Hematopoietic colony-stimulating factors. Uses in combination with standard chemotherapeutic regimens and in support of dose intensification

BACKGROUND

Three hematopoietic colony-stimulating factors (CSF) are currently approved for clinical use and several more are being used in clinical trials. These factors have impressive quantitative and/or functional effects on their respective target cell lines, but their best clinical uses have not been defined.

METHODS

The literature regarding the use of CSF in standard chemotherapy is reviewed data and from early Phase I-II studies the use of granulocyte-macrophage CSF (GM-CSF) in support of dose intensification without progenitor cell replacement are presented. Dose intensive cyclophosphamide (5000 mg/m2), etoposide (1500 mg/m2), and cisplatin (150 mg/m2) (DICEP) were administered during 3 days, followed by CSF until hematologic recovery was achieved. Patients had advanced types of cancer unlikely to respond to standard chemotherapy.

RESULTS

CSF can shorten the duration of leukocyte nadirs when given with standard chemotherapy, but a benefit to patients in terms of improved survival or quality of life has not been shown. Dose intensification has increased partial and complete response rates in several tumor types. The higher complete remission rate may translate into improved survival; no convincing data have been published to date supporting that possibility. The duration of severe leukopenia (absolute neutrophil count, less than 100/microliters) after DICEP can be shortened from 8.5 days to 5-6 days with either granulocyte CSF (G-CSF) or GM-CSF. GM-CSF has been shown to decrease the duration of hospital stay from 18.7 to 9.6 days and to decrease the need for readmittance to the hospital for cytopenic fever. A high complete remission rate (35%) was seen in patients with breast cancer and durable complete remissions were achieved in patients with refractory non-Hodgkin lymphoma.

CONCLUSIONS

CSF shortens the duration of postchemotherapy leukocyte nadirs and allows maintenance of dose when this is essential for a beneficial outcome. Substantial dose escalations are also possible with CSF support and can produce a high complete response rate that offers hope for improved survival in selected patients.

[Intra-arterial chemotherapy with granulocyte colony-stimulating factor for breast cancer before surgical treatment]

Intra-arterial chemotherapy (IAC) for far advanced breast cancer is now performed as a routine adjuvant chemotherapy before surgical treatment. However, the following problems remain unsolved; (1) serious adverse reactions such as myelosuppression, (2) unsuccessful insertion of catheter into the internal thoracic artery, and (3) long waiting-period from IAC to surgical treatment. The present studies were conducted to evaluate the utility of a one-route IAC, in which the subclavian artery alone is used, and the efficacy of granulocyte colony-stimulating factor (G-CSF). There was no significant difference in the antitumor effect between the patients with two-route IAC, in which both internal thoracic artery and subclavian artery are used, and the patients with one-route IAC. Administration of G-CSF in combination with IAC reduced both the frequency and the severity of IAC-induced side effects. G-CSF administration during IAC was more effective than after IAC. G-CSF prevented IAC-induced myelo-suppression and/or accelerated recovery from this complication and thus reduced significantly the waiting-period before surgical treatment.

[Role of polymorphonuclear leukocytes (PMN) and active oxygen species in hyperthermia--antitumor effect of hyperthermia combined with rhG-CSF]

We have reported that polymorphonuclear leukocytes (PMN) and active oxygen species from PMN may play an important role in the mechanism of the antitumor effect of hyperthermia. At this time, we focused our experimental studies on rat AH109A carcinoma treated with hyperthermia combined with arterial injection of rhG-CSF. Rats with transplantable AH109A carcinoma at the hind leg received hyperthermia. These tumors showed mild suppression of further development only by hyperthermia. However, when arterial injection of rhG-CSF was applied together with hyperthermia, marked suppression of tumor development was observed. Our data suggest that hyperthermia combined with rhG-CSF is closely related to the generation of free radical-mediated tumor cell killing, and it can be an effective treatment for cancer.

[A case of complete response of locally advanced breast cancer to arterial infusion chemotherapy: cannulation through the right femoral artery and combined use of G-CSF]

We reported a case of locally advanced breast cancer who was cannulated into the right internal thoracic artery through the right femoral artery by Seldinger's method for intra-arterial chemotherapy and obtained good results. In general, aggressive chemotherapy is often accompanied by bone marrow suppression necessitating discontinuation of chemotherapy. However, this patient recovered from this complication by G-CSF. It was suggested that Seldinger's method is suitable for locally advanced breast cancer and that G-CSF has an immediate effect of bone marrow suppression caused by aggressive chemotherapy.

Effects of granulocyte colony-stimulating factor in modifying mortality from Pseudomonas aeruginosa pneumonia after hemorrhage

BACKGROUND AND METHODS

Alterations in immune function occurring after hemorrhage and trauma may contribute to the high occurrence rates of nosocomial pneumonia, multiorgan system failure, morbidity, and mortality in this setting. Therapy with granulocyte colony-stimulating factor (G-CSF) can increase neutrophil numbers and function, and enhance resistance to infection in experimental and clinical settings associated with abnormal immune function. To investigate whether treatment with G-CSF could increase resistance to pneumonia after hemorrhage, we bled mice 30% of the blood volume and treated them with various doses of G-CSF, starting either immediately or 2 days after hemorrhage. Pseudomonas aeruginosa pneumonia was induced by the intratracheal instillation of 2 x 10(7) colony-forming units of P. aeruginosa 4 days after blood loss, and mortality was assessed over the next 7 days.

RESULTS

Treatment of mice with 100 or 500 micrograms/kg/day G-CSF, but not with 50 micrograms/kg/day, resulted in significant increases in the numbers of circulating polymorphonuclear cells. Platelet counts significantly decreased in mice given 500 micrograms/kg/day G-CSF. Mice given 100 micrograms/kg/day G-CSF starting 2 days after blood loss had improved outcome compared with vehicle-treated controls (38% survival rate in the G-CSF treated group vs. 8% in controls, p less than .05). There also was a trend toward an improved survival rate in mice treated with 50 micrograms/kg/day G-CSF for 4 days after hemorrhage (46% survival rate in G-CSF treated vs. 17% in controls).

CONCLUSIONS

G-CSF prophylactically administered after hemorrhage can improve survival from pneumonia due to P. aeruginosa. However, the protection afforded by G-CSF was highly dependent on the dosing schedule used.

