PB1729 AGGRESSIVE OR LESS AGGRESSIVE SALVAGE CHEMOTHERAPY FOR RELAPSED OR REFRACTORY ACUTE MYELOID LEUKEMIA BASED ON LEUKEMIA BURDEN: ANALYSIS OF 181 PATIENTS
Authors: Hu J. , Chen Y. , Chen Y. , Yang T. 
Published: June 2019

Background:

The prognosis of patients with relapsed or refractory (R/R) acute myeloid leukemia (AML) is poor,and the recommendation of aggressive or less aggressive re‐induction regimen for these patients remains controversial.

Aims:

To compared the treatment outcome and explored prognostic factors of R/R AML patients who had received either aggressive or less aggressiveregimens for re‐induction chemotherapy based on leukemia burden using retrospectively analysis.

Methods:

181R/R AML patients diagnosed with relapsed or primary refractory AML (except APL with t (15;17) (q22; q12); PML‐RARA, subtypes) with good performance status (ECOG PS ≤ 2) received aggressive or less aggressive regimens for re‐induction chemotherapywere enrolled in this study. The patients included 106 males and 75 females, 79 with primary refractory AML, 102 with relapsed AML. The patients’ age ranged from 15 to 76 years old, and the median age was 46 years old. Aggressive regimen included high‐dose cytarabine, granulocyte colony‐stimulating factor(G‐CSF) plus fludarabine(FLAG; n=45) or cladribine(CLAG; n=19); or standard‐dose cytarabine plus mitoxantrone and homoharringtonine (MAH; n=62). Less aggressive regimen contained decitabine,low‐dose cytarabine, aclarubicin, and G‐CSF (DCAG; n=45).

Results:

After re‐induction treatment, the overall response (OR) rate was 39.8% and complete remission (CR) rate was 36.5%. Overall survival (OS) was calculated from diagnosis to the date of the last follow‐up or death. The median OS was 14.7 months, and the 1‐year, 3‐year OS rates were 63.1%, 21.7%, respectively. Patients treated with aggressive chemotherapy were younger and had higher white blood cell (WBC), blasts, lactate dehydrogenase (LDH) than those receiving less aggressive chemotherapy. The long‐term survival showed not significant difference in aggressive and less aggressive group. The median OS for patients receiving MAH, FLAG, CLAG and DCAG as re‐induction therapy were 15.9 months, 12.3 months, 19.0 months and 18.7 months, respectively(P = 0.483). 1‐year and 3‐year OS rates in MAH group were 66.4% and 22.0%, while they were 51.9% and 16.4% in FLAG group, 68.9% and 34.5% in CLAG group, and 67.8% and 23.3% in DCAG group, respectively. The early mortality and 6‐monthrelapseratesin four groups showed no difference. The outcome of patients received salvage Allo‐HSCT was significant superior to those only treated with chemotherapy, median OS was 30.7 months in Allo‐HSCT group, compared to 14.5months in chemotherapy group.Univariate analysis identified following as adverse prognostic factors for CR and OS:primary refractorydisease, relapse within 6 months, poor cytogenetics at diagnosis, blasts more than 20% in bone marrow, WBC higher than 10 × 109/L, LDH ≥upper normal limitbefore re‐induction.

Summary/Conclusion:

Aggressive regimen is more suitable for fit patients with higher leukemia burden, while fragile patients with fewer blasts may benefit from less aggressive regimen. In order to improve the outcome, Allo‐HSCT should be considered for R/R AML patients when it is feasible.

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