Chemotherapy Combined with Venetoclax Followed by Allo-Hematopoietic Stem Cell Transplantation for Treatment of Blastic Plasmacytoid Dendritic Cell Neoplasm

Abstract

To investigate the efficacy and safety of chemotherapy combined with venetoclax followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) for the treatment of blastic plasmacytoid dendritic cell neoplasm (BPDCN). The clinical data of 3 patients with BPDCN undergoing allo-HSCT in Department of Hematology, Wuhan First Hospital from July 2017 to November 2021 were collected and retrospectively analyzed. Among the 3 patients, there were 1 male and 2 females, aged 27-52 years old. Skin lesions were observed during initial diagnosis, and it could also be characterized by acute leukemia. Characteristic molecular markers of tumor cells, such as CD4, CD56, CD123, and CD303 were positive. In addition, the expression detection of Bcl-2 in 3 patients were positive. Chemotherapy combined with venetoclax in the initial induction of chemotherapy (1 case) or disease recurrence and progress (2 cases) was performed. There were 2 cases evaluated as complete remission (CR) and 1 case as partial remission (PR) before allo-HSCT. The patients all received a nonmyeloablative conditioning without total body irradiation (TBI). The prevention programme of graft-versus-host disease (GVHD) was antithymocyte globulin + mycophenolate mofetil + cyclosporin A/FK506 ± methotrexate. The number of mononuclear cell (MNC) count was (16.73-18.35)×108/kg, and CD34+ cell count was (3.57-4.65)×106/kg. The 3 patients were evaluated as CR after allo-HSCT (+21 to +28 d), the donor-recipient chimerism rate was 100%, and Ⅲ-Ⅳ GVHD was not observed. One patient died at +50 d after transplantation, two patients were followed up for 28 months and 15 months, respectively, and achieved disease-free survival (DFS). BPDCN is a highly aggressive malignant tumor with poor prognosis. Chemotherapy combined with venetoclax followed by allo-HSCT may lead to long-term DFS or even cure. Post-transplant maintenance is still unclear.