Low-dose long-term oral idarubicin in maintenance treatment of elderly acute myeloid leukemia.

BACKGROUND AND OBJECTIVE

Low-dose long-term oral IDA may play a role in maintainance treatment of elderly patients with AML; in fact, continuous exposure to IDA and IDAol could be efficacious in the disease control possibly inducing cell-differentiation and/or apoptosis.

METHODS

We enrolled 25 previous responder patients in standard induction therapy to receive maintenance oral IDA 5 mg daily on days 1-14 at 2-week intervals for at least 6 months. We also evaluated the cell-cycle and apoptosis in leukemic cells from patients after IDA administration and, as a control, from HL60 lines exposed to IDA and IDAol in vitro.

RESULTS

Long-term long-dose IDA was well-tolerated. Neutrophil and platelet count never below under 1 x 10(9)/L and 50 x 10(9)/L respectively in CR patients, and no infectious complications were encountered. Non-hematological toxicity was also acceptable: easily controlled nausea and vomiting, non-recorded diarrhea or mucositis were reported. The convenience of oral administration contributed to excellent compliance. DNA analysis performed in vivo after IDA and IDAol exposure showed an increase of G2/M cell frequencies and evidence of sub-G1 peak.

INTERPRETATION AND CONCLUSIONS

In conclusion, long-term low doses of oral IDA would appear valuable as a maintenance regimen for elderly patients. Our results seem to confirm the preliminary hypothesis that IDA + IDAol induce an increase of apoptosis in leukemic cells.