The FDA approved Ionis Pharmaceuticals’ antisense therapy Zanvastro (zilganersen) for Alexander disease in both pediatric and adult patients, marking the first disease-modifying treatment for the ultra-rare, progressive disorder. The approval establishes a new pillar for Ionis’ wholly owned neurology franchise and shifts Alexander care away from purely symptomatic management. The approval follows pivotal trial results reported around gait stabilization on the 10-Meter Walk Test at week 61 and supportive findings across motor function endpoints, with most adverse events described as mild to moderate. Ionis said Zanvastro will be available in the coming weeks and launched an access support program to help patients navigate coverage. Separately, regulatory attention also remains high on rare CNS programs as the FDA’s willingness to move into expedited pathways continues to expand the bar for mechanism-based therapies in orphan neurology.