[Role of polymorphonuclear leukocytes (PMN) and active oxygen species in hyperthermia--enhancing effect of G-CSF on superoxide generation from PMN]

We examined in vitro the effect of G-CSF and temperature on superoxide (O2-) generation by Cypridina luciferin analog (CLA) dependent chemiluminescence. PMN significantly generated O2- at the concentration of G-CSF 25 ng/ml or more at 37 degrees C within the range of 0.1 from 1,000 ng/ml. O2- generation from PMN was remarkably enhanced, stimulated by opsonized zymosan (OZ) and phorbol myristate acetate (PMA), at 41 degrees C as compared with 37 degrees C. O2- generation was enhanced with the addition of 25 ng/ml of G-CSF at 41 degrees C as compared to without it at 41 degrees C. A significant enhancement of O2- generation from PMN was observed at 25 ng/ml G-CSF and 41 degrees C.

Treatment of chemotherapy-induced neutropenia in children with subcutaneously administered recombinant human granulocyte colony-stimulating factor

Fifty-six children with various malignancies were treated subcutaneously with recombinant human granulocyte colony-stimulating factor (rhG-CSF, KRN 8601) for neutropenia induced by cancer chemotherapy. Patients received the first chemotherapy without rhG-CSF (control course). In the second course, rhG-CSF was given once daily, starting 3 days after completion of identical chemotherapy (day 3) and continuing until day 12. At day 12, the white blood counts and neutrophil counts were found to be 6.8 and 30 times higher in the rhG-CSF course than in the control course (P = .0001) Nadirs of white blood counts and neutrophils were significantly elevated in the rhG-CSF course (P = .003 and .0001, respectively). rhG-CSF administration shortened the neutropenic period in the majority of patients. Children tolerated the rhG-CSF administration well and we have hereby confirmed that rhG-CSF administration is useful for proceeding with chemotherapy in children with cancer.

Hematopoietic stem cell depletion by restorative growth factor regimens during repeated high-dose cyclophosphamide therapy

We studied the effects of six cycles of repeated cyclophosphamide (CTX) therapy followed by restorative therapy with either granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF on the hematopoietic stem cell compartment. Stem cell function was assessed by serially transferring bone marrow cells from CTX-CSF-treated mice into lethally irradiated recipient mice. Bone marrow cells from mice that initially received either G-CSF or GM-CSF after CTX therapy more rapidly lost the ability to repopulate the recipient lymphoid organs, showed a dramatic loss of hematopoietic progenitors, a more rapid loss of CFU-S capacity, and a 40% to 50% reduction in marrow repopulating ability (MRA). Interleukin-1 (IL-1) appeared to have little effect on the CTX-treated mice when used alone. However, when administered before the CTX-CSF regimen, IL-1 prevented the stem cell depletion as determined by CFU-C, CFU-S, and MRA through the serial transplantation procedures. These results support the hypothesis that repeated treatments with myelosuppressive drugs followed by stimulation with the CSFs may induce damage to the host stem cell compartment, and further suggest that pretreatment with IL-1 before CTX therapy may prevent this stem cell damage.

Pharmacokinetics of subcutaneous recombinant human granulocyte colony-stimulating factor in children

Fifteen children (age 1.2 to 9.4 years) with advanced neuroblastoma were treated with myelosuppressive chemotherapy (cyclophosphamide, cisplatin, doxorubicin) followed by 5 (n = 5), 10 (n = 5), or 15 (n = 5) micrograms/kg recombinant granulocyte colony-stimulating factor (rG-CSF) subcutaneously (SC) once daily for 10 days, starting the day after chemotherapy. Serial serum samples obtained on days 1 and 10 were analyzed for G-CSF activity by a specific proliferation assay using NFS-60 cells. G-CSF serum concentration-time data were best described by a one-compartment model, with zero-order absorption and first-order elimination. After SC injection, absorption was prolonged, with peak concentrations of G-CSF (3 to 117 ng/mL) being reached after 4 to 12 hours. The relatively slow absorption, with a mean elimination half-life of 5.8 hours on day 1 and 4.5 hours on day 10, provided measurable G-CSF concentrations for the entire 24-hour dosing interval in all patients at each dosage level. The median apparent clearance of G-CSF on day 10 was significantly higher than on day 1 (0.57 v 0.31 mL/min/kg, P = .02), and was positively correlated with the absolute neutrophil count (ANC) (r2 = .33, P = .003). Systemic exposure to G-CSF was dose-related, but interpatient pharmacokinetic variability yielded overlap in area under the concentration-time curve (AUC) at all three dosage levels. Stepwise regression analysis showed that G-CSF AUC could be predicted by a model that includes rG-CSF dosage and ANC on the day of administration (r2 = .82, P = .0001).

The clonal proliferation of normal mouse hematopoietic cells: enhancement and suppression by colony-stimulating factor combinations

Combinations of relatively high concentrations of the four colony-stimulating factors (CSFs) in cultures of normal mouse bone marrow cells stimulated subadditive responses in the number of colonies developing but, with some combinations, superadditive increases in mean cell numbers per colony. This latter effect was due largely to the induced development of small numbers of giant colonies containing macrophages with or without granulocytes. However, in cultures including a combination of granulocyte-macrophage-CSF (GM-CSF) with macrophage-CSF (M-CSF), a selective reduction in the number of pure macrophage colonies was observed together with a change in the morphology of those colonies that did develop. Recloning studies on macrophage colonies showed that the inhibitory action of the GM-CSF plus M-CSF combination was a direct one on the colony cells. The example of inhibition observed suggests that combined stimulation by two positive growth factors can sometimes result in a selective reduction of the production of certain cells, a possibility needing further exploration.

[High dose chemotherapy with autologous bone marrow transplantation and G-CSF for hematologic malignancies]

High dose chemotherapy (HDCT) followed by autologous bone marrow transplantation (ABMT) is one of the cure-oriented therapies for hematologic malignancies. Colony stimulating factors (CSFs) are currently used to stimulate hematopoiesis in various cytopenic conditions including post BMT. Granulocyte CSF (G-CSF) significantly accelerates granulocyte recovery after ABMT. Earlier recovery of neutrophils is associated with lower incidence of severe infections and shorter duration of reverse barrier nursing and hospitalization. Widespread use of G-CSF in ABMT may contribute to managing this treatment safely in multi-centers. Further prospective clinical study to define the optimal application and timing of HDCT with ABMT in hematologic malignancies is required.

