2nd Edition of Public Health World Conference (PHWC) 2026

Abstract

The landscape of allogeneic hematopoietic cell transplantation (HCT) has undergone a profound transformation with the advancement of post-transplant cyclophosphamide (PTCy), enabling safe and effective transplantation from haploidentical and HLA-mismatched unrelated donors. As donor availability has expanded, the challenge has shifted from identifying a suitable donor to selecting the optimal donor and transplant platform for an individual patient.

Contemporary evidence demonstrates that, in the context of PTCy-based graft-versus-host disease (GVHD) prophylaxis, outcomes after haploidentical and mismatched unrelated donor transplantation are broadly comparable but remains debated. Instead, donor selection should be individualized, prioritizing immunologic compatibility, particularly avoidance of donor-specific

anti-HLA antibodies—alongside with donor age, ethnicity, urgency of transplantation, quality of HLA mismatch, and institutional experience. Across multiple registry and retrospective studies, younger donor age consistently emerges as a dominant predictor of overall survival, often outweighing donor type itself. In addition, early and parallel donor searches are essential to minimize delays to transplant, especially for patients with high-risk or rapidly progressive malignancies. This evolving paradigm underscores the need for a patient-centered, risk-adapted approach to donor selection, integrating biological, clinical, and logistical factors to optimize outcomes in modern allogeneic HCT.