A Study to Evaluate the Effectiveness and Safety of Sibeprenlimab in Participants With Primary Membranous Nephropathy, Immune-mediated Focal Segmental Glomerulosclerosis, and Minimal Change Disease

Who can take part

• For people with pMN:
• Be experiencing their first episode of pMN, or have pMN that has returned after getting better (relapsed), with ongoing signs of significant kidney disease based on urine and blood tests
• Have a blood test showing high levels of antibodies against PLA2R, a protein linked to pMN, and these antibody levels must not have improved significantly over the previous 8 to 24 weeks
• Be taking a stable, maximum tolerated dose of a kidney-protective medication (such as an angiotensin converting enzyme (ACE) inhibitor or angiotensin II receptor blockers [ARB]) for at least 3 months before screening. Other medications that help reduce protein in the urine may also be allowed if the dose has remained unchanged for at least 3 months; For people with IM-FSGS or MCD:
• Have previously been diagnosed with IM-FSGS or MCD, confirmed by a kidney biopsy
• Currently have their disease well controlled, either in complete remission or partial remission, based on urine and blood test results
• Have a disease that depends on immunosuppressive treatment (medications that reduce immune system activity), meaning:; They need ongoing treatment with medications such as steroids or calcineurin inhibitors (CNIs) to keep the disease under control; and; Within the last 18 months, they experienced a return of nephrotic syndrome (severe kidney disease symptoms) shortly after reducing or stopping immunosuppressive treatment
• Be taking a stable dose of steroids or CNIs for at least 4 weeks before screening

Who cannot take part

• Have a kidney condition other than pMN, IM-FSGS or MCD, or have previously received a kidney transplant
• Have recently received certain immune-suppressing treatments or other medications that could interfere with the study
• Are currently participating in another clinical trial or have recently received an investigational medicine
• Have another serious autoimmune disease that could affect their health or study results
• Have a serious active infection, such as human immunodeficiency virus (HIV), hepatitis B, hepatitis C, tuberculosis (TB), or other significant chronic infections
• Have a serious medical condition, including certain cancers, that could make study participation unsafe
• Have Type 1 diabetes or poorly controlled Type 2 diabetes
• Have a history of a severe allergic reaction to ingredients in the study drug
• Have uncontrolled high or low blood pressure
• Have recent alcohol or substance abuse that could interfere with participation
• Are unable to follow study procedures or attend required study visits; Note: Other protocol-specified Inclusion/Exclusion criteria may apply