A comparison of therapeutic schedules for administering granulocyte colony-stimulating factor to nonhuman primates after high-dose chemotherapy

Granulocyte colony-stimulating factor (G-CSF) has been shown to be effective in clinical trials for reducing the period of neutropenia after chemotherapy. In this study, we compared the timing for initiating G-CSF administration after chemotherapy with the duration of neutropenia and hematopoietic regeneration. Nonhuman primates treated with high-dose chemotherapy (mechloroethamine, 1.5 mg/kg, intravenously) and not administered G-CSF therapy experienced 8 days of neutropenia (absolute neutrophil count [ANC] less than 1,000/mm3) and had an ANC nadir of 124 +/- 64/mm3 at day 7. Monkeys receiving G-CSF (5 micrograms/kg/d, subcutaneously) began treatment on either days 1, 3, 5, or 7 after chemotherapy. Monkeys treated with G-CSF had an earlier ANC recovery and the number of days with an ANC less than 500/mm3 and ANC less than 1,000/mm3 was reduced by approximately 50% in all treatment strategies. All G-CSF-treated animals, irrespective of the time that G-CSF was initiated, reached an ANC of 10,000/mm3 on day 13 +/- 1 day after chemotherapy. These results demonstrated that the duration of G-CSF therapy was almost twice as long for monkeys treated on day 1 as it was for monkeys that received therapy beginning on day 7. A comparison of the results for all treated monkeys identified a distinct difference in the responses of monkeys treated on day 1 from that of animals treated with G-CSF at later times. G-CSF initiated 1 day after chemotherapy led to an earlier onset of neutropenia and a more rapid and augmented recovery of myeloid progenitor cells in the peripheral blood when compared with control and delayed therapy groups. This study demonstrates that neutropenia due to a single dose of mechloroethamine can be equally reduced with both early and delayed initiation of G-CSF. Further, initiating G-CSF therapy after 7 days required approximately 50% less days of therapy to reach an appropriate termination point. The applicability of these findings to other chemotherapy regimens and for repeated cycles is uncertain and needs to be further evaluated. This is a US government work. There are no restrictions on its use.

Case report: alternation therapy with antileukemic agents and recombinant human granulocyte colony-stimulating factor for RAEB in transformation

Under the assumption that in some patients with refractory anemia with excess of blasts (RAEB), the abnormal clones might be less responsive to granulocyte colony-stimulating factor than normal clones, the authors tried alternation therapy with a recombinant form of this factor (rhG-CSF) and antileukemic agents in the treatment of two patients with RAEB in transformation. After repetition of the short-cycled alternation therapy, the hematologic findings of both patients were completely normalized and have remained so without any adverse side effects under the continuation of this therapy for more than 5 months. Judging from our clinical experience, the alternation therapy may be a new efficient therapeutic strategy for RAEB and some types of slowly progressive leukemia.

Effect of recombinant human granulocyte colony-stimulating factor in patients receiving chemotherapy for urogenital cancer. Urological rhG-CSF Study Group

We evaluated the efficacy and safety of recombinant human granulocyte colony-stimulating factor (G-CSF) in patients with leukopenia after chemotherapy for urogenital cancers. Recombinant human G-CSF was administered at 100 micrograms./m.2 intravenously in 36 patients and at 75 micrograms. per body weight subcutaneously in 37 for 8 days after methotrexate, vinblastine, doxorubicin and cisplatin (M-VAC) therapy or for 14 days after other chemotherapies. Cycle 1 of chemotherapy was given without recombinant human G-CSF, while at cycle 2, recombinant human G-CSF was given additionally. Therefore, cycle 1 of the regimen served as a control to cycle 2 in each patient. An elevation in the median white blood cell nadir was noted: 1,500 versus 3,200 (intravenous) and 2,100 versus 3,200 (subcutaneous) on M-VAC therapy, and 1,800 versus 2,100 (intravenous) and 1,700 versus 2,500 (subcutaneous) on other chemotherapeutic regimens. A shortening of the leukopenic period was observed in cycle 2. There were no significant adverse side effects attributed to the use of recombinant human G-CSF. The results indicate that recombinant human G-CSF may be safely and effectively used against leukopenia after chemotherapy for urogenital cancer. This remedy will become useful for completion of the schedule and dose intensification of chemotherapy in the future. Subcutaneous administration is considered to be the more preferable route.

[Successfully treated locally advanced breast cancer by intra-arterial infusion chemotherapy: a case report]

A 40-year-old female was admitted to our hospital with a large right breast tumor that was over 15 cm in diameter. We treated this locally advanced breast cancer by intra-arterial infusion chemotherapy. Through a catheter placed in the right subclavian artery, doses of 20-30 mg of ADM were injected intermittently with MMC and 5-FU. When a total of 120 mg of ADM had been infused, leukopenia developed, but this was immediately improved by G-CSF. With this treatment, her breast tumor and lung metastases were almost completely disappeared. Thus, an intra-arterial infusion chemotherapy was considered to be an effective treatment for locally advanced breast cancer.

Treatment of myelodysplastic syndromes with cytokines and cytotoxic drugs

Clinical trials with hematopoietic growth factors (granulocyte-macrophage colony-stimulating factor [GM-CSF], granulocyte colony-stimulating factor [G-CSF], interleukin-3, erythropoietin] have been done in patients with myelodysplastic syndromes. Treatment with GM-CSF or G-CSF has resulted in an increase of neutrophil counts into the normal range in the vast majority of patients. Progression to acute leukemia does not appear to occur more frequently in the patients receiving GM-CSF or G-CSF. Increases in platelet counts and hemoglobin levels have been reported after treatment with interleukin-3 and erythropoietin, respectively, although the response is only seen in a minority of treated patients. Combination therapy with GM-CSF and low-dose cytosine arabinoside has been studied, but present data do not indicate an advantage over other treatment strategies. Cytogenetic and molecular genetic analyses demonstrate that both normal and malignant precursor cells are stimulated by cytokine therapy.

