Poor Hematopoietic Stem Cell Mobilizers in Multiple Myeloma:A Single Institution Experience.

Abstract

4237 High-dose chemotherapy rescued by autologous peripheral blood stem cell transplantation is considered standard of care for patients with multiple myeloma. Hematopoietic stem cell mobilization is accomplished by administration of hematopoietic growth factors combined or not with myelosuppressive chemotherapy. In a single institution, in a group of twenty eight myeloma patients deemed eligible for autologous transplant, stem cell mobilization was attempted using only filgrastim: Twenty six individuals were given 31 autografts employing one to four (median three) apheresis sessions, to obtain a target stem cell dose of 1 × 106 CD34 viable cells / Kg of the recipient. The median number of grafted cells was 7.56 × 106 CD34 viable cells / Kg of the recipient; the range being 0.92 to 14.8. By defining as poor mobilizers individuals in which a cell collection of less than 1 × 106 CD34 viable cells / Kg was obtained, a subset of eight poor mobilizers was identified; in two patients the autograft was aborted because of an extremely poor CD34 cell yield (less than 0.2 × 106 CD34 viable cells / Kg of the recipient) after four apheresis sessions. The long-term overall survival of the patients grafted with more than 1 × 106 CD34 viable cells / Kg was better (80% at 80 months) than those grafted with less than 1 × 106 CD34 viable cells / Kg (67% at 76 months). Methods to improve stem cell mobilization are needed and may result in obtaining better results when autografting multiple myeloma patients. Disclosures: No relevant conflicts of interest to declare.

Reduced‐dose plerixafor as a mobilization strategy in autologous hematopoietic cell transplantation: a proof of concept study

“…Many risk factors have been associated with poor stem cell mobilization, including age, obesity, the underlying diagnosis (myeloma and lymphoma), previous radiotherapy or chemotherapy, disease status, among others . In a previous study analyzing the prevalence of poor mobilization in patients with myeloma or lymphoma stimulated with G‐CSF monotherapy, a median of 7.5 × 10 6 CD34+ cells/kg were harvested in three apheresis sessions (range, 2‐4); in most cases (51.6%) 1‐2 × 10 6 CD34+ cells/kg were obtained, whereas in 29% >2 × 10 6 CD34+ cells/kg were collected; 19.3% were identified as poor CD34+ cell mobilizers (<1 × 10 6 CD34+ cells/kg) . To guarantee adequate PBSC collection different cellular mobilization schemes have been developed, including the use of plerixafor.…”