Treatment of children with acute promyelocytic leukemia: results of the first North American Intergroup trial INT0129.

BACKGROUND

This report focuses on the children enrolled on the first North American Intergroup study of APL (INT0129). This study was designed to compare the rates of CR, disease-free survival (DFS), overall survival (OS) and toxicity of therapy with all-trans-retinoic acid (ATRA) for remission induction and/or maintenance compared to conventional chemotherapy in patients with previously untreated APL.

PROCEDURE

Fifty-three patients who were documented to have the t(15;17) translocation were able to be evaluated for toxicity of treatment, outcome of induction, and survival.

RESULTS

The overall CR rate was 81%. The estimated 5-year DFS from time of CR was 41% for all patients. The estimated 5-year OS for all patients from entry into the study was 69%. The 5-year DFS from time of CR for patients who were randomized to ATRA for induction or maintenance or both was 48% compared to 0% for patients who never received ATRA (P < 0.0001).

CONCLUSIONS

The most important finding of our study is that a significant DFS advantage exists for children with APL who received ATRA during induction or maintenance or both compared to children who received no ATRA. Furthermore, remissions in these children appear durable as the OS rates are stable at 10 years.