Last Modified: June 11, 2007
Scientific Session: Effect of consolidation with arsenic trioxide (As2O3) on event-free survival (EFS) and overall survival (OS) among patients with newly diagnosed acute promyelocytic leukemia (APL): North American Intergroup Protocol C9710
Acute promyelocytic leukemia (APL) comprises approximately 10% of acute leukemias and is initially treated with all-trans retinoic acid (ATRA), which can induce a remission in up to 90% of patients. This study investigated the early addition of arsenic trioxide (AT) as consolidation therapy (therapy given after remission has been achieved) in adults and children with APL.
This was a phase III, randomized study that gave 2 courses of AT to patients who achieved a remission after treatment with ATRA, daunorubicin, and cytarabine. Half of the patients then received AT, the other did not. All patients then received consolidation with ATRA and daunorubicin. Patients who were in complete remission after this were further randomized to receive ATRA for one year or ATRA, 6-MP, and methotrexate for one year.
The group treated with AT had improved event-free survival (that is survival without disease progression), 81% versus 66% in the no AT arm. Despite this, the overall survival (survival with or without disease progression) was not statistically improved. Toxicity was similar in the two groups. Upon further analysis and comparing this study data to other studies, it appears that using AT for consolidation can allow one to use lower doses of chemotherapy, reducing the risk of complications both short- and long-term.