There is an increased risk of GVHD and of non-relapse mortality (NRM) after allogeneic stem cell transplantations (alloSCT) when mismatched unrelated donors (MMUD) are used. In Europe, it is standard practice to use rabbit anti-thymocyte globulin (rATG) to reduce the high NRM and GVHD risks after MMUD alloSCT. As an alternative to rATG, post-transplantation Cyclophosphamide (PTCy) is in increasing clinical use. It is currently impossible to give general recommendations regarding preference for one method over another since comparative evidence from larger data sets is lacking. To improve the evidence base, we analyzed the outcome of rATG vs. PTCy prophylaxis in adult patients with hematologic malignancies undergoing first peripheral blood alloSCT from MMUD (9/10 antigen match) between Jan 2018 and June 2021 in the database of the European Society for Blood and Marrow Transplantation (EBMT). We performed multivariate analyses using the Cox proportional-hazards regression model. We included 2123 patients in the final analyses (PTCy, n = 583; rATG, n = 1540). p values and hazard ratios (HR) presented here are multivariate outcomes. Two years after alloSCT we found a lower NRM in the PTCy group of 18% vs. 24.9% in the rATG group; p = 0.028, HR 0.74. Overall survival in the PTCy cohort was higher with 65.7% vs. 55.7% in the rATG cohort; p < 0.001, HR 0.77. Progression-free survival was also better in the PTCy patients with 59.1% vs. 48.8% when using rATG; p = 0.001, 0.78. The incidences of chronic GVHD and acute GVHD were not significantly different between the groups. We found significantly lower NRM as well as higher survival in recipients of peripheral blood alloSCTs from MMUD receiving PTCy as compared to rATG. The results of the current analysis suggest an added value of PTCy as GVHD prophylaxis in MMUD alloSCT.

当使用不匹配的无关供体 (MMUD) 时，同种异体干细胞移植 (alloSCT) 后发生 GVHD 和非复发死亡率 (NRM) 的风险会增加。在欧洲，标准做法是使用兔抗胸腺细胞球蛋白 (rATG) 来降低 MMUD alloSCT 后的高 NRM 和 GVHD 风险。作为 rATG 的替代品，移植后环磷酰胺 (PTCy) 的临床应用日益增多。由于缺乏来自较大数据集的比较证据，目前不可能就一种方法相对于另一种方法的偏好给出一般建议。为了完善证据基础，我们在欧洲学会数据库中分析了 2018 年 1 月至 2021 年 6 月期间接受首次外周血异体干细胞移植 (MMUD)（9/10 抗原匹配）的成年血液恶性肿瘤患者的 rATG 与 PTCy 预防的结果。血液和骨髓移植（EBMT）。我们使用 Cox 比例风险回归模型进行多变量分析。我们在最终分析中纳入了 2123 名患者（PTCy，n  = 583；rATG，n  = 1540）。这里提出的p值和风险比 (HR) 是多变量结果。alloSCT 两年后，我们发现 PTCy 组的 NRM 较低，为 18%，而 rATG 组为 24.9%；p  = 0.028，HR 0.74。PTCy 队列的总生存率较高，为 65.7%，而 rATG 队列的总生存率为 55.7%；p  < 0.001，HR 0.77。PTCy 患者的无进展生存率也更高，为 59.1%，而使用 rATG 时为 48.8%；p  = 0.001, 0.78。慢性GVHD和急性GVHD的发生率在各组之间没有显着差异。我们发现，与 rATG 相比，接受 PTCy 的 MMUD 外周血同种异体干细胞移植受者的 NRM 显着降低，且存活率较高。当前分析的结果表明 PTCy 在 MMUD alloSCT 中作为 GVHD 预防具有附加价值。