San Diego-based ADARx Pharmaceuticals priced an upsized initial public offering of 26.25 million shares at USD 17 per share, raising approximately USD 446.3 million in gross proceeds. The company began trading on Nasdaq under the ticker ADRX on September 25, 2026.
The financing could bring in substantially more capital alongside a concurrent private placement with AbbVie, which agreed to invest enough to own approximately 4.9% of ADARx following the transactions, subject to a USD 100 million cap. ADARx expects combined gross proceeds of approximately USD 535.2 million from the IPO and AbbVie investment, before any exercise of the underwriters’ option to purchase additional shares.
The IPO provides capital for a clinical-stage siRNA pipeline led by onvuzosiran (ADX-324), a long-acting therapy for hereditary angioedema now enrolling in the Phase III STOP-HAE trial. Onvuzosiran targets prekallikrein mRNA and is being developed for dosing as infrequently as once every six months; the program holds FDA Fast Track and Orphan Drug designations.
ADARx is also advancing agazisiran, an siRNA targeting Complement Factor B across complement-mediated renal, ophthalmic, and hematologic diseases, and ADX-626, a Factor XI-targeting siRNA in Phase I development for thromboembolic indications. The company’s broader pipeline extends into cardiovascular, metabolic, and central nervous system diseases.