IPO priced October 8
On October 8, 2026, TRex Bio announced the pricing of its initial public offering of 8,333,334 shares of common stock at $14.00 per share, all offered by the company. Gross proceeds are expected to be about $116.7 million before underwriting discounts, commissions and other offering expenses. The underwriters have a 30-day option to buy up to 1,250,000 additional shares at the IPO price, less underwriting discounts and commissions.
The company said its common stock was expected to begin trading on the Nasdaq Global Select Market on October 9, 2026, under the symbol TRXB, and that the offering is expected to close on October 13, 2026, subject to customary closing conditions. The registration statement, File No. 333-299018, became effective on October 8, 2026, according to the company and the SEC's notice of effectiveness on EDGAR.
The $14.00 price is the low end of the $14 to $16 range proposed in the October 5 amended S-1, which followed the first public S-1 on September 18. J.P. Morgan, Evercore ISI, Cantor and Stifel are the lead book-running managers, and Wedbush PacGrow is a book-running manager.
Eli Lilly's role
The S-1 says Eli Lilly has indicated an interest in buying shares at the IPO price, in an amount that, combined with the shares Lilly already owns, will not exceed 19.9% of the shares outstanding after the offering. Because the indication is not binding, Lilly may buy more, less or no shares, according to the filing.
Lilly is also TRex Bio's collaboration partner. Under a January 2023 agreement, Lilly paid a $55.0 million upfront payment and, in July 2024, a $15.0 million development milestone; TRex Bio is eligible for up to an additional $577.5 million in milestone payments and tiered royalties of six to ten percent, the S-1 says.
What TRex Bio is developing
TRex Bio is a clinical-stage biotech focused on tissue regulatory T cells (Tregs) and immunoregulatory medicines for autoimmune and inflammatory diseases. Its most advanced wholly owned candidate, TRB-061, is a TNFR2 agonist in a Phase 1a/b trial in healthy volunteers and patients with moderate-to-severe atopic dermatitis; the company expects Phase 1b topline data in mid-2027, according to the S-1.
The S-1 also says Lilly intends to move TRB-051, a program from the collaboration, into a Phase 2a trial in lupus with cutaneous involvement in the second half of 2026. TRex Bio reported a net loss of $29.3 million for the first half of 2026 and $90.9 million in cash, cash equivalents and marketable securities as of June 30, 2026.