[Induction of complete remission in a case of drug-resistant childhood acute megakaryoblastic leukemia by combination of G-CSF and chemotherapy]

In a 4-year-old girl having acute megakaryoblastic leukemia, recombinant human granulocyte colony-stimulating factor (G-CSF) was used in combination with chemotherapy for remission induction after the second relapse of her leukemia. G-CSF was given intravenously at a dose of 100 micrograms/m2/day 24 hours prior to chemotherapy until the peripheral neutrophil counts fully recovered. Cytosine arabinoside (Ara-c) [100mg/m2/day] and VP-16 [100mg/m2/day] were given from day 1 through day 10. Her leukemia was resistant to chemotherapy alone after the second relapse but complete remission and hematological recovery were achieved two months after the start of this therapy. Although in vitro clonal assay did not show significant stimulation of colony formation by G-CSF on leukemia cells of this patient, and the mechanism underlying remission induction by this combination therapy remains unclear, it may be of benefit to use G-CSF in combination with chemotherapy for patients with drug-resistant leukemia.

Interactions of granulocyte-macrophage colony-stimulating factor (CSF), granulocyte CSF, and tumor necrosis factor alpha in the priming of the neutrophil respiratory burst

Exposure of neutrophils to a range of cytokines augments their response to subsequent agonist-induced activation of the respiratory burst. We have examined the effects of several of these factors, both singly and in combination, on the priming of f-met-leu-phe (FMLP) and complement C5a-stimulated neutrophil H2O2 production, using a whole blood flow cytometric assay designed to minimize artefactual activation. Both granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF alpha) produced a similar degree of priming of the FMLP-stimulated burst in vitro (558% +/- 86%, n = 41, and 581% +/- 95%, n = 21, of the response seen with FMLP alone, respectively), but with markedly different kinetics (half-maximal response 20 minutes and 7 minutes, respectively). Preincubation with granulocyte colony-stimulating factor (G-CSF) alone caused only modest priming (202% +/- 39%, n = 14). Priming with cytokine combinations of the FMLP-stimulated burst showed that the combinations of G-CSF and TNF alpha and GM-CSF and TNF alpha are highly synergistic, with recruitment of neutrophils unresponsive to priming by single agents. Priming with the combination of GM-CSF and G-CSF was not significantly different to priming with GM-CSF alone. Similar results were obtained using C5a as the respiratory burst stimulus. Significant priming of the FMLP-stimulated respiratory burst was seen in vivo in patients receiving an infusion of GM-CSF (332% +/- 50% of preinfusion response to FMLP, P less than .005, n = 8). Priming was also seen in patients receiving G-CSF (152% +/- 58%, n = 5), although this did not reach conventional significance levels (.05 less than P less than .1). Although GM-CSF infusion caused priming in vivo, this was 48% less than predicted by preinfusion in vitro responses. This result was not due to inadequate GM-CSF levels as addition of further GM-CSF ex vivo did not correct the response. However, these neutrophils were still able to respond appropriately to ex vivo priming with TNF alpha, with a doubling in H2O2 production.

Recombinant human granulocyte-colony-stimulating factor in the treatment of patients with chronic benign granulocytopenia and congenital agranulocytosis (Kostmann's syndrome)

Seven patients with chronic benign granulocytopenia and nine patients with congenital agranulocytosis, received consecutive seven-day courses of recombinant human granulocyte-colony stimulating factor at a starting dose of 50 micrograms/m2/day, subcutaneously. If there was no response the doses were increased to 300 micrograms/m2. All patients with chronic benign granulocytopenia responded rapidly at the minimum dose within 1-3 days after administration. By contrast, only three of the nine patients with congenital agranulocytosis responded within 1-7 days at this dose. Four patients with congenital agranulocytosis showed a response between days 7-19 at a dose of granulocyte-colony-stimulating factor 100-200 micrograms/m2 but in the remaining two cases no response was obtained. The administration of granulocyte-colony-stimulating factor was shown to be safe and effective also in reducing infectious episodes in these patients. Previously it was reported that granulocyte-colony-stimulating factor 10-30 micrograms/kg/day was effective for patients with congenital agranulocytosis. These results indicate that patients with congenital agranulocytosis may require much higher doses of recombinant human granulocyte-colony-stimulating factor than patients with chronic benign granulocytopenia and that the response to ordinary doses of recombinant human granulocyte-colony-stimulating factor may be useful in differentiating between chronic benign granulocytopenia and congenital agranulocytosis.

Weekly Dose-Intensive Chemotherapy in Patients with Small-Cell Lung Cancer

The study was aimed to evaluate the feasibility of dose-intensive chemotherapy given on a weekly basis for 12 weeks. Seventeen [7 with limited disease (LD) and 10 with extensive disease (ED)] previously untreated patients with small-cell lung cancer (SCLC) were treated with the cisplatin, vincristine, doxorubicin, and etoposide (CODE) regimen. Recombinant human granulocyte colony-stimulating factor (rhG-CSF) was given to eight patients for the purpose of increasing the dose intensity. Overall response rate was 88%, with a 29% complete response. The median survival times were greater than 20.5 months for LD patients and 8.1 months for ED patients. Overall actual dose intensity was 88% of planned protocol. The major toxicity was myelosuppression. Fifteen patients (88%) had grade 3 or 4 leukopenia. Other problems were weight loss and worsening of performance status during the treatment. RhG-CSF significantly reduced leukopenic nadirs and shortened the neutropenic period. Our preliminary results indicate that 12 cycles of the CODE regimen on a weekly schedule is effective for SCLC, but is also associated with significant toxicity.

[Combination effect of KW-2228 and aminoglycoside antibiotics on systemic infection in cyclophosphamide-treated tumor-bearing mice]

A modified recombinant human granulocyte colony-stimulating factor (rhG-CSF), KW-2228, has some excellent properties such as high specific activity in stimulating granulocyte colony-formation in vitro, great biological stability in plasma, good pharmacokinetic profile and high potency in granulopoiesis in normal mice in vivo. Recently, the application of G-CSF against infectious diseases has been considered, and some animal experiments have been carried out to support its clinical applications. Patients with underlying diseases such as leukemia and cancer often have recurrent infections because of reduced numbers or functions of neutrophils, which mediate an early stage of host defense. In out present study, we established a new method to evaluate in vivo potency of G-CSF in colon 26 tumor-bearing mice. By using the method, we examined combination effects of KW-2228 with aminoglycoside antibiotics against a systemic infection caused by Pseudomonas aeruginosa. KW-2228 (1 microgram/mouse/day) was administered (s.c.) once a day for 4 days before the bacterial infection was introduced in colon 26 tumor-bearing mice receiving cyclophosphamide 3 days after the transplantation of tumor. Antibiotics were administered (s.c.) 2 hours after the introduction of the bacterial infection. ED50 of gentamicin (GM) alone and that of the combination with KW-2228 were 40.7 mg/kg and 3.6 mg/kg, respectively. ED50 of astromicin (ASTM) alone and that of the combination with KW-2228 were 386 mg/kg and 17.8 mg/kg, respectively. Thus the combination therapy of KW-2228 with GM or ASTM exhibited excellent protective effects in comparison to the treatment with antibiotic alone.(ABSTRACT TRUNCATED AT 250 WORDS)

