Effective mobilization with etoposide and cyclophosphamide for collection of peripheral blood stem cell in patients with multiple myeloma.

Purpose: To evaluate the efficacy and toxicity of etoposide and cyclophosphamide for mobilization peripheral stem cells in multiple myeloma patients.

Methods: We retrospectively analyzed 46 patients with multiple myeloma who underwent peripheral blood stem cell collection for upfront autologous hematopoietic stem cell transplantation in the First Affiliated Hospital of Xi'an Jiaotong University between January 2010 and July 2019. The mobilization protocols included cyclophosphamide 2.0 g/m2 with G-CSF (CTX group) before January 2015, and two-days of 5 mg/kg.d etoposide and 1.0 g/m2.d cyclophosphamide with G-CSF (EC group) after January 2015.

Results: The success rate of harvest (≥2×106 cells/kg) during the first mobilization attempt was 82.1% in the EC group and 50.0% in the CTX group, and the rate of adequate harvest (≥4×106 cells/kg) was 57.1% in the EC group and 15.8% in the CTX group. After the second mobilization, a sufficient number of CD34+/kg cells for an auto-HSCT was obtained for all patients in the EC group and the majority (68.4%) of patients in CTX group. There was no significant difference of non-hematological adverse events between two groups. The mean neutrophil engraftment time was 11.22±1.56 days and 9.89±2.81days for the CTX and EC groups, respectively (P>0.05). Platelet engraftments were significantly faster in the EC group than the CTX group (P0.05).

Conclusion: The etoposide and cyclophosphamide regimen could be an effective and safe method for mobilization in patients with multiple myeloma.