A Phase 3, Single-Arm, Open-Label Extension Study Evaluating the Long-Term Safety and Efficacy of Povetacicept in Adults With Immunoglobulin A Nephropathy

Key Inclusion Criteria: * Completed the Week 104 visit in the parent study VX24-AIS-D08 (NCT06564142) and has not permanently discontinued study drug * Estimated glomerular filtration rate (eGFR) greater than or equal to (≥) 15 milliliters per minute (mL/min)/1.73 square meter (m\^2) within 45 days of Day 1 of this study Key Exclusion Criteria: \- Planned participation in another interventional, therapeutic clinical trial (other than the parent study). Other protocol defined Inclusion/Exclusion criteria may apply.