This study will look at how safe and effective the study drug, ALLO-329, is for people with autoimmune diseases like lupus. Participants will get one dose through an IV. The goal is to find the safest amount of the treatment that could help people stay in remission longer.

This is a study looking at the effects of Belimumab, a medication approved by the FDA to treat lupus, in people who have been recently diagnosed with lupus. It proposes that the early use of Belimumab may prevent long-term tissue damage from the disease. The study will last 2 years with clinic visits every 4 weeks.