Use of all-trans retinoic acid in combination with arsenic trioxide for remission induction in patients with newly diagnosed acute promyelocytic leukemia and for consolidation/maintenance in CR patients.

In the present study, 90 patients with newly diagnosed acute promyelocytic leukemia (APL) were studied for all-trans retinoic acid (ATRA) and arsenic trioxide (As(2)O(3)) combination treatment in remission induction and postremission therapy. In addition, 20 APL patients who had achieved complete remission (CR) with an ATRA-based regimen received ATRA/As(2)O(3) combination for consolidation and maintenance were also enrolled. The results showed that ATRA/As(2)O(3) combination therapy yielded a high CR rate of 93.3% and a significantly shorter time to enter CR (median: 31 days; range: 18-59 days) compared to the ATRA-based regimen (n = 72; median: 39 days; range: 25-62 days). With the ATRA/As(2)O(3) combination for CR maintaining, regardless of the way by which CR was attained, the relapse-free survival was significantly better than with an ATRA plus cytotoxic chemotherapy regimen (92.9 +/- 3.2% vs. 72.4 +/- 7.6%, for the 3-year Kaplan-Meier estimate of relapse-free survival). The drug toxicity profile showed that with the use of As(2)O(3), the incidence of hepatotoxicity was obviously high during remission induction but decreased significantly during postremission treatment. We conclude that APL patients may benefit from the early use of the combination of ATRA and As(2)O(3), in either remission induction or consolidation/maintenance.