Otsuka Pharmaceutical, a healthcare company developing treatments and diagnostics for both physical and psychological health conditions, has announced that its Dawnzera (donidalorsen) has received approval from the European Commission (EC) for the prevention of recurrent attacks of hereditary angioedema (HAE) in adults and adolescents aged 12 years and older.
HAE is a genetic condition characterised by episodes of unpredictable swelling in areas including the face, abdomen and extremities. Around half of HAE patients first experience symptoms before the age of 10. The majority of patients also experience their first HAE attack before reaching adulthood.
The EC’s approval was based on results from the phase 3 OASIS-HAE study. The study showed that an 80mg dose of Dawnzera every four weeks caused an 81% reduction in the four-weekly rate of HAE attacks compared to placebo. Dosing every eight weeks demonstrated a 55% reduction in attacks.
The study did not identify any serious safety signals. The most common adverse events associated with Dawnzera included injection site reactions and hypersensitivity, including anaphylaxis.
The Committee for Medicinal Products for Human Use (CHMP) previously issued a positive opinion on Dawnzera in November 2025. Dawnzera is now licensed as a treatment option across all 27 EU member states, as well as Iceland, Liechtenstein and Norway.
“As the first European-approved ribonucleic acid (RNA)-targeted therapy for HAE, donidalorsen represents a welcome development in therapeutic options for preventing attacks,” said Henrik Balle Boysen, president of HAE International (HAEi). “Today’s approval gives people living with HAE and their physicians another choice for aligning treatment with individual needs.”
