Aims: The optimal maintenance therapy for patients with acute promyelocytic leukemia (APL) who achieved complete remission (CR) and complete consolidation chemotherapy is still controversial. Whether the use of arsenic trioxide (ATO) alone or along with all-trans retinoic acid (ATRA) improves overall survival (OS) or disease-free survival (DFS) is still debated.
Methods: A retrospective reivew was conducted of 20 patients diagnosed with APL according to the French – American – British system. After achieving CR and receiving consolidation chemotherapy, nine patients were given maintenance therapy for 1 year (ATRA 45 mg/m2/day p.o., mercaptopurine 60 mg/m2/day p.o. and ATO 0.15 mg/kg/day × 5 days/week for six cycles in five patients; ATRA 45 mg/m2/d p.o. alternating with ATO 0.15 mg/kg/day × 5 days/week in 1 patient; ATRA only in three patients).
Results: In all patients the rates of CR, 3-year OS and 5-year OS were 75, 71 and 57%, respectively. For patients treated with ATO maintenance, the rates were 100% for both 5-year OS and 5-year DFS. Four of six patients on ATO maintenance had grade 1 or grade 2 adverse events. Excluding the two patients who died from intracerebral hemorrhage within 4 days after diagnosis, these rates were 85, 82 and 78%, respectively.
Conclusion: Upfront ATO maintenance therapy for one year is safe and appears to be effective, with the benefits restricted to patients with APL with t(15;17) translocation. Larger studies will be required to confirm this observation.