Treatment Significantly Prolongs Life in Children With Spinal Muscular Atrophy

Although a study in Sweden did not provide conclusive evidence of a nationwide improvement in spinal muscular atrophy (SMA) survival after the introduction of nusinersen therapy, it did link nusinersen with decreased mortality when patients received the treatment. Researchers published their findings in the European Journal of Paediatric Neurology.

“SMA patients receiving nusinersen therapy had a dramatically increased overall survival compared to patients not receiving therapy,” the authors wrote. “This indicates that nusinersen treatment has an effect on survival, in patients diagnosed with SMA, in a nationwide real-world setting.”

Clinical trials have previously demonstrated a positive effect of nusinersen on survival of infants with SMA type 1, but survival data outside clinical trials is scarce. Consequently, researchers aimed to fill the gap by analyzing survival rates in patients diagnosed with SMA before age 2 for three distinct calendar periods: before, during, and after the introduction of nusinersen in Sweden.

Among the 155 patients identified, researchers did not find conclusive evidence that survival differed between the three time periods. Compared with the first period, hazards were lower in the middle and third period, according to the study, but confidence intervals were wide.

Nevertheless, treatment with nusinersen was associated with a decreased mortality rate, the study showed. Researchers reported a hazard ratio of 0.05.

“The introduction of nusinersen has led to significant prolongation of life expectancy in children with SMA in Sweden,” wrote the research team, who advised that the findings warranted larger studies.

Reference:
Berglund A, Berkö S, Lampa E, Sejersen T. Survival in patients diagnosed with SMA at less than 24 months of age in a population-based setting before, during and after introduction of nusinersen therapy. Experience from Sweden. Eur J Paediatr Neurol. 2022 Sep;40:57-60. doi:10.1016/j.ejpn.2022.07.005