AbbVie-Backed Adarx Revives IPO Plans to Fund RNA Drug Trials

U.S. biotech company Adarx, backed by AbbVie, is again pursuing an initial public offering (IPO) to fund clinical trials of next-generation RNA therapies.

Adarx has not yet set the size or price of its share offering for a Nasdaq listing, according to U.S. biotech publication Fierce Biotech on the 7th (local time). The company plans to devote a substantial portion of the proceeds to developing three clinical-stage therapies.

First, the company will use the funds for a phase 2 trial of adazisiran, an siRNA therapy targeting complement factor B. The trial will evaluate the drug in kidney diseases, including IgA nephropathy, C3 glomerulopathy and immune complex-mediated membranoproliferative glomerulonephritis, as well as paroxysmal nocturnal hemoglobinuria and geographic atrophy secondary to age-related macular degeneration.

In a filing with the U.S. Securities and Exchange Commission (SEC), the company said it had also allocated some funds to begin phase 3 trials for the same indications, depending on the phase 2 results.

Another candidate, onbuzisiran, has already entered a phase 3 trial for the prevention of hereditary angioedema. IPO proceeds will also support continuation of the trial and prelaunch activities.

The third clinical asset, ADX-626, targets coagulation factor XI and is being studied in a phase 1 trial in healthy participants. The company also aims to secure funding for the trial, a phase 2 study for secondary stroke prevention and an exploratory trial of stroke prevention in patients with atrial fibrillation.

The remaining funds will be used to advance the obesity drug ADX-077 and the Alzheimer’s disease drug ADX-199 into clinical development next year.

siRNA therapies target the messenger RNA of disease-causing proteins to block their production. Adarx has emphasized that its approach can produce long-lasting effects without genetic modification.

AbbVie has shown interest in this approach. Last year, AbbVie paid $335 million upfront for options on next-generation siRNA therapies across several disease areas.

The payment exceeded the $200 million Series C financing Adarx raised in 2023. Investors in that round included BlackRock, Lilly Asia Ventures, OrbiMed and SR One Capital Management.

Funding and the AbbVie deal left Adarx with $427.3 million in cash as of early 2026. However, the company needs additional funding to support its broad clinical development plans.

The company currently employs 100 full-time staff and is led by co-founder and CEO Jeon-ri. He previously worked at Arrowhead Pharmaceuticals and Merck, and first told Fierce Biotech in 2023 that the company was considering an IPO.

The U.S. biotech IPO market has been strong this year, with Parabilis Medicines and Kylera Therapeutics recording some of the largest offerings on record.