Otsuka Pharmaceutical and Ionis Pharmaceuticals reported positive Phase 3 results from the Fusion study of ulefnersen in patients with FUS-associated amyotrophic lateral sclerosis. The antisense oligonucleotide met statistically significant improvements in function and survival, in a rare ALS subtype that has no approved targeted therapies. The companies said the data position ulefnersen for potential expedited regulatory discussions. The program is designed to target FUS biology in a way intended to modify disease progression rather than only manage symptoms. The Phase 3 success extends the momentum behind RNA-targeted precision medicine in neurodegeneration, as developers seek paths to accelerate access for genetically defined populations where unmet need remains high.