Salvage Treatment Options for Post-Transplant Relapse in Children with Early/Very Early Relapse of Acute Lymphoblastic Leukemia: A Single Center Experience

This study aimed to evaluate salvage treatment options for posttransplant relapse in children with early/very early relapse of acute lymphoblastic leukemia (ALL). Forty consecutive high-risk ALL cases were divided into two groups based on the salvage treatment for posttransplant relapse: Group 1 (n=9) received purine nucleoside analogs (fludarabine/clofarabine-based regimens), while Group 2 (n=8) received targeted agents (blinatumomab, bortezomib, and chimeric antigen receptor T-cells). In Group 1, seven children received a fludarabine-based regimen and two received a clofarabine-based regimen. In Group 2, five children received bortezomib-based regimens, two received blinatumomab, and one received chimeric antigen receptor T-cells. Group 2 showed a significantly higher cumulative survival rate (75% vs. 22%) and lower grade 3 and 4 toxicity rates (13% vs. 66%) compared to Group 1 (p<0.05). Based on our limited data, targeted agents may constitute an effective treatment option and can be directly recommended for posttransplant relapse in children with high-risk ALL.