Graft-Versus-Host Disease Following Myeloablative Busulfan Plus Fludarabine and Busulfan Plus Cyclophosphamide For Allogeneic Hematopoietic Stem Cell Transplantation In Acute Myeloid Leukemia In First Complete Remission

Results from single institutions had shown that compared with busulfan plus cyclophosphamide (BuCy) conditioning, limiting tissue damage by myeloablative busulfan plus fludarabine (BuFlu) conditioning might decrease cytokines release, leading a lower incidence of the graft-versus-host disease (GVHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). In our prospective, multicenter and parallel-group study, further comparison was made of the incidences and severities of GVHD following BuCy and BuFlu myeloablative conditioning regimens in patients undergoing allo-HSCT for AML in first complete remission (CR1), and analyzed plasma cytokines before and after the conditioning.

A total of 148 patients with AML-CR1 undergoing allo-HSCT were enrolled into BuCy (busulfan1.6mg/kg, iv q12 hours, -7 ∼ -4d; cyclophosphamide 60 mg/kg.d, -3 ∼ -2d) or BuFlu (busulfan 1.6 mg/kg, iv q12 hours, -5 ∼ -2d; fludarabine 30 mg/m2.d, -6 ∼ -2d) group between January 2007 and January 2013. For patients enrolled between January 2012 and January 2013, plasma concentrations of IL-6, IL-1β, TNF-α, CXCL-10 and IL-17A before and after conditioning were measured by Enzyme-linked immunosorbent assay (ELISA) and compared between the two groups. Regimen-related toxicity (RRT), incidences and severities of acute and chronic GVHD, and overall survival were compared between the two groups.

Of the 148 patients enrolled in the study, the data of 142 cases were used to determine the endpoints in the intent-to-treat population (72 in BuFlu group and 76 in BuCy group). The levels of TNF-α and IL-6 were significantly higher after the conditioning (5.60±4.40 vs 8.94±5.50 and 2.19±1.24 vs 6.06±12.16 pg/ml, P <0.001 and P =0.045 ), however, there were no significant differences on these cytokines between the two groups. The levels of CXCL-10 in BuCy group was significantly higher than that in BuFlu group (P =0.012). The incidence of I-II° and III-IV° acute GVHD were 42.1% and 6.8%, and 36.1% and 5.7%, respectively, in BuCy and BuFlu group (P=0.363 and P=0.770, respectively). Chronic GVHD occurred in 29 of 69 (41.7%) and 30 of 72 (41.7%) patients, respectively, in BuCy and BuFlu group (P= 1.000). And the incidence of extensive chronic GVHD were 14.3% and 16.7%, respectively, in BuCy and BuFlu group (P= 0.670). The median follow up duration was 824 (range, 3–2345) days. The 5 year overall survival were 79.2 ± 4.4% and 78.6 ± 76.1% (P= 0.555), respectively in BuCy and BuFlu group

In this report, the incidences and severities of acute GVHD as well as chronic GVHD were similar between BuFlu and BuCy regimen in AML-CR1 patients undergoing allo-HSCT.

Liu:National Natural Science Foundation of China (Grant No.81000231, No.81270647) and Science and Technology Program of Guangzhou of China (11A72121174).: Research Funding; It was supported by 863 Program (No. 2011AA020105), National Public Health Grand Research Foundation (Grant No. 201202017): Research Funding.