Thiotepa-Based Conditioning for Haploidentical Hematopoietic Stem Cell Transplantation in Older Patients With Severe Aplastic Anemia

This prospective, single-center observational cohort study will follow participants aged 50 years or older with severe or very severe aplastic anemia who receive haploidentical hematopoietic stem cell transplantation with a thiotepa-based conditioning regimen as part of routine clinical care. Treatment decisions, including conditioning, prevention of graft-versus-host disease, and supportive care, are made by the clinical care team and are not assigned or changed by this study. The study will collect routine clinical and follow-up information for 1 year after transplantation to describe transplant-related mortality, survival, engraftment, graft failure, graft-versus-host disease, infections, and serious adverse events.