Parabilis moved to the public markets with an IPO filing a day after signing an up-to-$2.3 billion-plus Regeneron collaboration. The Helicon-based antibody-drug conjugate platform deal centers on discovering and developing an initial set of five candidates, while Regeneron will buy about $75 million of Parabilis shares in a concurrent private placement at 90% of the IPO price. The filing includes a placeholder IPO figure and outlines multiple priorities spanning ongoing development of zolucatetide (FOG-001) across desmoid tumors and additional indications such as familial adenomatous polyposis and hepatocellular carcinoma. Parabilis also described a planned Phase III registrational trial topline timeline. For biotech financing, the combination of a major platform partnership and an IPO filing highlights how Helicon ADC differentiation is being positioned to bridge early clinical proof to larger-scale registrational studies.