AbbVie-backed ADARx plans IPO to bankroll array of clinical

ADARx Pharmaceuticals has reinvigorated its ambitions to go public as the AbbVie-backed biotech looks to fund ongoing clinical trials of a range of next-gen small interfering RNA (siRNA) medicines. The San Diego-based company has yet to set out how much stock it’s planning to offer—or at what price—but the lion’s share of the proceeds will go towards advancing three clinical-stage medicines. They include bankrolling agazisiran through ongoing phase 2 studies in various complement-mediated diseases. These programs cover renal diseases like IgA nephropathy, complement 3 glomerulopathy and immune complex membranoproliferative glomerulonephritis, as well as the rare blood disorder paroxysmal nocturnal hemoglobinuria, along with an eye condition called geographic atrophy secondary to age-related macular degeneration. Depending on how those mid-stage studies perform, ADARx will also reserve some of the IPO proceeds to potentially kick off phase 3 studies of the complement factor B-targeting siRNA therapy in the same indications, the company explained in a Securities and Exchange Commission filing Friday. ADARx has already taken a prekallikrein-targeted siRNA med called onvuzosiran into phase 3 development to prevent hereditary angioedema, and the IPO funds are expected to continue this study as well as “support pre-commercial activities,” according to the filing. The final part of ADARx’s trio of clinical-stage siRNA assets is the factor XI-targeted ADX-626, which is undergoing a phase 1 study in healthy participants. The biotech is hoping the IPO will able to not only fund this trial but finance a phase 2 study of the therapy for secondary stroke prevention and an exploratory trial for stroke prevention in atrial fibrillation. The remaining proceeds from the planned Nasdaq listing will be used to take two other siRNA therapies, the adipose-targeted obesity program ADX-077 and the Alzheimer’s disease-focused ADX-199, into the clinic next year. The aim of siRNA meds is to prevent the production of disease-causing proteins by targeting the protein’s respective messenger RNA. ADARx has touted its therapies as offering long-lasting effects without genome alterations and the associated long-term safety concerns. This approach has attracted interest from AbbVie, which paid $335 million upfront last year to secure options on next-gen siRNA therapeutics across several disease areas. The hefty upfront fee from that deal was even larger than the impressive $200 million series C that ADARx brought in back in 2023. The round was backed by the likes of Blackrock, Lilly Asia Ventures, OrbiMed and SR One Capital Management Thanks to the fundraise and the AbbVie deal, ADARx entered 2026 with $427.3 million still in the bank—although the company will need more to bankroll such a wide-ranging clinical agenda. The biotech currently employs 100 full-time staffers, led by CEO and co-founder Zhen Li, Ph.D., a veteran of both Arrowhead Pharmaceuticals and Merck & Co. Li first hinted to Fierce that he was considering an IPO way back in 2023, but the company has clearly been biding its time. ADARx’s leadership will likely be hoping for a similarly warm reception on the public markets to that received by the growing list of biotechs that have already gone public this year. The bumper run of IPOs in 2026 has included record-breaking listings from the likes of Parabilis Medicines and Kailera Therapeutics.