[Combination effect of KW-2228 and cephem antibiotics in a systemic infection model in neutropenic mice]

A modified recombinant human granulocyte colony-stimulating factor (rhG-CSF), KW-2228, has some excellent properties such as high specific activity in stimulating granulocyte colony-formation in vitro, great biological stability in plasma, good pharmacokinetic profile and high potency in granulopoiesis in normal mice in vivo. Recently, the application of G-CSF against infectious diseases has been considered, and some animal experiments have been carried out to support its clinical applications. In this paper, we investigated protective effects of KW-2228 against systemic infections caused by Klebsiella pneumoniae in mice with leukopenia induced by the administration of cyclophosphamide. KW-2228 (1 microgram/mouse) was administered (s.c.) once a day for 4 days following cyclophosphamide administration, then mice were challenged with K. pneumoniae (i.p.) 4 hours after the last administration of KW-2228. An antibiotic was administered (s.c., p.o.) 2 hours after the bacterial challenge. Combination effects of KW-2228 with cefazoline, cefmetazole, ceftazidime or cefaclor were evaluated in the systemic infection with K. pneumoniae. Each combination therapy using KW-2228 with each of the cephems exhibited an excellent protective effect in comparison to the therapy with a cephem alone. These results show the possibility that KW-2228 could be of use in treating obstinate infections not successfully treated with an antimicrobial agent alone.

Phase II study of cisplatin as a 5-day continuous infusion with vindesine plus recombinant human granulocyte-colony-stimulating factor in the treatment of advanced non-small-cell lung cancer

A total of 36 patients with advanced non-small-cell lung cancer (NSCLC) were treated with a combination of 5-day continuous i.v. infusion of cisplatin (25 mg/m2 daily), bolus infusion of vindesine (3 mg/m2) on days 1 and 8, and s.c. injection of recombinant human granulocyte-colony-stimulating factor (2 micrograms/kg daily) on days 6-21. Treatment was repeated every 3-4 weeks. Responding patients with stage IIIA or IIIB disease received chest radiation therapy (50-60 Gy) after this treatment. One complete response and 23 partial responses were observed, for an overall response rate of 66.7% (24/36; 95% confidence limits, 51.3%-82.1%). The median duration of response was 5.7 months and the median overall survival was 10.1 months. WHO grade 3 or 4 leukopenia and neutropenia occurred in 22 (61%) and 27 (75%) patients, respectively, but the mean duration of leukopenia (< 2,000/mm3) and neutropenia (< 1,000/mm3) was 3.4 and 3.5 days, respectively, and there was no instance of life-threatening infection. Thrombocytopenia and anemia of grade 3 or 4 occurred in 28% and 36% of our subjects, respectively. Grade 2 nausea and vomiting occurred in 47% of the patients. Elevated serum creatinine levels (> 1.5 mg/dl) were observed in 3 (8%) of the 36 patients. One patient died of acute renal failure induced by hemorrhage of a gastric ulcer. This regimen is effective in the treatment of NSCLC and further studies of this combination are warranted.

[Protective effect of KW-2228 in a systemic infection model of CPA-treated tumor-bearing mice]

A modified recombinant human granulocyte colony-stimulating factor (rhG-CSF), KW-2228, has some excellent properties such as high specific activity in stimulating granulocyte colony-formation in vitro, great biological stability in plasma, good pharmacokinetic profile and high potency in granulopoiesis in normal mice in vivo. Recently, the application of G-CSF against infectious diseases has been considered, and some animal experiments have been carried out to support its in clinical applications. Patients with underlying diseases such as leukemia or cancer often have recurrent infections because of reduced number and functions of neutrophils, which mediate an early stage of host defense. We investigated the prophylactic effect of KW-2228 against an experimental systemic infection with Pseudomonas aeruginosa in tumor-bearing mice (colon 26: BALB/c) treated with cyclophosphamide. KW-2228 (0.25-2.0 micrograms/mouse) was administered (s.c.) once a day for 4 days before the experimental bacterial infection. As a result of KW-2228 administration, the reduction in peripheral blood neutrophils usually caused by the injection with cyclophosphamide was prevented markedly. KW-2228 displayed excellent protective potency dose-dependently against the infection with P. aeruginosa in tumor-bearing mice. These data show the possibility that prophylactic therapy with KW-2228 may augment the host defense of immunocompromised patients to infections. It present, clinical efficacy studies on KW-2228 are under way.

[Combination effects between KW-2228 and antibiotics against systemic infections in normal and neutropenic mice]

KW-2228, a mutationally modified recombinant human granulocyte colony-stimulating factor (rhG-CSF), possesses some excellent properties such as high specific activity in stimulating granulocyte colony-formation in vitro, great biological stability in plasma, good pharmacokinetic profile and high potency in granulopoiesis in normal mice in vivo. Recently, the application of G-CSF against infectious diseases has been considered, and some animal experiments have been carried out to support such an application on human infectious diseases. In this paper, we examined combination effect of KW-2228 with various chemotherapeutic drugs in experimental infectious in mice. A combination effect of KW-2228 with ceftazidime (CAZ) was evaluated in a systemic infection with Pseudomonas aeruginosa in normal mice. Combination effects of KW-2228 with CAZ, astromicin and amphotericin B were also evaluated in experimental systemic infections caused by P. aeruginosa, Serratia marcescens and Candida albicans in immunosuppressed mice treated with cyclophosphamide. Synergistic effects were generally observed at KW-2228 doses from 1 to 5 micrograms per mouse with all combinations. We concluded that combination therapies of KW-2228 with various chemotherapeutic drugs in experimental infections in mice showed that it should be effective in normal and immunosuppressed host. These results of our laboratory studies suggest that KW-2228 in combination with antibiotics would be useful in the clinical treatment of microbial infections. Recently, clinical efficacy studies of KW-2228 have been initiated in Japan.

