Milestone follows disclosure of compelling preliminary data presented at the ESMO Congress and the CTOS 2025 Annual Meeting showing clinically meaningful anti-tumor activity in desmoid tumors
CAMBRIDGE, Mass., November 12, 2025 — Parabilis Medicines, a clinical-stage biopharmaceutical company committed to creating extraordinary medicines for people living with cancer, today announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track product designation to FOG-001 for the treatment of desmoid tumors, reflecting significant unmet need and the potential of this first-in-class therapy to transform patient care. FOG-001, Parabilis’s lead investigational Helicon peptide, is the first and only direct inhibitor of the “undruggable” β-catenin:TCF interaction.
The FDA’s Fast Track designation is intended to help facilitate the development and expedite the review of new therapies for serious conditions that address an unmet medical need. A therapy may qualify if it targets a disease with no existing treatments, or if it offers a meaningful advantage over available options – such as showing superior effectiveness, avoiding serious side effects, or decreasing toxicities that frequently cause discontinuation of treatment. Fast Track designation enables more frequent interactions with the FDA throughout development and provides eligibility for features like Rolling Review and potential Priority Review, helping promising medicines reach patients sooner.
“Obtaining Fast Track designation for FOG-001 reinforces our confidence in its potential to offer meaningful clinical benefit to patients with desmoid tumors, who today have no therapies that directly address the underlying disease biology,” said Fawzi Benzaghou, M.D., Chief Medical Officer of Parabilis Medicines. “More than half of patients do not respond to current treatment options, which are also associated with high toxicities. By inhibiting the β-catenin:TCF interaction, FOG-001 has the potential to intervene at the source of disease and marks an important step forward in advancing our mission to drug the undruggable.”
This designation follows preliminary data, first released at ESMO and to be presented this week at the Connective Tissue Oncology Society (CTOS) 2025 Annual Meeting, demonstrating that FOG-001 has shown evidence of clinically meaningful antitumor activity in desmoid tumors. Desmoid tumors are rare, locally invasive soft-tissue tumors that form in the connective tissues of the body, often causing pain, limited mobility, disfigurement, and organ dysfunction. Despite its impact on quality of life, there are no FDA-approved therapies that directly target the underlying biology of the disease.