Donidalorsen: First Approval.

Donidalorsen (DAWNZERA™) is a first-in-class, RNA-targeted antisense oligonucleotide (ASO), developed by Ionis Pharmaceuticals for the prevention of hereditary angioedema (HAE) attacks. It received its first approval on 21 August 2025 in the USA for the prophylaxis of HAE attacks in adult and paediatric patients aged 12 years and older. Donidalorsen is currently under regulatory review in the EU and in phase III development in several other countries. This article summarizes the key milestones in the development of donidalorsen leading to its first approval for HAE.