⁃ The subjects voluntarily participate in this study, sign the informed consent form, and have good compliance;

⁃ Age ≥18 years (calculated from the date of informed consent);

⁃ Eastern Cooperative Oncology Group (ECOG) score 0 \

• 2 points;

⁃ Expected survival greater than 12 weeks;

⁃ Histological or cytological diagnosis of diffuse large B-cell lymphoma in accordance with the World Health Organization (WHO) diagnostic criteria in 2022;

⁃ Pathological diagnosis results containing CD20 positive expression and Myc rearrangement negative after anti-CD20 treatment must be provided;

⁃ Subjects with relapsed or refractory diffuse large B-cell lymphoma who have received at least 1 line of systemic therapy;

⁃ Not suitable for hematopoietic stem cell transplantation;

⁃ According to the Lugano criteria in 2014, there is at least one measurable lesion, that is, the long diameter of lymph node lesions \> 15 mm or extranodal lesions \> 10 mm according to CT cross-sectional images; Positron emission tomography - computerized tomography (PET-CT) scan shows PET positive;

⁃ Laboratory tests meet specific criteria;

⁃ Adopt effective contraceptive measures;