Relmacabtagene Autoleucel As Second-Line Therapy in Adult Patients with Aggressive B-cell NHL

Inclusion Criteria: 1. Age≥18 years; 2. Signed written informed consent obtained prior to any study procedures; 3. Histologically confirmed relapsed or refractory (R/R) aggressive B-cell NHL of the following histologiesLBCL as defined by the World Health Organization (WHO) Classification 2022:Diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS), high-grade B-cell lymphoma (HGL) with MYC and BCL2 rearrangements,HGL-NOS, Primary mediastinal large B-cell lymphoma, Follicular lymphoma Grade 3B (FL3B),Indolent B-NHL-transformed large B-cell lymphoma with adequate prior treatment with anthracycline-containing agents and rituximab or other CD20-targeted agents; 4. Subjects must meet the definition of refractory or relapsed; 5. Subjects were not eligible for HDCT/ASCT based on the investigator's assessment ; 6. Adequate organ function; 7. Presence of positive PET assessable lesions as determined by the Lugano criteria ; 8. Eastern Cooperative Oncology Group (ECOG) performance status of 0-2; 9. Expected survival greater than 12 weeks; 10. Adequate vascular access for leukapheresis procedure; 11. Women of childbearing potential must agree to use highly effective methods of contraception for at least 28 days prior to lymphocyte clearance chemotherapy through 2 year after Relmacabtagene Autoleucel infusion; Males who have partners of childbearing potential must agree to use an effective barrier contraceptive method for 2 year after Relmacabtagene Autoleucel infusion; Exclusion Criteria: 1. Subjects with non-Hodgkin's lymphoma who have received second or more line therapy; 2. Lymphoma of the primary center (subjects with secondary central nervous system lymphoma are allowed to enroll; 3. History of another primary malignancy that has not been in remission for at least 2 years; 4. Subjects has active HBV, HCV, HIV or syphilis infection at the time of screening; 5. Deep venous thrombosis (DVT)/Pulmonary embolism (PE), or DVT/PE requires anti-coagulation within 3 months prior to signing the ICF; 6. Subjects with uncontrolled systemic fungal, bacterial, viral or other infection; 7. Uncontrolled diabetes and hypertension; 8. Presence of acute or chronic graft-versus-host disease (GVHD); 9. Active autoimmune disease requiring immunosuppressive therapy; 10. History of any serious cardiovascular disease or presence of clinically relevant CNS pathology; 11. Pregnant or nursing women; 12. Subjects Received an autologous or allogeneic hematopoietic stem cell transplant; 13. Uncontrolled conditions or unwillingness or inability to follow the procedures required in the protocol; 14. Received CAR T-cell or other genetically-modified T-cell therapy previously; 15. Received live vaccination within 6 weeks prior to lymphocyte clearance chemotherapy; 16. History of severe hypersensitivity reactions to any of the drug ingredients used in this study product.