07:40 AM EDT, 07/21/2025 (MT Newswires) -- Ionis Pharmaceuticals ( IONS ) said Monday results from a Phase 3 study showed that its investigational therapy donidalorsen led to a 62% reduction in mean monthly attack rate among hereditary angioedema patients who switched from other prophylactic treatments.

Ionis said 84% of patients surveyed preferred donidalorsen citing improved disease control, quicker administration, and fewer injection-site reactions.

Donidalorsen was generally well tolerated, with no serious treatment-related adverse events.

The therapy is currently under review by the US Food and Drug Administration for the prevention of HAE attacks in patients aged 12 and older with a target action date of Aug. 21.