Younger vs. Older Donors in Allo-HSCT: TTE

June 22, 2026 updated by: The First Affiliated Hospital of Soochow University

Prognostic Comparison of Allogeneic Hematopoietic Stem Cell Transplantation Using Younger Versus Older Donors: A Target Trial Emulation Study

Hematopoietic stem cell transplantation is an important therapeutic approach for hematologic malignancies, and the impact of donor age on transplant outcomes remains an active area of investigation. Older donors may be associated with impaired stem cell fitness, delayed immune reconstitution, and reduced T-cell function. However, randomized controlled trials directly comparing transplant outcomes by donor age are difficult to conduct because of ethical constraints, and previous retrospective studies have yielded inconsistent findings due to confounding bias and limited causal interpretability. Target trial emulation (TTE) is a methodological framework that uses observational data to emulate the design principles of a randomized trial, thereby reducing biases such as immortal time bias, time-varying confounding, and prevalent-user bias, and improving the validity of causal inference. Therefore, this study will use a large single-center retrospective clinical cohort to perform a TTE analysis, aiming to approximate the causal framework of an randomized trial and systematically evaluate the effect of donor age on clinical outcomes after allo-HSCT, thereby providing higher-quality evidence to optimize donor selection strategies.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
5000

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

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

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

This study includes adult patients with hematologic malignancies who underwent allogeneic hematopoietic stem cell transplantation at the study center. Eligible patients will be identified from retrospective clinical records and grouped according to donor age recorded at the time of transplantation.

Description

Inclusion Criteria:

  • Age 18 years or older.
  • Diagnosis of hematologic malignancy.
  • Underwent first allogeneic hematopoietic stem cell transplantation.
  • HLA matching level of 0.5 or higher.
  • Available donor age information.
  • Available clinical follow-up and outcome data.

Exclusion Criteria:

  • Previous autologous or allogeneic hematopoietic stem cell transplantation.
  • HLA matching level below 0.5.
  • Missing donor age information.
  • Missing key exposure-defining or outcome-defining data required for the analysis.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Younger Donor Group
Patients who underwent allogeneic hematopoietic stem cell transplantation with donors younger than 50 years. Grouping was based on donor age recorded in retrospective clinical data.
Older Donor Group
Patients who underwent allogeneic hematopoietic stem cell transplantation with donors aged 50 years or older. Grouping was based on donor age recorded in retrospective clinical data.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Overall Survival
Time Frame: From the date of transplantation to the date of death from any cause or last follow-up, assessed up to 15 years.
Overall survival was defined as the interval between hematopoietic stem cell transplantation and death from any cause.
From the date of transplantation to the date of death from any cause or last follow-up, assessed up to 15 years.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
The First Affiliated Hospital of Soochow University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 15, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 15, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 21, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 15, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 22, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 24, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 24, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 22, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • TTE DONOR AGE

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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