Tuneable peptide biotech Parabilis files IPO
Parabilis is led by Mathai Mammen, who was previously global head of R&D at Johnson & Johnson.
Fresh from agreeing a wide-ranging alliance with Regeneron worth up to $2.3 billion, Parabilis Medicines has decided to chance its arm with an IPO.
The Cambridge, Massachusetts-based company filed a prospectus yesterday to list on the Nasdaq under the PBLS symbol, seeking to raise additional cash for a planned phase 3 programme for lead drug zolucatetide (FOG-001), a beta-catenin inhibitor in development for desmoid tumours.
Founded in 2015 and known as FogPharma until a rebrand in 2024, Parabilis looks poised to have a banner year in 2026, with the IPO and Regeneron alliance following a bumper $305 million private financing in January. Regeneron paid $50 million upfront to the biotech and has also pledged to buy $75 million of Parabilis stock in a concurrent private placement tied to the IPO.
The company's Helicon technology platform generates stabilised alpha-helical peptides (Helicons) that can penetrate into cells and engage with intracellular targets, including those that have proved intractable with even small-molecule drugs. It is developing the peptides on their own and also as antibody-Helicon conjugates (AHCs), similar to antibody-drug conjugates but able to interact with a broader set of cellular targets.
The deal with Regeneron covers both Helicons and AHCs and spans five targets across multiple, undisclosed therapeutic categories.
Proceeds from the IPO – which according to Renaissance Capital has a placeholder value of $100 million but is likely to raise more than that – will go towards funding the trials of zolucatetide in desmoid tumours and follow-up indications such as familial adenomatous polyposis (FAP) and hepatocellular carcinoma (HCC).
The drug, which is directed at cancers driven by the Wnt/beta-catenin signalling pathway, showed activity as a monotherapy in a range of tumour types in a phase 1/2 trial reported last year, with a 74% objective response rate. A phase 3 programme is due to start in the first half of 2027, while phase 1/2 studies of zolucatetide in FAP and HCC are already underway.
Until the approval in 2023 of Merck/SpringWorks' oral gamma secretase inhibitor Ogsiveo (nirogacestat), there were no therapies specifically approved to treat desmoid tumours.
Some of the money will also go towards advancing other pipeline candidates, including an ERG and ARON degraders for prostate cancer and a follow-up beta-catenin degrader, into phase 1 testing.
Parabilis is led by Mathai Mammen, who was previously global head of R&D at Johnson & Johnson.
