Ionis Pharmaceuticals reported positive phase 3 trial results for zilganersen, an antisense oligonucleotide for Alexander disease, a rare neurogenetic disorder. The drug demonstrated significant improvements in mobility as measured by a standardized gait speed test, marking a milestone as the first therapeutic candidate to advance in this indication. Ionis plans to submit a New Drug Application early next year, potentially bringing the first approved treatment to this ultra-rare disease population. This development underscores ongoing advances in RNA-based therapies for neurological conditions.