The Efficacy and Safety Assessment of Allogeneic γδ T Cells in Patients With MRD-positive AML After Allo-HSCT

This is a single-center, randomized, open label phase I clinical trial to evaluate the efficacy and safety of ex-vivo expanded allogeneic γδ T cells in patients with MRD-positive AML after allo-HSCT. The infusion doses of γδ T cells were 2E8 cells/kg and 4E8 cells/kg.

Inclusion criteria

• Patients should sign informed consent form voluntarily before the trail and comply with the requirements of this study.
• Age≥18 years old, gender unlimited.
• All the subjects met the 2016 WHO classification and were diagnosed with AML via MICM (Morphology,Immunophenotyping, Cytogenetics, and Molecular genetics).
• AML patients receiving allo-HSCT.
• Subjects classified into the favorable -to-intermediate risk group according to the 2022 European Leukemia Net (ELN) risk stratification guidelines.
• All subjects were detected positive for MRD, and MRD was positive by flow cytometry (MFC) or/and positive for fusion genes/gene mutations by RQ-PCR.
• ECOG performance status score: 0-2.
• Inactive GVHD (acute GVHD grade II-IV or moderate to severe chronic GVHD).
• Adequate bone marrow reserve, defined as: absolute neutrophil count (ANC) > 0.5E9/L and platelet count ≥20E9/L.
• Adequate organ function as per protocol.
• Male and female patients of reproductive potential must agree to use birth control during the study and for at least 28 days post study.

Exclusion criteria

• Post-transplant relapse or extramedullary disease: AML patients post-allo-HSCT with ≥5% blasts in peripheral blood or bone marrow (excluding causes such as bone marrow regeneration after consolidation chemotherapy) or extramedullary leukemia infiltration.
• Active GVHD: Subjects with active GVHD within 30 days before screening.
• Active infections: HBV, HCV, HIV, syphilis (TP), active CMV, or EBV infection.
• Neurological disorders: active autoimmune or inflammatory neurological diseases, clinically significant active cerebrovascular disease.
• Unstable systemic diseases, including: unstable angina, cerebrovascular accident or transient ischemic attack (within 6 months before screening), myocardial infarction (within 6 months before screening), NYHA Class III/IV heart failure, refractory hypertension (defined as failure to control blood pressure despite lifestyle modifications and treatment with ≥4 antihypertensive drugs, including diuretics, for >1 month), clinically significant arrhythmias requiring medication, severe hepatic, renal, or metabolic disorders.
• Major surgery: Subjects who underwent major surgery within 4 weeks before screening, as deemed ineligible by the investigator.
• Concurrent non-hematologic malignancies.
• Cardiac abnormalities, meeting any of the following: Left ventricular ejection fraction (LVEF) ≤45%. NYHA Class III/IV congestive heart failure. QTc interval >480 msec. Other cardiac conditions considered unsuitable by the investigator.
• History of epilepsy or other active CNS disorders.
• Uncontrolled infections: active systemic infections requiring treatment (e.g., sepsis, bacteremia, fungemia, tuberculosis, opportunistic infections).
• Recent participation in other interventional trials: Subjects who participated in another interventional clinical study within 30 days prior to enrollment.
• Other conditions: Any other circumstances deemed by the investigator to compromise subject safety or trial integrity.