The purpose of this study is to determine if the investigational (not FDA approved) drug VIB4920 can be an effective treatment for patients with active Lupus Nephritis (LN).

This study will compare treatment with MMF (mycophenolate mofetil), Prednisone, plus the study medication VIB4920 to treatment with MMF and Prednisone alone.

Participants will have 16 scheduled visits that will involve routine monitoring of disease activity, up to two kidney biopsies, and blood and urine specimen collections. Participation in this study will last approximately 1 year and 2 months. Compensation is available for participation.

This study is a one-time visit for newly diagnosed lupus patients and healthy control subjects. Volunteers will be asked to answer questions about their medical, social, and diet history. Participants will also have blood, urine, and stool samples collected for testing. The purpose of this study is to understand what role organisms in the human gut and environmental exposures have on the development of autoimmune disease. This is not a drug study.