Successful mobilization of peripheral blood stem cells after addition of ancestim (stem cell factor) in patients who had failed a prior mobilization with filgrastim (granulocyte colony-stimulating factor) alone or with chemotherapy plus filgrastim.
This study assessed the ability of recombinant human stem cell factor (rHuSCF) to mobilize stem cells in 44 patients who had failed a prior mobilization (CD34(+) yield 0.5-1.9 x 10(6)/kg BW) with filgrastim-alone or chemotherapy-plus-filgrastim. The same mobilization regimen was used with the addition of rHuSCF. In the filgrastim-alone group (n=13), rHuSCF 20 microg/kg was started 3 days before filgrastim and continued for the duration of filgrastim. In the chemotherapy-plus-filgrastim group (n=31), rHuSCF 20 microg/kg/day plus filgrastim 5-10 microg/kg/day were administered concurrently. Leukaphereses were continued to a maximum of four procedures or a target of >or=3 x 10(6) CD34(+) cells/kg. In both groups, CD34(+) yield (x 10(6)/kg BW) of the study mobilization was higher than that of the prior mobilization (median: 2.42 vs 0.84 P=0.002 and 1.64 vs 0.99 P=<0.001, respectively). In all 54 and 45% of patients in the filgrastim-alone group and chemotherapy-plus-filgrastim group, respectively, reached the threshold yield of 2 x 10(6)/kg. The probability of a successful mobilization was the same in those with a CD34+ yield of 0.5-0.75 x 10(6)/kg BW in the prior mobilization as in those with 0.76-1.99 x 10(6)/kg BW. Downmodulation of c-kit expression and a lower percentage of Thy-1 positivity in the mobilized CD34(+) cells were noted in the successful mobilizers compared with those in the poor mobilizers. This study shows that rhuSCF is effective in approximately half the patients who had failed a prior mobilization and allows them to proceed to transplant. It also points to the likely role of the SCF/c-kit ligand pair in mobilization.
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LB
Division of Haematology, Hanson Centre for Cancer Research, Adelaide, Australia.
Bashford
J
J
Durrant
S
S
MacMillan
J
J
Schwarer
A P
AP
Prince
H M
HM
Gibson
J
J
Lewis
I
I
Swart
B
B
Marty
J
J
Rawling
T
T
Ashman
L
L
Charles
S
S
Cohen
B
B
D000328:Adult; D000368:Aged; D018952:Antigens, CD34 / Q000032:analysis; D005260:Female; D000069585:Filgrastim; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D019650:Hematopoietic Stem Cell Mobilization; D006801:Humans; D008297:Male; D008875:Middle Aged; D036102:Peripheral Blood Stem Cell Transplantation; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D011994:Recombinant Proteins / Q000494:pharmacology; D019089:Stem Cell Factor / Q000494:pharmacology*
D018952:Antigens, CD34; D011994:Recombinant Proteins; D019089:Stem Cell Factor; D016179:Granulocyte Colony-Stimulating Factor; D019009:Proto-Oncogene Proteins c-kit; D000069585:Filgrastim