing treatment response, such as disease duration and genetic profile.

Main Methods:

• A multi-center study involving 34 children with SMA treated with risdiplam from September 2021 to November 2024.
• Standardized motor function assessments including the Children's Hospital of Philadelphia infant test of neuromuscular disorders (CHOPINTEND), Hammersmith functional motor scale expanded (HFMSE), and Revised upper limb module (RULM) were used.
• Generalized estimating equation analysis quantified monthly motor function improvements.

Main Results:

• Significant improvements were observed in CHOPINTEND, HFMSE, and RULM scores post-treatment compared to baseline.
• Motor function gains were substantial, with CHOPINTEND scores increasing by an average of 1.8-2.7 points per month.
• The most common adverse event was pneumonia; laboratory tests showed no significant abnormalities, indicating a favorable safety profile.

Conclusions:

• Risdiplam demonstrates efficacy in improving motor function in children with SMA.
• The drug exhibits a good safety profile in this pediatric population.
• The extent of motor function improvement is associated with the duration of the disease prior to initiating risdiplam treatment.