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

Inclusion criteria

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 * Evidence of active LN at screening Inclusion Criteria for systemic sclerosis (SSc): * Age ≥ 18 years * Diffuse Systemic Sclerosis (SSc) according to ACR/EULAR 2013 classification criteria with active skin disease and/or progressive SSc-interstitial lung disease (ILD) OR limited SSc with progressive ILD. * Refractory or intolerance to 1 of the following for a minimum of 3 months and/or contraindication: mycophenolate mofetil or its derivatives, methotrexate, tocilizumab (or other IL-6 inhibitor), rituximab (or other B-cell depleting agent), nintedanib (or other antifibrotic agents), cyclophosphamide. * High-resolution computer tomography (HRCT) scan and pulmonary function test (PFT) within 3 months prior to screening. Inclusion Criteria for idiopathic inflammatory myopathy (IIM): * Age ≥ 18 years * Probable or definite IIM based on EULAR/ACR 2017 classification (excluding inclusion body myositis). * Active disease demonstrated by electromyography (EMG), magnetic resonance imaging (MRI) or muscle enzymes * Moderate to severe disease activity * Positive for myositis specific antibodies for patients with non-dermatomyostitis IIM * HRCT scan and PFT within 3 months prior to screening. * Refractory or intolerance to at least 1 month of glucocorticoids and standardized use of at least 2 immunosuppressant/modulator (eg, intravenous gamma globulins, methotrexate, mycophenolate mofetil and its derivatives, azathioprine, cyclophosphamide, calcineurin inhibitors, Janus kinase (JAK) inhibitors, rituximab or other B-cell depleting agent). Inclusion Criteria for all Cohorts: * Adequate hepatic, renal, pulmonary, and cardiac function. Key