Cousin vs. Sibling Donors in Haplo-HSCT

Comparison of Outcomes of Haploidentical Hematopoietic Stem Cell Transplantation From Cousin Donors Versus Sibling Donors in Patients With Hematological Malignancies: A Target Trial Emulation Study

This observational study aims to emulate a hypothetical pragmatic, multicenter, non-blinded clinical trial enrolling adult patients undergoing haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with grafts derived from either cousin or sibiling donors.

The main research question is whether cousin donor-derived haplo-HSCT is associated with inferior clinical outcomes relative to sibling donor-derived haplo-HSCT.

Study participants consist of adult patients diagnosed with hematological malignancies who underwent cousin or sibiling haplo-HSCT between 2017 and 2024, and all eligible recipients will receive regular follow-up assessments.

Study Overview

• Status: Not yet recruiting
• Conditions: Haploidentical Hematopoietic Stem Cell Transplantation; Donor; Hematopoietic Malignancies

• Study Type: Observational
• Enrollment (Estimated): 1000

Contacts and Locations

Study Locations

• China
  • Jiangsu
    • Suzhou, Jiangsu, China, 215000
      • The First Affiliated Hospital of Soochow University

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

This multicenter, retrospective observational study included adult patients with hematological malignancies undergoing their first haploidentical hematopoietic stem cell transplantation at four clinical centers between 2017 to 2024. Eligible patients were identified through retrospective clinical records and stratified by donor kinship recorded at transplant, classified as either cousin or sibling donor graft recipients.

Description

Inclusion Criteria:

• Adult patients diagnosed with hematological malignancies, including acute leukemia (AL), chronic myeloid leukemia (CML), myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), and non-Hodgkin lymphoma (NHL)
• Receipt of first haploidentical hematopoietic stem cell transplantation between 2017 and 2024
• Documented exact date of transplantation available in medical charts
• Verifiable donor kinship classified as either cousin or sibiling
• Complete longitudinal follow-up data accessible for outcome assessment

Exclusion Criteria:

• Prior receipt of any form of hematopoietic stem cell transplantation
• An age difference of more than 18 years between the donor and recipient
• Failure of successful infusion of donor-derived hematopoietic stem cells following conditioning regimen

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Cousin haplo-HSCT; Patients who underwent haploidentical hematopoietic stem cell transplantation with cousin donors. Grouping was based on donor age recorded in retrospective clinical data.
Sibling haplo-HSCT; Patients who underwent haploidentical hematopoietic stem cell transplantation with sibling donors. Grouping was based on donor age recorded in retrospective clinical data.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall survival	estimated overall survival at 2 year	2 years after transplantation
Graft-versus-host disease-free and relapse-free survival	estimated graft-versus-host disease-free and relapse-free survival at 2 year	2 years after transplantation
Cumulative incidence of acute graft-versus-host disease	estimated cumulative incidence of acute graft-versus-host disease at 180 day	180 days after transplantation
Cumulative incidence of chronic graft-versus-host disease	estimated cumulative incidence of chronic graft-versus-host disease at 2 year	2 years after transplantation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cumulative incidence of relapse	estimated cumulative incidence of relapse at 2 year	2 years after transplantation
Non-relapse mortality	estimated non-relapse mortality at 2 year	2 years after transplantation
Cumulative incidence of grade III-IV acute graft-versus-host disease	estimated cumulative incidence of grade III-IV acute graft-versus-host disease at 180 day	180 days after transplantation
Cumulative incidence of extensive chronic graft-versus-host disease	estimated cumulative incidence of extensive chronic graft-versus-host disease at 2 year	2 years after transplantation

Collaborators and Investigators

• Sponsor: The First Affiliated Hospital of Soochow University
• Collaborators: Ruijin Hospital; Zhejiang University; Nanfang Hospital, Southern Medical University
• Investigators: Principal Investigator: Yang Xu, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): October 31, 2027

Study Registration Dates

• First Submitted: June 16, 2026
• First Submitted That Met QC Criteria: June 16, 2026
• First Posted (Actual): June 23, 2026

Study Record Updates

• Last Update Posted (Actual): June 23, 2026
• Last Update Submitted That Met QC Criteria: June 16, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Hematologic Diseases; Hemic and Lymphatic Diseases; Hematologic Neoplasms
• Other Study ID Numbers: TTE2026610

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