Long survival of leukemic mice by repeated combination treatment of cyclophosphamide and recombinant human granulocyte colony-stimulating factor

The therapeutic and hematological effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in combination with cyclophosphamide (CY) were investigated in a murine myeloid leukemia model. Ten daily administrations of rhG-CSF following CY prolonged the survival time of leukemic mice more than either agent alone. Hematological examination indicated that this effect was attributable to suppression with rhG-CSF of the leukemic repopulation after CY injection. In addition, rhG-CSF accelerated recovery from CY-induced neutropenia. Based on these hematological changes, a treatment regimen was established consisting of a single injection of CY on day 1 and daily injections of rhG-CSF on days 2-6; this combination treatment was given to the leukemic mice for up to four cycles, with a pause of one day between each cycle. The leukemic mice completed each cycle of treatment with few failures, and it resulted in a long survival time for the leukemic mice. The mean survival time of the mice receiving four cycles of treatment was 47 days, 30 days longer than that of the untreated mice. Hematological examination performed at the end of each cycle showed that the leukemic cell population was controlled at a level equal to or below the pre-treatment level, and peripheral blood neutrophils were maintained at a level equal to or above the normal level. These results indicate the possible effectiveness of combining rhG-CSF with chemotherapeutic drugs in controlling leukemic cell growth, and the effectiveness of rhG-CSF in enhancing neutrophil recovery after chemotherapy. However, it was found that the leukemic cells became resistant to treatment with rhG-CSF after four cycles of combination treatment, suggesting that great care should be taken in the clinical application of rhG-CSF, even when the growth of acute myelogenous leukemia cells is not apparently stimulated by it.

Sequential administration of interleukin-6 and granulocyte-colony stimulating factor in newborn rats: modulation of newborn granulopoiesis and thrombopoiesis

During states of increased demand, neonatal host defense is characterized by dysregulation of granulopoiesis, resulting in a high incidence of neutropenia. This study investigated the modulation of neonatal rat hematopoiesis by 14-d administration of recombinant human (rh) IL-6, rh-granulocyte-colony stimulating factor (G-CSF), or sequential combination of rhIL-6 and rhG-CSF. Specifically, newborn Sprague-Dawley rats were treated with either rhIL-6 (5 micrograms/kg/d for 14 d), rhG-CSF (5 micrograms/kg/d for 14 d), rhIL-6 for 7 d followed by rhG-CSF for 7 d, PBS/BSA for 7 d followed by rhG-CSF for 7 d, or PBS/BSA for 14 d. RhIL-6 alone significantly increased the peripheral platelet count during the latter part of the 2nd wk of administration (d 13: 980 +/- 42 versus 716 +/- 23 x 10(3)/mm3) (p = less than 0.001) (mean +/- SEM). Treatment with rhIL-6 for 7 d followed by rhG-CSF significantly increased the peripheral neutrophil count compared with 7 d of PBS/BSA and 7 d of G-CSF (d 14 absolute neutrophil count 4888 +/- 12 versus 2720 +/- 317/mm3) (p = less than 0.05). Similarly, sequential rhIL-6/rhG-CSF significantly increased the d-14 bone marrow neutrophil storage pool (9873 +/- 882 versus 3564 +/- 159/mm3) (p = less than 0.005). Lastly, sequential rhIL-6/rhG-CSF induced the highest increase in bone marrow (p less than 0.01) and liver/spleen CFU-GM pool (p less than 0.001) compared with any other treatment group. These studies suggest that rhIL-6 alone is associated with a significant increase in the neonatal platelet count.(ABSTRACT TRUNCATED AT 250 WORDS)

Granulocyte and granulocyte-macrophage colony-stimulating factors for treatment of neutropenia in glycogen storage disease type Ib

Two children with glycogen storage disease type Ib associated with numerous recurrent bacterial infections as a result of neutropenia and neutrophil dysfunction were treated with recombinant human granulocyte colony-stimulating factor (G-CSF). One of the two patients was previously treated with recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF); therapy had to be discontinued because of severe local side effects. Both colony-stimulating factors at dosages of 3 and 8 micrograms/kg/per day, respectively, increased the average neutrophil counts from less than 300 cells/microliters to more than 1200 cells/microliters. Two subpopulations of neutrophils could be identified by their capacity to produce H2O2: one subpopulation generated H2O2 normally and a second was defective in H2O2 production. The doses of G-CSF effectively enhanced and maintained that subpopulation of neutrophils which produced normal amounts of H2O2. Moreover, these colony-stimulating factor-induced neutrophils demonstrated effective phagocytosis of zymosan particles and killing of staphylococci. Chemotaxis was decreased and could not be normalized by treatment with G-CSF. We conclude that maintenance treatment with G-CSF improved the quality of life in both patients: The number and severity of bacterial infections decreased markedly during treatment. Long-term treatment with G-CSF (12 and 10 months, respectively) was well tolerated, and no adverse clinical events were observed.

[A case of RAEB-t treated by G-CSF showing complete remission after MST-16 treatment for subsequent reversible leukemia]

A seventy-five-year-old female with general fatigue, high fever and anemia was admitted. Her chest X-ray film revealed pneumonia. She was diagnosed as RAEB-t with the normal karyotype by peripheral blood film and bone marrow aspiration; 125 micrograms/ml of G-CSF was administered s.c. daily in order to increase neutrophil count because of the prolongation of pneumonia. Her blast cells in both peripheral blood and bone marrow showed a remarkable increase by G-CSF. After the cessation of G-CSF administration, blast cells decreased rapidly, and neutrophil count in the peripheral blood increased. Her pneumonia was then cured. After 5 months of stable hematological state, 60% of her bone marrow cells became occupied by blast cells again. So 2 consecutive courses of 14 days p.o. administration of 1,200 mg MST-16/day were tried. Three months after the first MST-16 trial, her bone marrow showed complete remission (CR) which lasted about 4 months. But she died of sepsis after the first relapse. Her bone marrow in CR still revealed several features of dyspoiesis.

