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

## TL;DR

This study evaluates the safety and effectiveness of risdiplam in adults with spinal muscular atrophy, finding it generally safe and beneficial for motor and respiratory function.

## Contribution

The study provides new evidence on risdiplam's long-term safety and efficacy in adult SMA patients, a group with limited prior data.

## Key findings

- CHOP-ATEND scores improved at 12 and 24 months, suggesting motor function benefits.
- Risdiplam was safe and well-tolerated over 24 months with minimal serious adverse events.
- Gastrointestinal issues were the most common self-reported adverse effects.

## Abstract

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.

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.

Eighteen patients (mean age 41.11 years) met inclusion criteria. CHOP-ATEND scores increased at 12 (+1.99, p = 0.030) and 24 months (+2.12; p = 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.

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.