Lilly-backed TRex Bio raises $117M in IPO as hypertension biotech Retension secures $45M listing

TRex Bio, a biotech backed by Eli Lilly, completed its initial public offering, generating $116.7 million in gross proceeds. The company sold 8.3 million shares at $14 each, landing at the lower end of its $14‑$16 price range.

If underwriters exercise their option to purchase an additional 1.3 million shares, total proceeds could rise by roughly $17.5 million. Net proceeds are estimated between $111.3 million and $128.7 million depending on final pricing and option uptake.

TRex, based in South San Francisco, first raised $59 million in a Series A round in 2021. It has attracted attention for a platform that modulates regulatory T cells, a key component of tissue inflammation. The company previously partnered with Johnson & Johnson and received a $55 million licensing payment from Lilly in 2023.

In the same market wave, hypertension‑focused Retension Pharmaceuticals raised $45 million from its IPO, adding to a strong year for biotech listings.