G-CSF and GM-CSF

Filgrastim and sargramostim are hematopoietic growth factors that are now produced on a large scale through recombinant DNA technology. Both agents are effective in increasing blood cell counts following chemotherapy and bone marrow transplantations. Investigational work is still being conducted to determine their potential use.

Effect of combination therapy with recombinant human granulocyte colony-stimulating factor (rG-CSF) and antibiotics in neutropenic mice unresponsive to antibiotics alone

The effect of recombinant human granulocyte colony-stimulating factor (rG-CSF) in enhancing antimicrobial chemotherapy was investigated. Combined treatments of rG-CSF with cefotaxime, cefazolin, fosfomycin, gentamicin or amphotericin B were evaluated in systemic infections with Pseudomonas aeruginosa, Escherichia coli, Serratia marcescens, Staphylococcus aureus and Candida albicans in leucopenic mice induced by pretreatment with cyclophosphamide. Administration of appropriate antibiotics afforded a dose-related inhibition of death from infection in normal mice and mice treated with rG-CSF after cyclophosphamide injection. In cyclophosphamide-treated mice, even larger doses of the antibiotics failed to provide protection against infection with the same inoculum size. These results suggest the possibility that rG-CSF could be of help in treatments with antimicrobial agents against infections in leucopenic patients.

[Tumor markers--personal experience. A case of advanced extragonadal germ-cell tumor showing complete remission by high-dose combination chemotherapy with autologous bone marrow transplantation]

A twenty-four-year-old male patient with stage III advanced extragonadal germ-cell tumor obtained complete remission after comprehensive treatment including high-dose combination chemotherapy with autologous bone marrow transplantation. He had massive tumors in cervical, mediastinal, abdominal and inguinal lymph nodes, bilateral lungs and liver. Ascites, plural effusion and pericardial effusion were also noted. Cancer cells were demonstrated from his bloody sputum, pericardial drainage and an aspirate from supraclavicular tumor. His tumor produced hCG, AFP, placental ALP and LDH, and hCG was the best marker for the diagnosis and monitoring. The initial serum hCG level was high at 460,000 mIU/ml, but fell to 13 mIU/ml after 3 courses of PVP therapy. However, it rose ten-fold in a week. After ultra-high dose combination chemotherapy with autologous BMT, the patient's hCG fell to 1.8 mIU/ml and remained at that level thereafter. He has remained well with no sign of recurrence after 25 months.

Pharmacokinetics of recombinant human granulocyte colony-stimulating factor conjugated to polyethylene glycol in rats

The pharmacokinetics of recombinant human granulocyte colony-stimulating factor conjugated to polyethylene glycol (PEG-rhG-CSF) and rhG-CSF were studied in male Sprague-Dawley rats. The serum concentration after i.v. administration at a dose of 100 micrograms protein/kg was investigated by a bioassay. The serum rhG-CSF concentration decreased steadily after injection with a terminal half-life of 1.79 h. The PEG-rhG-CSF concentration after injection decreased much more slowly with a half-life of 7.05 h. The slower disappearance of PEG-rhG-CSF resulted in a greater area under the concentration-time curve. The neutrophil count after 100 micrograms of protein/kg of rhG-CSF administration reached a peak 12 h after injection and returned to the control level 48 h after injection. The neutrophil count after 100 micrograms of protein/kg of PEG-rhG-CSF administration was identical to that of rhG-CSF after 12 h but the highest level was maintained for 24 to 72 h after injection and returned to the control level after 168 h. These data indicated that PEG-rhG-CSF administration exerted a sustained biological effect on peripheral blood neutrophils. It is expected that PEG-rhG-CSF may contribute greatly to human G-CSF treatment because it has a prolonged neutrophil-proliferating activity enabling fewer administrations.

A phase II trial of recombinant human granulocyte colony-stimulating factor in the myelodysplastic syndromes

We conducted a phase II study of the intravenous administration of a glycosylated recombinant human granulocyte colony-stimulating factor (rhG-CSF) for 7-14 d in 41 patients with the myelodysplastic syndromes (MDS). Administration of rhG-CSF elicited striking rises in both leucocyte and neutrophil counts in the majority of the patients irrespective of the FAB subtypes of MDS. The rises in neutrophil counts were dose dependent and 5 micrograms/kg/d of rhG-CSF yielded approximately an 8-fold increase in neutrophil counts. Leucocytes and neutrophil counts started to increase shortly after the first injection of 5 micrograms/kg, was maintained at significantly elevated levels during 14 d of treatment, and returned to the pretreatment levels within several days following discontinuation of rhG-CSF. The action of rhG-CSF was specific for neutrophils since leucocytosis was due exclusively to neutrophilic increase associated with an increased marrow myeloid maturation. There were no consistent changes in the monocyte, eosinophil, lymphocyte, platelet or reticulocyte counts. After treatment, the percentage of marrow blast cells was reduced in eight of 13 evaluable patients with refractory anaemia with an excess of blasts (RAEB) or RAEB in transformation (RAEB-t). No patients developed acute leukaemia during the treatment or in the immediate follow-up period. The treatment was well tolerated with only minimal toxicity. The results suggest that rhG-CSF is a safe and effective way to promptly improve neutropenia in MDS patients.

Effect of recombinant human granulocyte colony-stimulating factor administration in normal and experimentally infected newborn rats

We investigated the effects of repetitive recombinant human granulocyte colony-stimulating factor (rhG-CSF) administration at three different doses (every 12 h times six doses, starting at 12-24 h of age) on the kinetics of neutrophil production in Sprague-Dawley rats. We determined WBC counts, differentials, the number of total nucleated cells, the myeloid mitotic pool cells (promyelocytes and myelocytes), the storage pool cells (metamyelocytes, bands, and polymorphonuclear cells [PMNs]) and the granulocyte-macrophage (granulocyte-macrophage colony-forming units, CFU-GM) and macrophage (macrophage colony-forming units, CFU-M) progenitor cells of the bone marrow, spleen, and the liver before the first dose of rhG-CSF administration and 12 h after the second, fourth, and sixth dose. Control animals were given the diluent by the same schedule. Recombinant human G-CSF-treated rats showed a significant dose-dependent increase in the number of total WBC and neutrophil counts at all time points compared to control rats. The total number of CFU-GM and myeloid mitotic pool cells (marrow plus spleen plus liver) progressively increased with age in both control and G-CSF groups, but the G-CSF treated groups showed a significantly larger number of mitotic pool cells at hour 24, continuing up to hour 72, compared to the control group. However, there was no significant difference at any time point in the number of CFU-G/GM as detected by the granulocyte-macrophage colony-stimulating factor (GM-CSF)-supported culture system. Priming of newborn rats with injections every 12 h of rhG-CSF times two doses, or six doses followed by inoculation of group B streptococci (GBS) did not significantly change the sepsis death rate of animals, although the neutrophil counts in infected rhG-CSF-primed animals were significantly larger than the infected control animals. Injection of human i.v. gammaglobulin 3 h following inoculation with GBS significantly improved the survival of animals compared to G-CSF administration or administration of the diluent alone (control). Thus G-CSF alone may not be beneficial for the treatment of neonates with sepsis. Additional work is needed to determine whether combination of G-CSF with antibiotics or other cytokines, such as GM-CSF or interleukin 6 (IL-6) may be of benefit.

