ADARx Pharmaceuticals has overshot its own IPO ambitions, as fellow RNA-focused biotech City Therapeutics also plans a public listing.
San Diego-based ADARx had previously expected to sell 21.9 million shares priced between $15 and $17. But the company’s Nasdaq IPO this morning will see ADARx offer 26.3 million shares priced at the top end of this range.
It means the biotech expects to bring in gross proceeds of $446.3 million from this morning’s IPO—above the $350 million it had been anticipating under its previous figures. This haul could rise by a further $66.9 million if underwriters fully take up their option to buy an additional 3.9 million shares at the same price.
ADARx had also been banking on its partner AbbVie buying around $100 million of stock in a private placement, although the company didn’t namecheck this part of the offering in yesterday’s release.
Top of the list of spending priorities is bankrolling the complement factor B-targeting small interfering RNA (siRNA) therapy 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.
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.
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 hopes the IPO will not only fund this trial but also 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 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.
City builds out IPO ambitions
City is another RNA-focused biotech that is considering trying its luck on the Nasdaq. The company has yet to reveal how much stock it’s hoping to offer, or at what price, but wants to use some of the cash to fund the Factor XI-targeting RNA interference (RNAi) therapeutic CITY-FXI through an ongoing phase 1 study and into a mid-stage trial for patients who’ve undergone knee surgery, a setting where thrombosis is common.
City’s plan is to pursue Factor XI silencing in patients who are unable to be treated with existing anticoagulants that target a similar protein called Factor Xa, due to the risk of bleeding.
The company will also continue a phase 1 study of a GalNAc-conjugated siRNA therapeutic called CITY-RBP4 and prepare to evaluate it for Stargardt disease and geographic atrophy, according to a Securities and Exchange Commission filing.
There’s also money needed for another GalNAc-conjugated asset dubbed CITY-TFR2, which is due to enter a trial in China later this year as a potential treatment for anemia. City has plans to expand into other chronic conditions where anemia is prevalent, like chronic kidney disease and inflammatory diseases, including inflammatory bowel disease.
City broke ground in 2024 with the backing of RNAi pioneers from Alnylam Pharmaceuticals, like John Maraganore, Ph.D., Mark Keating, M.D., and Tracy Zimmermann, Ph.D.
When the 81-strong company hooked a $99.5 million series B in June, City CEO Andy Orth told Fierce that RNAi drugs are primed to revolutionize medicine in the same way antibodies once did.
“The underlying belief set here is this is going to be a really meaningful class of medicines,” Orth told Fierce at the time. “Within that, just like within the antibodies, there's room for innovation.”
As well as the series B funds, City has also inked partnerships with the likes of Bausch + Lomb and Biogen.