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We have previously reported that continuous intravenous (IV) administration of recombinant granulocyte-macrophage colony-stimulating factor (rHuGM-CSF) to humans following high-dose alkylating agent chemotherapy and autologous bone marrow support (ABMS) results in myeloid bone marrow maturation, accelerated granulocyte recovery, and reduced treatment-related toxicity. However, we found that leukocyte counts declined rapidly after discontinuation of rHuGM-CSF therapy, which suggests possible growth factor effects on leukocyte margination and migration. For these reasons we studied granulocyte margination by using 111In-labeled autologous granulocytes and found similar granulocyte margination before (21.5% +/- 13.4%) and during continuous IV rHuGM-CSF infusion (23.3% +/- 9.6%). Phagocytosis of Cryptococcus neoformans and granulocyte hydrogen peroxide production was similar before and during rHuGM-CSF infusion and similar to patients treated with the same high-dose chemotherapy and ABMS but not receiving growth factor. However, migration of granulocytes to a sterile inflammatory site was markedly reduced during continuous rHuGM-CSF infusion (1.2 +/- 0.9 WBCs/cm2, 24 hr) as compared with baseline (39.6 +/- 17.7 WBCs/cm2/24 hr; P less than .0008). These findings may be of relevance when extravascular granulocytes are required for host defense.

Recombinant human granulocyte-macrophage colony-stimulating factor (rHuGM-CSF) produces dose-related therapeutic and toxic effects; however, relationships between its pharmacokinetics and pharmacodynamics have not been extensively evaluated. The following studies were undertaken to investigate patterns in the disposition of rHuGM-CSF administered after high-dose chemotherapy (cyclophosphamide, cisplatin, carmustine) and autologous bone marrow support. Continuous 14 or 21 day intravenous infusions or daily 4-hour infusions were studied at doses of 1.2 to 19.2 micrograms/kg/d. GM-CSF was measured by an enzyme-linked immunosorbent assay from serum and urine samples collected throughout drug administration. Pharmacokinetic parameters were determined by compartmental (4-hour infusions) or noncompartmental methods (continuous infusions). GM-CSF was rapidly eliminated from the serum. Average systemic exposure increased with dose, although wide interpatient variability was evident. Approximately one half of the patients receiving continuous infusions demonstrated increasing GM-CSF clearance that corresponded to the appearance of white blood cells in the periphery. Conversely, clearance decreased in those experiencing renal dysfunction during the infusion. The percentage of a GM-CSF dose found in 24-hour urine collections was substantially reduced in the latter group. A subset of patients who developed renal dysfunction also experienced significant hypotension. Rapidly increasing serum GM-CSF concentrations corresponded to the hypotensive episodes. GM-CSF serum concentration monitoring may be useful for evaluation of therapeutic and toxic effects in patients receiving high-dose chemotherapy with autologous bone marrow support.

4-Hydroperoxycyclophosphamide (4-HC), a commonly used marrow-purging agent, is active against many tumors, but is also toxic to normal marrow progenitors. Amifostine (WR-2721) is a sulfhydryl compound with chemoprotectant activity. Preclinical studies using suspensions of bone marrow and breast cancer cells demonstrated that ex vivo treatment with amifostine followed by 4-HC resulted in protection of marrow progenitors, with no compromise in the antitumor effect of 4-HC. This fact stimulated the development of a clinical trial. Bone marrow was harvested from 15 poor-prognosis breast cancer patients and randomly assigned to ex vivo treatment with amifostine followed by 4-HC (amifostine + 4-HC), or treatment with 4-HC alone. High-dose chemotherapy was then administered followed by infusion of the purged autologous bone marrow support (ABMS). Leukocyte engraftment, defined as a white blood cell count > or = 1 x 10(9)/L, was achieved in an average of 26 days for patients whose marrow was purged with amifostine + 4-HC versus 36 days for patients whose marrow was purged with 4-HC alone (P = .032). The average number of platelet transfusions (12 v 29; P = .017) and days of antibiotic therapy (28 v 40; P = .012) were significantly less for patients whose marrow was exposed to amifostine + 4-HC, compared with 4-HC alone. Unpurged backup marrow fractions were infused into three patients whose marrow was purged with 4-HC alone, because of inadequate marrow recovery. None of the patients who received amifostine + 4-HC-purged marrow required a backup marrow fraction. Complete remissions were achieved in 83% of patients with measurable disease, with no difference between the two cohorts. Forty- three percent of patients remained alive and progression-free at a mean of 13 months posttransplant. There was no significant difference in the rate or pattern of relapse for patients whose marrow was purged with amifostine + 4-HC compared with those whose marrow was purged with 4-HC alone. Ex vivo treatment of marrow with amifostine significantly shortens the time to marrow recovery, thereby reducing the risk of myelosuppressive complications in breast cancer patients receiving high- dose chemotherapy and 4-HC-purged ABMS. Since supportive care requirements are also significantly decreased, amifostine may reduce the cost of such therapy.

