Comparison of intensive chemotherapy, allogeneic, or autologous stem-cell transplantation as postremission treatment for children with very high risk acute lymphoblastic leukemia: PETHEMA ALL-93 Trial

Abstract

Purpose: The optimal postremission therapy for children with very high-risk (VHR) acute lymphoblastic leukemia (ALL) is not well established. This randomized trial compared three options of postremission therapy: chemotherapy and allogeneic or autologous stem-cell transplantation (SCT).

Patients and methods: All 106 VHR-ALL patients received induction with five drugs followed by intensification with three cycles of chemotherapy. Patients in complete remission (CR) with an HLA-identical family donor were assigned to allogeneic SCT (n = 24) and the remaining were randomly assigned to autologous SCT (n = 38) or to delayed intensification followed by maintenance chemotherapy up to 2 years in CR (n = 38).

Results: Overall, 100 patients achieved CR (94%). With a median follow-up of 6.5 years, 5-year disease-free survival (DFS) and overall survival (OS) probabilities were 45% (95% CI, 37% to 54%) and 48% (95% CI, 40% to 57%), respectively. The three groups were comparable in the main pretreatment ALL characteristics. Intention-to-treat analysis showed no differences for donor versus no donor in DFS (45%; 95% CI, 27% to 65% v 45%; 95% CI, 37% to 55%) and OS (48%; 95% CI, 30% to 67% v 51%; 95% CI, 43% to 61%), as well as for autologous SCT versus chemotherapy comparisons (DFS: 44%; 95% CI, 29% to 60% v 46%; 95% CI, 32% to 62%; OS: 45%; 95% CI, 31% to 62% v 57%; 95% CI, 43% to 73%). No differences were found within the different subgroups of ALL and neither were differences observed when the analysis was made by treatment actually performed.

Conclusion: This study failed to prove that, when a family donor is available, allogeneic SCT produces a better outcome than autologous SCT or chemotherapy in children with VHR-ALL.