TRexBio Announces Development Candidate, TRB-061, a Novel TNFR2 Agonist for the Treatment of Inflammatory Diseases

• TRB-061 is designed to preferentially augment tissue Treg for the treatment of inflammatory diseases in skin and gut

• TRB-061 is currently in IND-enabling studies, with first in-human trials anticipated in the first half of 2025

SOUTH SAN FRANCISCO, November 14, 2023 – TRex Bio, Inc., (“TRexBio”), a biotechnology company decoding human tissue immune biology to create revolutionary therapeutics, today announced the selection of development candidate TRB-061, an agonist targeting TNF receptor 2 (TNFR2). TRB-061 expands regulatory T cells (Tregs) to restore homeostasis in the tissue at the site of inflammation.

“This is an important milestone for TRexBio. We believe that by harnessing the power of Tregs and leveraging the body’s own immune system, we may be able to deliver durable clinical benefits for patients suffering from autoimmune diseases,” said Johnston Erwin, Chief Executive Officer of TRexBio. “TRB-061, directed toward TNFR2, is the most advanced wholly-owned candidate in our growing pipeline. IND-enabling studies are ongoing, and we are targeting first-in-human studies in early 2025.”

TNFR2 is highly expressed on immunosuppressive Tregs, a subset of T cells which play a key role in maintaining immune homeostasis. The therapeutic potential of TNFR2 agonism for the treatment of autoimmune and inflammatory disease is widely recognized. TRexBio’s high-resolution tissue transcriptomics and internally generated translational data show agonism of TNFR2 induces expansion and a suppressive state in tissue Tregs. TRB-061 has demonstrated potent in vivo Treg expansion in humanized mice, and TRexBio has obtained in vivo proof of concept in both colitis and skin inflammation models.

“We built our Deep Biology platform to efficiently identify and functionally characterize targets instrinsic to tissue Treg regulatory pathways,” said Melanie Kleinschek, DVM, Ph.D., Chief Scientific Officer of TRexBio. “TNFR2 is a tissue Treg-enriched gene predominantly expressed by suppressive Tregs in skin and gut. Our development candidate TRB-061 is designed to selectively agonize TNFR2, a mechanism we believe has potential across a broad range of autoimmune indications.”

TRexBio aims to progress TRB-061 into the clinic following completion of ongoing preclinical and IND-enabling studies. The company’s pipeline is focused on programs designed to address unmet need in autoimmune and inflammatory diseases of the skin and gut through the pharmacological modulation of tissue Tregs. TRexBio anticipates nominating its next development candidate in 2024.

About TRexBio
TRexBio is a biotechnology company leveraging cutting edge computational biology tools, a focus on human tissue, and expertise in immunobiology to develop revolutionary therapeutics for immune-mediated diseases. Our powerful Deep Biology platform maps human tissue Treg behavior to disease processes to identify and characterize novel targets for therapeutic intervention. Leveraging this platform, we are building a broad portfolio of novel therapies that modulate the immune system to restore human tissue immune homeostasis. TRexBio was founded and seed funded by SV Health Investors in 2018 and is headquartered in South San Francisco, California. For more info, visit

Company: Laura Berner, Chief Operating Officer, TRex Bio, Inc., 650-243-7412,
Media: Jessica Yingling, Ph.D., Little Dog Communications Inc., 858-344-8091,