aibioParabilis Medicines prices IPO of 33,500,000 shares at $20.00, $670,000,000 in total
Tickers PBLS
Parabilis Medicines priced 33,500,000 shares at $20.00 each, and Regeneron agreed to buy $75.0 million of stock at 90% of the IPO price, as the company's net loss reached $145,889 thousand in 2025.
Key facts
- Company
- Parabilis Medicines, Inc. (NASDAQ: PBLS)
- News type
- Financings
- Primary source
- Parabilis Medicines, Inc. 424B4 (2026-06-10)
Parabilis Medicines, Inc. priced its initial public offering of 33,500,000 shares of voting common stock at $20.00 per share, according to a Form 424B4 prospectus dated June 9, 2026. The offering totals $670,000,000 before costs. Underwriting discounts and commissions are $1.40 per share, or $46,900,000 in total, leaving proceeds before expenses of $18.60 per share, or $623,100,000. The prospectus estimates net proceeds of about $618.2 million after offering expenses.
The underwriters hold an option to buy up to 5,025,000 more shares at the IPO price. If they exercise it in full, the prospectus estimates net proceeds of about $711.7 million. The shares are approved for listing on The Nasdaq Global Select Market under the symbol PBLS.
Who is underwriting
The five underwriters named on the cover are Leerink Partners, BofA Securities, Evercore ISI, Guggenheim Securities and LifeSci Capital. The prospectus does not describe any of them as sole or lead book-running manager. The prospectus text does not name counsel for the company or for the underwriters.
Regeneron and the share count
Regeneron Pharmaceuticals, Inc. has agreed to buy approximately $75.0 million of common stock in a concurrent private placement at 90% of the IPO price. A Form 8-K dated June 9, 2026 says the company entered into a stock purchase agreement with Regeneron that day for an aggregate of 4,166,666 shares of voting common stock. The underwriters receive no fee on the placement. The company expects to receive $75.0 million in net proceeds from it. Regeneron is entitled to certain piggyback registration rights, which let it include its shares when the company registers other shares for sale.
The 8-K also describes the company's seventh amended and restated certificate of incorporation, which the company filed in connection with the IPO. It authorizes 800,000,000 shares of common stock, including 600,000,000 voting shares and 200,000,000 non-voting shares.
The prospectus says the total of common stock and non-voting common stock outstanding immediately after the offering and the placement would be 118,145,780 shares. That figure rises to 123,170,780 shares if the underwriters exercise their option in full.
The losses behind the raise
The company's net loss was $117,914 thousand in 2024 and $145,889 thousand in 2025. Research and development expense was $100,829 thousand in 2024 and $125,583 thousand in 2025. General and administrative expense was $25,296 thousand and $26,496 thousand in those years. Net loss allocable to common stockholders, after cumulative dividends on convertible preferred stock, was $186,933 thousand in 2025. In the first quarter of 2026 the net loss was $45,316 thousand, against $38,326 thousand a year earlier.
The prospectus says the company will use the net proceeds to continue clinical development of zolucatetide in desmoid tumors and across several additional indications, to advance other programs, and for the Helicon platform, working capital and general corporate purposes. It does not give a split among those uses.
The clinical bet
Zolucatetide is the company's lead candidate. The prospectus says it has been evaluated in more than 150 patients. In desmoid tumors the company reports tumor reductions in 100% of patients and a 74% objective response rate among patients who had at least two post-baseline scans. The company defines that subgroup itself.
The company plans to start a global registrational Phase 3 trial in desmoid tumors in the first half of 2027. It also reports ongoing Phase 1/2 enrollment of FAP-desmoid patients, with a dedicated FAP cohort planned. The prospectus does not give readout dates for those studies.
The prospectus describes the company's Helicon platform as the basis for its pipeline. Its collaboration with Regeneron centers on Antibody-Helicon Conjugates, which the company says combine antibody targeting with a Helicon payload. The prospectus says the company expects a $50.0 million upfront payment from Regeneron under that collaboration, separate from the placement. The company says the net proceeds, together with existing cash and that upfront payment, will be sufficient to fund operations into the second half of 2029, but it adds that its operating plan may change and it may need more money sooner.