Effects of bacterially synthesized recombinant human granulocyte-macrophage colony-stimulating factor in patients with advanced malignancy

STUDY OBJECTIVE: To define the clinical and hematologic effects of subcutaneously administered bacterially synthesized recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF). DESIGN: Single arm nonrandomized dose escalation study. PATIENTS: Twenty-one patients with advanced malignancy who were not receiving concurrent myelosuppressive therapy. INTERVENTIONS: Subcutaneous administration of rhGM-CSF by once-daily injection to groups of two to four patients at doses of 0.3 to 30 micrograms/kg body weight.d for 10 consecutive days. Some patients received a second 10-day period of daily rhGM-CSF treatment after a 10-day nontreatment interval followed by alternate-day treatment. Clinical status and hematologic values were monitored frequently. MEASUREMENTS AND MAIN RESULTS: All doses of rhGM-CSF caused an immediate transient fall of 84% to 99% in circulating neutrophils, eosinophils, and monocytes. Continued daily dosing caused a leukocytosis of up to 10-fold with increases in numbers of circulating neutrophils, eosinophils, monocytes, and lymphocytes. There appeared to be a plateau in the increase in neutrophils in the dose range 3 to 15 micrograms/kg.d. Marrow aspirates showed increased proportions of promyelocytes and myelocytes. Alternate-day injection of 15 micrograms/kg maintained a leukocytosis. At doses up to 15 micrograms/kg.d, rhGM-CSF was well tolerated but adverse effects included bone pains, myalgias, rashes, and liver dysfunction. At doses exceeding 15 micrograms/kg.d, pericarditis was a dose-limiting toxicity. Idiopathic thrombocytopenic purpura was reactivated by rhGM-CSF in one patient. CONCLUSIONS: Bacterially synthesized rhGM-CSF induces a leukocytosis in the dose range of 3 to 15 micrograms/kg.d. These doses are appropriate for phase II studies.     

Stimulation of canine hematopoiesis by recombinant human granulocyte-macrophage colony-stimulating factor

The effect of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on canine hematopoiesis was evaluated. rhGM-CSF stimulated granulocyte-macrophage colony formation of canine marrow depleted of accessory cells up to tenfold. Stimulation of colony formation was abrogated by anti-rhGM-CSF antiserum or heat inactivation. rhGM-CSF also stimulated in vivo canine hematopoiesis both when given as continuous i.v. infusion and as intermittent s.c. injections. Neutrophil, monocyte, and lymphocyte counts were increased three- to eightfold above controls, whereas values for eosinophils, reticulocytes, and hematocrits were not changed. Bone marrow histology after 2 weeks of treatment with rhGM-CSF showed hypercellularity with myeloid hyperplasia and left-shifted granulocytopoiesis. After discontinuation of rhGM-CSF, peripheral leukocyte counts returned to control level within 3-7 days. Platelet counts decreased rapidly after starting rhGM-CSF, to 5000-15,000 platelets/mm3, and increased within 24 h after stopping rhGM-CSF treatment, whereas marrow histology after 2 weeks of rhGM-CSF application showed the normal number and morphology of megakaryocytes.     

Immunization with recombinant human granulocyte-macrophage colony-stimulating factor as a vaccine adjuvant elicits both a cellular and humoral response to recombinant human granulocyte-macrophage colony-stimulating factor

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is an important cytokine for the generation and propagation of antigen-presenting cells and for priming a cellular immune response. We report here that use of recombinant human GM-CSF (rhGM-CSF), administered as an adjuvant in a peptide-based vaccine trial given monthly by intradermal injection, led to the development of a T-cell and antibody response to rhGM-CSF. An antibody response occurred in the majority of patients (72%). This antibody response was not found to be neutralizing. In addition, by 48-hour delayed type hypersensitivity (DTH) skin testing, 17% of patients were shown to have a cellular immune response to the adjuvant rhGM-CSF alone. Thymidine incorporation assays also showed a peripheral blood T-cell response to rhGM-CSF in at least 17% of the patients. The generation of rhGM-CSF-specific T-cell immune responses, elicited in this fashion, is an important observation because rhGM-CSF is being used as a vaccine adjuvant in various vaccine strategies. rhGM-CSF-specific immune responses may be incorrectly interpreted as antigen-specific immunity, particularly when local DTH responses to vaccination are the primary means of immunologic evaluation. We found no evidence of hematologic or infectious complications as a result of the development of rhGM-CSF-specific immune responses.     

