An efficient therapeutic approach to patients with acute promyelocytic leukemia using a combination of arsenic trioxide with low-dose all-trans retinoic acid.

The use of arsenic trioxide (As2O3, ATO) combined with all-trans retinoic acid (ATRA) has recently been reported to induce remission in patients with acute promyelocytic leukemia (APL). However, its efficiency remains inconclusive mainly due to the small number of the available cases. In this study, therefore, we present a clinical study using a combination of ATO with low-dose ATRA (LD-ATRA) to treat 108 APL patients (80 newly diagnosed patients, 28 relapsed patients). Therapeutic outcomes using the ATO/LD-ATRA approach were compared with those of APL patients treated either with ATO alone (65 patients) or ATRA alone (51 patients). The results showed that the ATO/LD-ATRA approach provided significantly better therapeutic outcomes as compared to either ATO or ATRA alone, as evidenced by lower mortality, a higher CR rate and a reduced period to CR. In addition, the toxic side-effects have been no worse with the combined ATO/LD-ATRA treatment than with either ATO or ATRO alone and in some cases have been reduced. These data suggest that the ATO/LD-ATRA regimen is superior to either regimen given alone to patients with APL. Copyright 2004 John Wiley & Sons, Ltd.