ADARx IPO 2026: The $1.81B Valuation, the $446M Raise, and the AbbVie Stake Behind ADRX's Debut

ADARx Pharmaceuticals priced its IPO at $17 a share on September 25, 2026, raising $446.3 million and valuing the RNA-therapeutics company at $1.81 billion — with AbbVie adding an $89 million private placement on top of that.

The San Diego, California biotech sold 26,250,000 shares on Nasdaq under the ticker ADRX, upsizing the deal and pricing at the top of its $15-17 marketed range, according to ADARx's own SEC filings. It is the latest sign that public-market investors still have an appetite for clinical-stage RNA biotechs with a late-stage pipeline and a pharma partner already attached — in this case, AbbVie, which owns roughly 4.9% of ADARx after its own concurrent purchase.

ADARx IPO: How ADRX Priced and What It Is Worth

ADARx's shares began trading on the Nasdaq Global Select Market on September 25, 2026. The company sold 26,250,000 shares at $17.00 apiece — an upsized deal from its original share count — for gross proceeds of $446.3 million before underwriting discounts and offering expenses, putting the company's pricing-day valuation at roughly $1.81 billion. Concurrent with the offering, existing partner AbbVie purchased $89 million of stock in a private placement, a deal that (combined with the IPO itself) brought ADARx's total haul to $535.3 million and gave AbbVie approximately a 4.9% stake in the company post-close.

From a $52.5M Series A to a $1.81B IPO: ADARx's Five-Year Funding Climb

ADARx raised $352.5 million across four private venture rounds before going public, according to its SEC filings and deal-tracking data. The company closed a $31.5 million Series A in May 2021 at a $52.5 million post-money valuation, followed by a $75 million Series B in September 2021 that pushed the post-money mark to roughly $362 million, backed by investors including Lilly Asia Ventures, OrbiMed, Sirona Capital, and SR One Capital Management. A $46 million Series B-1 in January 2023 brought the valuation to $484.3 million, and a $200 million Series C in August 2023, led by Bain Capital, TCG Crossover, and HBM Healthcare Investments, valued the company at $839.6 million. The IPO priced a little over three years after that round, at roughly 2.2x the Series C mark.

Sources: ADARx Pharmaceuticals Form S-1/A (SEC EDGAR, September 2026); funding-round data compiled by Multiples.vc; AbbVie collaboration terms per FierceBiotech, May 2025.

What ADARx Actually Makes: siRNA Drugs and ADX-324

ADARx, founded in 2019 and led by CEO Zhen Li, builds short-interfering RNA (siRNA) therapeutics — drugs that silence the specific genes responsible for a disease rather than treating its symptoms. Its lead program, ADX-324, targets the PKK (prekallikrein) protein to prevent attacks of hereditary angioedema (HAE), a rare genetic condition that causes sudden, painful swelling episodes. The company dosed the first patient in ADX-324's Phase 3 STOP-HAE trial in 2026, according to Rare Disease Advisor's reporting on the trial, which the FDA has granted orphan drug designation. Beyond ADX-324, ADARx has three clinical-stage programs and two advanced preclinical programs in its broader pipeline, spanning genetic, cardiometabolic, and central nervous system diseases.

That pipeline is also what drew AbbVie in. The two companies signed a collaboration and license-option agreement in May 2025 covering next-generation siRNA therapeutics across neuroscience, immunology, and oncology — pairing ADARx's RNA discovery platform with AbbVie's antibody-engineering and tissue-delivery expertise.

The AbbVie Relationship, in Dollars

AbbVie's involvement with ADARx predates the IPO by more than a year and runs through two separate transactions. FierceBiotech reported that AbbVie paid ADARx a $335 million upfront payment in May 2025 for the siRNA collaboration, with up to $385 million more available in option fees and option-exercise payments, and up to $7.5 billion in potential development, regulatory, and commercial milestone payments across the partnered programs — money that is contingent on drugs actually advancing, not guaranteed. Then, concurrent with the September 2026 IPO, AbbVie separately purchased $89 million of ADARx common stock in a private placement at the $17.00 IPO price, landing it roughly a 4.9% equity stake in the now-public company. The upfront and milestone payments are deal economics tied to specific drug programs; the private placement is a straightforward equity stake, and the two should not be added together as if they describe the same thing.

How ADRX Has Traded Since the IPO

ADRX opened its first trading day at $22.10 — a 30% pop over the $17.00 IPO price — before settling to a $19.35 close that same session. The stock held most of that first-day gain through its first week, closing at $20.64 on September 29, 2026, roughly 21% above where the deal priced four trading days earlier. On a fully diluted share count of roughly 107 million shares implied by the pricing-day math, that Monday close puts ADARx's market value near $2.2 billion — though that figure is this publication's own extrapolation from the disclosed share price and share count, not a number ADARx itself has reported.

Total Capital Raised: Venture, AbbVie, and the IPO

Across its full history — private venture rounds, the AbbVie collaboration's upfront payment, the IPO itself, and AbbVie's private placement — ADARx has now brought in roughly $1.22 billion in disclosed capital. The IPO alone accounts for more than a third of that total, a reminder of how much a single offering can outweigh years of private fundraising for a clinical-stage biotech.

What the headline misses

A 21% first-week pop and a AbbVie-backed cap table make for a clean IPO story, but ADARx is still a clinical-stage biotech with zero approved products. ADX-324 is in a Phase 3 trial, not an FDA submission, and Phase 3 trials fail or get delayed regularly even with a favorable Phase 1/2 safety profile behind them. The siRNA field ADARx is entering is not empty ground either: Alnylam Pharmaceuticals already has five approved siRNA drugs on the market and a delivery platform that has become something close to an industry standard, alongside established public competitors like Arrowhead Pharmaceuticals and Ionis Pharmaceuticals. ADARx's edge is a strong pharma partner and a differentiated pipeline, not an uncontested market.

The AbbVie relationship also cuts both ways. A $335 million upfront payment and a 4.9% equity stake signal real conviction from a large pharma partner, but most of the $7.5 billion in potential milestone payments FierceBiotech reported are just that — potential, contingent on specific drugs clearing clinical and regulatory hurdles years from now. And like most newly public biotechs, ADARx's early insiders and venture backers are typically locked up from selling for roughly 180 days after the IPO; if that overhang weighs on the stock once it lifts, the first week's gain is not guaranteed to hold.

The Bottom Line

ADARx went from a $52.5 million Series A valuation in 2021 to a $1.81 billion IPO valuation in September 2026, raising $446.3 million on Nasdaq and pulling in another $89 million from AbbVie in the same transaction. That is a real validation of ADARx's siRNA platform and its relationship with a major pharma partner, and the stock's first-week trading backs that up. What is still unproven is the thing that determines whether any of it holds up: whether ADX-324 and the rest of the pipeline clear Phase 3 and actually reach patients, in a field where Alnylam already has a five-year head start on approved drugs.