ThirtyFiveBio

Executive Summary

ThirtyFiveBio is a privately held UK biotechnology company founded in 2021, focused on developing oral small molecule antagonists of GPR35, a G-protein-coupled receptor implicated in gut epithelial barrier dysfunction. The company's lead program targets ulcerative colitis (UC) by creating a 'gut epithelial shield'—a novel mechanism aimed at protecting the intestinal lining from inflammatory damage and improving disease resolution rates. Unlike existing therapies that broadly suppress inflammation, ThirtyFiveBio's approach directly addresses underlying epithelial dysfunction, potentially offering a differentiated and disease-modifying therapeutic option. The company is leveraging deep expertise in GPCR biology and small molecule drug discovery to advance its proprietary candidates. While still in preclinical stages, ThirtyFiveBio represents a high-risk, high-reward opportunity in the inflammatory bowel disease landscape, with the potential to address significant unmet need in UC patients who fail conventional or biologic therapies. The company's near-term focus is on completing IND-enabling studies and advancing toward first-in-human trials. Given the early stage and lack of disclosed funding or partnerships, the conviction score is moderate, reflecting the potential of the science balanced by the inherent uncertainties of preclinical development and the competitive UC market.

Upcoming Catalysts (preview)

• Q2 2026IND Filing for Lead GPR35 Antagonist Program40% success
• Q4 2026Initiation of Phase 1 Clinical Trial in Healthy Volunteers35% success
• Q3 2026Preclinical Proof-of-Concept Data Presented at Major Medical Conference (e.g., UEGW or DDW)60% success