Long-term efficacy and safety of arsenic trioxide for first-line treatment of elderly patients with newly diagnosed acute promyelocytic leukemia.

Abstract

The prognosis of acute promyelocytic leukemia (APL) in the elderly is poorer than that of younger patients after treatment with all-trans retinoic acid plus chemotherapy, which is the current standard therapy for APL. A significantly higher mortality during consolidation therapy was found, which is mainly due to deaths from sepsis following chemotherapy-induced myelosuppression. A total of 33 patients aged 60 years or older with de novo APL were treated with single-agent arsenic trioxide (ATO) for remission induction and postremission therapy. The postremission therapy continued for up to 4 years. Twenty-nine patients (87.9%) achieved a hematologic complete remission, and the most common adverse event during remission induction was leukocytosis (63.6%). Definite differentiation syndrome was observed in 5 patients. Nonhematologic adverse events were all manageable and reversible. Twenty-eight patients proceeded to postremission therapy. Adverse effects during postremission therapy were mild, transient, and no treatment was required. No patients died from ATO-related toxicities. With a median follow-up of 99 months, the 10-year cumulative incidence of relapse, overall survival, disease-free survival, and cause-specific survival were 10.3%, 69.3%, 64.8%, and 84.8%, respectively, which are comparable with those in the younger APL partners. No significant risks for development of chronic arsenicosis or second malignancy were observed during the follow-up period. The results indicate that the single-agent ATO regimen is safe and effective with long-term durable remission, and could be used as first-line treatment for elderly patients with de novo APL.