Parabilis Medicines is gearing up for an IPO that could eventually bring in as much as $476 million to fund the phase 3 development of its desmoid tumor prospect.
The Massachusetts biotech, formerly known as FogPharma, announced plans last month to list on the Nasdaq, and has now put some figures behind that ambition. Parabilis reckons it can offer 25 million shares priced between $17 and $19 apiece, according to a Securities and Exchange Commission filing Thursday.
Should the final price fall in the middle of this range, the company expects the IPO to rake in net proceeds of $413.6 million—rising to $476.4 million if underwriters fully take up their offer to buy an additional 3.7 million shares at the same price.
That’s on top of the cool $50 million upfront payment and $75 million equity investment coming over from Regeneron as part of a deal that would see the pharma not only explore the use of Parabilis’ helicons as standalone therapies but also conjugate them with the U.S. pharma’s own antibodies.
Still, Parabilis will need all the financial firepower it can get. The company is expecting to spend $150 million to develop its Wnt/β-catenin pathway inhibitor zolucatetide for desmoid tumors, it explained in the filing.
Desmoid tumors are rare noncancerous growths that form in connective tissue. Zolucatetide snagged a fast-track designation from the FDA for the indication in November 2025. Parabilis is now looking at launching a phase 3 trial in this indication.
Another $120 million has been earmarked to continue the phase 1 trials of zolucatetide in the rare genetic condition familial adenomatous polyposis, the liver cancer hepatocellular carcinoma, and other solid tumors that harbor Wnt pathway-activating mutations.
Then there’s the $130 million that Parabilis is planning to spend to advance its other assets into the clinic, including ERG, AR, and ß-catenin degraders.
The company, which oversees 145 full-time employees along with 31 full-time consultants, is led by CEO Mathai Mammen, M.D., Ph.D., former global head of R&D at Johnson & Johnson. Mammen told Fierce Biotech in an interview back in January that his vision is to grow Parabilis into a “big, important company.”
“I want to be a company that does research, development, manufactures and commercializes products,” the CEO said at the time.
Zolucatetide is one example of Parabilis’ helicon peptides, which are engineered to attach to flat surfaces that would otherwise make traditional small-molecule binding difficult.
The company's strategy has been enough to secure regular infusions of investor cash, including a $107 million series C back in 2021, followed by a $178 million D round in 2022, a $145 million series E in 2024 and a $305 million series F to kick off this year.
If the IPO goes ahead, Parabilis will be joining a growing influx of new biotech entrants to the Nasdaq this year, including Seaport Therapeutics, Hemab Therapeutics, Odyssey Therapeutics and Generate:Biomedicines. In April, obesity biotech Kailera Therapeutics made history with an upsized $625 million offering that served as a welcome sign that the IPO window remains open.