TRex Bio IPO: Shares of Eli Lilly's Partner Pharmaceutical Company Are Now Available

Pre-market trading in shares of TRex Bio, a developer of therapies for autoimmune and inflammatory diseases, began on the Freedom client trading platform. Industry giants have invested in the company, including Eli Lilly—the world’s most valuable pharmaceutical company—as well as the venture capital arms of Pfizer and Johnson & Johnson. Later on October 9, the shares will be listed on Nasdaq under the ticker symbol TRXB.

The biotechnology company TRex Bio raised nearly $116.7 million through its IPO on the Nasdaq. It sold 8.33 million shares at $14 each, which is at the lower end of the previously announced price range ($14–16). Specifically, the company reported that its long-standing partner and investor, Eli Lilly, planned to purchase its shares during the initial public offering, after which its stake would not exceed 19.9%. TRex Bio’s announcement does not specify whether Eli Lilly purchased shares or, if so, in what quantity. Based on the results of the offering, Bloomberg estimates that TRex Bio’s entire business is valued at $384 million.

JPMorgan, Cantor, Evercore ISI, Stifel, and Wedbush PacGrow served as underwriters for the offering. They received a 30-day option from the company to purchase up to 1.25 million of its shares.

TRex Bio plans to allocate a portion of the proceeds from the transaction to the development of the experimental drug TRB-061, which it is studying in patients with atopic dermatitis (a chronic skin condition) and alopecia areata (pathological hair loss), according to the IPO prospectus. Another portion will be used to continue research on another candidate—TRB-071, which has not yet reached human trials—as well as to replenish working capital and for other corporate purposes, the documents state.

TRex Bio was founded in 2018 with the support of a consortium of investors, including the venture capital fund SV Health Investors, pharmaceutical giant Eli Lilly, and the venture capital arms of Johnson & Johnson and Pfizer. The company focuses on discovering and developing drugs designed to restore immune balance and tissue function in patients with autoimmune and inflammatory diseases.

Since its founding, the startup has focused on studying regulatory T cells (Tregs), a special type of cell in the immune system. The company’s work is based on the hypothesis that, in human tissues, these cells are not passive suppressors of inflammation, but rather active “coordinators” of the immune response and tissue regeneration. This means that by studying the behavior of these cells, it is possible to develop drugs that mimic it and thereby help the body “bring the disease under control.” This scientific discovery was not made by TRex Bio; however, in 2025, three scientists were awarded the Nobel Prize in Physiology or Medicine for it.

At first, TRex Bio operated within the Eli Lilly ecosystem, according to VCBeat. A turning point for the startup came in 2021, when the company was preparing to emerge from “stealth mode” and enter the capital markets. Johnston Erwin, who had worked at Eli Lilly for 36 years, left the company at that time to become CEO of TRex Bio, according to VCBeat. In 2022, the biotech company completed its first round of funding, and in 2024, its second. In total, the company has raised $220 million since its inception, according to the IPO prospectus.

TRex Bio’s portfolio currently includes two in-house compounds—TRB-061 and TRB-071. It is also investigating another experimental drug, TRB-051, in partnership with Eli Lilly. This molecule has completed the first phase of clinical trials—in healthy volunteers—and testing in patients with lupus (an autoimmune connective tissue disease) is scheduled to begin by the end of the year.

The main risk is that all of the startup’s projects are still in the early stages of clinical trials, notes VCBeat. Failure to obtain regulatory approval for the drugs or poor trial results could negatively impact the stock price in the future, warns Freedom analyst Alem Bektemirov. The brokerage firm has set a price target of $17 for TRex Bio shares, which implies a 21.4% upside from the offering price.

Eli Lilly’s participation in TRex Bio’s IPO is a positive development for investors, according to a VCBeat article. The pharmaceutical giant’s willingness to increase its stake to 19.99% during the offering sends a strong signal of confidence to institutional investors, notes IPO expert Donovan Jones in a post on SeekingAlpha. Among other positive factors, he highlights the company’s financial position. As of mid-2026, the company had $90.9 million in cash and cash equivalents, with liabilities of $9.9 million.

VCBeat believes that the next 12–18 months will be critical for the biotech sector. Phase II trials for TRB-051 will begin in 2026, and new data on two other pipeline candidates are expected in 2027. “Each milestone represents a major test for TRex Bio,” concludes VCBeat.