Allo-HSCT outcomes in AYA patients with acute leukemia

Results from a British Society of Blood and Marrow Transplantation and Cellular Therapy registry study, evaluating outcomes following allogeneic hematopoietic stem cell transplantation (allo-HSCT) in adolescent and young adult (AYA; defined as 16–24 years in this study) patients with acute leukemia, were published in the British Journal of Haematology by McIlroy et al. The study included 940 AYA patients, alongside comparator cohorts of pediatric patients (n = 1,145; 1–15 years) and adults (n = 1,431; 25–39 years).

Key data: In acute lymphoblastic leukemia (ALL), 5‑year overall survival (OS) was 55% in pediatric patients, 55% in AYA patients, and 51% in adults. In acute myeloid leukemia (AML), 5‑year OS was 55%, 53%, and 51%, respectively. In adjusted analyses, OS in ALL worsened with increasing age (pediatric vs AYA, p = 0.081; AYA vs adult, p = 0.007), but did not differ across age groups in AML (pediatric vs AYA, p = 0.354; AYA vs adult, p = 0.902). Non-relapse mortality was not significantly different between AYA and pediatric patients (ALL, p = 0.379; AML, p = 0.117), but was higher in adults vs AYA patients (ALL, p = 0.001; AML, p = 0.009). The 5‑year cumulative incidence of chronic graft-versus-host disease (cGvHD) in AYA patients (ALL, 41%; AML, 41%) was similar to that in adults (ALL, 49%; AML, 48%; p = 0.130), and higher than in pediatric patients (ALL, 17%; AML, 20%; p < 0.001).

Key learning: AYA patients undergoing allo-HSCT for acute leukemia demonstrate distinct outcomes compared with both pediatric and adult populations, with a higher burden of cGvHD, highlighting an unmet need for strategies to reduce transplant-related morbidity in this group.