Treatment of active Crohn's disease with recombinant human granulocyte-macrophage colony-stimulating factor

Treatment for Crohn's disease is aimed at immunosuppression. Yet inherited disorders associated with defective innate immunity often lead to development of a Crohn's-like disease. We performed an open-label dose-escalation trial (4-8 microg/kg per day) to investigate the safety and possible benefit of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the treatment of 15 patients with moderate to severe Crohn's disease. No patients had worsening of their disease. Adverse events were negligible and included minor injection site reactions and bone pain. Patients had a significant decrease in mean Crohn's disease activity index (CDAI) score during treatment (p<0.0001). After 8 weeks of treatment, mean CDAI had fallen by 190 points. Overall, 12 patients had a decrease in CDAI of more than 100 points, and eight achieved clinical remission. Retreatment was effective, and treatment was associated with increased quality-of-life measures. GM-CSF may offer an alternative to traditional immunosuppression in treatment of Crohn's disease.     

Recovery from severe hematopoietic suppression using recombinant human granulocyte-macrophage colony-stimulating factor

The ability of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) to enhance recovery of a radiation-suppressed hematopoietic system was evaluated in a nonuniform radiation exposure model using the rhesus monkey. Recombinant human GM-CSF treatment for 7 days after a lethal, nonuniform radiation exposure of 800 cGy was sufficient to enhance hematopoietic reconstitution, leading to an earlier recovery. Monkeys were treated with 72,000 U/kg/day of rhGM-CSF delivered continuously through an Alzet miniosmotic pump implanted subcutaneously on day 3. Treated monkeys demonstrated effective granulocyte and platelet levels in the peripheral blood, 4 and 7 days earlier, respectively, than control monkeys. Granulocyte-macrophage colony-forming unit (CFU-GM) activity in the bone marrow was monitored to evaluate the effect of rhGM-CSF on marrow recovery. Treatment with rhGM-CSF led to an early recovery of CFU-GM activity suggesting that rhGM-CSF acted on an earlier stem cell population to generate CFU-GM. Thus, the effect of rhGM-CSF on hematopoietic regeneration, granulocyte recovery, and platelet recovery are evaluated in this paper.     

Effects of recombinant murine granulocyte colony-stimulating factor on granulocyte-macrophage and blast colony formation

We performed the present study to define the in vitro hemopoietic activity of murine recombinant (r) granulocyte colony-stimulating factor (G-CSF) using murine hemopoietic culture systems of normal bone marrow cells, fetal liver cells, and spleen cells of 5-fluorouracil (FU)-treated mice. Recombinant G-CSF supported only neutrophil and/or macrophage colony formation by normal bone marrow cells. It did not enhance the formation of erythroid bursts in the fetal liver cell assay, but interleukin-3 (IL-3) did. Paradoxically, rG-CSF could support the colony formation of multilineage colonies as well as blast colonies from the spleen cells of 5-FU-treated mice, while r-granulocyte-macrophage colony-stimulating factor (GM-CSF) and r-erythropoietin (Ep) did not. When blast colonies, formed in the presence of G-CSF, were replated to dishes containing IL-3, they were able to differentiate along multilineage pathways. However, when they were replated to dishes containing rG-CSF, they could differentiate only into neutrophils and macrophages. Single cells transferred from blast colonies formed only neutrophil-macrophage colonies. These data indicate that rG-CSF had a direct effect on the growth and development of GM progenitors at a late stage and a significant effect on multipotential hemopoietic precursors. Although it remains to be clarified how G-CSF acts on multipotential stem cells, this unique effect is important in the understanding of its pluripotent hemopoietic activity in vivo.     

A pilot study of low-dose recombinant human granulocyte-macrophage colony-stimulating factor in chronic neutropenia

Summary. Recombinant human granulocyte macrophage colony stimulating factor (rhGM-CSF) is under investigation for the treatment of a wide range of haematological disorders. At commonly used doses of > 120 μg/m²/d, extramedullary toxicity is common. We report the effects of low-dose (LD) rhGM-CSF in patients with chronic neutropenia related to HIV infection, myelodysplastic syndrome and idiopathic neutropenia. Nine patients with a mean pre-treatment neutrophil count of 0·6 × 10⁹/1 (range 0·2–1·4 × 10⁹/1) received daily rhGM-CSF at doses of between 5 and 15 μg/m², Eight patients responded with a mean post-treatment ANC of 3·2 × 10⁹/1 (range 1·9–4·6 × 10⁹/1). There was no significant therapy-related morbidity. We conclude that in chronic neutropenia, LD rhGM-CSF is an acceptable treatment which has important cost/benefit implications.     

