ADARx Pharmaceuticals has raised approximately $446.3 million in an upsized US initial public offering, pricing 26.25 million shares at $17 each, the top end of the company’s previously indicated $15 to $17 range, according to Bloomberg. The San Diego based late stage biotechnology company is expected to begin trading on the Nasdaq Global Select Market on September 25 under the ticker ADRX, with the offering scheduled to close on September 28. The IPO was larger than the $371.9 million maximum the company had initially targeted earlier in the week, reflecting continued investor appetite for late stage biotechnology companies. Reuters reported that ADARx is seeking to advance RNA based medicines targeting rare and chronic diseases across several therapeutic areas.
The IPO is accompanied by a strategic investment from pharmaceutical giant AbbVie, which has agreed to purchase ADARx shares at the same $17 price in a concurrent private placement. AbbVie will invest up to $100 million and is expected to hold approximately 4.9% of ADARx following the transactions. Combined gross proceeds from the IPO and private placement are expected to reach approximately $535.2 million, excluding any exercise of the underwriters’ option to purchase an additional 3.94 million shares. The relationship builds on a $335 million research collaboration and licence option agreement announced by AbbVie and ADARx in 2025 covering siRNA therapeutics in neuroscience, immunology and oncology.
ADARx is developing next generation small interfering RNA therapeutics designed to selectively reduce the production of disease driving proteins. Its lead programme, onvuzosiran, is in late stage clinical development for hereditary angioedema, a rare genetic disorder characterised by recurrent swelling attacks, while other programmes target kidney, cardiovascular, neurological, metabolic and immune related diseases. BioPharma Dive reported that ADARx is the first RNA interference focused biotechnology company in more than a decade to price a traditional US IPO, highlighting the renewed investor interest in the sector. The successful listing also gives ADARx substantial new capital to advance its clinical pipeline as the company moves towards potentially pivotal development milestones.
