ValenzaBio Announces Positive Preliminary Data from Phase 1b/2a Trial of VB119, an Anti-CD19 Monoclonal Antibody for the Treatment of Primary Membranous Nephropathy

- VB119 resulted in profound reductions in B-cells and anti-PLA2R autoantibodies
- Three of four evaluable patients had rapid reduction in proteinuria less than one month after initiation of therapy
- Complete remission of proteinuria was achieved for the single patient with ≥40 weeks follow up
- VB119 was well-tolerated; no study drug related SAEs were reported

Bethesda, MD., October 12th, 2022, -- ValenzaBio, Inc., a biopharmaceutical company developing monoclonal antibody (mAb) therapeutics for autoimmune and inflammatory indications, today announced positive initial results from its open label Phase 1a/2b clinical trial of VB119, a B-cell depleting mAb with enhanced antibody-dependent cellular cytotoxicity and potent binding to CD19, for the treatment of primary membranous nephropathy (PMN). These data represent the first clinical proof-of-concept for an anti-CD19 antibody in this disease and demonstrate potential differentiation from other therapies used in this indication.

The data will be presented today during a poster session titled, "Glomerular Diseases: Podocytopathies and Nephrotic Syndromes" at the 2022 American Society of Nephrology (ASN) Annual Meeting from 10:00 AM to 12:00 PM ET (Abstract #TH-PO456). The poster can be found on the ValenzaBio website at the following address: https://valenzabiotech.com/posters/asn2022/.

Primary Membranous Nephropathy (PMN)
PMN, also known as idiopathic membranous nephropathy, is an autoimmune glomerular disease and is one of the leading causes of non-diabetic nephrotic syndrome. PMN causes the body to lose considerable amounts of protein in the urine (called proteinuria) and can lead to impaired kidney function over time. Approximately 70% of cases of PMN are caused by autoantibodies directed against the phospholipase A2 receptor (PLA2R) that are secreted from mature B-cells, such as plasmablasts and plasma cells. VB119 aims to reduce the production of pathogenic autoantibodies via the depletion of CD19-expressing B-cells with the potential to provide a disease modifying treatment for patients with PMN.

Initial proof-of-concept results from Phase 1b

The Phase 1b/2a trial is an open-label, sequential-cohort, dose-escalation and dose-expansion study to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of VB119 in patients with PMN. Findings presented today are from an initial five participants enrolled in the trial as of October 3, 2022, across two dose cohorts in which patients received either 100 mg or 200 mg doses of VB119. Four patients administered at least two doses of VB119 have available follow up data out to at least Week 4. Of those patients, three have received the 100 mg dose and one patient has received the 200 mg dose. The three patients at the 100 mg dose level achieved complete (<5 cells/µL) and durable B-cell depletion by Week 12, and experienced substantial reductions in proteinuria, ranging from 34% to 95%. One patient in the 100 mg dose cohort achieved a complete remission of proteinuria, from a baseline proteinuria of 4.10 g/g to 0.20 g/g at Week 40. Two patients in the 100 mg dose cohort were anti-PLA2R antibody positive at baseline, and both achieved >50% reduction in serum anti-PLA2R autoantibodies from baseline to levels <20 RU/mL. The single patient enrolled in the 200 mg dose cohort achieved complete depletion of B-cells by Week 4. VB119 has been well-tolerated to date; one patient experienced an SAE that was deemed unrelated to study drug.

“PMN is a debilitating glomerular disease with limited treatment options, none of which produce high rates of complete remission,” said Dr. Greg Keenan, M.D., chief medical officer of ValenzaBio. “We believe these data demonstrate that CD19-directed B-cell depletion is capable of targeting pathogenic cell types in this disease, namely plasmablasts and plasma cells, which can potentially result in more rapid responses and higher rates of complete remission.”

“Available treatment regimens fail to achieve complete remission in most patients with primary membranous nephropathy. More effective therapies with limited toxicity are needed to improve outcomes in this population,” noted Frank B. Cortazar, M.D., Director of the New York Nephrology Vasculitis and Glomerular Center, and a principal investigator for the VB119 trial. “The preliminary VB119 data are encouraging, with rapid declines in PLA2R antibody levels and improvements in proteinuria, providing an early signal for efficacy in a disease process that remains a therapeutic challenge for clinicians and patients.”

About ValenzaBio, Inc.

ValenzaBio is a privately held biopharmaceutical company developing safe and effective therapies for autoimmune and inflammatory diseases. The company is advancing a pipeline of differentiated monoclonal antibodies with best-in-class properties, targeting clinically validated mechanisms of action, to provide improved treatment options for patients.

For more information, please visit www.valenzabiotech.com.

ValenzaBio Contact
Alicia Davis
THRUST Strategic Communications
alicia@thrustsc.com