Parabilis Medicines, a clinical-stage cancer drug developer, said it has closed an oversubscribed $305 million Series F financing to fund ongoing clinical development of its lead candidate FOG-001 (zolucatetide) across multiple tumor types and to expand a broader pipeline built on its Helicon peptide platform. The round was co-led by RA Capital Management, Fidelity Management & Research Company, and Janus Henderson Investors. Parabilis said new investors in the financing included Frazier Life Sciences, Soleus Capital, and a life science-dedicated investment fund, alongside participation from a broad syndicate of existing backers including venBio Partners, Cormorant Asset Management, ARCH Venture Partners, GV, accounts advised by T. Rowe Price Associates, Marshall Wace, General Catalyst, Invus, Farallon Capital Management, Foresite Capital, Rock Springs Capital, HBM Healthcare, Samsara BioCapital, Catalio Capital Management, and others.
The company said the financing was completed at a higher valuation than its prior round. Parabilis plans to use the proceeds to continue development of zolucatetide, which it describes as the first and only direct inhibitor of the β-catenin:TCF interaction, a key protein-protein interaction in the Wnt/β-catenin pathway. The company said the program is progressing toward a registrational study in desmoid tumors while also being evaluated across both genetically simple and more complex cancers. Additional funds will support targeted discovery efforts, including a prostate cancer-focused franchise, and further work to apply the Helicon platform to intracellular targets the company characterizes as historically “undruggable.”
The company said it presented preliminary data in the fourth quarter of 2025 from an ongoing Phase 1/2 study of zolucatetide, reporting early signs of single-agent activity across five low-complexity tumor types associated with Wnt/β-catenin alterations, including desmoid tumors and adamantinomatous craniopharyngioma. Parabilis also said the initial findings provided rationale for combination strategies in more biologically complex cancers, including microsatellite-stable colorectal cancer, and that it plans to share additional clinical data in desmoid tumors and early evidence in hepatocellular carcinoma and familial adenomatous polyposis at next week’s J.P. Morgan Healthcare Conference, with additional readouts expected in 2026.
Beyond zolucatetide, Parabilis said its Helicon platform is generating additional candidates, including preclinical “Helicon degrader” programs targeting ERG and allosteric ARON in prostate cancer—two targets the company said have been difficult to address with conventional drug modalities. Parabilis said its Helicons are stabilized, cell-penetrant, alpha-helical peptides designed to engage intracellular proteins that are not readily accessible to antibodies and can be challenging for small molecules to bind.
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“Our goal at Parabilis is to develop medicines with the potential to deliver truly life-changing impact for patients who urgently need new treatment options. We are deeply grateful for the support and confidence of our world-class investors, which will enable us to advance zolucatetide across a range of rare and common tumor types – creating the opportunity for a pipeline within a product – while continuing to build a unique and differentiated pipeline through our Helicon platform designed to address biology that has remained out of reach for decades.”
Mathai Mammen, M.D., Ph.D., Chairman, CEO and President, Parabilis Medicines
“Successfully drugging a target long considered undruggable requires both deep biological insight and a differentiated technological approach. With Helicons, Parabilis has established a platform with the potential to generate a robust pipeline of impactful therapies. We believe this financing positions the Parabilis team to build enduring value by translating the company’s recent data and breakthroughs into multiple development opportunities.”
Jake Simson, Ph.D., Partner, RA Capital
