Treatment of children with newly diagnosed acute promyelocytic leukemia with arsenic trioxide: a single center experience

A total of 11 children ( five males and six females) with hypergranular type of acute promyelocytic leukemia (APML) were treated with intravenous arsenic trioxide (As2O3) between December 1998 and October 2003. Eight cycles of As2O3 (0.15 mg/kg/day) were administered ( induction, consolidation and six cycles of maintenance) over a period of 12 months. The median WBC count at diagnosis was 3400/mm(3) ( range: 800 9800). In all, 10 patients (91%) achieved hematological remission at a mean duration of 48 days ( range: 41 - 60) with all 10 patients achieving molecular remission at a median duration of 81 days ( range: 64 - 109). Toxicity was minimal with leukocytosis in six patients, ichthyosis and hyperpigmentation of skin in five and mild peripheral neuropathy in one patient. One patient who relapsed 6 months after completing therapy achieved a second hematological and molecular remission with As2O3. With a median follow-up of 30 months ( range: 4 - 62), the overall (OS) survival is 91% with a relapse-free survival (RFS) of 81%. As2O3 achieves hematological and molecular remission in majority of newly diagnosed children with APML with minimal toxicity, but long-term follow-up is required to evaluate late effects of As2O3 and study the minimum dose and duration required for a sustained remission.