RecruitingPhase 2Biological interventionObe-cel in Severe, Refractory Systemic Lupus Erythematosus (SLE) With Active Lupus Nephritis (LN)The purpose of this trial is to evaluate the efficacy and safety of obecabtagene autoleucel (obe-cel) administered once following lymphodepletion in participants with severe, refractory systemic lupus erythematosus (SLE) and active lupus nephritis (LN).