Efficacy and Safety of Etoposide Combined with Cyclophosphamide for Autologous Peripheral Blood Stem Cell Mobilization in Patients with Multiple Myeloma

Abstract

To evaluate the efficacy and safety of etoposide combined with cyclophosphamide (EC) regimen for mobilization of autologous peripheral blood stem cells (APBSCs) in patients with multiple myeloma (MM). The clinical data of 48 MM patients who received APBSC transplantation (APBSCT) in Department of Hematology of the First Affiliated Hospital of Nanchang University from January 2015 to October 2021 were retrospectively analyzed. The mobilization success rate and mobilization optimal rate of EC regimen were counted, and its effect on transplant efficacy, adverse reactions, hematopoietic reconstitution after transplantation, and survival time of MM patients were analyzed. APBSCs were collected on day 14 (10-19) after EC administration. The median of collected CD34+ cells was 6.82 (1.27-22.57)×106/kg, and the median number of apheresis session was 2 (1-4). The mobilization success rate (collecting CD34+ cells≥2×106 cells/kg after completion of apheresis) was 98% (47/48), and mobilization optimal rate (collecting CD34+ cells≥5×106 cells/kg after completion of apheresis) was 71% (34/48). The depth of remission were improved after APBSCT, and the complete remission (CR) rate increased from 45.8% before transplantation to 87.5% after transplantation (P <0.01). There was no transplant-related death, no blood transfusion during mobilization, and no mucositis occurred in the patients. The most common complication was neutropenia, with an incidence of 75.0% (36/48). After transplantation, all the patients successfully achieved hematopoietic reconstitution. The median time to neutrophil engraftment was 10 (9-26) days, and median time to platelet engraftment was 10 (8-33) days. By the end of follow-up, both the median progression-free survival (PFS) and overall survival (OS) time were not reached. The 5-year estimated PFS rate and OS rate was 53.8% and 82.4%, respectively. The EC regimen for mobilization of APBSC has a high acquisition success rate and controllable adverse reactions, which can be an effective and safe mobilization regimen in MM patients.