RNA therapy company Adarx Pharmaceuticals (ADRX.US) plans to raise up to $372 million in a US IPO; pharmaceutical giant AbbVie (ABBV.US) has agreed to invest up to $100 million.

Late-stage clinical RNA therapy company Adarx Pharmaceuticals plans to raise up to $371.9 million through a U.S. initial public offering (IPO). Based on the upper end of the proposed offering price range, the company's market value after listing is expected to reach approximately $1.74 billion. According to a filing Adarx submitted to the U.S. Securities and Exchange Commission (SEC) on Monday, the San Diego-based biotech company plans to offer 21.875 million shares at a price range of $15 to $17 per share. According to investor presentation materials, the IPO is expected to be priced on September 24, and the company plans to list on the Nasdaq Global Market under the ticker symbol "ADRX." Adarx is backed by several well-known biopharmaceutical and institutional investors, including OrbiMed Advisors. At the same time, pharmaceutical giant AbbVie (ABBV.US), which has established a partnership with Adarx, also plans to further become a shareholder. According to the prospectus, AbbVie has agreed to purchase Adarx shares through a private placement at the IPO offering price, with an investment amount of up to $100 million. After the transaction is completed, AbbVie is expected to hold approximately 4.9% of Adarx. Adarx mainly develops small interfering RNA (siRNA) drugs, with target indications covering multiple areas including ophthalmic diseases, kidney diseases, obesity, and Alzheimer's disease. siRNA therapies work by interfering with the expression of specific genes, targeting disease mechanisms at the genetic level, while not causing permanent changes to a patient's genome or DNA. As RNA drug technology continues to mature, this field has become one of the key areas of focus for major global pharmaceutical companies and biotech companies in recent years. Currently, Adarx has three candidate therapies in clinical development, with another two programs in the preclinical stage. However, like most biotech companies still in the research and development stage, Adarx has not yet achieved profitability. The prospectus shows that for the six months ended June 30, the company recorded a net loss of $48.4 million and collaboration revenue of $2.9 million; in the same period a year earlier, the net loss was $33.6 million and collaboration revenue was only $208,000. AbbVie not only plans to participate in this IPO, but has also previously established a sizable R&D partnership with Adarx. In May 2025, Adarx reached a collaboration agreement with AbbVie and received an upfront payment of $335 million. Under the relevant collaboration arrangements, Adarx is also eligible to receive potentially billions of dollars in future payments, including option-related fees, R&D and commercialization milestone payments, as well as tiered royalties calculated on sales. AbbVie's plan to further invest in Adarx alongside the IPO also means that the relationship between the two parties will extend further from R&D collaboration to the equity level. Adarx's shareholder lineup has also attracted market attention. According to the prospectus, after the IPO is completed, OrbiMed's shareholding is expected to decrease from the current 31% to 23%, but it will remain an important shareholder of the company. LAV's shareholding is expected to decrease from 16% to 12%; Adarx Chief Executive Officer Zhen Li's shareholding will decrease from 13% to 10%; and SR One's shareholding will decrease from 11% to 8.2%. In addition, Adarx's previous financing also attracted many large Wall Street investment institutions. In 2023, Bain Capital Life Sciences and TCGX co-led Adarx's $200 million Series C financing, with BlackRock, Inc., Invus, Marshall Wace, and T. Rowe Price Group and other institutions joining at the time as new investors. This IPO is being led by JPMorgan, Morgan Stanley, Toronto-Dominion Bank, UBS Group AG, and LifeSci Capital. If ultimately priced at the upper end of the offering range at $17 per share, Adarx could raise approximately $371.9 million by issuing 21.875 million shares and obtain a listing valuation of approximately $1.74 billion. At the same time, AbbVie's concurrent private placement investment of up to $100 million will further provide the company with R&D funding.