RecruitingPhase 3Drug trialA Study to Evaluate the Efficacy and Safety of Sefaxersen (RO7434656) in Participants With Primary Immunoglobulin A (IgA) Nephropathy at High Risk of ProgressionThe purpose of this study is to evaluate the efficacy, safety, and pharmacokinetics of sefaxersen (RO7434656), a novel Antisense Oligonucleotide (ASO) therapy in participants with primary IgA nephropathy (IgAN) who are at high risk of progressive kidney disease despite optimized supportive care.