Myeloid cell kinetics in mice treated with recombinant interleukin-3, granulocyte colony-stimulating factor (CSF), or granulocyte-macrophage CSF in vivo

Myeloid cell kinetics in mice treated with pure hematopoietic growth factors have been investigated using tritiated thymidine labeling and autoradiography. Mice were injected subcutaneously with 125 micrograms/kg granulocyte colony-stimulating factor (G-CSF) (in some cases 5 micrograms/kg), or 10 micrograms/kg of granulocyte-macrophage CSF (GM-CSF), or interleukin-3 (IL-3) every 12 hours for 84 hours. 3HTdR labeling was performed in vivo after 3 days of treatment. G-CSF increased the peripheral neutrophil count 14-fold and increased the proportion and proliferation rate of neutrophilic cells in the marrow, suppressing erythropoiesis at the same time. Newly produced mature cells were released into the circulation within 24 hours of labeling, compared with a normal appearance time of about 96 hours. By contrast, GM-CSF and IL-3 had little effect on either marrow cell kinetics or on the rate of release of mature cells, although GM-CSF did stimulate a 50% increase in peripheral neutrophils. Monocyte production was also increased about eightfold by G-CSF and 1.5-fold by GM-CSF, but their peak release was only slightly accelerated. While the peripheral half-lives of the neutrophilic granulocytes were normal, those of the monocytes were dramatically reduced, perhaps due to sequestration in the tissues for functional purposes. The stimulated monocyte production in the case of G-CSF required an additional five cell cycles, a level that might have repercussions on the progenitor compartments.

Bone modulation in sustained hematopoietic stimulation in mice

To understand the etiology of bone modulation and hypercalcemia observed in granulocytosis of a tumor-bearing animal model and to gain insight into the implication of sustained hematopoietic stimulation on the bone tissue, in vivo responses of normal mouse hematopoietic and bone tissues to long-term injections of recombinant human and murine granulocyte colony-stimulating factor (G-CSF), murine granulocyte-macrophage CSF (GM-CSF), and human erythropoietin were quantitatively analyzed. Osteoclast activation was estimated by the osteoclast-endosteal ratio, determined by morphometric analyses of femoral sections. Medullary and bone areas were measured on transverse ground bone sections of the tibia. Recombinant murine G-CSF provoked marked granulocytosis associated with significant increases in the number of marrow granulocytes and their progenitors, and caused expansion of granulopoietic marrow into fatty marrow. The bone of G-CSF-treated mice showed a significant increase in endosteal osteoclast numbers with medullary area enlargement and a reduction in the bone thickness; indicative of endosteal bone resorption. Although GM-CSF had little effect on granulopoiesis, it caused peritoneal macrophages to increase and induced similar bone changes as those observed in G-CSF treatment. Enhanced erythropoiesis stimulated by erythropoietin was also associated with evidence of endosteal bone resorption. Bone changes induced by these growth factors were not associated with hypercalcemia. These animal studies document association of bone modulation in sustained stimulation of hematopoiesis, and implicate important physiologic effects of hematopoietic growth factors on skeletal tissue in vivo.

Combined therapy with recombinant granulocyte colony-stimulating factor and erythropoietin decreases hematologic toxicity from zidovudine

Twenty-two patients with acquired immunodeficiency syndrome (AIDS) or severe AIDS-related complex and multilineage hematopoietic defects were treated with recombinant granulocyte colony-stimulating factor (G-CSF) and erythropoietin (EPO) in a phase I/II trial. All patients were neutropenic and anemic after withdrawal of all bone marrow-suppressive drugs. Daily, G-CSF was subcutaneously self-administered until an absolute neutrophil count (ANC) greater than 6,000/microL was achieved and maintained for 2 weeks. Subcutaneous EPO was added to the regimen and the dose increased until an increase of 15 g/L of hemoglobin was observed. Groups of patients were administered increasing doses of zidovudine to determine their tolerance. G-CSF and EPO therapy was continued with dose modification to maintain an ANC greater than 1,500/microL and hemoglobin greater than 100 g/L. The dose of zidovudine was not altered. All 22 patients responded to G-CSF with a mean 10-fold increase in neutrophils occurring in less than 2 weeks. Significant increases in CD4 and CD8 cell number, lymphocyte proliferative response, and bone marrow cellularity were seen. EPO therapy increased hemoglobin in all 20 evaluable patients within 8 weeks. Sixteen patients received 1,000 mg and four patients received 1,500 mg of zidovudine per day. The reinstitution of zidovudine resulted in a decline in reticulocytes and hemoglobin and the reappearance of transfusion requirements in eight of the 20 patients, six of whom had the study medications stopped. No patient had the study medications stopped because of neutropenia or thrombocytopenia. Toxicities were mild and did not require dose modifications. Limiting dilution plasma and lymphocyte co-cultures for HIV as well as serum p24 antigen levels did not change significantly during G-CSF or combined G-CSF and EPO therapy. HIV p24 antigen decreased significantly with zidovudine therapy. Opportunistic infections occurred in 14 patients but were successfully treated with myelosuppressive antimicrobial agents, including ganciclovir, without the development of neutropenia. These results suggest that combined therapy with G-CSF and EPO may improve the neutropenia and anemia of AIDS. Combined therapy may allow the resumption of full-dose zidovudine in most patients intolerant of the hematologic effects of zidovudine without apparent alteration of HIV expression or the efficacy of zidovudine.