Respiratory and Bulbar Support in Spinal Muscular Atrophy Type I Treated with Nusinersen

Area of Science:

• Neurology
• Pediatrics
• Genetics

Background:

• Spinal muscular atrophy (SMA) type 1 is a severe genetic neuromuscular disorder.
• Nusinersen is a treatment for SMA, targeting the underlying genetic cause.
• Respiratory and feeding support are critical for managing SMA type 1.

Purpose of the Study:

• To evaluate the long-term (24 months) respiratory and feeding support needs in children with SMA type 1 treated with nusinersen.
• To compare outcomes based on age at treatment initiation (≤2 years vs. >2 years).

Main Methods:

• Retrospective analysis of SMA type 1 patients from the Canadian Neuromuscular Disease Registry (2017-2023).
• Patients were grouped by age at nusinersen initiation: ≤2 years or >2 years.
• Primary outcomes: time to death or full-time ventilation, time to feeding tube support. Secondary outcomes: support needs at 24 months.

Main Results:

• Thirty-two children were analyzed; median initiation ages were 3.2 months (≤2 yrs group) and 51.2 months (>2 yrs group).
• Median age for death or full-time ventilation was 8.6 months (≤2 yrs) and 10.5 months (>2 yrs).
• At 24 months, no significant differences in respiratory or feeding support needs were observed between the two groups.

Conclusions:

• Most Canadian children with SMA type 1 treated with nusinersen continue to require respiratory and feeding support.
• Treatment initiated after symptom onset did not eliminate the long-term need for significant supportive care.