Both of these drugs are appropriate for stem cell mobilization but it is unusual to use both of them together.
There are numerous effective techniques to successfully mobilize stem cells to use as peripheral blood stem cells (PBSC) for hematopoietic stem cell transplants. Growth factor (GF) — typically G-CSF — mobilization of the donor or patient is the simplest method. Chemotherapy followed by growth factors (CT/GF), with collection on the neutrophil rebound is another alternative. Most comparative studies with CT/GF mobilization have demonstrated substantially higher numbers of stem cells collected compared with GF alone (more cells are collected with fewer apheresis procedures required). GM-CSF has not performed as well as G-CSF.
Three studies reported on combined use. The first study by Bachier and colleagues was a randomized trial comparing G-CSF (10 mcg/kg/day) alone, GM-CSF (500 mcg/m2/day) alone, and the combination of G-CSF plus GM-CSF (10 mcg/kg plus 250 mcg/m2/day) for PBSC mobilization of normal donors. The highest number of CD34+ cells collected was in the combination G-CSF/GM-CSF group. There was no significant difference between the G-CSF group and the combination group. The other two studies evaluated the combination of G-CSF and GM-CSF in patients who had failed initial mobilization.