In vitro and in vivo activity of human recombinant granulocyte-macrophage colony-stimulating factor in dogs

Although it is well documented that human granulocyte-macrophage colony-stimulating factor (GM-CSF) controls the production and functional activity of human and nonhuman primate granulocytes and macrophages, relatively little is known about its effects on cells obtained from other species. The molecular cloning of the complementary DNA for human GM-CSF has made it possible to determine the cross-reactivity of the purified recombinant human material (rhGM-CSF) on cells of other species. The results presented herein show that specific receptors for human GM-CSF exist on dog bone marrow cells and mature circulating dog granulocytes. The number of the receptors and the apparent binding affinity of the rhGM-CSF to its receptors on granulocytes were similar to those observed either on human or monkey cells. In cultures of dog bone marrow cells, rhGM-CSF was capable of promoting colony formation in a dose-dependent manner. Human GM-CSF also primed dog granulocytes for increased production of reactive oxygen metabolites in response to either phorbolmyristic acetate-or zymosan-activated dog serum. In vivo, s.c. administration to healthy dogs of rhGM-CSF in daily doses of 15, 50, or 150 micrograms/kg body weight over a period of 7-20 days induced a dose-dependent rise of up to a maximum of a fourfold increase in peripheral WBC counts. The rise in WBC counts was mainly due to elevated neutrophil levels, but an increase in the numbers of monocytes and eosinophils was also observed. However, the rhGM-CSF-induced leukocytosis in dogs was not as dramatic as that observed in nonhuman primates. In all rhGM-CSF-treated dogs, circulating platelet counts dropped to nadir levels of about 20%-30% of normal numbers. Dogs that were treated with 150 micrograms/kg rhGM-CSF developed specific antibodies after about 10-12 days of treatment. These antibodies were able to neutralize the effect of rhGM-CSF in in vitro assays. In vivo WBC counts began to decline when specific antibodies developed, but they never dropped below normal levels. Taken together, the results suggest that human GM-CSF does not appear to exhibit absolute species specificity.     

Effect of recombinant human granulocyte-macrophage colony-stimulating factor on myelopoiesis in patients with refractory metastatic carcinoma

The effect of human recombinant GM-colony-stimulating factor (CSF) was evaluated in ten patients with refractory metastatic carcinoma. Initially they received an intravenous (IV) bolus injection of 5 or 25 micrograms/m2 for assessment of acute responses. Six days later, continuous IV infusions of 100 or 500 micrograms/m2 were initiated for a 14-day treatment course. All patients developed profound leukopenia within five to 30 minutes of the bolus injection. This appeared to result from increased expression of an adhesion-promoting glycoprotein (GP) on neutrophils and monocytes as judged by increased reactivity to the Mo1 monoclonal antibody (MoAb). Leukocyte counts returned to normal levels within two hours as cells were released from marrow stores. With the continuous infusion, leukocyte counts increased by 24 hours; peak values of 22,960 and 75.900/microL were achieved after ten to 14 days of treatment with the two dose levels of GM-CSF. This leukocytosis was due to an increase in virtually all cell types. At the high dose level, there was a striking increase in neutrophils (49,400/microL) and eosinophils (20,905/microL) with a sixfold increase in monocytes and two- to threefold increase in lymphocytes. Leukocyte counts declined promptly after cessation of the infusion but remained above baseline for as long as 2 weeks in some patients. These results suggest that GM- CSF may be useful as an adjuvant therapy by stimulating myelopoiesis in cancer patients.     

