TRexBio Announces Pipeline Progress, Naming TRB-071 as a CD30 Agonist for Immune-Mediated Diseases and Advancement of Lilly-Partnered TRB-051

• TRB-071, a CD30 agonist antibody designed to activate and expand tissue Tregs and block the CD30L-mediated inflammatory pathway, is progressing through IND-enabling studies
• TRB-051, which is partnered with Lilly, is expected to advance into Phase 2a clinical development in lupus with cutaneous involvement

SOUTH SAN FRANCISCO, Calif.--(BUSINESS WIRE)--TRex Bio, Inc. (“TRexBio”), a clinical-stage biopharmaceutical company focused on tissue Treg biology for the discovery and development of immunoregulatory medicines, today announced progress across its wholly owned and partnered pipeline. TRexBio disclosed development candidate TRB-071, currently in IND-enabling studies, as a CD30 agonist antibody and the planned advancement of its Eli Lilly and Company (“Lilly”) partnered program, TRB-051, into Phase 2a clinical development in lupus with cutaneous involvement.

“TRB-071 is an important example of how our Deep Biology drug discovery and design platform can uncover tissue Treg biology that is both disease-relevant and therapeutically actionable,” said Ali Zarrin, Ph.D., Chief Scientific Officer of TRexBio. “By combining CD30 agonism with CD30L blocking activity, TRB-071 has the potential to modulate Tregs in inflamed tissue while dampening pathogenic inflammatory pathways, an approach that we believe could have meaningful therapeutic potential in IBD and other autoimmune and inflammatory diseases.”

TRB-071 is an investigational monoclonal antibody designed to agonize CD30, a TNF superfamily receptor highly enriched on tissue Tregs. TRB-071 is designed to activate and expand Tregs, which may increase their immune-regulatory capacity, while modulating the inflammatory pathway of the CD30-associated ligand (“CD30L”). Human genetic studies have associated variants in CD30 and CD30L with inflammatory bowel disease susceptibility.

Preclinical data demonstrated that CD30 agonism via TRB-071 induced Treg activation and expansion, potentially enhancing immune-regulatory capacity and reducing inflammation in colitis models. In non-human primate studies, TRB-071 induced activation and expansion of Tregs with minimal effects on other immune cell populations. TRexBio believes these findings support the potential of TRB-071 as a differentiated approach to restoring immune balance. The company is currently conducting a three-month GLP toxicology study of TRB-071 in cynomolgus monkeys.

TRexBio also announced that its collaboration partner Lilly intends to initiate a Phase 2a clinical trial of TRB-051 in lupus with cutaneous involvement in the second half of 2026. TRB-051, an investigational modulator of immune effector cells, was first identified and advanced under a multiyear discovery collaboration between TRexBio and Lilly, leveraging TRexBio’s Deep Biology platform. TRexBio previously announced that Lilly initiated a first-in-human Phase 1 study for TRB-051 in 2024.

“TRexBio was founded on the idea that a deeper understanding of tissue Treg biology could lead to a new generation of therapeutics for autoimmune and inflammatory diseases,” said Johnston Erwin, Chief Executive Officer of TRexBio. “The progress of TRB-071, together with the continued advancement of our partnered clinical program, reflects our ability to generate and advance multiple differentiated programs toward the clinic. We believe this growing pipeline underscores the productivity of our platform and positions TRexBio to address significant unmet therapeutic needs across inflammatory and autoimmune diseases, where many patients continue to need more durable and disease-modifying treatment options.”

About TRexBio

TRexBio is a clinical-stage biotechnology company focused on tissue Treg biology for the discovery and development of immunoregulatory medicines designed to restore immune balance and promote tissue repair to address unmet needs of patients with autoimmune and inflammatory diseases. The Company’s Deep Biology platform decodes Treg functionality in human tissue, mapping key drivers of immune dysregulation and uncovering novel targets and insights that inform drug discovery and translational efforts. This platform has generated multiple therapeutic development candidates across TRexBio’s wholly owned pipeline and through collaborations with leading pharma partners. TRexBio is led by an experienced management team and headquartered in South San Francisco, California. For more information, visit www.trex.bio.