Preliminary clinical investigation of the maintenance treatment regimen of acute promyelocytic leukemia after complete remission by all-trans retinoic acid

Objective:To investigate the new maintenance chemotherapy of acute promyelocytic leukemia(APL) after complete remission by all-trans retinoic acid(ATRA), thereby increasing the long disease-free survival time of APL.Method:21 newly-diagnosed APL patients who achieved CR by ATRA administered a new maintenance chemotherapy method: to administer arsenic trioxide(As_2O_3)、ATRA and 6-mercaptopurine (6-MP)+methotrexate(MTX) alternately for 3 years to the patients. The efficacy and side effects of these chemotherapy were observed, and minimal residual disease(MRD) of the patients were monitored by RT-PCR of PML/RARα.Result:All 21 APL patients had a high degree of compliance with these treatment. Up to now, all patients have being remained in CR1, and 11of 21 patients have being treated with maintenance chemotherapy over 2 years. The PML/RARα fusion gene was positive in all 21 patients when diagnosed. 12 of 21 patients who were monitored MRD turned to be negative continuously, and 11 of 12 were the patients who have being treated with maintenance chemotherapy over 2 years. The side effects of these two regimens were less and light.Conclusion:The preliminary efficacy of the chemotherapy which were used in 21 newly-diagnosed APL patients who gained CR after treatment of ATRA is satisfactory. The side effects is less than the combined chemotherapy. Maybe the maintenance chemotherapy method of alternate administration of As_2O_3、ATRA and 6-MP+MTX plays an important role in it.