(Incorporated in Delaware)

We are a clinical-stage biopharmaceutical company focused on tissue Treg biology for the discovery and development of immunoregulatory medicines designed to restore immune balance and promote tissue repair to address unmet needs of patients with autoimmune and inflammatory diseases. TRexBio was built on a pivotal scientific insight: that regulatory T cells (“Tregs”) in human tissue are not merely passive suppressors of inflammation, but active orchestrators of tissue immune homeostasis and repair. Leveraging our Deep Biology drug discovery and design platform, we integrate tissue-level insights into human biology and Treg function to identify and characterize novel targets and approaches for therapeutic intervention. Our tissue-first conviction and unique insights in Treg biology are the foundation of our pipeline of therapeutic candidates aimed at restoring immune balance and promoting tissue repair for more durable disease control.

Our pipeline is focused on augmenting tissue Tregs to address critical treatment gaps in autoimmune and inflammatory diseases. Our most advanced wholly-owned product candidate, TRB-061, is an investigational tumor necrosis factor receptor 2 (“TNFR2”) agonist designed to expand and activate Tregs in inflamed tissues. We believe TRB-061 has broad, multi-indication potential, and are currently conducting a Phase 1a/b clinical trial of TRB-061 in healthy volunteers and patients with moderate-to-severe atopic dermatitis (“AD”). We expect to announce topline data from the Phase 1b portion of the TRB-061 trial in patients with moderate-to-severe AD in mid-2027. Our second wholly-owned product candidate, TRB-071, is an investigational TNF receptor superfamily member 8, better known as TNFRSF8 (or “CD30”) agonist designed to both augment tissue Tregs and block immune system inflammatory signaling axes. Genetic studies support the involvement of CD30 and its ligand in inflammatory bowel disease (“IBD”). TRB-071 is currently in IND-enabling studies and, subject to regulatory allowance to proceed, is expected to enter a Phase 1 trial in the first half of 2027. We believe TRB-071 has the potential to address the significant unmet need in IBD by directly targeting the immune system dysfunction in the gut barrier that drives disease pathology.

(Note: TRex  Bio, Inc. filed its S-1 for its IPO on Sept. 18, 2026, without disclosing the terms. Estimated proceeds are $100 million, a placeholder figure.)