08:37 AM EDT, 06/25/2025 (MT Newswires) -- Biogen (BIIB) said Wednesday that results from the phase 1 study of salanersen have encouraged it to advance to registrational studies.

The study showed that children with spinal muscular atrophy previously treated with gene therapy experienced a substantial slowing of neurodegeneration. Exploratory clinical data also showed "clinically meaningful improvements in motor function," the company said in a statement.

The cumulative data from the study indicate that salanersen has a generally well tolerated safety profile, with most adverse events mild to moderate in severity, according to the statement.

Biogen said it is currently engaging with global health authorities regarding the design of the phase 3 studies for the investigational antisense oligonucleotide therapy.

Biogen licensed the global development, manufacturing and commercialization rights for salanersen from Ionis Pharmaceuticals ( IONS ) , which discovered the therapy, the statement said.