• Age ≥ 18 years old, gender unrestricted;

• Confirmed diagnosis of relapsed/refractory malignant hematological tumors, including B-ALL, B-cell lymphoma and multiple myeloma;

• ECOG performance status score 0-2, with an expected survival period of ≥ 3 months;

• Blood routine test results during the screening period meet the following criteria:

• ① Hemoglobin ≥ 6 g/dL (no red blood cell transfusion within 1 week before screening), recombinant human erythropoietin (rhEPO) is allowed; for patients meeting the hemoglobin ≥ 6 g/dL criterion, red blood cell transfusion can be used to maintain hemoglobin ≥ 6 g/dL;

⁃ Absolute neutrophil count (ANC) ≥ 600/μL (no use of granulocyte colony-stimulating factor \[G-CSF\] within 1 week before screening, or no use of pegylated G-CSF within 2 weeks before screening); ③ Platelet count ≥ 50,000/μL; ④ Lymphocyte count ≥ 500/μL;

• Normal renal function during the screening period: creatinine clearance rate (CrCl) ≥ 45 mL/min (calculated using the Cockcroft-Gault formula);

• Liver function during the screening period meets the following criteria:

• ① Alanine aminotransferase (ALT), aspartate aminotransferase (AST) ≤ 3.0 × ULN;

• ② Total bilirubin (TBIL) ≤ 2.0 × ULN (except for congenital hyperbilirubinemia such as Gilbert's syndrome, direct bilirubin can be relaxed to ≤ 1.5 × ULN);

• Cardiac function during the screening period meets the following criteria:

• ① Left ventricular ejection fraction (LVEF) ≥ 40% (measured by echocardiography or MUGA scan);

• ② No clinically significant pericardial effusion;

• ③ No clinically significant electrocardiogram (ECG) abnormalities;

• Pulmonary function during the screening period meets the following criteria: blood oxygen saturation (SpO₂) ≥ 90%;

• Women of childbearing age must have a negative pregnancy test during the screening period and before drug administration, and must not be in the lactation period;

⁃ Men and women of childbearing age must agree to take effective contraceptive measures and not donate reproductive cells (including sperm or eggs) from the time of signing the informed consent form until 1 year after the end of study drug administration;

⁃ The subject or their legally authorized representative has signed the informed consent form (ICF), indicating their understanding of the purpose and procedures of the study and their voluntary participation in this study.