Two hematopoietic colony-stimulating factors, granulocyte colony- stimulating factor (G-CSF) and granulocyte-macrophage CSF (GM-CSF), have been shown to accelerate leukocyte and neutrophil recovery after high-dose chemotherapy and autologous bone marrow (BM) support. Despite their use, a prolonged period of absolute leukopenia persists during which infections and other complications of transplantation occur. We collected large numbers of peripheral blood (PB) progenitors after CSF administration using either G-CSF or GM-CSF and tested their ability to affect hematopoietic reconstitution and resource utilization in patients undergoing high-dose chemotherapy and autologous BM support. Patients with breast cancer or melanoma undergoing high-dose chemotherapy and autologous BM support were studied in sequential nonrandomized trials. After identical high-dose chemotherapy, patients received either BM alone, with no CSF; BM with either G-CSF or GM-CSF; or BM with G-CSF or GM-CSF and G-CSF or GM-CSF primed peripheral blood progenitor cells (PBPC). Hematopoietic reconstitution, as well as resource utilization, was monitored in these patients. The use of CSF- primed PBPC led to a highly significant reduction in the duration of leukopenia with a white blood cell (WBC) count under 100 and 200 cells/mL, and neutrophil count under 100 and 200 cells/mL with both GM- and G-CSF primed PB progenitor cells, compared with the use of the CSF with BM or with historical controls using BM alone. In addition, the use of CSF-primed PBPC resulted in a significant reduction in median number of antibiotics used, days in the Bone Marrow Transplant Unit, and hospital resources used. Patients receiving G-CSF primed PBPC also experienced a reduction in the median number of days in the hospital, red blood cell (RBC) transfusions, platelet transfusions, days on antibiotics, and discounted hospital charges. Phenotypic analysis of the CSF-primed PBPC indicated the presence of cells bearing antigens associated with both early and late hematopoietic progenitor cells. The use of CSF-primed PBPC can significantly improve hematopoietic recovery after high-dose chemotherapy and autologous BM support. In addition, the use of G-CSF-primed PBPC was associated with a significant reduction in hospital resource utilization, and a reduction in hospital charges.

Endogenous cytokines are thought to mediate numerous biologic processes and may account for some adverse effects experienced following the administration of recombinant proteins. This study describes the pattern of endogenous cytokine exposure following high-dose chemotherapy. Blood concentrations of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), macrophage colony-stimulating factor (M-CSF), and erythropoietin (EPO) were measured by enzyme-linked immunosorbent assay (ELISA) methods in 68 patients receiving the same ablative chemotherapy regimen (cyclophosphamide, cisplatin, carmustine). Patients were grouped according to cellular support (autologous bone marrow [BM] CSF-primed peripheral blood progenitor cells [PBPCs]) and prescribed growth factor (recombinant human granulocyte or granulocyte-macrophage colony-stimulating factor [rHuG- CSF or rHuGM-CSF]). Leukocyte reconstitution was most accelerated in the groups treated with PBPCs and rHuG-CSF. IL-6, M-CSF, and TNF-alpha concentrations were higher in the groups treated with rHuGM-CSF and without PBPCs. Maximal endogenous cytokine concentrations occurred approximately 12 days after BM reinfusion. High concentrations of EPO occurred in patients experiencing significant hypotension despite routine transfusions for hematocrit < 42%. High M-CSF and IL-6 levels were associated with increased platelet transfusion requirements. Concentrations of all four cytokines were significantly higher in patients experiencing renal or hepatic toxicity, with elevations occurring in a predictable sequence and M-CSF elevations occurring first. This report shows that endogenous cytokine concentrations may be influenced by either cellular or CSF support and are associated with differences in platelet reconstitution and organ toxicity.