Nusinersen in spinal muscular atrophy: Respiratory outcomes at tertiary care centers

Objectives: The objective of the study wasto describe the effect of nusinersen therapy and its 1st-year associated outcomes, weaning of ventilator support, and length of stay in pediatric intensive care among ventilator-dependent spinal muscular atrophy (SMA) patients. Methods: This is a multicenter, retrospective case series study that was conducted in four tertiary care centers in Saudi Arabia. We report all the genetically diagnosed SMA ventilator-dependent patients who were admitted to the pediatric intensive care unit (PICU) and received a course of nusinersen therapy from (January 2017 to March 2018). The study endpoints were success to wean or extubate the patient and discharge from the PICU. Results: Five patients from four tertiary PICUs were included in this report. All five patients received a minimum of four doses of nusinersen intrathecally as per the manufacturer. At 12 months postinitiation of therapy, only one patient showed clinical improvement, while the other four patients did not experience improvement in their respiratory status following the administration of nusinersen. These four patients are still admitted in the PICU due to the inability to wean them from respiratory support. The remaining patient was discharged to home successfully and neither require any home ventilatory support nor oxygen therapy. Conclusion: In conclusion, our clinical experience and data suggest that the response to nusinersen therapy is very likely but mostly dependent on the time of initiation of nusinersen therapy and the cumulative number of doses among other variables related to disease severity. However, further studies targeting a larger group of patients with better standardized respiratory care are needed to investigate the effect of nusinersen on particularly the long-term outcomes.