A Phase 2 Study of Budoprutug in Subjects With Primary Membranous Nephropathy

To evaluate the safety and tolerability of three dose regimens of budoprutug in subjects with PMN

Budoprutug is a humanized, immunoglobulin (Ig) G1 monoclonal antibody that selectively binds to CD19 and is projected to deplete targeted cells through antibody-dependent cellular cytotoxicity (ADCC). This Phase 2, open-label, multicenter study evaluates the safety, pharmacodynamics, and preliminary efficacy of three intravenous dose regimens of budoprutug in adult subjects with primary membranous nephropathy (PMN) who are anti-PLA2R antibody positive and have persistent proteinuria despite optimized RAAS inhibition. Approximately 45 subjects will be enrolled across three sequential dose cohorts, each receiving a single IV dose of budoprutug on Day 1, Day 15, Day 169 and Day 183. Subjects will be followed through Week 48, with extended follow-up for B-cell recovery as needed.

Inclusion Criteria: * Confirmed diagnosis of PMN with positive anti-PLA2R antibodies * CD19+ B cell count ≥40 cells/μL * UPCR ≥2.0 g/g * eGFR ≥35 mL/min/1.73 m² * Stable RAAS inhibitor therapy * Blood pressure \<150/90 mmHg at baseline * Adequate hematologic, hepatic, and renal function * Willing to use effective contraception (both sexes) * Other inclusion criteria may apply Exclusion Criteria: * Secondary Membranous Nephropathy * Rapidly progressive glomerulonephritis or other glomerulopathies * Prior B cell-depleting therapy within 24 weeks * Recent use of immunosuppressants * Active or high-risk infections * History of malignancy * Pregnancy or breastfeeding * Recent major surgery or hospitalization * Other exclusion criteria may apply