Changes in Ventilatory Support Requirements of Spinal Muscular Atrophy (SMA) Patients Post Gene-Based Therapies

Spinal muscular atrophy (SMA) is a genetic neuromuscular disease resulting in global muscular weakness and, frequently, in respiratory failure and premature death. Gene-based therapies like Nusinersen are now available for patients with SMA. The aim of this review was to assess in "real world" studies, whether novel treatments would have a positive impact on the mechanical ventilatory support requirements of SMA patients, already initiated on ventilatory support prior to treatment administration. A literature search was performed in Pubmed using multiple combinations of MESH terms and the snowball procedure. A total of 14 publications were discussed in this review. Considering all patients included in the published studies who were on ventilatory support and were treated with Nusinersen, 13/172 (7.5%) had reduced needs for ventilatory support, 1/172 (0.6%) did not need ventilation post-treatment, and 122/172 (70.9%) were maintained on the same ventilator settings. Moreover, 2/41 (4.9%) children who were offered gene therapy had no need for further ventilatory support and 12/41 (29.2%) had reduced requirements. In conclusion, available evidence suggests that among children with SMA, who are on mechanical respiratory support either noninvasively or via tracheostomy at the time of gene-based treatment, only a few will be weaned off the ventilator or have reduced ventilator needs per 24 h. Children will usually require the same level of support as before treatment.