Parabilis filed for an initial public offering days after securing a major strategic pact with Regeneron to pursue antibody–peptide conjugates aimed at historically difficult intracellular targets. The Regeneron collaboration could reach up to about $2.3 billion in milestone economics across five initial targets, using Regeneron antibodies paired with Parabilis’ “Helicons” stabilized peptides. In its IPO filings, Parabilis tied proceeds to funding a global Phase 3 push for its Wnt/β-catenin pathway inhibitor zolucatetide in desmoid tumors, following an FDA fast-track designation. Early desmoid data cited in the filing include tumor reductions in 100% of evaluable patients and a 74% objective response rate among those with sufficient imaging. The combined moves—deal plus IPO—place Parabilis at a pivotal financing and execution point, with next milestones now oriented around registrational trial funding and program expansion.