Parabilis Medicines targets $2.3 billion valuation in upsized US IPO

Drug developer Parabilis Medicines is targeting a valuation of up to nearly $2.3 billion in its upsized initial public offering in the U.S., as biotech IPOs continue to run hot.

The Cambridge, Massachusetts-based company is now marketing 33.3 million shares priced between $17 and $19, it said on Tuesday. It had earlier planned to sell 25 million shares.

The biotech IPO market has bounced back strongly after a choppy 2025 as a string of well-received listings such as those of Kailera and Veradermics has encouraged more drug developers to test the waters.

Parabilis is developing Helicons, a new class of peptides shaped as alpha helixes to allow drugs to more easily penetrate cells and bind to proteins. Peptides are the building blocks of proteins.

Parabilis' lead candidate using Helicons, zolucatetide, is being evaluated in trials for multiple solid tumors, with more than 150 patients dosed to date.

Formerly known as Fog Pharmaceuticals, Parabilis was founded in 2015 by WeiQing Zhou and longtime Harvard professor Greg Verdine.

The firm has raised over $800 million in financing since its inception, from investors such as ARCH Venture Partners, Fidelity Investments, GV and RA Capital.

Separately, drugmaker Regeneron Pharmaceuticals is set to buy about $75 million worth of Parabilis shares in a concurrent private placement.

The two companies last month had unveiled a partnership wherein Parabilis could receive up to $2.2 billion in milestone payments to develop new treatments for hard-to-reach diseases.

Leerink Partners, BofA Securities, Evercore ISI, Guggenheim Securities and LifeSci Capital are the underwriters for the offering.

Parabilis is expected to begin trading on the Nasdaq under the symbol "PBLS" on Wednesday.

(Reporting by Arasu Kannagi Basil in Bengaluru; Editing by Sahal Muhammed)

Copyright Reuters or USA Today Network via Reuters Connect

This story was originally published June 9, 2026 at 5:17 AM.