Date

2025-06-25

Protocol

Protocol changed

Item Changed

Secondary outcome

Previous Version

• Annualized rate of change from baseline (slope) of eGFR [ Time Frame: Over 24 months] • Proportion of subjects achieving urine total protein < 1.0 g/day and ? 25% reduction from baseline. [ Time Frame: At 12 months] Annualized slope of eGFR [ Time Frame: Over 12 months]

Next Version

Key Secondary Efficacy: The annualized slope of eGFR estimated over the course of approximately 24 months. Efficacy: • Mean change of eGFR from baseline at 24 months. • Progression to CKF, as assessed by: o Time to progression to CKF (time from the randomization date to first occurrence of CKF). o Proportion of subjects with progression to CKF. CKF is defined as meeting 1 or more of the following criteria based on observed assessments or therapy: sustained doubling of serum creatinine compared with baseline based on 2 measurements at least 4 weeks apart, sustained 40% reduction in eGFR compared with baseline based on 2 measurements at least 4 weeks apart, sustained eGFR < 15 mL/min/1.73 m2 based on 2 measurements at least 4 weeks apart, or the requirement of renal replacement therapy (chronic dialysis for ? 4 weeks or kidney transplantation). Pharmacodynamics: Change from baseline in total serum IgA, IgG, and IgM concentrations. Safety: Incidence of TEAEs graded by severity, clinical laboratory tests, vital sign measurements, physical examinations, and injection site reactions. Other: Evaluation of serum ADA.