A Study of KITE-363 in Participants With Refractory Autoimmune Diseases

Key Inclusion Criteria: Inclusion Criteria for systemic lupus erythematosus (SLE) and lupus nephritis (LN): * Age ≥ 18 years * Meet the European Alliance of Associations for Rheumatology (EULAR)- American College of Rheumatology (ACR) 2019 classification criteria for SLE * Presence of either double-stranded deoxyribonucleic acid (DNA) anti- double-stranded DNA (anti-dsDNA) and/or anti-Smith antibodies at screening per local laboratory. * Moderate to severe, active disease defined as at least one British Isles Lupus Assessment Group (BILAG-A) score or 2 BILAG B (excluding constitutional and/or neuropsychiatric organ system). * Refractory to steroids and inadequate response or intolerance to at least 2 of the following treatments, used for at least 3 months each: cyclophosphamide, mycophenolate mofetil or its derivatives, belimumab, anifrolumab, rituximab, obinutuzumab, methotrexate, azathioprine, cyclosporin, tacrolimus, or voclosporin. * For LN: Refractory to steroids and inadequate response or intolerance to at least 2 of the following treatments, used for at least 3 months each: cyclophosphamide, mycophenolate mofetil or its derivatives, belimumab, rituximab, obinutuzumab, azathioprine, cyclosporin, tacrolimus, or voclosporin Inclusion Criteria for LN: * Renal biopsy-proven Class III or intravenous (IV) ± V LN according to the revised International Society of Nephrology and Renal Pathology Society (ISN/RPS) criteria within 6 months prior to or during screening * Evidenc…