This is a Phase 3, randomized, double-blind, placebo-controlled, multicenter study to evaluate the efficacy, safety, and tolerability of oral Nefecon compared to matching placebo in patients with primary IgAN on a background of optimized RAS inhibitor therapy. The study will consist of 2 parts, Part A and Part B. Part A will include a 9 month blinded Treatment Period, and a 3-month Follow up Period. Part B of the study will consist of a 12-month observational Follow up Period; no study drug will be administered during Part B. Part A and B will be blinded. Safety will be monitored by an independent Data Safety Monitoring Board.
