Peripheral blood progenitor cells (PBPCs) were collected without prior association with
chemotherapy but after the administration of
granulocyte-macrophage colony-stimulating factor (
GM-CSF) produced in Chinese hamster ovary cells (CHO-GM,
regramostim), Escherichia coli (E. coli-GM,
molgramostim), or yeast (Yeast-GM,
sargramostim) and used in conjunction with autologous bone marrow after high-dose
chemotherapy in 69 patients with
breast cancer or
melanoma. The mean peripheral white blood cell (WBC) counts increased by 2.2 to 2.7-fold after
regramostim, 4.5 to 7.3-fold after
molgramostim and 4.3-fold after
sargramostim. All patients underwent three leukaphereses. The mean (+/- standard error) total nucleated pheresed cells per kg x 10(8) were 4.15 +/- 0.56, 15.10 +/- 1.77 and 7.24 +/- 1.00 for patients receiving
regramostim,
molgramostim or
sargramostim respectively. The mean (+/- standard error) granulocyte-macrophage colony-forming units per kg x 10(4) mobilized into the PB were 8.75 +/- 3.63, 71.03 +/- 17.85, and 65.11 +/- 18.74 for patients receiving
regramostim,
molgramostim, or
sargramostim respectively. The total mean (+/- standard error) CD34+ cells per kg x 10(7) collected by three leukaphereses were 3.28 +/- 1.62, 1.34 +/- 0.51 and 2.57 +/- 1.93, for patients receiving
regramostim,
molgramostim or
sargramostim respectively. The use of either
molgramostim- or
sargramostim-primed PBPCs led to complete elimination of absolute
leukopenia with a WBC count under 100/mm3 in 64% and 77% of patients treated, respectively. Patients receiving
molgramostim-primed PBPCs required fewer red blood cells transfusions than patients receiving
regramostim-primed PBPCs (p = 0.0062). Our data indicate that PBPCs collected without prior association with
chemotherapy but after either
molgramostim or
sargramostim with autologous bone marrow support and
GM-CSF shorten the hematopoietic recovery after myeloablative
chemotherapy in patients with
breast cancer or
melanoma.