aibioADARx Pharmaceuticals closes IPO of 26,250,000 shares at $17.00 each
Tickers ADRX
ADARx Pharmaceuticals sold 26,250,000 shares at $17.00 in its IPO for about $446.3 million gross, and AbbVie bought 5,255,542 shares in a concurrent private placement worth about $89.3 million. The company had net losses of $46.4 million in 2024 and $73.1 million in 2025.
Key facts
- Company
- ADARx Pharmaceuticals, Inc. (NASDAQ: ADRX)
- News type
- Financings
- Primary source
- ADARx Pharmaceuticals, Inc. 424B4 (2026-09-28)
The offering
ADARx Pharmaceuticals, Inc. (Nasdaq: ADRX) closed its initial public offering on September 28, 2026, selling 26,250,000 shares of common stock at $17.00 each. The prospectus, dated September 24, 2026, shows gross proceeds of $446,250,000, underwriting discounts of $1.19 a share or $31,237,500 in total, and $415,012,500 in proceeds to the company before expenses. The underwriters have a 30-day option to buy up to 3,937,500 more shares.
The shares trade on The Nasdaq Global Select Market. The company's September 4 filing had applied for the Nasdaq Global Market, so the listing tier changed between the two documents. Up to 2% of the shares were reserved at the IPO price for directors, officers, employees, investors and friends and family. The company effected a 1-for-1.1717 reverse stock split on September 17, 2026.
The banks
The prospectus names J.P. Morgan, Morgan Stanley, TD Cowen, UBS Investment Bank and LifeSci Capital as underwriters, and does not label a lead or sole bookrunner. The 8-K names the placement agents for the private placement by entity: J.P. Morgan Securities LLC, Morgan Stanley & Co. LLC, TD Securities (USA) LLC, UBS Securities LLC and LifeSci Capital LLC. The company paid them a fee of 2.0% of the private placement's purchase price. The prospectus cover and the 8-K do not name counsel to the company or the underwriters.
The AbbVie placement
ADARx signed a Common Stock Purchase Agreement with AbbVie Inc. on September 13, 2026. AbbVie bought 5,255,542 shares at $17.00 in a private placement that closed alongside the IPO, for gross proceeds of about $89.3 million before placement fees and expenses. The agreement caps AbbVie's purchase at $100.0 million and sets the number of shares so that AbbVie owns about 4.9% of the common stock after both closings. The prospectus, calculated from shares outstanding on June 30, 2026, gives 5,233,264 shares; the 8-K gives 5,255,542, and neither document explains the difference.
AbbVie is also ADARx's collaborator. In May 2025 the two signed a discovery-stage option agreement on siRNA drugs. The prospectus says ADARx received a $335.0 million upfront payment, and is eligible for up to $385.0 million in option payments, up to $7.45 billion in contingent milestones and royalties from the high single digits to mid-teens.
Proceeds and dilution
The company estimates net proceeds from the IPO and the private placement of about $495.3 million, or about $557.5 million if the underwriters take their full option. It will use them, with existing cash and short-term investments, to advance agazisiran through phase 2 and possibly phase 3, to complete the phase 3 STOP-HAE trial of onvuzosiran and support pre-commercial activities, to advance ADX-626, ADX-077 and ADX-199, and for research, working capital and general corporate purposes.
The prospectus shows 75,318,061 shares outstanding at June 30, 2026, after the conversion of all convertible preferred stock. After the offering and private placement, 106,801,325 shares will be outstanding, or 110,738,825 if the option is exercised in full.
The losses and the pipeline
The company was incorporated in December 2019, has not completed any clinical program and has no approved product. Its net losses were $46.4 million in 2024 and $73.1 million in 2025. Collaboration revenue was $3,449 thousand in 2025. For the six months ended June 30, 2026, the net loss was $48,426 thousand.
ADARx describes itself as a late-clinical stage siRNA company with three clinical programs and two advanced preclinical programs. The lead program, onvuzosiran, targets prekallikrein to prevent hereditary angioedema attacks. A randomized, double-blind, placebo-controlled phase 3 trial, STOP-HAE, is enrolling 90 adults, with topline data expected by the end of 2027. The FDA granted Fast Track designation in August 2026. Agazisiran, aimed at complement factor B, is in three phase 2 trials in kidney disease, paroxysmal nocturnal hemoglobinuria and geographic atrophy, with initial data expected in mid- to second half of 2027.
The obesity program ADX-077 and the Alzheimer's program ADX-199 are preclinical, with phase 1 trials planned for 2027 and by the end of 2027 or early 2028. The prospectus summary gives no patient-level results for any clinical program.