TBI/Ratg-Based Conditioning for Haploidentical Allogeneic Hematopoietic Stem Cell Transplantation in 11 Cases of Chemotherapy-Resistant Advanced-Stage Peripheral T-Cell Lymphoma

Abstract

Objectives: To evaluate the clinical outcomes and safety of haploidentical allogeneic hematopoietic stem cell transplantation(haplo-HSCT)with total body irradiation (TBI)/rabbit Anti-thymocyte globulin (rATG) based conditioning regimen in chemotherapy-resistant advanced-stage peripheral T-cell lymphoma (PTCL). Methods: From September 2019 to December 2022, eleven chemotherapy-resistant advanced-stage PTCL patients who underwent haplo-HSCT were enrolled in our study. All of them received TBI/rATG-based conditioning regimen in our centers. Results: ①Among 11 patients, there were 6 males and 5 females with a median age of 40(range：22~58) years old. Six cases of them are peripheral T-cell lymphoma not otherwise specified (PTCL NOS), 3 cases are angioimmunoblastic T-cell lymphoma (AITL), 1 case is large-cell transformation of mycosis fungoides (MF-LCT), and 1 case is T-cell large granular lymphocytic leukemia(T-LGLL). The Lugano stage was III or IV in all cases, and 8 patients had B symptoms. The median number of previous chemotherapy exposure before transplantation was 4 (range: 2~10) lines and the disease status before transplantation was progressive diseases (PD) in all cases. The median time from diagnosis to transplantation was 17(range：6~36) months.②The conditioning regimen consisted of TBI 2Gy d-8, 4Gy from day-7 to -6, rATG 2.5 mg/kg/d day-5 to -2, etoposide 15mg/kg/d day-5 to -4, cyclophosphamide (CTX) 50mg/kg/d, day-3 to -2. The patients with central nervous system involvement received a regimen of thiotepa 5 mg/kg/d， from day -5 to -4 instead of CTX and etoposide, and add 2.0 g/m2 of cytarabine twice a day, from day -3 to day -2 into the conditioning.③All patients were successfully engrafted. Only one patient developed Grade III-IV acute graft-vs-host disease (aGvHD). Among the 8 survivors, 4 cases developed chronic graft-vs-host disease (cGvHD).④After transplantation, CR was obtained in 9 patients. ⑤Regimen related toxicities: all were non-fatal. Hematopoietic suppression occurred in all patients after conditioning. Three patients had diarrhea and four had mucositis and three had elevated transaminase/bilirubin levels. Seven patients had infections.⑥The 1-year cumulative non-relapse mortality (NRM) and 1-year cumulative incidence of relapse (CIR) was 22.5±14.0% and 20.2±12.7%, respectively. The 1-year overall survival (OS) and 1-year disease-free survival (DFS) was 72.7±13.4% and 63.6±14.5%, respectively Conclusions: TBIand rATG based conditioning regimen is effective and safe for haplo-HSCT in chemotherapy-resistant advanced-stage PTCL.