Combination of cyclophosphamide and cytarabine as induction regimen for newly diagnosed adult acute myeloid leukemia

Optimizing the induction therapy of acute myeloid leukemia (AML) may improve the remission rate and reduce the risk of relapse, thereby extend survival. Cyclophosphamide (CTX) shows benefit in treating relapsed and refractory AML patients, but it has not been reported in first-line induction regimens. To assess the efficacy and safety of CTX and moderate-dosage cytarabine (Ara-C) as induction chemotherapy in newly diagnosed adult AML, 40 patients were enrolled to receive CTX (20 mg/kg/d) for 4 consecutive days and Ara-C for 3 (1 g/m2 q12h, CA4+3) or 5 (1 g/m2 qd, CA4+5) days. With one course of induction chemotherapy, the overall response rate and the complete remission rate (CR) was 82.5% (33/40) and 77.5% (31/40), respectively. The expected 5 years overall survival and relapse-free survival was 64% in patients experienced CR and fulfilled consolidation therapy. The neutrophil and platelet recovery time were 17 (range, 10-20) days and 16.5 (range, 12-30) days in the CA4+3 group, faster than that of 20 (16-36) days and 20 (14-36) days in the CA4+5 group (P = .006 and P = .006). The cyclophosphamide and cytarabine (CA) regimen was generally safe and had reversible adverse effects. The patients who failed to respond to the CA regimen did not benefit from a second course of other traditional induction chemotherapy either. In conclusion, the combined regimen of CTX and Ara-C represents a promising therapeutic approach to induce the first CR of newly diagnosed adult AML.