WAL-0921

Fully Enrolled Second Cohort in Phase 2 Basket Study of WAL0921 In Chronic Kidney Disease Plans to Initiate Rare Kidney Diseases Cohort in Early 2025 Company to Attend 43rd Annual J.P. Morgan Healthcare Conference CAMBRIDGE, Mass., Jan. 10, 2025 (GLOBE NEWSWIRE) -- Walden Biosciences, Inc. (“Walden”), a private, venture-backed biotechnology company advancing the development of disease-modifying therapies to transform the treatment of kidney disease, today announced recent business highlights and strategic priorities for 2025 in advance of the Company’s attendance at the 43rd Annual J.P. Morgan Healthcare Conference from January 13–16, 2025, in San Francisco, CA. “We are pleased to be in San Francisco during the J.P. Morgan Healthcare Conference, where we will provide an update on our Phase 2 study (WAL0921-02), the upcoming data readouts anticipated this year, and our plans beyond 2025,” said Blaine McKee, Ph.D., Chief Executive Officer of Walden Biosciences. “Initial dosing from the first two Cohorts evaluating Walden’s anti-suPAR antibody in patients with diabetic nephropathy is complete and fully supports continued enrollment in the study’s Rare kidney disease patient population. We look forward to sharing data from the study, as Walden continues to advance our strategy of developing breakthrough, disease-modifying medicines that target the kidney.” Several members of Walden’s leadership team including Blaine McKee, Curt Dewan, CFA, Chief Financial Officer, and Andrew Blair, M.D., Chief Medical Officer, will be meeting with investors and other industry leaders in San Francisco during the conference, where they will highlight the Company’s recent accomplishments and priorities for 2025. 2024 Accomplishments Completed a first-in-human Phase 1+ clinical study of WAL0921, the Company’s first-in-class, antibody directed against suPAR, in healthy subjectsReported data from the Phase 1+ study that showed WAL0921 was well-tolerated, and demonstrated proof-of-biology through a rapid reduction in suPARCompleted Investigational New Drug-enabling studies to support initiation of clinical studies for WAL0623, the Company’s first-in-class small molecule dynamin stabilizer 2025 Priorities Initiate the third Cohort of the Phase 2 Basket study (WAL0921-02) in Rare glomerular kidney diseases, including focal segmental glomerulosclerosis (FSGS), treatment resistant minimal change disease (TR-MCD), IgA nephropathy (IgAN), and primary membranous nephropathy (PMN)Raise capital to support the advancement of Walden’s pipeline of disease-modifying therapies for the treatment of Rare glomerular kidney diseasesInitiate a first-in-human Phase 1 clinical study of WAL0623Deliver interim data on WAL0921-02 in Rare glomerular kidney diseases About the Phase 2 Clinical Study of Walden’s Anti-suPAR AntibodyThe Phase 2 clinical study (WAL0921-02) is an adaptive, prospective, multi-center, randomized, double-blind, placebo-controlled study to evaluate the safety, efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of WAL0921 in subjects with glomerular kidney diseases and proteinuria, including diabetic nephropathy (DN) and Rare glomerular kidney diseases, including focal segmental glomerulosclerosis (FSGS), treatment-resistant minimal change disease (TR-MCD), IgA nephropathy (IgAN), and primary membranous nephropathy (PMN). The study will enroll up to 96 subjects, randomized three-to-one (active:placebo). Initially, 44 subjects will be enrolled, with the Rare kidney disease Cohorts following the DN Cohorts. The study is flexible and will be adapted to reflect the emerging data from the initial 44 subjects. Up to 52 additional subjects may be adaptively enrolled to further explore safety, efficacy, PK, and PD of WAL0921 by expanding or adding Cohorts (e.g., to improve statistical powering, explore alternative dosing schedules, or explore alternative dose levels). Subjects will be administered seven sequential IV doses of WAL0921 or placebo every 14 days over a 12-week treatment period and will be followed for an additional 24 weeks. About Walden BiosciencesWalden Biosciences is a private, venture-backed clinical development-stage company focused on developing breakthrough, disease-modifying medicines to treat kidney diseases. Walden is applying novel, multi-disciplinary approaches that directly target the kidney to prevent damage, slow disease progression, and restore kidney function. Walden’s programs address novel targets for therapeutic intervention, directly targeting two cell types critical for kidney function: podocytes and proximal tubular cells. Dysfunction of these cells are critical hallmarks of the majority of kidney diseases. Walden’s Phase 2 clinical-stage program is a humanized monoclonal antibody that inhibits suPAR, a cause of podocyte dysfunction and kidney disease, which is being evaluated in a Basket study. Walden’s second most advanced program is an IND-ready small molecule 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. All of Walden’s programs offer the promise to deliver disease-modifying, breakthrough therapies that are readily combinable with the standard of care to transform the treatment of kidney disease. For more information, please visit www.waldenbiosciences.com. Investor Contact:Anne Marie FieldsManaging DirectorPrecision AQ (formerly known as Stern Investor Relations)annemarie.fields@precisionaq.com Media Contacts:FTI ConsultingRobert StanislaroRobert.Stanislaro@fticonsulting.com-OR-Helen O’GormanHelen.OGorman@fticonsulting.com

