Outcomes of CAG Regimen for Refractory Biphenotypic Acute Leukemia Patients.

Biphenotypic acute leukemia (BAL) involves both myeloid and lymphoid cells, and there is lack of uniformity in treatment at present. Optimal approach for therapy of BAL is unknown, and BAL usually becomes refractory to conventional chemotherapy. It was found that CAG regimen [low-dose cytosine arabinoside (Ara-C) plus aclarubicin with concurrent administration of granulocyte colony-stimulating factor (G-CSF)] is effective for both myeloid leukemia and refractory acute lymphoblastic leukemia. To explore the efficiency of CAG regimen for refractory BAL, 12 BAL patients who were failed to daunorubicin/mitoxantrone, cytosine arabinoside, vincristine, prednisone (D/MAOP) regimen, were treated by CAG. 8 were males and 4 was female, with ages ranging from 20 to 43 years (median=34 years). Immunophenotype of B lymphoid lineage/myeloid lineage showed in 8 patients, and T lymphoid lineage/myeloid lineage showed in 4 patients. The patients whose blast cells did not decrease 50% after induction regimen with lymphoid and/or myeloid drugs were defined as refractory cases.

12 refractory BAL patients were treated by CAG regimen (cytosine arabinoside 10 mg/m² subcutaneously every 12 hours, day 1-14; aclarubicin 5-7 mg/m² intravenously daily, day 1-8; and concurrent use of granulocyte colony-stimulating factor 200μg·m^-2·d^-1 subcutaneously) from November 2002 to April 2009. The efficacy of the regimen was evaluated by response rate, and the side-effects was also measured.

The major chemotherapy toxicity was bone marrow depression, mainly showing as pancytopenia. Median duration of absolute neutrophil count (ANC)<0.50×10⁹/L and of platelet (PLT) count<20×10⁹/L was 13 (range, 1-17) days and 1 day (range, 0-5 days), respectively. Median transfusion of red cells and PLT was 4 (range, 1.5-12) U and 20 (range, 0-40) U, respectively.

Besides bone marrow depression, other side-effects such as infection, bleeding, nausea and vomiting also occurred during therapy. According to chemotherapy toxicity assessment of WHO, there were 7 patients confronting infection, among whom only 2 patient occurred III-‡W infection. No serious nausea vomiting or hepatic function damage happened.

No relevant conflicts of interest to declare.