Abstract: INFO06-SA
Study Design of the Pivotal Phase 3, Randomized, Placebo-Controlled Trial (A.M.IgA): Efficacy and Safety of Mezagitamab for the Treatment of Primary IgAN
Session Information
- Informational Posters - 3
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- No subcategory defined
Authors
- Barratt, Jonathan, Mayer IgA Nephropathy Laboratories, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- Lafayette, Richard A., Division of Nephrology, Stanford University Medical Center, Stanford, California, United States
- Liew, Adrian, The Kidney and Transplant Practice, Mount Elizabeth Novena Hospital, Singapore, Singapore
- Suzuki, Yusuke, Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
- Trimarchi, Hernan, Division of Nephrology and Renal Transplantation, Hospital Británico de Buenos Aires, Buenos Aires, Argentina
- Zhang, Hong, Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Allik, Anet, Takeda Development Center Americas, Inc., Cambridge, Massachusetts, United States
- Kiani, Salma, Takeda Development Center Americas, Inc., Cambridge, Massachusetts, United States
- Li, Cheryl, Takeda Development Center Americas, Inc., Cambridge, Massachusetts, United States
- Zhu, Jiaqiang, Takeda Development Center Americas, Inc., Cambridge, Massachusetts, United States
- Patwari, Parth, Takeda Development Center Americas, Inc., Cambridge, Massachusetts, United States
Description
Mezagitamab is an anti-CD38 antibody that depletes plasma cells and thus may deplete the cells producing galactose-deficient IgA1 (Gd-IgA1). In a proof-of-concept study (TAK-079-1006, NCT05174221), participants with IgA nephropathy (IgAN) receiving mezagitamab (in combination with stable background therapy) had reduced proteinuria, stable kidney function, and decreased serum Gd-IgA1 levels that were sustained up to 18 months after the last dose.
We present here the design of a pivotal, randomized, double-blind, placebo-controlled, phase 3 study (NCT06963827) assessing the efficacy and safety of subcutaneous mezagitamab 600 mg in participants with IgAN. This study started on 15Jul2025 and will enroll participants in ~29 countries.
Adults with primary IgAN confirmed by kidney biopsy, on stable background therapy for IgAN, and either urine protein-creatinine ratio (UPCR) ≥0.8 g/g or urine protein excretion ≥1 g/day and estimated glomerular filtration rate (eGFR) >30 mL/min/1.73m2 are eligible for the main study. The trial comprises a 22-week treatment period and an 82-week follow-up period. Approximately 297 participants are to be randomized 2:1 to receive subcutaneous mezagitamab 600 mg or placebo once weekly for 9 doses then biweekly for 7 doses. An additional cohort of ~ 50 participants, with proteinuria or eGFR lower than the eligibility criteria for the main study, will receive open-label mezagitamab with the same dosing regimen.
The primary study endpoint is change from baseline in proteinuria at week 36 based on 24-hour UPCR. Key secondary endpoints are change from baseline in eGFR at weeks 52 and 104, eGFR total slope at week 104, time to the first occurrence of sustained decline in eGFR ≥30% from baseline over ≥4 weeks, time to the first occurrence of any of the prespecified clinical outcomes indicative of kidney failure, and achievement of ≥30% reduction from baseline in proteinuria at week 104. Safety evaluations include incidence of treatment-emergent adverse events (TEAEs) and treatment-related TEAEs occurring in ≥5% of the safety population, respectively, severe TEAEs, and clinically significant abnormal laboratory test results and vital signs.
Funding
- Takeda Development Center Americas, Inc.