Mediar Advances First-in-Class Anti-SMOC2 Antibody MTX-439 Into Phase 1 Trial for CKD-Associated Fibrosis

Mediar Therapeutics has announced dosing of the first cohorts in a phase 1 clinical trial evaluating MTX-439, a first-in-class monoclonal antibody designed to inhibit SMOC2, a protein implicated in the development and progression of kidney fibrosis.¹

The randomized, double-blind, placebo-controlled study will assess the safety, tolerability, pharmacokinetics, and immunogenicity of MTX-439 in healthy volunteers and adults with diabetic kidney disease.¹ The investigational therapy is being developed for fibrosis associated with chronic kidney disease (CKD), a condition that affects approximately 37 million adults in the US and remains a leading cause of kidney failure.^1,2

According to Mediar, MTX-439 is designed to neutralize SMOC2, a secreted matricellular protein that promotes extracellular matrix assembly, cell adhesion, and fibrotic remodeling within the kidney.^1,3 Elevated SMOC2 expression has been associated with kidney fibrosis severity, making the protein both a potential therapeutic target and biomarker for disease progression.¹

"Initiating this clinical study of MTX-439 is an exciting milestone for Mediar that underscores our ongoing commitment to developing first-in-class fibrosis therapies," said Jeff Bornstein, MD, chief medical officer of Mediar Therapeutics, in a company statement.¹

Why is fibrosis an important target in chronic kidney disease?

Fibrosis is widely recognized as a key driver of CKD progression, contributing to irreversible tissue scarring and declining kidney function.⁴ While currently available therapies may slow disease progression, no approved treatments directly reverse renal fibrosis.⁴

Preclinical studies cited by Mediar demonstrated that MTX-439 reduced fibrotic activity by disrupting SMOC2-mediated signaling pathways involved in myofibroblast activation and extracellular matrix deposition.¹ The company's broader strategy focuses on targeting the myofibroblast, a cell type considered central to fibrosis development across multiple organ systems.¹

How does MTX-439 fit into Mediar's fibrosis pipeline?

MTX-439 is the third anti-fibrotic antibody program from Mediar to enter clinical development.¹ The company is also advancing MTX-474, an anti-EphrinB2 antibody in phase 2a testing for systemic sclerosis, and MTX-463, a WISP1-targeting antibody being evaluated in idiopathic pulmonary fibrosis through a partnership with Eli Lilly.^1,3

In conjunction with the phase 1 initiation, Mediar expanded its clinical advisory board with nephrology experts from Harvard Medical School, the University of Michigan, the University of Toronto, and the University of Leicester to support future development in CKD.¹

The company plans to advance MTX-439 into randomized phase 2 studies if early clinical findings support continued development. As interest in fibrosis-targeted therapies grows, the program could provide new insight into whether directly targeting SMOC2 can alter the course of kidney disease and potentially address a major unmet need in nephrology.^1,3

References

1. Mediar Therapeutics Announces First Cohorts Dosed in Phase 1 Clinical Trial of MTX-439 for Fibrosis Associated with Chronic Kidney Disease (CKD) and Additions to Clinical Advisory Board. (2026 Jun 23). PR Newswire. https://www.prnewswire.com/news-releases/mediar-therapeutics-announces-first-cohorts-dosed-in-phase-1-clinical-trial-of-mtx-439-for-fibrosis-associated-with-chronic-kidney-disease-ckd-and-additions-to-clinical-advisory-board-302807065.html
2. Chronic Kidney Disease in the United States, 2026. Centers for Disease Control and Prevention. https://www.cdc.gov/kidney-disease/php/data-research/index.html
3. Mediar Therapeutics Pipeline Overview. Mediar Therapeutics. https://www.mediartx.com/our-pipeline/
4. Granata S, Barberio L, D'Agostino R, et al. (2026 Feb 7). Emerging therapeutic pipelines on kidney fibrosis: challenges in translational research. J Transl Med. https://pmc.ncbi.nlm.nih.gov/articles/PMC12977584/