--- title: "Parabilis Medicines files for IPO; Regeneron agrees to buy about $75.0" url: "https://aibio.space/news/parabilis-medicines-files-ipo-regeneron-agrees-buy-about-75-0-million/" publisher: "aibio.space (Biotech Investor Relations News)" date: "2026-05-19" section: "Financings" tickers: "NASDAQ:PBLS" source: "https://www.sec.gov/Archives/edgar/data/1657677/000119312526230994/ck0001657677-20260519.htm" summary: "Parabilis Medicines filed its IPO registration on May 19, 2026, with a $75.0 million Regeneron private placement tied to a collaboration, while its net los" --- By the aibio.space news desk. Sources - [Parabilis Medicines, Inc. S-1 (2026-05-19)](https://www.sec.gov/Archives/edgar/data/1657677/000119312526230994/ck0001657677-20260519.htm) [PBLS](https://aibio.space/companies/parabilis-medicines/) 2026-05-19 # Parabilis Medicines files for IPO; Regeneron agrees to buy about $75.0 million of stock Tickers [PBLS](https://aibio.space/companies/parabilis-medicines/) Parabilis Medicines filed its IPO registration on May 19, 2026, with a $75.0 million Regeneron private placement tied to a collaboration, while its net loss grew to $145,889 thousand in 2025. ## Key facts - **Company**: Parabilis Medicines, Inc. (NASDAQ: PBLS) - **News type**: Financings - **Primary source**: [Parabilis Medicines, Inc. S-1 (2026-05-19)](https://www.sec.gov/Archives/edgar/data/1657677/000119312526230994/ck0001657677-20260519.htm) *Midtown Manhattan and a downtown tower in haze. CC0, via rawpixel. The picture shows the field, not the companies named.* Parabilis Medicines, Inc. filed a Form S-1 registration statement with the Securities and Exchange Commission on May 19, 2026 for an initial public offering of its voting common stock. The Cambridge, Massachusetts company says that after the offering it will have two classes of common stock, voting and non-voting. It has applied to list the stock on The Nasdaq Global Market under the symbol PBLS. The filing leaves the number of shares, the price range and the proceeds blank. ## The underwriters and the placement The cover page lists five underwriters: Leerink Partners, BofA Securities, Evercore ISI, Guggenheim Securities and LifeSci Capital. The filing does not describe any of them as sole or lead book-running manager. The underwriters have an option to buy additional shares at the offering price, less underwriting discounts and commissions. The copies-to block names Goodwin Procter LLP and Covington & Burling LLP as counsel. It does not say which of them represents the company and which represents the underwriters. Regeneron Pharmaceuticals, Inc. has agreed to buy approximately $75.0 million of Parabilis common stock in a concurrent private placement. The price per share would be 90% of the initial public offering price. The placement would close with the offering and depends on it, but the offering does not depend on the placement. The underwriters will receive no fee on the placement, and the company expects to sign a stock purchase agreement with Regeneron. The placement comes with a collaboration. The filing says the company recently entered into a collaboration with Regeneron to evaluate Antibody-Helicon Conjugates, and that Regeneron will pay a non-refundable upfront payment of $50.0 million under the agreement. ## The losses The company's own figures show net losses that rose from $117,914 thousand in 2024 to $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. The first quarter of 2026 brought a net loss of $45,316 thousand, against $38,326 thousand in the first quarter of 2025. The filing says the company has financed its operations mainly through sales of convertible preferred stock, borrowings under a term loan with Silicon Valley Bank, and a SAFE. The term loan carries covenants that restrict the company's actions, and the filing warns that a failure to comply could lead to default and acceleration. The filing states that the company will require substantial additional capital to finance its operations. It says the proceeds of the offering and the placement, together with existing cash and the $50.0 million upfront, will be sufficient to fund operations through a date the document leaves blank. ## The science and the pipeline The lead product candidate is zolucatetide, which the company says, to its knowledge, is the first drug to directly target the interaction between beta-catenin and the T-cell factor family of transcription factors. The filing says zolucatetide has been evaluated in more than 150 patients. Its lead indication is desmoid tumors, where the company reports a 74% objective response rate in patients who had at least two post-baseline scans. That subgroup is defined by the company, and the summary describes the clinical data as promising. The company plans to start a global registrational Phase 3 trial for zolucatetide in desmoid tumors in the first half of 2027. The filing says the company's preclinical programs target the ERG and androgen receptor in prostate cancer, and that the ERG and AR ON degrader programs are moving toward IND-enabling studies. The company's platform is built on what it calls Helicons, stabilized helical peptides designed to bind proteins that conventional drugs struggle to reach. The filing states that all of its programs and product candidates are still in research, preclinical or clinical development. ## What the filing leaves open The offering size, the price and the placement's share count all depend on a price range the registration statement does not yet give. Against a 2025 net loss of $145,889 thousand, the $50.0 million upfront payment and the $75.0 million placement are the new money the filing points to, and the funding period is left blank. [Report an error](https://aibio.space/reputation/#correction) ## Companies in this story PBLS Parabilis Medicines, Inc. NASDAQ ยท United States Open the starter desk ## More in Financings Financings ### [INmune Bio raises $4.50 million in registered direct offering with warrants](https://aibio.space/news/inmune-bio-raises-4-50-million-registered-direct-offering-warrants/) Oct 29, 2026 Financings ### [Lexeo Therapeutics files $300 million shelf registration](https://aibio.space/news/lexeo-therapeutics-files-300-million-shelf-registration/) Oct 29, 2026 Financings ### [ProKidney files $650 million shelf with $200 million Jefferies sales program](https://aibio.space/news/prokidney-files-650-million-shelf-200-million-jefferies-sales-program/) Oct 29, 2026 --- Source page: https://aibio.space/news/parabilis-medicines-files-ipo-regeneron-agrees-buy-about-75-0-million/. Facts in aibio.space stories are checked against company filings and releases; opinion is labelled. Cite as: aibio.space, "Parabilis Medicines files for IPO; Regeneron agrees to buy about $75.0", 2026-05-19, https://aibio.space/news/parabilis-medicines-files-ipo-regeneron-agrees-buy-about-75-0-million/