A Study of LUCAR-G79D in Subjects With Relapsed/Refractory Systemic Lupus Erythematosus (r/r SLE) and Idiopathic Inflammatory Myopathies (r/r IIM)

Inclusion Criteria: 1. Subjects voluntary agreement to provide written informed consent. 2. Aged 18 to 70 years, either sex. 3. Adequate organ function meet screening criteria. 4. Positive test for cluster of differentiation antigen 19 (CD19). SLE: * Have been diagnosed of SLE at least 6 months before screening. * At screening, antinuclear antibody, and/or anti-dsDNA antibody, and/or anti-Smith antibody should be positive. * Fulfill relapsed/refractory SLE conditions. IIM: * Have been diagnosed of IIM before screening. * Positive test for myositis-associated antibodies or myositis-specific antibodies at screening. * Fulfill relapsed/refractory IIM conditions. Exclusion Criteria: 1. Active infections such as hepatitis and tuberculosis. 2. Other autoimmune diseases. 3. Serious underlying diseases such as tumor, uncontrolled diabetes. 4. Female subjects who were pregnant, breastfeeding. 5. Those with a history of major organ transplantation.