Ponatinib in pediatric patients with Philadelphia chromosome-positive leukemia: a retrospective survey of the Japan Children's Cancer Group.

Ponatinib is effective in adults with Philadelphia chromosome-positive (Ph+) leukemia, resistant or intolerant to second-generation tyrosine kinase inhibitors, but there are limited data on its use in children. The clinical courses of nine pediatric patients with Ph+ acute lymphoblastic leukemia (Ph+ ALL) and four with chronic myeloid leukemia (CML) who received ponatinib therapy were retrospectively reviewed. The median age at the start of ponatinib therapy was 12 years (range 8-16 years). Nine patients were male and four were female. Six patients received ponatinib alone, three received ponatinib with prednisolone, one received ponatinib with rituximab intrathecal therapy, and one received ponatinib with conventional chemotherapy. Two patients received ponatinib both alone and in combination with chemotherapy. The median dose and duration of ponatinib were 16.9 mg/m2 (7-34.3) and 1.1 months (0.2-22.7), respectively. Six patients with Ph+ ALL and two with CML responded to ponatinib. One of the eight patients who received ponatinib alone had grade 4 increased lipase levels. Grade 3 non-hematologic toxicities included elevated alanine aminotransferase levels (25%), elevated aspartate aminotransferase levels (25%), elevated gamma-glutamyl transferase levels (12.5%), hypertension (12.5%), and polymorphic erythema (12.5%). Ponatinib may be safe and effective in pediatric patients with Ph+ leukemia.