TRex Bio, a Phase 1 biotech developing medicines for autoimmune and inflammatory diseases, announced terms for its IPO on Monday.
The South San Francisco, CA-based company plans to raise $125 million by offering 8.3 million shares at a price range of $14 to $16. Eli Lilly intends to purchase $13 million worth of shares in the offering (10% of the deal). At the midpoint of the proposed range, TRex Bio would command a fully diluted market value of $453 million.
TRexBio is a clinical-stage biopharmaceutical company developing medicines that augment regulatory T cells in inflamed human tissue, aiming to restore immune balance and repair barrier damage rather than broadly suppress the immune system. Its Deep Biology platform maps Treg function in fresh human skin, gut and lung tissue to identify targets, then validates them in a proprietary in vitro Treg model and a high-throughput functional assay suite. Lead candidate TRB-061, a TNFR2 agonist, is in Phase 1b for moderate-to-severe atopic dermatitis with topline data expected in mid-2027, while a second wholly-owned candidate, TRB-071, targets CD30 for inflammatory bowel disease and is set to enter Phase 1 in the first half of 2027. Eli Lilly is both an investor and a discovery partner, and is advancing a third candidate found on the platform into a Phase 2a lupus trial.
TRex Bio was founded in 2018. It plans to list on the Nasdaq under the symbol TRXB. J.P. Morgan, Evercore ISI, Cantor Fitzgerald, Stifel, and Wedbush Securities are the joint bookrunners on the deal. It is expected to price during the week of October 5, 2026.
