A Study of CC-97540, CD-19-Targeted Nex-T CAR T Cells, in Participants With Severe, Refractory Autoimmune Diseases (Breakfree-1)

Inclusion Criteria \- Diagnosis of Systemic Lupus Erythematosus (SLE) defined as follows:. i) Fulfilling the 2019 European League Against Rheumatism (EULAR) / American College of Rheumatology (ACR) classification criteria of SLE. ii) Presence of anti-dsDNA, anti-histone, anti-chromatin, anti-Ro (anti-SS-A), anti-La (anti-SS-B), or anti-Sm antibodies at screening. \- SLE disease activity:. i) Active disease at screening, with recent ≥ 1 major organ system with a BILAG A score (excluding musculoskeletal, mucocutaneous, and/or constitutional organ system). ii) Inadequate response to glucocorticoids and to at least 2 of the following treatments, used for at least 3 months each: cyclophosphamide, mycophenolic acid or its derivatives, belimumab, azathioprine, anifrolumab, methotrexate, rituximab, obinutuzumab, cyclosporin, tacrolimus or voclosporin. * Diagnosis of Idiopathic Inflammatory Myopathy (IIM) defined as follows:. i) Fulfilling the 2017 EULAR/ACR classification criteria for probable or definite IIM. ii) Participant diagnosed with the following IIM subgroups: dermatomyositis (DM), immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASyS), and polymyositis (PM). iii) Presence of at least 1 myositis specific antibody (MSA), associated antibody (MAA), or ANA at screening or prior to screening. * IIM disease activity:. i) Severe/moderate muscle AND/OR skin involvement. ii) Proof of activity as documented by:. A. An active myositis-associated…