Comparative Efficacy of Autologous Hematopoietic Stem Cell Mobilization Regimens in Multiple Myeloma Patients

Abstract

Aim. To compare the efficacy of mobilization regimens (MR) differing in their composition and intensity, with the purpose of defining the criteria to personalize the choice of MR based on clinical and hematological characteristics of multiple myeloma (MM) patients.
 Materials & Methods. A retrospective analysis of the autologous hematopoietic stem cell (HSC) mobilization and autograft harvesting results was performed in 177 patients with newly diagnosed MM. The patients were divided into 4 groups. Group 1 included 62 patients with the median age of 53 years who were treated with single injection of cyclophosphamide (CF) dose 3 g/m2 as MR. Group 2 consisted of 71 patients with the median age of 58 years who received vinorelbine 35 mg/m2. Granulocyte colony-stimulating factor (G-CSF) as a monoregimen was administered to group 3 consisting of 33 patients with the median age of 55 years. Group 4 included 11 patients with the median age of 57 years who received G-CSF enhanced by plerixafor administration. G-CSF 10 µg/kg was used as MR. In all chemomobilization cases, daily G-CSF 10 µg/kg started on Day 4 from the administration of the chemotherapy drug prescribed as MR.
 Results. In the analyzed groups, the median time from MR start to the first leukocyte apheresis session was 11, 8, 5, and 5 days, respectively. On the first leukocyte apheresis day, the median CD34+ cell collection in group 3 was significantly lower than in groups 1, 2, and 4: 2.2 × 106/kg vs. 3.79 × 106/kg, 7.22 × 106/kg, and 3.9 × 106/kg, respectively. The total CD34+ cell collection after two leukocyte apheresis sessions was also the lowest in group 3 compared with groups 1, 2, and 4: 3.22 × 106/kg vs. 5.2 × 106/kg, 4.95 × 106/kg, and 7.5 × 106/kg, respectively. In the analyzed groups, the rate of mobilization with CD34+ cell collection < 2.0 × 106/kg was 6.5 %, 5.6 %, 18.2 %, and 9.1 %. The evaluation of the results in all patients showed a direct correlation of CD34+ cell collection with lenalidomide administered before autologous HSC mobilization. A significant difference in CD34+ cell collection in lenalidomide recipients vs. non-recipients was reported when vinorelbine as MR and G-CSF as monoregimen (р = 0.001 and р = 0.022, respectively) were used. No significant differences were observed either with CF or G-CSF combined with plerixafor treatment.
 Conclusion. Based on the findings, age of a MM patient, comorbidities, and prior lenalidomide administration can be regarded as key criteria for choosing one of 4 MRs.