EFFECTS OF GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR PRODUCED IN CHINESE-HAMSTER OVARY CELLS (REGRAMOSTIM), ESCHERICHIA-COLI (MOLGRAMOSTIM) AND YEAST (SARGRAMOSTIM) ON PRIMING PERIPHERAL-BLOOD PROGENITOR CELLS FOR USE WITH AUTOLOGOUS BONE-MARROW AFTER HIGH-DOSE CHEMOTHERAPY

Peripheral blood progenitor cells (PBPCs) were collected without prior association with chemotherapy but after the administration of granulo cyte-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 conju nction with autologous bone marrow after high-dose chemotherapy in 69 patients with breast cancer or melanoma. The mean peripheral white blo od 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, mol gramostim 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 f or patients receiving regramostim, molgramostim, or sargramostim respe ctively. The total mean ( +/- standard error) CD34(+) cells per kg x 1 0(7) collected by three leukaphereses were 3.28 +/- 1.62, 1.34 +/- 0.5 1 and 2.57 +/- 1.93, for patients receiving regramostim, molgramostim or sargramostim respectively. The use of either molgramostim- or sargr amostim-primed PBPCs led to complete elimination of absolute leukopeni a with a WBC count under 100/mm(3) in 64% and 77% of patients treated, respectively. Patients receiving molgramostim-primed PBPCs required f ewer red blood cells transfusions than patients receiving regramostim- primed PBPCs (p = 0.0062). Our data indicate that PBPCs collected with out 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 patien ts with breast cancer or melanoma.