Effect of chemotherapy with alkylating agents on the yield of CD34+ cells in patients with multiple myeloma. Results of the Spanish Myeloma Group (GEM) Study

Grupo Espanol de Mieloma. delarubia_jav@gva.es BACKGROUND AND OBJECTIVES: Although alkylating agents are clearly beneficial in multiple myeloma (MM), their deleterious effect on bone marrow hematopoietic progenitor cells usually precludes their use as front-line therapy in patients scheduled to undergo autologous stem cell transplantation (ASCT). We analyzed the impact of first-line chemotherapy with alkylating agents on stem cell collection in MM patients. DESIGN AND METHODS: Seven hundred and eighty-nine patients included in the Spanish multicenter protocol GEM-2000 underwent mobilization therapy after four courses of alternating VBMCP/VBAD chemotherapy. RESULTS: The mobilization regimens consisted of standard or high-dose granulocyte colony-stimulating factor (G-CSF) in 551 (70%) patients, and chemotherapy and G-CSF in 206 (26%) patients. The CD34+ cell yield was lower than 4x10(6)/kg in 388 patients (49%), and equal or greater than 4x10(6)/kg in 401 patients (51%). Multivariate analysis indicated that advanced age (p