Trex Bio has filed for an initial public offering to list its common stock on the Nasdaq stock exchange under the ticker symbol TRXB. The filing marks the biotechnology company's entry into public markets, seeking capital through a structured equity offering.

Deal Structure and Underwriting

The company appointed a consortium of financial institutions to manage the transaction. J.P. Morgan, Evercore ISI, Cantor Fitzgerald, Stifel, and Wedbush PacGrow are serving as underwriters for the IPO.

Strategic Investor Interest

A significant aspect of the filing is the disclosed interest from major pharmaceutical player Eli Lilly. The company indicated it intends to purchase up to 19.9% of Trex Bio's common stock as part of this offering. This substantial stake suggests strong institutional confidence in Trex Bio's pipeline or business model, providing immediate liquidity and strategic alignment with a large-cap partner.

What the Numbers Show

The structure of this deal highlights a dependency on strategic capital rather than purely public market discovery. With Eli Lilly targeting nearly one-fifth of the equity, the IPO serves partly as a monetization or partnership vehicle for the pharma giant, potentially influencing governance and future strategic direction more than a standard public listing would.

TRexBio announced progress across its pipeline, naming TRB-071 as a CD30 agonist antibody and detailing the planned advancement of its Eli Lilly and Company partnered program, TRB-051, into Phase 2a clinical development in lupus with cutaneous involvement. The company is conducting IND-enabling studies for TRB-071, while Lilly intends to initiate the Phase 2a trial for TRB-051 in the second half of 2026.

TRB-071 is an investigational monoclonal antibody designed to agonize CD30, a TNF superfamily receptor enriched on tissue Tregs. The candidate is designed to activate and expand Tregs to increase immune-regulatory capacity while modulating the inflammatory pathway of the CD30-associated ligand. Human genetic studies have associated variants in CD30 and CD30L with inflammatory bowel disease susceptibility. Ali Zarrin, Ph.D., Chief Scientific Officer of TRexBio, stated that combining CD30 agonism with CD30L blocking activity could modulate Tregs in inflamed tissue and dampen pathogenic inflammatory pathways.

Preclinical data showed that CD30 agonism via TRB-071 induced Treg activation and expansion, reducing inflammation in colitis models. In non-human primate studies, TRB-071 induced activation and expansion of Tregs with minimal effects on other immune cell populations. TRexBio is currently conducting a three-month GLP toxicology study of TRB-071 in cynomolgus monkeys.

Pipeline Progression

TRB-051, an investigational modulator of immune effector cells, was identified and advanced under a multiyear discovery collaboration between TRexBio and Lilly. Lilly initiated a first-in-human Phase 1 study for TRB-051 in 2024. Johnston Erwin, Chief Executive Officer of TRexBio, said the progress reflects the company's ability to generate and advance differentiated programs toward the clinic.

Key Development Candidates