After raising $800M, Parabilis seeks an IPO to pursue ‘undruggable’ targets

Dive Brief:

Parabilis Medicines, a well-funded startup that is advancing a science it believes can reach “undruggable” targets in oncology, on Tuesday filed papers outlining an initial public offering.
The IPO follows on a $305 million Series F venture capital round in January as well as a potentially $2 billion research deal with Regeneron Pharmaceuticals. The company has also already reported data from an early-stage trial testing its lead candidate on rare, non-cancerous growths called desmoid tumors.
Founded as FogPharma in 2015 by serial biotech entrepreneur Gregory Verdine, Parabilis has raised more than $800 million in private funding and has so far spent nearly $600 million on drug research, according to its IPO filing. It’s developing “Helicons,” spiral-shaped peptide drugs designed to reach cancer-driving proteins that can’t be accessed by conventional methods.

Dive Insight:

Parabilis is the latest example of the kind of mature biotech startup that’s waited out a prolonged IPO downturn while raising substantial amounts of private financing to push its drugs forward. That blueprint has worked well so far in 2026, with 11 companies raising an average of about $286 million in their offerings, substantially more than what’s been seen in recent years, BioPharma Dive data show.

Like many of those successfully pricing offerings this year, Parabilis also aims to enter the public markets with a clinical-stage drug candidate — a therapy initially being targeted for a rare condition, but that has the potential to expand into more common cancer types. The company hopes its technology could be used to tackle other difficult-to-reach cellular targets, too.

Early study data in desmoid tumors showed the drug, called FOG-001, can shrink tumors or stabilize disease in most patients who received it. The Food and Drug Administration awarded FOG-001 orphan drug and fast-track designations that could reduce development costs and speed its eventual review, if successful in testing.

Parabilis is currently planning its Phase 3 trial in desmoid tumors. It also has collected data in an inherited condition resulting in polyp growth in the digestive tract as well as a rare brain tumor.

FOG-001 targets an interaction between the transcription factors β-catenin and TCF, the hyperactivation of which is associated with the development and progression of a number of types of cancer. Parabilis has also tested the drug in liver and colorectal tumors, and is additionally working on treatments for prostate cancer.

The technology emerged from the Harvard University labs of Verdine, who led the company through 2023. Afterwards, the former head of Johnson & Johnson’s research department, Mathai Mammen, took over as its leader.

Fidelity Management & Research holds the largest stake in Parabilis, at 11.3%. Other investors include RA Capital Management, Cormorant Asset Management, Arch Venture Partners, GV and venBio.