Chidamide combined with a modified Bu-Cy conditioning regimen improves survival in patients with T-cell acute lymphoblastic leukemia/lymphoma undergoing allogeneic hematopoietic stem cell transplantation.

Abstract This study aimed to evaluate the efficacy and safety of chidamide (Chi) combined with a modified Busulfan-Cyclophosphamide (mBuCy) conditioning regimen for T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). Twenty-two patients received chidamide combined with mBuCy conditioning regimen (Chi group). A control (CON) group of 82 patients received mBuCy only in the same period. The leukemia-free survival (LFS), overall survival (OS), cumulative incidence of relapse (CIR), and non-relapse-related mortality (NRM) were evaluated. Patients in the Chi group were associated with lower 2-year CIR (19.0 vs. 38.4%, P= 0.030), better 2-year LFS (76.1 vs. 51.6%, P = 0.027), and had a trend towards better 2-year OS (80.5 vs. 60.4%, P= 0.063). Patients with minimal residual disease (MRD) positive before HSCT in the Chi group exhibited an advantage in 2-year OS and LFS, despite no significant differences (75.0 vs. 18.6%, P = 0.068; 75.0 vs. 24.1%, P = 0.070, respectively). The cumulative incidence rates of grade II-IV aGVHD were similar (36.4 vs. 39.0%, P = 0.820). The most common non-hematologic adverse event was gastrointestinal tract. Hepatic dysfunction was more often observed in the Chi group. 20 patients in Chi group evinced an elevation in γ-glutamyltransferase, as compared to the mBuCy group (90.9 vs. 65.9%, P= 0.021). No transplantation-related mortality was documented within the first 100 days after transplantation. The results demonstrate that the chidamide intensified regimen may be an effective and acceptable safety option for T-ALL/LBL undergoing allo-HSCT.