Mere months after obesity biotech Kailera Therapeutics netted the biggest initial public offering the sector has ever seen, with a whopping $625 million, Parabilis Medicines has upsized its own IPO plans with the potential to eclipse that record.
Parabilis announced it was prepping to raise $476 million through an IPO just last week, but has since revised its expected fundraising goal up to $553.1 million, according to a filing with the Securities and Exchange Commission. Should all options be exercised, that number could hit $636.8 million, potentially setting a new benchmark for biotech listings.
Once known as FogPharma, the cancer biotech plans to offer 33,333,334 shares of common stock priced between $17 and $19 apiece.
Whatever cash Parabilis does secure from the offering will primarily support phase 3 development of desmoid tumor prospect zolucatetide, which the Massachusetts biotech estimates in the filing will cost around $150 million.
Desmoid tumors are rare noncancerous growths that form in connective tissue. Parabilis garnered a fast-track designation from the FDA for zolucatetide in the indication in November 2025.
The rest of the proceeds would go toward development of zolucatetide in other rare tumors and further advancement of Parabilis’ pipeline.
Parabilis is led by former Johnson & Johnson research leader Mathai Mammen, M.D., Ph.D., who intends to grow the outfit into a “big, important company,” he previously told Fierce. The biotech’s platform consists of a novel type of drug called helicon peptides, which are designed to cling to targets long thought to be undruggable.
One such target is the Wnt/b-catenin cell signaling pathway, which is vital for cell growth and division and is overactive in many cancers.
“Drugging this critical node eluded three decades of intensive efforts to do so across the pharmaceutical industry,” Parabilis wrote in its filing. “To our knowledge, our lead product candidate, zolucatetide, is the first-ever drug to directly target the interaction between b-catenin and the T-cell factor family of transcription factors.”
Private investors have had no qualms about backing Parabilis’ ambitions. The start-up raised 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.
Should the IPO move forward, Parabilis would join Kailera and a suite of other biotechs—including Seaport Therapeutics, Hemab Therapeutics, Odyssey Therapeutics and Generate:Biomedicines—as a new entrant to the Nasdaq.