TRex Bio, Inc.

What the company does

TRex Bio is a clinical-stage biopharmaceutical company focused on tissue Treg biology for the discovery and development of immunoregulatory medicines for autoimmune and inflammatory diseases. Its most advanced wholly-owned candidate, TRB-061, is an investigational TNFR2 agonist in a Phase 1a/b trial in healthy volunteers and patients with moderate-to-severe atopic dermatitis. Its second candidate, TRB-071, is an investigational CD30 agonist in IND-enabling studies for inflammatory bowel disease.

Use of proceeds

The company intends to use the net proceeds, together with existing cash, cash equivalents, and marketable securities, to advance the clinical development of TRB-061, including to fund Phase 2 trials for patients with AD and AA through topline data, and TRB-071, including initiating and completing a Phase 1 trial in healthy volunteers. The remainder will be used for working capital and other general corporate purposes.

Underwriters

Extracted from 424B4 0001193125-26-419203, filed Oct 9, 2026 and verified against that filing text.

Key risk factors

• Clinical-stage, substantial losses

  “We are a clinical-stage biopharmaceutical company with a limited operating history and no products approved for commercial sale; we have incurred substantial losses since our inception, and we anticipate incurring substantial and increasing losses for the foreseeable future;”

• Need for additional capital

  “Even if this offering is successful, we will require substantial additional financing to achieve our goals, and failure to obtain additional capital when needed, or on acceptable terms, would cause us to delay, limit, reduce or terminate our product development efforts;”

• Dilution

  “You will incur immediate and substantial dilution as a result of the completion of this offering.”

• Clinical development uncertainty

  “Clinical development is lengthy and expensive, characterized by uncertain outcomes, with results of earlier studies and trials often failing to predict future trial results or results in other indications of a product candidate.”

• Material weakness

  “We have identified a material weakness in our internal control over financial reporting.”

• Competition

  “We face potential competition from different sources that have made substantial investments into the rapid development of novel treatments for autoimmune and inflammatory indications, including large and specialty pharmaceutical and biotechnology companies, many of which already have approved therapies in our current indications;”

• Regulatory approval uncertainty

  “Even if we complete the necessary clinical trials, we cannot predict when, or if, we will obtain regulatory approval to commercialize any product candidate in the United States or any other jurisdiction, and any such approval may be for a more narrow indication than we seek;”

• Reliance on third parties

  “We have relied and expect to continue to rely on third parties to conduct our preclinical studies and clinical trials. If those third parties do not perform as contractually required, fail to satisfy legal or regulatory requirements, miss deadlines or terminate the relationship, our development programs could be delayed, more costly or unsuccessful, and we may never be able to seek or obtain regulatory approval for or commercialize our product candidates;”