Six of 12 evaluable participants receiving WAL0921 treatment experienced proteinuria (UACR) reduction greater than 20 percent; median 32.4 percent UACR reduction among responders
Initial clinical results provide proof-of-concept for suPAR reduction in proteinuric kidney disease
Ongoing basket study expected to report proteinuria reduction data from primary membranous nephropathy, FSGS, and IgAN cohorts in coming months
CAMBRIDGE, Mass., Oct. 22, 2026 (GLOBE NEWSWIRE) -- Walden Biosciences, Inc. (“Walden” or “the Company”), a private, clinical-stage biotechnology company dedicated to developing disease-modifying medicines to treat rare chronic kidney diseases, today announced initial results from Phase 1 and Phase 2 studies of WAL0921, a humanized monoclonal antibody that inhibits the pathological activity of the soluble and cell surface-bound urokinase plasminogen activator receptor (suPAR/uPAR) system. Notably, the Phase 2 data demonstrated a clinically meaningful reduction in proteinuria as measured by urine albumin-creatine ratio (UACR) among diabetic kidney disease patients after seven doses over 12 weeks of treatment.
The initial Phase 2 data were presented in a late-breaking poster session during the 2026 American Society of Nephrology’s Kidney Week. An additional poster being presented at the meeting showcases Phase 1 data that demonstrate WAL0921 is safe and well-tolerated in healthy volunteers and reduces plasma suPAR levels, demonstrating target engagement and proof of biology.
“Patients with diabetic kidney disease frequently fail to reach guideline-recommended albuminuria levels even when treated with standard of care therapy,” said Laura Kooienga, M.D., Division Director, CKC Research Department, Colorado Kidney Care in Denver, Colorado, and principal investigator on the Phase 2 study. “WAL0921 is incredibly exciting because it introduces a novel, disease-modifying mechanism that produces clinically meaningful reduction of proteinuria in a substantial proportion of patients despite extensive background medical therapy, and offers the potential to prevent progression to end-stage kidney disease for patients across a range of rare and common kidney conditions.”
In the initial dose-finding stage of the WAL0921 Phase 2 study, 19 participants with diabetic kidney disease were enrolled and received WAL0921 or placebo. Mean UACR before treatment exceeded 1,100 mg/g for both dose groups (2 mg/kg and 6 mg/kg) as well as the placebo group; all participants had a score of two (2) or greater on the Charlson Comorbidity Index, indicating a substantially elevated mortality risk. Participants remained on their existing standard of care treatments during the study.
In a preliminary analysis of 12 evaluable participants who received WAL0921 treatment, six showed a >20 percent reduction in UACR starting at Week 12, with median reduction among the responders of 32.4 percent. UACR reductions persisted in a majority of responders for up to 24 weeks after the final dose. At both dose levels, median suPAR reduction reached at least 95 percent.
“These data strongly validate Walden’s hypothesis that targeting suPAR and uPAR, a signaling pathway that drives multiple cellular processes involved in proteinuric kidney disease, represents a disease-modifying approach that is completely independent of existing modalities,” said Blaine McKee, Ph.D., Chief Executive Officer at Walden Biosciences. “We are currently enrolling patients in additional cohorts within our basket study of rare chronic kidney diseases, including FSGS, IgAN, and primary membranous nephropathy, where reduction in proteinuria has been increasingly recognized by regulatory agencies as a surrogate endpoint predicting clinical benefit. We expect to provide additional evidence for the safety and efficacy of WAL0921 in the coming months.”
Additional information on the ongoing Phase 2 basket study of WAL0921 is available at www.rareCKDstudy.com.
About the WAL0921 Phase 2 Study
The WAL0921-02 Phase 2 study is an adaptive prospective, multi-center, randomized, double-blind, placebo-controlled study to evaluate the safety, efficacy, pharmacokinetics, and pharmacodynamics of WAL0921 in patients with glomerular kidney disease and proteinuria, including diabetic kidney disease (DKD), focal segmental glomerulosclerosis (FSGS), IgA nephropathy (IgAN) and primary membranous nephropathy (PMN). Two dose levels are being investigated: 2 mg/kg and 6 mg/kg. Study drug is administered every two weeks for seven doses (12 weeks), followed by a 24-week observation period.
About Walden Biosciences
Walden Biosciences is a private, clinical-stage biotechnology company focused on developing disease-modifying medicines to treat rare chronic kidney diseases. Walden is applying unique, multi-disciplinary approaches designed to prevent kidney damage and stop disease progression. Walden’s product candidates are well-differentiated from current therapies as they have novel mechanisms of action and are not hemodynamic modulators and are non-immunosuppressive.
Walden’s programs directly target two cell types critical for kidney function: podocytes and proximal tubular cells. Dysfunction of these cells is a critical hallmark of the majority of proteinuric kidney diseases. Walden’s Phase 2 program, WAL0921, is a humanized monoclonal antibody that inhibits urokinase plasminogen activator in both its soluble (suPAR) and membrane bound (uPAR) forms and is being evaluated in a global basket study (NCT06466135). Walden’s second most advanced program is a Phase 1 small molecule, WAL0623, that is designed to stabilize and restore the function of dynamin, an enzyme responsible for the maintenance of the cytoskeletal architecture and function of podocytes and proximal tubule cells. Both programs offer the promise to deliver breakthrough therapies that transform the treatment of kidney disease. For more information, please visit www.waldenbiosciences.com or follow us on LinkedIn.
For More Information
Investor Contact:
Precision AQ
Anne Marie Fields
annemarie.fields@precisionaq.com
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