Kidney Week

Abstract: TH-PO1245

Activity of the Novel Anti-Soluble Urokinase Plasminogen Activator Receptor (suPAR) Monoclonal Antibody WAL0921 in People with Diabetic Kidney Disease

Session Information

• Late-Breaking Research Posters
  October 22, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Kooienga, Laura, Colorado Kidney Care, Denver, Colorado, United States

Laura Kooienga, MD

• El-Shahawy, Mohamed A., Academic Medical Research Institute, Los Angeles, California, United States

Mohamed A. El-Shahawy, MD, MPH, FASN

• Echeverri, Diego, South Florida Research Institute, Lauderdale Lakes, Florida, United States

Diego Echeverri, MD, FASN

• Pergola, Pablo E., Renal Associates PA, San Antonio, Texas, United States

Pablo E. Pergola, MD, PhD

• Mathur, Ritesh A., Clinical Trial Network, Houston, Texas, United States

Ritesh A. Mathur, MD

• Abichandani, Rekha, Walden Biosciences, Inc, Cambridge, Massachusetts, United States

Rekha Abichandani, MD

• Mandayam, Sreedhar A., The University of Texas MD Anderson Cancer Center, Houston, Texas, United States

Sreedhar A. Mandayam, MD, MBA, MPH, FASN

• Udani, Suneel M., Nephrology Associates, Oak Park, Illinois, United States

Suneel M. Udani, MD, FASN

Background

High levels of circulating soluble urokinase plasminogen activator receptor (suPAR) are a prognostic factor for glomerular kidney disease and may play a causal role in disease pathogenesis. WAL0921, a humanized IgG1 monoclonal antibody, is being developed to therapeutically target glomerular kidney diseases where the pathogenesis is mediated by the suPAR-uPAR system. In a Phase 1 single ascending dose (SAD) study in healthy volunteers, WAL0921 was well tolerated and rapidly reduced circulating suPAR. We present preliminary results of a Phase 2 study of WAL0921 in diabetic kidney disease (DKD)

Methods

WAL0921-02 is a prospective global multicenter adaptive double-blind Phase 2 study of WAL0921 in proteinuric kidney diseases including two multiple ascending doses (MAD) in DKD and a basket study in rare chronic kidney diseases. The primary objective of the study is safety; secondary objectives include pharmacokinetics, pharmacodynamics, and efficacy (changes in proteinuria and eGFR).
Participants were randomized 3:1 (WAL0921: placebo) in two multiple ascending dose cohorts (2 mg/kg and 6 mg/kg); received 7 IV doses QOW over 12 weeks, and then followed for an additional 24 weeks. Key eligibility criteria for participants with DKD included age 18-75 years; baseline UACR 500-3,500 mg/g; stable dose of standard of care medications; and eGFR ≥ 30 mL/min/1.73m².

Results

WAL0921 was well tolerated at both 2 mg/kg and 6 mg/kg. Most adverse events (AEs) were mild-moderate, and no participants discontinued due to an AE. Only 1 drug-related AE, headache, was reported. Circulating suPAR levels decreased rapidly after WAL0921 dosing, indicating successful target engagement. There was a dose-dependent decrease in suPAR levels.
In a preliminary analysis, 6 of 12 evaluable participants with median UACR 1,107 mg/g and median eGFR 46.5 mL/min/1.73m² who received WAL0921 achieved ≥ 20% UACR reduction from baseline on top of background SOC therapy at 2 or more timepoints starting at week 12. The median UACR percent change from baseline among responding participants was -32.4% at week 18.

Conclusion

WAL0921 was well tolerated and produced robust, dose-dependent suPAR target engagement. Preliminary reductions in albuminuria despite background standard-of-care therapy support further evaluation of suPAR-uPAR pathway inhibition in proteinuric kidney disease. Evaluation of WAL0921 in rare CKD in the WAL0921-02 study is ongoing.

Funding

• Commercial Support – Walden Biosciences, Inc