ADARx Raises $446M in Upsized Nasdaq IPO, Adds AbbVie Investment for siRNA Pipeline
核心洞察
ADARx Pharmaceuticals (搜索) priced an upsized IPO of 26.25 million shares at $17 each, raising about $446.3 million in gross proceeds.
AbbVie agreed to a concurrent private placement that would give it roughly 4.9% of ADARx, capped at $100 million.
Combined gross proceeds are expected to reach approximately $535.2 million before any underwriters' option exercise.
ADARx Pharmaceuticals (搜索) priced an upsized initial public offering of 26.25 million shares at $17 per share, raising approximately $446.3 million in gross proceeds. The San Diego-based RNAi drug developer began trading on Nasdaq under the ticker ADRX on September 25, 2026. The offering was initially marketed at 21.875 million shares at $15 to $17 per share before being upsized and priced at the top of that range.
Alongside the IPO, development partner AbbVie agreed to invest through a concurrent private placement enough to own approximately 4.9% of ADARx following the transactions, subject to a $100 million cap. ADARx expects combined gross proceeds of approximately $535.2 million from the IPO and the AbbVie investment, before any exercise of the underwriters' option to purchase additional shares.
Onvuzosiran Leads the Pipeline in Hereditary Angioedema
The financing supports a clinical-stage siRNA pipeline led by onvuzosiran (搜索) (ADX-324), a long-acting therapy for hereditary angioedema (搜索) that is now enrolling in the Phase III STOP-HAE trial. Onvuzosiran targets prekallikrein (搜索) mRNA and is being developed for dosing as infrequently as once every six months. The program holds FDA Fast Track and Orphan Drug designations.
Early-stage study results showed the drug could drive down levels of the protein plasma kallikrein (搜索) by as much as 93%. Lowering plasma kallikrein is known to reduce swelling episodes in HAE. A different kind of RNA-based therapy from Ionis Pharmaceuticals is available for HAE, and ADARx has claimed onvuzosiran (搜索) could be more potent and be dosed as infrequently as twice yearly. Early data from the Phase III study are expected by the end of 2027, according to the IPO filing.
Agazisiran and Earlier-Stage Assets
ADARx is also advancing agazisiran (搜索), an siRNA targeting Complement Factor B (搜索) across complement-mediated renal, ophthalmic and hematologic diseases. The company described the drug as a "pipeline-in-a-product opportunity" for certain kidney diseases, geographic atrophy (搜索) and the rare blood disorder paroxysmal nocturnal hemoglobinuria (搜索), and is conducting multiple mid-stage trials for it.
Behind agazisiran (搜索) sits ADX-626 (搜索), a Factor XI (搜索)-targeting siRNA in Phase I development for thromboembolic indications, aimed at stroke prevention. The company's broader pipeline extends into cardiovascular, metabolic and central nervous system diseases, including two prospects for obesity and neurological disorders that act on targets outside the liver.
Delivery Limits Shape the RNAi Strategy
ADARx is one of a handful of companies specializing in RNA interference, a form of drugmaking that involves stopping the body from producing problematic proteins. Biotechs including Alnylam Pharmaceuticals and Arrowhead Pharmaceuticals have successfully brought RNAi drugs to market. In its IPO filing, ADARx referred to the technology as "constrained" by delivery and potency challenges that have blunted its "broader potential." So far, every marketed RNAi medicine aims at drug targets in the liver, while ADARx has a pipeline of therapies directed at targets in the liver and elsewhere. The company is relying on tools it believes have created "optimized" RNA interference therapies for chronic conditions.
The AbbVie investment strengthens an existing relationship between the two companies. ADARx has a collaboration and license option agreement with AbbVie covering siRNA therapeutics across multiple disease areas, including neuroscience, immunology and oncology.