Ionis announces positive topline results for zilganersen in Alexander disease trial.

Ionis Pharmaceuticals announced positive topline results from a pivotal study of zilganersen in Alexander disease, a rare and often fatal neurological condition. Zilganersen demonstrated statistically significant and clinically meaningful stabilization on the primary endpoint of gait speed compared to control. The company plans to submit a New Drug Application in Q1 2026.

Ionis Pharmaceuticals, Inc. (Nasdaq: IONS) today announced positive topline results from a pivotal study of zilganersen in children and adults living with Alexander disease (AxD), a rare, progressive, and often fatal neurological condition with no approved disease-modifying treatments. The study demonstrated statistically significant and clinically meaningful stabilization on the primary endpoint of gait speed as assessed by the 10-Meter Walk Test (10MWT) compared to control at week 61 (mean difference 33.3%, p=0.0412) Ionis announces positive topline results from pivotal study of zilganersen in Alexander disease^[1].

Zilganersen, an investigational antisense oligonucleotide medicine, showed consistent benefit in key secondary endpoints, indicating evidence of slowed disease progression, stabilization, or improvement. These results mark the first time an investigational medicine has shown a positive disease-modifying impact in AxD. The study enrolled 54 participants with Alexander disease (AxD) between the ages of 1.5 and 53 years across 13 sites in eight countries Ionis announces positive topline results from pivotal study of zilganersen in Alexander disease^[1].

Ionis plans to submit a New Drug Application (NDA) to the U.S. Food and Drug Administration in Q1 2026 and is evaluating the potential to initiate an Expanded Access Program (EAP) in the U.S. Detailed data will be presented at an upcoming medical conference Ionis announces positive topline results from pivotal study of zilganersen in Alexander disease^[1].