Comparison of clinical remission and survival between CLAG and FLAG induction chemotherapy in patients with refractory or relapsed acute myeloid leukemia: a prospective cohort study.

PURPOSE: To compare the clinical remission and survival between CLAG and FLAG induction chemotherapy in treating patients with refractory or relapsed acute myeloid leukemia (R/R AML). METHODS: 103 R/R AML patients were consecutively enrolled in this prospective cohort study. 55 patients were treated by CLAG induction chemotherapy as follows: 5 mg/m2/day cladribine (days 1-5); 2 g/m2/day cytarabine (days 1-5) and 300 µg/day filgrastim (days 0-5). While 48 patients were treated by FLAG: 30 mg/m2/day fludarabine (days 1-5), 2 g/m2/day cytarabine (days 1-5), and 300 µg/day filgrastim (days 0-5). RESULTS: CLAG induction chemotherapy achieved 61.7% complete remission rate (CR) and 78.7% overall remission rate (ORR), which was similar with FLAG chemotherapy which realized 48.7% CR and 69.2% ORR. No difference of overall survival (OS) was discovered between two groups either. Age cytarabine 60 years, secondary disease, poor risk stratification and BM blast ≥ 42.7% and second or higher salvage therapy were independent factors for worse prognosis. Subgroups analysis revealed that in patients with second or higher salvage therapy, CLAG seemed to achieve a higher CR than FLAG. And in patients with relapsed disease, poor risk stratification or CR at first induction, CLAG seemed to realize a prolonged OS compared to FLAG. CONCLUSION: CLAG was equally effective to FLAG induction chemotherapy in total R/R AML patients, while CLAG seemed to be a better option than FLAG in patients with relapsed disease, poor risk stratification, CR at first induction or second or higher salvage therapies.