2g/m2 Ara-c induced more favorable outcome than 1g/m2 Ara-c in CLAG treatment for refractory or relapsed acute myeloid leukemia without increase toxicity: a multicenter propensity score matching analysis

This study compared the efficacy and toxicity of two cytarabine doses (1 g/m² vs. 2 g/m²) within the CLAG regimen for relapsed/refractory acute myeloid leukemia (R/R AML) patients. In this multicenter retrospective analysis, 183 R/R AML patients received the CLAG regimen (86 in the 1 g/m² group; 97 in the 2 g/m² group). After excluding 12 unevaluable cases, 171 patients (82 vs. 89) were analyzed. Propensity score matching (PSM) created 102 well-balanced pairs. Endpoints included complete remission rate (CRR), overall remission rate (ORR), overall survival (OS), leukemia-free survival (LFS), and toxicity. A significantly higher complete response (CR) rate was observed in the 2 g/m² group compared with the 1 g/m² group, both in the overall population (71.9% vs. 53.7%; p = 0.013) and in the propensity score-matched (PSM) cohort (68.6% vs. 49.0%; p = 0.044). The 2 g/m² regimen was also associated with superior 2-year overall survival (OS) in the overall analysis (46.2% vs. 13.4%; p = 0.004), with a strong trend toward significance in the PSM cohort (33.9% vs. 13.7%; p = 0.07). Toxicity profiles were similar except for a longer neutropenia duration in the 2 g/m² group (18 vs. 16 days, p = 0.003). Allogeneic HSCT post-remission was a significant predictor for improved OS. The 2 g/m² cytarabine dose in the CLAG regimen yielded superior response rates and survival outcomes in R/R AML patients eligible for transplant bridging, without increasing significant toxicity.