EBMT‑PDWP registry study: Impact of aGvHD on allo-HSCT outcomes in pediatric ALL

Results from a retrospective European Society for Blood and Marrow Transplantation (EBMT)-Pediatric Diseases Working Party (PDWP) registry study, evaluating the impact of acute (a) graft-versus-host disease (GvHD) severity on transplant outcomes in 3,328 children with acute lymphoblastic leukemia (ALL) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT), were published in Bone Marrow Transplantation by Szmit et al. Investigational points included the relationship between aGvHD and relapse incidence (RI), non-relapse mortality (NRM), leukemia-free survival (LFS), overall survival (OS), chronic (c) GvHD, and extensive cGvHD. 

Key data: With a median follow-up of 3.1 years, the 100‑day incidence rates of Grade II–IV and Grade III/IV aGvHD were 35.4% and 11.3%, respectively. The 2‑year incidence rates of cGvHD and extensive cGvHD were 16.6% and 7.9%, respectively. At 2 years, NRM was 9.9%, RI was 24.8%, OS was 74.1%, LFS was 65.3%, and GvHD-free/relapse-free survival (GRFS) was 51.2%. Grade I (hazard ratio [HR], 0.8; 95% confidence interval [CI], 0.6–1.0; p = 0.03), II (HR, 0.7; 95% CI, 0.6 – 0.9; p < 0.001), and III/IV (HR, 0.7; 95% CI, 0.5–0.9; p = 0.008) aGvHD were associated with reduced risk of relapse. Grade III/IV aGvHD increased NRM (HR, 5.0; 95% CI, 3.4–7.4; p < 0.001) and reduced OS (HR, 1.8; 95% CI, 1.4–2.3; p < 0.001). Patients with Grade II aGvHD had higher LFS rates compared with those without aGvHD (p = 0.008). 

Key learning: Results suggest that Grade II aGvHD was associated with improved LFS, emphasizing a potential graft-versus-leukemia (GvL) effect. Grade III–IV aGvHD conferred reduced OS and increased NRM. These findings support moderate aGvHD as a clinically meaningful marker of GvL activity in pediatric ALL.