Mobilization of peripheral blood stem cells in myeloma with either pegfilgrastim or filgrastim following chemotherapy

Quality and quantity of mobilized peripheral blood stem cells determine the safety of tandem autologous transplants in myeloma. Using the same mobilization chemotherapy with DT-PACE in two consecutive protocols, robustness of stem cell collection and rapidity of engraftment after transplantation were assessed. We employed either twice a day filgrastim versus two doses of pegfilgrastim. Advantages of pegfilgrastim were: (i) a higher percentage of patients collected 15×10⁶/kg in the first three days (p<0.001); (ii) the median number of CD34 cells/kg collected on day 1 was higher (p=0.004 ); (iii) the median number of growth factor injections was 2 versus 26 (p<0.0001); (iv) post-transplantation neutrophil recovery was faster after first and second transplant (p<0.001) and (v) platelet recovery was faster after first transplant (when less stem cells were infused) (p=0.01). Pegfilgrastim may be considered the standard of care for stem cell mobilization.