VIBRANT: VIB4920 for Active Lupus Nephritis

Seventy-four eligible participants with active lupus nephritis (LN) will be randomized to receive VIB4920 1500 mg or placebo intravenously at Weeks 0, 2, 4, 8, 12, 16, 20, and 24. Participants will receive a total of 1000 mg of methylprednisolone according to either of the following schedules: * 1000 mg methylprednisolone IV at Day 0, or * 500 mg methylprednisolone IV at Day 0 and at Day 1. Participants who previously received 1000 mg of methylprednisolone IV within 42 days of Visit 0 will not receive additional methylprednisolone IV on Day 0. Participants who previously received less than 1000 mg of methylprednisolone IV within 42 days of Visit 0 will receive an additional dose of methylprednisolone IV at Day 0, according to the following formula, where X is the intravenous dose previously received and Y is the intravenous dose administered on Day 0: 1000 mg - X = Y. Participants will also receive MMF 2-3 g per day and will receive prednisone 25 mg/d beginning on Day 0, or on the day after completion of methylprednisolone. Prednisone will be tapered to 5 mg/d by Week 8.