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

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

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Acute Myeloid Leukemia; Relapsed/Refractory Acute Myeloid Leukemia; AML, Relapsed/Refractory
• Intervention / Treatment: Procedure: Haploidentical Allogeneic Hematopoietic Stem Cell Transplantation (haplo-HSCT); Drug: Post-transplant Maintenance Therapy

• Study Type: Observational
• Enrollment (Estimated): 40

Contacts and Locations

• Study Contact: Name: wei MD, PhD; Phone Number: +86 027-85726003; Email: shiwei076@hust.edu.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This is a single-center prospective observational study enrolling adult patients (18-65 years) with relapsed/refractory acute myeloid leukemia (R/R AML) who have active disease (bone marrow blasts >5% or extramedullary involvement) and are scheduled to undergo salvage haploidentical allogeneic hematopoietic stem cell transplantation (haplo-HSCT) at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. The study population consists of high-risk AML patients with HCT-CI ≤5 who are eligible for intensive transplant therapy according to institutional practice.

Description

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

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Salvage Haploidentical HSCT Cohort; Patients with relapsed/refractory acute myeloid leukemia (R/R AML) who have active disease (bone marrow blasts >5% or extramedullary involvement) before transplantation, aged 18-65 years, and HCT-CI score ≤5. All patients in this single-arm prospective observational cohort will receive salvage haploidentical allogeneic hematopoietic stem cell transplantation (haplo-HSCT) followed by standardized post-transplant relapse prevention strategies. Participants will be followed for 24 months after transplantation.

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-transplant cyclophosphamide (PTCY) is used. Immunosuppressants are tapered within 100 days if no significant GVHD.; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Cumulative Incidence of Relapse (CIR)	Up to 24 months post-transplantation
Overall Survival (OS)	Up to 24 months post-transplantation

Secondary Outcome Measures

Outcome Measure	Time Frame
Incidence of Acute GVHD (aGVHD)	Within 100 days post-transplantation
Incidence of Chronic GVHD (cGVHD)	Up to 24 months post-transplantation

Collaborators and Investigators

• Sponsor: Union Hospital, Tongji Medical College, Huazhong University of Science and Technology

Study record dates

Study Major Dates

• Study Start (Estimated): April 30, 2026
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): December 1, 2028

Study Registration Dates

• First Submitted: May 3, 2026
• First Submitted That Met QC Criteria: May 3, 2026
• First Posted (Actual): May 7, 2026

Study Record Updates

• Last Update Posted (Actual): May 7, 2026
• Last Update Submitted That Met QC Criteria: May 3, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Neoplasms; Disease Attributes; Neoplasms by Histologic Type; Hematologic Diseases; Leukemia, Myeloid; Leukemia; Pathological Conditions, Signs and Symptoms; Hemic and Lymphatic Diseases; Recurrence; Leukemia, Myeloid, Acute
• Other Study ID Numbers: [2025]num(0970)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No