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

According to Market Watch, late-stage clinical RNA therapy company Adarx Pharmaceuticals is planning to raise up to $371.9 million through its initial public offering (IPO) in the United States. Based on the upper end of the proposed price range, the company's market capitalization after listing is expected to reach around $1.74 billion.

According to documents filed by Adarx with the U.S. Securities and Exchange Commission (SEC) on Monday, the San Diego-based biotech company plans to issue 21.875 million shares at a price range of $15 to $17 per share. Based on 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. Meanwhile, pharmaceutical giant AbbVie (ABBV.US), which has established a collaboration 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 price, with an investment not exceeding $100 million. Upon completion of the transaction, AbbVie is expected to hold approximately 4.9% of Adarx's shares.

Adarx primarily develops small interfering RNA (siRNA) drugs targeting a range of indications including ophthalmic diseases, kidney diseases, obesity, and Alzheimer's disease. siRNA therapies work by intervening in the expression of specific genes, addressing diseases at the genetic level, without causing permanent changes to the patient’s genome or DNA. With the continuous advancement of RNA-based drug technologies, this field has become one of the primary areas of focus for major global pharmaceutical and biotech companies in recent years.

Currently, Adarx has three candidate therapies in clinical development and two more projects in the preclinical stage. However, like most biotech companies still in the R&D phase, Adarx is not yet profitable. According to the prospectus, the company recorded a net loss of $48.4 million and collaboration revenue of $2.9 million for the six months ended June 30; in the same period last year, 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 significant R&D partnership with Adarx. In May 2025, Adarx reached a collaboration agreement with AbbVie, receiving a $335 million upfront payment. Under the relevant cooperation terms, Adarx is also eligible for billions in potential additional payments including option fees, R&D and commercialization milestone payments, as well as tiered royalties based on sales.

AbbVie's plan to further invest in Adarx concurrent with the IPO also means the relationship between the two parties will extend from R&D collaboration to the equity level.

The shareholder line-up behind Adarx is also drawing market attention. According to the prospectus, after the IPO, OrbiMed’s shareholding is expected to drop from 31% to 23%, but will still make it a major shareholder. LAV’s shareholding is expected to decrease from 16% to 12%; Adarx CEO Zhen Li’s stake will fall from 13% to 10%; SR One’s holding will drop from 11% to 8.2%.

In addition, Adarx’s previous fundraising has also attracted many major Wall Street investment institutions. In 2023, Bain Capital Life Sciences and TCGX co-led Adarx’s $200 million Series C financing round, while BlackRock, Invus, Marshall Wace, and T. Rowe Price joined as new investors.

This IPO is co-led by J.P. Morgan, Morgan Stanley, TD Securities, UBS Group, and LifeSci Capital. If priced at the upper end of the range at $17 per share, Adarx could raise about $371.9 million through the issuance of 21.875 million shares and achieve an estimated listing value of $1.74 billion. Meanwhile, AbbVie’s concurrent private investment of up to $100 million will further provide funding for R&D.