Abstract: TH-OR040
Targeting of CLDN1 Reduces Kidney Injury and Macrophage Infiltration in FSGS
Session Information
- Glomerular Precision Nephrology: Novel Mechanisms, Biomarkers, and Therapeutic Targets
November 06, 2025 | Location: Room 310A, Convention Center
Abstract Time: 05:00 PM - 05:10 PM
Category: Glomerular Diseases
- 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology
Authors
- Teixeira, Geoffrey, Alentis Therapeutics AG, Allschwil, BL, Switzerland
- Delbet, Jean-Daniel, Paris Centre de Recherche Cardiovasculaire, Paris, Île-de-France, France
- Polini, Elisa, Alentis Therapeutics AG, Allschwil, BL, Switzerland
- Cavadini, Silvia, Alentis Therapeutics AG, Allschwil, BL, Switzerland
- Chanemouga, Isabelle, Alentis Therapeutics AG, Allschwil, BL, Switzerland
- Anquetil, Vincent, Alentis Therapeutics AG, Allschwil, BL, Switzerland
- Herbert, Corentin, Alentis Therapeutics AG, Allschwil, BL, Switzerland
- Anquetil, Florence, NovAliX SAS, Strasbourg, Grand Est, France
- Bourcier, Aurelia, NovAliX SAS, Strasbourg, Grand Est, France
- Comas, Daniel, NovAliX SAS, Strasbourg, Grand Est, France
- Kers, Jesper, Amsterdam UMC Locatie AMC, Amsterdam, NH, Netherlands
- Rabelink, Ton J., Leids Universitair Medisch Centrum, Leiden, ZH, Netherlands
- Iacone, Roberto, Alentis Therapeutics AG, Allschwil, BL, Switzerland
- Tharaux, Pierre-Louis, Paris Centre de Recherche Cardiovasculaire, Paris, Île-de-France, France
Background
Primary podocytopathies often progress to focal segmental glomerulosclerosis (FSGS) despite immunosuppressive treatment, driven by persistent podocyte injury and activation of parietal epithelial cells (PECs). In FSGS lesions, the tight junction protein claudin-1 (CLDN1) becomes aberrantly exposed outside junctions, where it may promote pro-fibrotic signaling, immune cell recruitment, and extracellular matrix (ECM) remodeling. Lixudebart (ALE.F02), a first-in-class monoclonal antibody (mAb) developed by Alentis, selectively targets exposed CLDN1 on activated renal epithelial cells. This study assessed whether CLDN1 inhibition mitigates kidney injury in a model of maladaptive FSGS.
Methods
CLDN1 expression was assessed in renal tissues from patients with FSGS and minimal change disease (n = 49) using multicolor immunofluorescence and immunohistochemistry, and its association with eGFR and proteinuria was evaluated. The preclinical efficacy of an anti-CLDN1 mAb was tested in the DOCA-salt/unilateral nephrectomy FSGS model. Mechanistic studies employed in vitro and ex vivo epithelial cell models to investigate interactions between CLDN1 and pro-inflammatory or pro-fibrotic mediators.
Results
In kidneys from FSGS patients, CLDN1 expression was upregulated in FSGS lesions. Co-expression of CLDN1 and CD44 on parietal epithelial cells was significantly associated with poor renal outcomes. In the DOCA-salt model, treatment with an anti-CLDN1 mAb reduced renal macrophage infiltration (CD68+ staining) and epithelial activation (CD44+ staining), with a trend toward attenuation of glomerulosclerosis and a lower urinary albumin-to-creatinine ratio. Ex vivo, Lixudebart disrupted CLDN1 interactions with CD44 and MMP14, key mediators of immune cell recruitment and ECM remodeling.
Conclusion
Exposed CLDN1 is upregulated in FSGS lesions. An anti-CLDN1 mAb effectively disrupted CLDN1 interactions in vitro and mitigated inflammation and renal injury in a preclinical FSGS model. In vitro and ex vivo studies linked aberrant CLDN1 exposure to immune cell recruitment and ECM remodeling. These findings support CLDN1 inhibition as a novel therapeutic strategy in FSGS.