Ionis Pharmaceuticals Inc (Nasdaq:IONS), a US-based provider of RNA-targeted medicines, and Japanese healthcare company Otsuka Pharmaceutical Co Ltd announced on Friday that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency has issued a positive opinion of DAWNZERA (donidalorsen) for routine prevention of hereditary angioedema (HAE) attacks in patients aged 12 and older.

This recommendation is now under review by the European Commission, with a decision expected in Q1 2026.

The opinion is based on Phase 3 OASIS-HAE and OASISplus studies showing a significant and sustained reduction in mean monthly HAE attack rates, including self-administration via autoinjector. DAWNZERA was previously approved by the US Food and Drug Administration in August 2025 for prophylaxis in the same patient population.

HAE is a rare, potentially life-threatening genetic condition affecting about 1 in 50,000 people worldwide, characterised by recurrent severe swelling in various body regions. Otsuka holds exclusive rights to commercialise donidalorsen across Europe and the Asia Pacific region.

DAWNZERA is an RNA-targeted therapy that inhibits plasma prekallikrein, a key protein in triggering inflammatory mediators during acute HAE attacks.