Refractory or relapsed acute myeloid leukemia (R/R AML) remains the major challenge of AML treatment. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only valid option to achieve cure, but the prognosis is still dismal. We conducted a retrospective analysis for the feasibility of CLAG regimens (cladribine, cytarabine, and granulocyte colony-stimulating factor) combined with total body irradiation (TBI) as new intensive conditioning chemotherapy prior to HSCT in R/R AML. A total of 70 patients, including 21 primary refractory and 49 relapsed AML, were analyzed. Forty-nine (70%) patients had extramedullary diseases, and 54 (77%) patients received haploidentical transplantation. Except for one who died before white blood cell engraftment, all of the 69 evaluable patients achieved measurable residual disease (MRD) negative complete remission. The 3-year overall survival (OS) and relapse-free survival (RFS) rates were 46.0% (95% confidence interval [CI], 33.5–57.7%) and 38.5% (95%CI, 26.8–50.0%). The 1-year cumulative incidences of relapse and non-relapse mortality (NRM) were 38.6% (95%CI, 27.3–49.3%) and 11.6% (95%CI: 5.4–20.3%), respectively. The presence of chronic graft-versus-host disease (cGVHD) showed a trend to be associated with a lower risk of relapse (P = 0.054) and extramedullary diseases with a higher risk of NRM (P = 0.074). Multivariate analyses identified low leukemia burden pre-HSCT (defined as bone marrow blasts ≤ 50%) and cGVHD as independent factors associated with favorable OS and RFS. In conclusion, intensive conditioning with CLAG regimens plus TBI may be an effective and well-tolerated choice for R/R AML patients undergoing allo-HSCT.

难治性或复发性急性髓系白血病（R/R AML）仍然是 AML 治疗的主要挑战。异基因造血干细胞移植（allo-HSCT）是实现治愈的唯一有效选择，但预后仍然不佳。我们对 CLAG 方案（克拉屈滨、阿糖胞苷和粒细胞集落刺激因子）联合全身照射（TBI）作为 R/R AML HSCT 前新的强化预处理化疗的可行性进行了回顾性分析。总共对 70 名患者进行了分析，其中包括 21 名原发性难治性 AML 和 49 名复发性 AML。 49 例（70%）患者患有髓外疾病，54 例（77%）患者接受了半相合移植。除一名在白细胞植入前死亡外，所有 69 名可评估患者均实现了可测量残留病 (MRD) 阴性完全缓解。 3年总生存率（OS）和无复发生存率（RFS）分别为46.0%（95%置信区间[CI]，33.5-57.7%）和38.5%（95%CI，26.8-50.0%）。复发和非复发死亡率 (NRM) 的 1 年累积发生率分别为 38.6% (95%CI, 27.3–49.3%) 和 11.6% (95%CI: 5.4–20.3%)。慢性移植物抗宿主病 (cGVHD) 的存在与较低的复发风险 ( P = 0.054) 和髓外疾病的 NRM 风险较高 ( P = 0.074) 相关。多变量分析确定 HSCT 前的低白血病负荷（定义为骨髓原始细胞≤ 50%）和 cGVHD 是与良好 OS 和 RFS 相关的独立因素。总之，对于接受异基因造血干细胞移植的 R/R AML 患者，CLAG 方案联合 TBI 强化调理可能是一种有效且耐受性良好的选择。