TRexBio Secures $84 Million Series B to Advance Immunology Programs to Clinical Stage

TRex Bio, Inc., a biotechnology firm based in South San Francisco, California, has successfully closed an oversubscribed $84 million Series B funding round. The financing was spearheaded by Delos Capital, with new investors including Avego BioScience Capital and Agent Capital. Existing investors such as Eli Lilly and Company, SV Health Investors, Pfizer Ventures, Johnson & Johnson Innovation – JJDC, Inc., Alexandria Venture Investments, and Polaris Partners also contributed to the round.

The raised capital will be utilized to advance TRexBio’s leading therapeutic candidate, TRB-061. This candidate is a specifically engineered TNFR2 agonist aimed at patients suffering from immune-mediated diseases like atopic dermatitis and ulcerative colitis. TNFR2 is a receptor prominently expressed on a subset of highly suppressive regulatory T cells (Tregs) in the skin and gut. TRB-061 is designed to selectively activate TNFR2, thereby stimulating tissue-licensed Tregs to treat various inflammatory and autoimmune conditions. The company plans to initiate a Phase 1 clinical trial for TRB-061 in the first half of 2025. Additionally, the funding will support the development of TRexBio’s pipeline, including an early-stage candidate, TRB-071. TRB-061 is set to be the second program from TRexBio’s proprietary platform to enter clinical trials, following TRB-051, which is currently in a Phase 1 trial in collaboration with Lilly.

Johnston Erwin, CEO of TRexBio, expressed gratitude for the support from investors, highlighting their shared vision for a unique approach to treating autoimmune and inflammatory diseases. According to Erwin, the company’s focus on immune homeostasis rather than mere suppression positions them to develop first- and best-in-class therapeutic programs that address significant unmet medical needs.

With the new financing, TRexBio also announced additions to its Board of Directors. Eric Huang, PhD, Partner at Delos; Joel S. Marcus, Executive Chairman & Founder at Alexandria Venture Investments; and Eric Pham, PhD, Managing Director at Avego, have joined the board. Dr. Eric Huang emphasized the potential of TRexBio’s lead program, TRB-061, to become a new standard in the treatment of autoimmune and inflammatory diseases. He praised TRexBio’s scientific rigor and innovative platform for leveraging the natural function of regulatory T cells to restore immune balance. Huang expressed confidence that TRexBio’s work would soon lead to the development of safe, durable, and effective medicines for patients.

TRexBio’s Deep Biology platform utilizes advanced computational biology tools, human tissue focus, and immunobiology expertise to map the behavior of Tregs in human tissue, identifying novel therapeutic targets. The company’s goal is to develop a wide array of therapies that modulate the immune system to reestablish immune homeostasis in human tissues. TRexBio was founded in 2018 with initial funding from SV Health Investors and operates out of South San Francisco, California. It was one of the first companies to join Lilly Gateway Labs, a shared innovation space created by Eli Lilly and Company to support early-stage biotech firms.

Delos Capital, founded in 2014, is a life sciences investment firm dedicated to transforming bold scientific ideas into medical breakthroughs. The firm’s approach involves a rigorous investment process that aligns cutting-edge science with clear clinical needs, aiming for a lasting positive impact on human health.