Salvage Haploidentical HSCT With DLI and Targeted Therapy for R/R AML

Official title

Salvage Haploidentical Allogeneic Hematopoietic Stem Cell Transplantation Combined With Post-transplant Relapse Prevention Strategies for Relapsed/Refractory Acute Myeloid Leukemia (AML): A Prospective Observational Study

Overview

This is a prospective, single-center, observational study to evaluate the efficacy and safety of salvage haploidentical allogeneic hematopoietic stem cell transplantation (haplo-HSCT) combined with post-transplant relapse prevention strategies in patients with relapsed/refractory acute myeloid leukemia (R/R AML). Eligible patients are adults aged 18-65 years with active AML (bone marrow blasts \>5% or extramedullary disease) and HCT-CI score ≤5. All patients will receive a uniform conditioning regimen consisting of fludarabine, busulfan, and MECCNU, with addition of targeted agents (such as sorafenib, midostaurin, or venetoclax) according to mutation status. Graft-versus-host disease (GVHD) prophylaxis includes reduced-dose ATG (6 mg/kg), FK506, MMF, and basiliximab. Post-transplant maintenance with targeted therapy or azacitidine and prophylactic donor lymphocyte infusion (DLI) will be administered to reduce relapse risk. The primary endpoints are cumulative incidence of relapse (CIR), overall survival (OS), and progression-free survival (PFS). Secondary endpoints include incidence of acute and chronic GVHD, CMV/EBV reactivation, non-relapse mortality (NRM), and GVHD-free, relapse-free survival. Patients will be followed for 24 months after transplantation. This study aims to explore an optimized transplant strategy to improve long-term survival in this high-risk population.

Interventions

• Procedure Haploidentical Allogeneic Hematopoietic Stem Cell Transplantation (haplo-HSCT)
  Salvage haploidentical allogeneic hematopoietic stem cell transplantation using a conditioning regimen of Fludarabine (120-180 mg/m²), Busulfan (3-4 mg/kg), and MECCNU 250 mg/m² (intensity adjusted based on prognostic index). Targeted agents (sorafenib, midostaurin, or venetoclax) are added according to genetic mutations (e.g., FLT3) until stem cell infusion. GVHD prophylaxis includes ATG 6 mg/kg, tacrolimus (FK506), mycophenolate mofetil (MMF), and basiliximab on day +4. No MTX or post-transpla
• Drug Post-transplant Maintenance Therapy
  Starting from approximately day +30 after transplantation, patients receive mutation-guided targeted therapy (sorafenib 200 mg daily for FLT3/ITD mutation) or azacitidine 75 mg/m² on days 1-3. Maintenance therapy aims to reduce the risk of relapse.

Primary outcome measures

• Cumulative Incidence of Relapse (CIR) [Time frame: Up to 24 months post-transplantation]
• Overall Survival (OS) [Time frame: Up to 24 months post-transplantation]

Secondary outcome measures (2)

• Incidence of Acute GVHD (aGVHD) [Time frame: Within 100 days post-transplantation]
• Incidence of Chronic GVHD (cGVHD) [Time frame: Up to 24 months post-transplantation]

Eligibility criteria

Inclusion criteria

• Signed and dated informed consent Willing and able to comply with all study procedures and follow-up Adults aged 18 to 65 years Diagnosis of acute myeloid leukemia (AML) Active disease before transplantation, defined as bone marrow blasts >5% or presence of extramedullary disease HCT-CI (Hematopoietic Cell Transplantation-Comorbidity Index) score ≤5

Exclusion criteria

• Bone marrow blasts ≤5% without extramedullary disease before transplantation Age <18 years or >65 years HCT-CI score >5 Patients with other diagnoses besides AML

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

Center list to be confirmed — check the primary protocol.

Identifiers

NCT: NCT07572695 · [2025]num(0970)

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