Immunoglobulin A Nephropathy (IgAN)

In this study, researchers will learn more about the use of felzartamab in participants with immunoglobulin A nephropathy (IgAN). IgAN is a kidney disease caused by the buildup of an antibody called IgA in the kidneys over time. In people with IgAN, abnormal IgA and other antibodies form clusters that build up in the small filters of the kidneys, which leads to inflammation and damage. Felzartamab is designed to target certain immune cells that produce these abnormal antibodies. This study will focus on participants who have protein in their urine (proteinuria) as a result of damaged kidneys. The main goal of the study is to learn about the effect felzartamab has on proteinuria. The main question that researchers want to answer is: • How much does the amount of protein in the urine change from the start of the study to Week 36? Researchers will learn about the effect felzartamab has on the kidneys' ability to filter blood. They will also learn more about the safety of felzartamab and how it is processed by the body. The study will be done as follows: * Participants will be screened to check if they can join the study. * Participants will be randomized to receive either felzartamab or a placebo. A placebo looks like the study drug but contains no real medicine. * Neither the researchers nor the participants will know what the participants will receive. * Participants will receive felzartamab or placebo as intravenous (IV) infusions. The treatment period will last 24 weeks. * Afterwards, participants will enter a follow-up period which will last 80 weeks. * In total, participants will have 17 study visits. Participants will stay in the study for about 2 years.

This is a Phase 2 study to assess the safety, efficacy, pharmacokinetics (PK) and pharmacodynamics of ADX-038 in adults with complement-mediated kidney diseases. The study will enroll Chinese adults with IgA nephropathy, complement 3 glomerulopathy (C3G) and immune complex membranoproliferative glomerulonephritis (IC-MPGN). The study will evaluate ADX-038 administered alone (Part A) and in combination with telitacicept (Part B).

The purpose of the study is to assess the effect of zigakibart on IgA nephropathy (IgAN) disease progression.

This is a multicenter, randomized, double-blind, parallel, placebo-controlled study and is being conducted to evaluate the efficacy and safety of HS-10542 capsules for primary IgA nephropathy.