Effects of recombinant granulocyte colony-stimulating factor (rG-CSF) and recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF) on acute radiation hematopoietic injury in mice

We have attempted to evaluate in vivo effects of granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) on acute radiation hematopoietic injury in mice. BDF1 mice, irradiated with 7.5-Gy x-rays, were injected i.p. twice daily for 10 days with 10(5) U recombinant human G-CSF, 3.75 x 10(5) U recombinant murine GM-CSF, or a combination of both. G-CSF significantly enhanced the recovery of not only peripheral leukocytes but also platelets and hematocrit on days 14 and 21 after irradiation. GM-CSF significantly enhanced the recovery of platelets on day 14 and peripheral leukocytes on day 21. G-CSF markedly enhanced the recovery of spleen colony-forming units (CFU-S), colony-forming units in culture (CFU-C), erythroid burst-forming units (BFU-E), and megakaryocyte colony-forming units (CFU-Meg) both in bone marrow and in the spleen. GM-CSF significantly enhanced the recovery of CFU-Meg in bone marrow on day 14. We found synergistic effects between G-CSF and GM-CSF on CFU-S, CFU-C, and CFU-Meg in the spleen on day 14, although we found antagonistic effects between G-CSF and GM-CSF on CFU-S and CFU-C in bone marrow on day 7, and on platelet counts on day 7. These results indicate that the administration of recombinant G-CSF and GM-CSF may be useful in accelerating hematopoietic recovery in patients with acute radiation hematopoietic injuries.     

Use of recombinant human granulocyte-macrophage colony-stimulating factor in graft failure after bone marrow transplantation

The effect of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) was evaluated in 37 patients with marrow graft failure after allogeneic (n = 15), autologous (n = 21), or syngeneic (n = 1) bone marrow transplantation. rhGM-CSF was administered by 2-hour infusion at doses between 60 and 1,000 micrograms/m2/d for 14 or 21 days. At doses of less than 500 micrograms/m2, rhGM-CSF was well-tolerated and did not exacerbate graft-versus-host disease in allogeneic transplant recipients. No patient with myelogenous leukemia relapsed while receiving rhGM-CSF. Twenty-one patients reached an absolute neutrophil count (ANC) greater than or equal to 0.5 x 10(9)/L within 2 weeks of starting therapy while 16 did not. None of seven patients who received chemically purged autologous marrow grafts responded to rhGM-CSF. The survival rates of GM-CSF-treated patients were significantly better than those of a historical control group.     

Use of recombinant human granulocyte-macrophage colony-stimulating factor in autologous marrow transplantation for lymphoid malignancies

The use of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) following autologous marrow transplantation for lymphoid malignancies was explored in a phase I/II dose escalation study. rhGM-CSF given as a 2-hour infusion daily for 14 days was well tolerated at doses up to 240 micrograms/m2/day. When compared with 86 disease-matched and treatment-matched historical controls, patients receiving greater than or equal to 60 micrograms/m2/day rhGM-CSF recovered neutrophil and platelet counts more rapidly, had fewer days with fever, and were discharged from the hospital sooner.     

Effects of recombinant human granulocyte-macrophage colony-stimulating factor in an intensive treatment program for children with Ewing's sarcoma.

BACKGROUND AND OBJECTIVES: A treatment program including polychemotherapy at progressively escalating doses and sequential hemi-body irradiation (HBI) was adopted between 1987-1994 at our Pediatric Unit for high risk Ewing's sarcoma. Granulocyte-macrophage colony-stimulating factor (GM-CSF) was added to the treatment program in a phase II study fashion to evaluate, in a pediatric setting, its tolerability, as well as its impact on drug dose escalation and on the need for supportive care. DESIGN AND METHODS: The study was open-label and sequential; GM-CSF administration (5 microg/Kg s.c./d x10) was planned after each chemotherapy cycle and after each HBI session in 18 consecutive patients (group A). Thirty-eight additional patients (group B) were treated by the same therapeutic program, without GM-CSF. In 12 patients (6 in each group) long-term bone marrow cultures (LTBMC) were performed to evaluate the myeloproliferative potential throughout the chemotherapeutic program. RESULTS: Seven of 18 (39%) patients experienced side effects from GM-CSF; 3/7 discontinued GM-CSF due to anaphylactic symptoms. The degree of neutropenia, as well as the frequency of infectious episodes and the need for supportive care were significantly lower in group A than in group B. Iatrogenic thrombocytopenia, and the possibility of performing drug-dose escalation were similar in the two groups. The 5-year event-free survival probabilities for group A and B were similar. LTBMC showed that the chemotherapy-related depletion of myeloid precursors could be more pronounced in patients receiving GM-CSF cyclically. INTERPRETATION AND CONCLUSIONS: In this series, GM-CSF was shown to be effective on iatrogenic neutropenia and related complications, with no impact on thrombopoiesis, drug dose escalation and outcome.     

