Immune Reconstitution After Allo-HSCT and Blinatumomab

Study Overview
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Brief Summary
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The goal of this observation study is to test in relapsed or refractory acute lymphoblastic leukemia (R/R ALL) patients undergoing allogeneic hemopoietic stem-cell transplantation (allo-HSCT). The main question it aims to answer is: • Effect of post-transplant blinatumomab treatment on immune reconstitution after transplantation. Participants will undergo immune repertoire sequencing(IR-SEQ) before blinatumomab treatment, 6 months and 1 year after transplantation. Researchers will compare patients who don't receive blinatumomab treatment after transplantation to see if TCR or BCR expression differs.

Official Title
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Immune Reconstitution After Allogeneic Hematopoietic Stem Cell Transplantation With Post-transplant Blinatumomab Maintenance Treatment

Conditions
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Leukemia, Lymphoid

Intervention / Treatment
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* Drug: blinatumomab


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 16-65 years old KPS score > 60 or ECOG score 0-2 diagnosed as B-ALL, a) disease status > CR1 at the time of transplantation; Patients beyond CR1 or induction failure could be free of minimal residual disease (MRD). b) any residual disease, defined as >0.01% leukemic cells by flow cytometry, BCR-ABL transcript ≥ 1 in 10000 by PCR, or high-risk genetic abnormality neutrophil count ≥0.5×10^9/L and platelet count ≥20×10^9/L creatinine clearance ≥30ml/min; Alanine aminotransferase/aspartate aminotransferase ≤5 times the upper detection limit; Total bilirubin ≤3 times the upper limit of detection The first initiation of berintuzumab therapy was within 60-100 days after transplantation without evidence of active acute graft-versus-host disease (aGvHD) Exclusion Criteria: With serious basic diseases of important organs, such as myocardial infarction, chronic cardiac insufficiency, decompensated liver dysfunction, renal dysfunction, gastrointestinal dysfunction, etc With clinically uncontrolled active infection Patients with central nervous system involvement before transplantation Poor graft function (PGF) occurred after allo-HSCT Patients with second allogeneic transplantation

Ages Eligible for Study
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Minimum Age: 16 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Blin-PTCY<br>Post-transplant cyclophosphamide is used as graft versus host disease (GvHD) prophylaxis. Treatment with blinatumomab was initiated within 60 to 90 days after transplantation and was administered bimonthly until 1 year after transplantation. | Drug: blinatumomab<br>* The dose of one course was as follows: day 1-2: 8ug/day, continuous intravenous drip for 24 hours, day 3-7: 16ug/day, continuous intravenous drip for 24 hours. Treatment with blinatumomab was initiated within 60 to 90 days after transplantation and was administered bimonthly until 1 year after transplantation. Dexamethasone 20mg was administered 1 hour before administration on days 1 and 3 to prevent adverse events.<br>|
| Blin-ATG<br>Antithymocyte globulin is used as graft versus host disease (GvHD) prophylaxis. Treatment with blinatumomab was initiated within 60 to 90 days after transplantation and was administered bimonthly until 1 year after transplantation. | Drug: blinatumomab<br>* The dose of one course was as follows: day 1-2: 8ug/day, continuous intravenous drip for 24 hours, day 3-7: 16ug/day, continuous intravenous drip for 24 hours. Treatment with blinatumomab was initiated within 60 to 90 days after transplantation and was administered bimonthly until 1 year after transplantation. Dexamethasone 20mg was administered 1 hour before administration on days 1 and 3 to prevent adverse events.<br>|
| Control<br>Patients don't take blinatumomab treatment after transplantation. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| T cell receptor expression | T cell receptor expression measured by Immune Repertoire sequencing(IR-SEQ) | before blinatumomab treatment , 6 months and 1 year | 
| B cell receptor expression | B cell receptor expression measured by Immune Repertoire sequencing(IR-SEQ) | before blinatumomab treatment , 6 months and 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| T cell subsets count | T cell subsets count including CD3+, CD4+, CD8+, CD19+, Treg, memory and cytotoxic T cells | before blinatumomab treatment , 6 months and 1 year |