Single-Dose gene therapy aims to reprogram immune cells against tough leukemia

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Patient or legal guardian voluntarily signs the informed consent form (ICF), demonstrating understanding of the study purpose and procedures, and willingness to participate. 2. Age 3 to 75 years, inclusive, male or female. 3. Diagnosis of relapsed or refractory acute leukemia per guideline criteria: Relapsed: reappearance of leukemic cells in peripheral blood or bone marrow blasts ≥5% after achieving complete remission (CR); Refractory: failure to achieve CR after 2 courses of standard induction chemotherapy; relapse within 12 months after consolidation/intensification therapy; relapse after 12 months with no response to conventional chemotherapy; 2 or more relapses; extramedullary leukemia relapse or persistence; relapse after allogeneic hematopoietic stem cell transplantation. 4.Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2. 5.Life expectancy ≥12 weeks. 6.Bone marrow morphology showing ≥5% primitive/immature lymphocytes (blasts). 7.Tumor cells positive for CD19, BCMA, or CD70 expression by flow cytometry. 8.Adequate major organ function, defined as: 1. Cardiac: left ventricular ejection fraction (LVEF) ≥40% by echocardiogram; 2. Renal: serum creatinine ≤2.0× upper limit of normal (ULN), or creatinine clearance ≥50 mL/min (Cockcroft-Gault formula); 3. Hepatic: ALT and AST ≤3.0×ULN (≤5.0×ULN if with liver involvement); total bilirubin ≤2.0×ULN (≤3.0×ULN for Gilbert's syndrome); 4. Pulmonary: oxygen saturation ≥92% on room air; 5. Hematologic: absolute neutrophil count (ANC) ≥1.0×10⁹/L, platelets ≥50×10⁹/L, hemoglobin ≥80 g/L (with bone marrow involvement, ANC ≥0.5×10⁹/L, platelets ≥20×10⁹/L permitted) - assessments allowed after transfusion or hematopoietic growth factor support. 9\. For women of childbearing potential, negative serum pregnancy test; all participants agree to use reliable (non-rhythm) contraceptive methods from ICF signing through 1 year post-PID23 infusion. Exclusion Criteria: 1. Prior treatment with CAR-T or other genetically modified cell therapies, unless the investigator determines that safety risks have been adequately excluded. 2. Received the following anti-tumor therapies prior to PID23 infusion: Chemotherapy or molecular targeted therapy within 14 days or 5 half-lives (whichever is longer) (excluding conditioning chemotherapy and intrathecal chemotherapy; intrathecal therapy must be stopped ≥1 week prior to PID23 infusion); Radiotherapy to non-hematopoietic sites within 7 days; Radiotherapy to hematopoietic sites within 14 days. 3. Any of the following cardiac conditions: (1) New York Heart Association (NYHA) Class III or IV congestive heart failure; (2) Myocardial infarction or coronary artery bypass grafting (CABG) within 6 months prior to enrollment; (3) Clinically significant ventricular arrhythmia, or unexplained syncope (excluding vasovagal or dehydration-related); (3) History of severe non-ischemic cardiomyopathy. 4.Active or uncontrolled infection requiring systemic therapy within 1 week prior to screening. 5.Grade 2-4 acute graft-versus-host disease (GVHD) or moderate-to-severe chronic GVHD within 4 weeks prior to screening. 6.Cerebrovascular accident or seizure within 6 months prior to screening. 7.Deep vein or arterial thrombosis event within 6 months prior to screening. 8.Active malignancy other than acute leukemia (excluding: inactive disease with treatment completed \>2 years; adequately treated cervical carcinoma in situ, basal/squamous cell skin carcinoma, localized prostate cancer post-curative surgery, ductal carcinoma in situ post-curative surgery). 9.Received (attenuated) live vaccine within 4 weeks prior to screening. 10.Any other condition that, in the investigator's judgment, makes the patient unsuitable for participation in this study.