Expects Topline Results from First Multiple Ascending Dose Cohort by Year-end 2024 and to Initiate Rare Kidney Disease Cohorts in Early 2025CAMBRIDGE, Mass., Sept. 30, 2024 (GLOBE NEWSWIRE) -- Walden Biosciences, Inc. (Walden), a private, venture-backed biotechnology company advancing disease modifying therapies to transform the treatment of kidney disease, today announced that it has completed initial dosing of all subjects in the first cohort of a Phase 2 basket study evaluating WAL0921 as a treatment for chronic kidney diseases. WAL0921 is Walden’s first-in-class, proprietary, humanized monoclonal antibody that binds soluble urokinase plasminogen activator receptor (suPAR) and inhibits the pathological activity of suPAR that causes podocyte dysfunction and kidney disease. The Phase 2 basket study will evaluate WAL0921 in individuals with glomerular kidney diseases and proteinuria. This study will enroll subjects with diabetic nephropathy (DN) and rare glomerular kidney diseases, including focal segmental glomerulosclerosis (FSGS), treatment resistant minimal change disease (TR-MCD), IgA nephropathy (IgAN), and primary membranous nephropathy (PMN). “This study is unique in that it will establish safety in a multiple ascending dose (MAD) study of WAL0921 in a diseased population and will also serve as proof-of-concept for each individual kidney disease being assessed. The study initially evaluates two ascending doses in subjects with diabetic nephropathy to establish safety and confirm the pharmacodynamic effect of lowering suPAR that we saw in healthy subjects in our Phase 1+ clinical study,” stated Dr. Andrew Blair, Chief Medical Officer of Walden Biosciences. “We look forward to generating topline data from cohort 1 by year-end 2024 and to advancing this Phase 2 basket study into rare kidney disease cohorts in early 2025,” added Dr. Blair. “We are pleased to have swiftly completed initial dosing of the first cohort in the MAD portion of our Phase 2 study as it moves us one step closer to bringing this potentially disease-modifying treatment to chronic kidney disease patients," stated Blaine McKee, Ph.D., Chief Executive Officer of Walden. “Based on the data from preclinical studies and our compelling early clinical study, we believe WAL0921 has substantial therapeutic potential.” The Phase 2 clinical study is supported by positive data from the recently completed Phase 1+ clinical study of WAL0921. The Phase 1+ clinical study was a single center, double-blind, placebo-controlled, single ascending dose study of WAL0921 in five cohorts that evaluated its safety, pharmacokinetics, and pharmacodynamics in 40 healthy subjects. Data from the study showed that WAL0921 was safe, well-tolerated, and demonstrated proof-of-biology through a rapid, dose-dependent reduction in free suPAR levels. The Phase 2 Clinical Study The Phase 2 clinical study is an adaptive, prospective, multi-center, randomized, double-blind, placebo-controlled study to evaluate the safety, efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of WAL0921 in subjects with glomerular kidney diseases and proteinuria, including diabetic nephropathy (DN) and rare glomerular kidney diseases including focal segmental glomerulosclerosis (FSGS), treatment-resistant minimal change disease (TR-MCD), IgA nephropathy (IgAN) and membranous nephropathy (MN). The study will enroll up to 96 subjects, randomized three-to-one (active:placebo). Initially, 44 subjects will be enrolled, with the rare kidney disease cohorts following the DN cohorts. The study is flexible and will be adapted to reflect the emerging data from the initial 44 subjects, and up to 52 additional subjects may be adaptively enrolled to further explore safety, efficacy, PK, and PD of WAL0921 by expanding or adding cohorts of subjects (e.g., to improve statistical powering, explore alternative dosing schedules, or explore alternative dose). Subjects will be administered seven sequential IV doses of WAL0921 or placebo every 14 days over a 12-week treatment period and will be followed for an additional 24 weeks. About Walden BiosciencesWalden Biosciences is a private, venture-backed Phase 2 clinical development-stage company focused on developing breakthrough, disease-modifying medicines to treat kidney diseases. Walden is applying novel, multi-disciplinary approaches that directly target the kidney to prevent damage, slow disease progression, and restore kidney function. Walden’s programs address novel targets for therapeutic intervention, directly targeting two cell types critical for kidney function: podocytes and proximal tubular cells. Dysfunction of these cells are critical hallmarks of the majority of kidney diseases. Walden’s clinical-stage program is a humanized monoclonal antibody that inhibits suPAR, a cause of podocyte dysfunction and kidney disease, which is being evaluated in a Phase 2 Basket study. Walden’s second most advanced program is an IND-ready small molecule 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. All of Walden’s programs offer the promise to deliver disease-modifying, breakthrough therapies that are readily combinable with the standard of care to transform the treatment of kidney disease. For more information, please visit www.waldenbiosciences.com. Investor Contact:Anne Marie FieldsManaging DirectorPrecision AQ (formerly known as Stern Investor Relations)annemarie.fields@precisionaq.com Media ContactsFTI ConsultingRobert StanislaroRobert.Stanislaro@fticonsulting.com-OR-Helen O’GormanHelen.OGorman@fticonsulting.com