SOUTH SAN FRANCISCO, April 29, 2026
TRexBio, Inc. has announced that the first patient has been dosed in the Phase 1b clinical trial of TRB-061, its novel TNFR2 agonist being developed for the treatment of moderate-to-severe atopic dermatitis (AD). This important milestone marks a major step forward in TRexBio’s mission to develop next-generation immunoregulatory medicines that restore immune balance by selectively enhancing regulatory T cells (Tregs), offering a differentiated approach to treating chronic inflammatory skin diseases.
Novel TNFR2 Agonist Targets Immune Balance and Skin Repair
TRB-061 is TRexBio’s lead wholly owned clinical program and is specifically designed to selectively activate TNFR2, a key regulator of immune homeostasis that supports tissue repair and controls inflammation. By selectively agonizing TNFR2, TRB-061 expands and activates tissue Tregs without stimulating other immune cells involved in inflammatory responses.
In patients with atopic dermatitis, where immune dysregulation and chronic skin inflammation are central disease drivers, this mechanism may provide a dual benefit of reducing inflammation while promoting skin barrier repair. Unlike many currently approved biologics that target broader inflammatory pathways, TRB-061 aims to restore immune homeostasis at the tissue level, potentially offering more durable disease control with improved long-term tolerability.
Phase 1b Study Designed to Deliver Proof-of-Concept Data
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The Phase 1b portion of the ongoing clinical trial is a randomized, double-blind, placebo-controlled study evaluating subcutaneous administration of TRB-061 in approximately 50 patients with moderate-to-severe atopic dermatitis. The primary endpoints focus on safety and tolerability, while secondary endpoints include pharmacokinetics and immunogenicity.
Exploratory endpoints will assess important pharmacodynamic markers such as Treg expansion in blood and skin tissue, along with clinical measures of disease activity. These results are expected to provide critical proof-of-concept data supporting the broader development of TRB-061 across inflammatory and autoimmune diseases. The company anticipates reporting 16-week Phase 1b data in the first half of 2027.
Large Unmet Need in Atopic Dermatitis Treatment
Atopic dermatitis is a chronic inflammatory skin disease characterized by severe itching, rash, and skin barrier dysfunction. It affects up to 20% of children and 10% of adults, representing approximately 204 million people worldwide. Moderate-to-severe AD is often associated with systemic immune activation, large body surface involvement, and major quality-of-life impairment.
Although biologic therapies have improved outcomes for some patients, more than half discontinue treatment within two years due to limited long-term effectiveness or side effects. This creates a major unmet need for new therapies with novel mechanisms of action and better long-term disease control.
TRexBio believes TRB-061 could represent a new therapeutic pillar in inflammatory disease treatment by combining immune modulation with tissue repair. With strong scientific rationale, clinical momentum, and a differentiated Treg-focused platform, the company is positioning itself as an emerging leader in next-generation immunology innovation.
Source: TRexBio press release
