CAMBRIDGE, Mass. — Parabilis Medicines said it has closed an oversubscribed $305 million Series F financing to support the continued clinical development of its lead candidate, FOG-001 (zolucatetide), across a broad range of tumor types and to advance its pipeline built on the company’s Helicon peptide platform.
The financing was co-led by RA Capital Management, Fidelity Management & Research Company, and Janus Henderson Investors, with participation from new investors including Frazier Life Sciences, Soleus Capital, and a life science-focused investment fund. Existing investors, including venBio Partners, Cormorant Asset Management, Nextech Invest, ARCH Venture Partners, Milky Way Investments, GV, accounts advised by T. Rowe Price Associates Inc., Marshall Wace, General Catalyst, Invus, Farallon Capital Management, Foresite Capital, Rock Springs Capital, HBM Healthcare, Samsara BioCapital, Catalio Capital Management, Sixty Degree Capital, Alderline Group, and others, also participated. The round was completed at a higher valuation than the company’s prior financing.
Proceeds will be used to advance zolucatetide, the company’s first-in-class Helicon peptide and a direct inhibitor of the β-catenin:TCF interaction, including progression toward a registrational trial in desmoid tumors and continued evaluation in both genetically simple and more complex cancers. The financing will also support development of Parabilis’s broader discovery pipeline, including its prostate cancer programs, and continued expansion of the Helicon platform to address disease targets long considered undruggable.
“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,” said Mathai Mammen, M.D., Ph.D., chairman, chief executive officer, and president of Parabilis Medicines. “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 while continuing to build a unique and differentiated pipeline through our Helicon platform.”
The financing follows the presentation of preliminary data in the fourth quarter of 2025 from an ongoing Phase 1/2 trial of zolucatetide, which targets a key downstream node in the Wnt/β-catenin signaling pathway. That pathway is implicated in millions of cancer cases each year but remains unaddressed by any approved therapies.
Early clinical data showed single-agent activity of zolucatetide across several low-complexity tumor types driven by Wnt/β-catenin alterations, including desmoid tumors, which have received Fast Track Designation from the U.S. Food & Drug Administration, and adamantinomatous craniopharyngioma. The data also supported the scientific rationale for combination approaches in more biologically complex cancers such as microsatellite-stable colorectal cancer. Parabilis said it plans to share additional data on desmoid tumors and early clinical signals in hepatocellular carcinoma and familial adenomatous polyposis, with further readouts expected in 2026.
Beyond zolucatetide, Parabilis said it continues to demonstrate the versatility of its Helicon platform, citing encouraging preclinical data from degrader programs targeting ERG and allosteric ARON, two historically challenging targets in prostate cancer.
“Successfully drugging a target long considered undruggable requires both deep biological insight and a differentiated technological approach,” said Jake Simson, Ph.D., partner at RA Capital. “With Helicons, Parabilis has established a platform with the potential to generate a robust pipeline of impactful therapies.”
Parabilis’s Helicon peptides are engineered to selectively engage intracellular disease-driving targets that are inaccessible to antibodies and poorly suited for traditional small-molecule approaches, offering a new strategy to address large portions of the human proteome that have remained beyond the reach of existing drug modalities.
