Results of a phase II trial testing interferon-alpha 2b and cytarabine in children and adolescents with chronic myelogenous leukemia†

BACKGROUND: Chronic myelogenous leukemia (CML) is a rare disease in children and only few data are available concerning the results of interferon based therapy in this age group. Before the imatinib mesylate era, a prospective phase II trial was conducted to assess the efficacy and tolerance of a combination of interferon-alpha 2b (IFN) and cytarabine in children with CML in first chronic phase without a suitable HLA-identical donor. PROCEDURE: Fourteen consecutive children were recruited from 12 pediatric centers. Children received daily IFN (5 million U/m2) and subcutaneous cytarabine (20 mg/m2) for 10 days every month. RESULTS: The median duration of follow-up is 13 months (range 2-32 months). Seven children achieved a complete hematologic response after a median time of treatment of 3 months (range 1 week-4 months). Three children were not evaluable for the cytogenetic response. A major cytogenetic response was achieved in seven patients (including complete cytogenetic response in two patient) within 12 months. The median time to major cytogenetic response was 7 months (range 3-12 months). Thirteen patients discontinued the treatment protocol after a median time of 11 months. Probability of progression free survival at 11 months was 83% (95% CI, 61%-100%). Grade 3 and 4 toxicity was observed in eight patients. The most frequently reported drug-related events were fever, mucositis, neutropenia, and thrombocytopenia. CONCLUSIONS: The combination of IFN and cytarabine provides hematologic and cytogenetic responses in children and adolescents with CML. In the imatinib mesylate era, the role of this combination as second line therapy in children with CML remains to be determined.