Objective: To observe the therapeutic efficacy and side effects of arsenic trioxide (As2O3)combined with low-dose all-trans retinoic acid (ATRA) on remission induction in newly-diagnosed and relapsed patients with acute promyeloeytic leukemia (APL).
Methods: 224 patients of APL, 156 newly diagnosed patients, aged 34 (13 approximately 62), with a male/female ratio of 1.56, and 28 relapsed patients, aged, aged 34 (12 approximately 63), with a male/female ratio of 1.89, underwent As2O3 + ATRA therapy. The therapeutic effects was compared with that of As2O3 alone treatment on 40 newly diagnosed patients and 25 relapsed patients and that of ATRA alone treatment on 36 newly diagnosed patients and 15 relapsed patients. The treatment protocol for the combination group was as following: As2O3 was administered intravenously at a dose of 10 mg/day and ATRA was given orally three times per day at a dose of 10 mg. The complete remission (CR) rate, period to CR, incidence of early death and side effects were observed in the three groups.
Results: In the newly-diagnosed patients, there was no significant difference in CR rate among the three groups (92.5% for the As2O3/LD-ATRA group, 83.8% for the ATRA group, and 90% for the As2O3 group respectively). In comparison with As2O3 alone, administration of LD-ATRA to the patients in the As2O3/LD-ATRA group significantly shortened the period to CR (the medium time to CR was 28 days for the As2O3/LD-ATRA group and 39 days for the As2O3 group respectively). As compared to ATRA alone, treatment with As2O3 with low-dose ATRA showed a significantly lower incidence of early death (2.5% for the As2O3/LD-ATRA group and 13.9% for the ATRA group respectively). In the relapsed patients, the CR rate was significantly higher in the group treated with As2O3/LD-ATRA (71.4% for the As2O3/LD-ATRA group, 32.0% for the ATRA group, and 43.0% for the As2O3 group respectively). The combined use of LD-ATRA with As2O3 did not further enhance toxic side effects as compared to As2O3 alone or ATRA alone.
Conclusion: As2O3/LD-ATRA regimen is superior to either regimen given alone to patients with APL. It is an efficient therapeutic approach to APL patients using a combination of As2O3 with low-dose ATRA.