Primary Membranous Nephropathy (pMN) is a kidney disease where the body's immune system mistakenly attacks the kidneys, causing damage. This study is testing a medicine called povetacicept to see if it helps people with pMN feel better and to check if it's safe and comfortable for them to take.

People can join the study if they have been diagnosed with pMN through a special test called a biopsy. If they haven't had this test before, they might need to have one done. People who are allergic to the study medicine cannot join. The study has other rules about who can and cannot join.

• Study Length: Participants will be in the study for several months to help researchers understand the medicine's effects over time.
• Visits Needed: Participants will need to visit the study site regularly for check-ups and to receive the medicine.
• Safety: The study will closely monitor participants for any side effects or discomfort from the medicine.