Younger vs. Older Donors in Allo-HSCT: TTE

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

Status

Not yet recruiting

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT07666568

Enrollment

5000

Registered

2026-06-24

Start date

2026-07-15

Completion date

2027-12-21

Last updated

2026-06-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION, A Target Trial Emulation Study, Donor Age

Brief summary

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.

Interventions

None listed

Study design

Observational model

COHORT

Time perspective

RETROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

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.

Design outcomes

Primary

Measure	Time frame	Description
Overall Survival	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.

Countries

China

Contacts

CONTACTYang Xu

xuyang1020@126.com+86-512-67781850

Outcome results