Variable effect of recombinant human granulocyte-macrophage colony-stimulating factor on bone marrow fibrosis in patients with myelodysplasia

Eleven patients with myelodysplastic syndrome (MDS) and bone marrow fibrosis were identified out of a group of 15 patients with MDS who received recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) as part of a phase I/II trial. Bone marrow biopsies were obtained before and after one or more courses of GM-CSF at 250 micrograms/m2 administered as a 12-h infusion each day for 14 days. The biopsies were blindly evaluated and reticulin formation and collagen deposition were graded on a scale of 0-4. Fibrosis unequivocally increased in three patients and decreased in three patients. There were equivocal increases in an additional two patients and decreases in one subject. It was unchanged in one subject and unevaluable in one patient. Although patients in whom fibrosis increased tended to have smaller increases in neutrophil and reticulocyte counts on therapy, the difference was not statistically significant. In this small group of patients, it was not possible to determine clinical features that predicted response. Although GM-CSF can lead to partial resolution of marrow fibrosis in some individuals, it can also accelerate its deposition; improvement in granulocyte or reticulocyte count does not preclude increasing marrow fibrosis. Thus, the use of GM-CSF in patients with myelodysplasia with marrow fibrosis must be undertaken with caution.     

Specific human granulocyte-macrophage colony-stimulating factor antagonists.

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic hemopoietic growth factor and activator of mature myeloid cell function. We have previously shown that residue 21 in the first helix of GM-CSF plays a critical role in both biological activity and high-affinity receptor binding. We have now generated analogues of GM-CSF mutated at residue 21, expressed them in Escherichia coli, and examined them for binding, agonistic, and antagonistic activities. Binding experiments showed that GM E21A, E21Q, E21F, E21H, E21R, and E21K bound to the GM-CSF receptor alpha chain with a similar affinity to wild-type GM-CSF and had lost high-affinity binding to the GM-CSF receptor alpha-chain-common beta-chain complex. From these mutants, only the charge reversal mutants E21R and E21K were completely devoid of agonistic activity. Significantly we found that E21R and E21K antagonized the proliferative effect of GM-CSF on the erythroleukemic cell line TF-1 and primary acute myeloid leukemias, as well as GM-CSF-mediated stimulation of neutrophil superoxide production. This antagonism was specific for GM-CSF in that no antagonism of interleukin 3-mediated TF-1 cell proliferation or tumor necrosis factor alpha-mediated stimulation of neutrophil superoxide production was observed. E. coli-derived GM E21R and E21K were effective antagonists of both nonglycosylated and glycosylated wild-type GM-CSF. These results show that low-affinity GM-CSF binding can be dissociated from receptor activation and have potential clinical significance for the management of inflammatory diseases and certain leukemias where GM-CSF plays a pathogenic role.     

Comparative pharmacokinetics of single-dose administration of mammalian and bacterially-derived recombinant human granulocyte-macrophage colony-stimulating factor

Abstract: Pharmacokinetics of recombinant human non-glycosylated bacterially-synthesized (E. coli) granulocyte-macrophage colony-stimulating factor (GM-CSF) were studied following single intravenous (i.v.) and subcutaneous (s.c.) bolus injection, and compared to equivalent doses of glycosylated mammalian-derived CHO-GM-CSF. Each route of administration gave a different GM-CSF concentration-time profile. The highest peak serum concentrations (C_max) were observed following i.v. bolus injection. After i.v. administration, a two-phase decline in concentration was noted for both types of GM-CSF with a significantly shorter ***t1/2 α of 7.8 minutes for the E. coli GM-CSF versus 20.0 min for the CHO-GM-CSF, while no significant difference was observed for the terminal phase. Following s.c. administration of equivalent doses, a higher peak serum concentration was observed in the E. coli-treated patients and, again, a faster elimination where pretreatment serum levels were reached after 16–20 h, versus more than 48 h after administration of CHO-GM-CSF. Although the non-glycosylated E. coli GM-CSF thus seems to undergo a faster elimination that the glycosylated CHO-GM-CSF no significant difference could be demonstrated in the in vivo effect of corresponding doses of the two compounds with respect to stimulation of granulopoiesis — with reservation for small patient numbers and a large individual variations in response.