Efficacy Analysis With Imatinib Monotherapy Was Superior To Allogeneic Hematopoietic Stem Transplantation In Pediatric Patients With Chronic Phase Of Chronic Myelogenous Leukemia

Whether allogeneic hematopoietic stem cell transplantation (allo-HSCT) or imatinib should be first-line therapy for childhood chronic myelogenous leukemia in the chronic phrase (CML-CP) is controversial. This study compared imatinib monotherapy and allo-HSCT for the management of CML-CP in pediatric patients.

This was a retrospective study of children (aged <18 years) with CML-CP, treated between January 2006 and September 2012 at a hospital in China. Patients were treated with imatinib (260 mg/m² body surface area) or allo-HSCT. Overall survival (OS), event-free survival (EFS) and adverse events (AEs) were compared.

62 patients (40 males, 22 females) were enrolled: 41 received imatinib, and 21 received allo-HSCT. Median follow-up in the imatinib and allo-HSCT groups was 29 and 56 months, respectively. Imatinib was well tolerated. In the imatinib group, the cumulative complete cytogenetic response (CCyR) and major molecular response (MMR) at 24 months were 96.6% (95%CI, 93.3–99.9%) and 85.6% (95%CI, 78.5–92.7%), respectively; patients achieved CCyR and MMR at a median of 3 and 6 months, respectively. In the allo-HSCT group, allografts were from an HLA-matched sibling (n=3), an HLA mismatched/haploidentical familial donor (n=15) or an unrelated donor (n=3). Twelve patients (57.1%) developed acute graft-versus-host disease (grades 2–6 in 7 patients), and 5 deaths were reported. 5-year OS in the imatinib and allo-HSCT groups was 97.1±2.9% and 73.7±10.3% (P=0.032), respectively, while 5-year EFS was 92.5±4.2% and 63.8±11.1% (P=0.041), respectively.

Treatment with imatinib yielded satisfactory cytogenetic and molecular responses, and superior 5-year OS and EFS to allo-HSCT.

No relevant conflicts of interest to declare.