Otsuka Pharmaceutical Co., Ltd. (Otsuka) announces the conclusion of an expanded licensing agreement for hereditary angioedema (HAE) drug candidate donidalorsen (genetic name) with Ionis Pharmaceuticals, Inc. (Ionis) to expand its development and sales area to the Asia-Pacific region, including Japan.

HAE is a rare and potentially life-threatening genetic condition that involves recurrent attacks of severe swelling (angioedema) in various parts of the body, including the hands, feet, genitals, stomach, face and/or throat.

Donidalorsen is an investigational, RNA-targeted prophylactic medicine designed to target prekallikrein (PKK), which plays an important role in activating inflammatory mediators associated with acute attacks of hereditary angioedema. Ionis recently reported positive results from the Phase 3 OASIS-HAE and OASISplus studies, presented at the 2024 European Academy of Allergy and Clinical Immunology (EAACI) Annual Congress in Valencia, Spain and published in The New England of Journal of Medicine*.

In December 2023, Otsuka and Ionis entered a licensing agreement for Otsuka to acquire exclusive rights to commercialize donidalorsen in Europe. Otsuka is preparing to submit a Marketing Authorization Application to the European Medicines Agency.

Under the terms of the expanded agreement covering Asia Pacific, Otsuka will pay Ionis an upfront payment of USD 20 million, plus milestone payments based on achievement of regulatory and sales targets. Ionis is also eligible to earn royalties on product sales. In addition to Europe, Otsuka will apply for regulatory approval and exclusively commercialize the product in Asian-Pacific markets.

Otsuka has developed drugs globally for rare diseases such as autosomal dominant polycystic kidney disease (ADPKD). Through this collaboration with Ionis, Otsuka will strive to deliver donidalorsen to patients across Asia Pacific and in Europe to address the unmet medical needs of patients with HAE.

*Riedl, M.A.et al. Efficacy and Safety of Donidalorsen for Hereditary Angioedema N Engl J Med . 2024 May 31. doi: 10.1056/NEJMoa2402478