TRex Bio sold 8.33 million shares at $14 each, the low end of its projected range, raising $117 million in one of nearly two dozen biotechnology IPOs in 2026. The company begins trading Friday on Nasdaq under the ticker TRXB. Eli Lilly is the largest equity holder, owning about 24 percent before the offering, and indicated interest in buying IPO shares.
The pipeline centers on regulatory T cells, the immune system’s calming mechanism. The lead candidate, TRB-061, is a fusion protein targeting tumor necrosis factor receptor 2 on Tregs, designed to spur those cells into action and multiply, easing inflammation in skin and gut without broadly suppressing immunity. A Phase 1 study is underway with topline data expected in 2027. A second candidate, TRB-071, aimed at the CD30 receptor on Tregs for inflammatory bowel disease, could enter testing next year. TRex has partnered with both Lilly and Johnson and Johnson to discover new anti-inflammatory drugs, and has banked $220 million in venture financing to date, including $50 million raised earlier this year.
Retension Pharmaceuticals, a hypertension biotech, went public the same day with an upsized $45 million offering, according to the Endpoints report. A William Blair analysis this week said public-market investment in biotechs has accelerated at an unprecedented clip in 2026 across IPOs, reverse mergers and SPAC deals. BioPharma Dive’s count puts 2026 biotech IPOs at 23, six of them, or just over a quarter, in immune-disease companies. Pricing at the low end of the range is the standard discount for getting the deal done, but the volume of immunology paper finding buyers suggests investors are funding mechanisms, not just late-stage assets.