Short-term administration of granulocyte-macrophage colony stimulating factor decreases hematopoietic toxicity of cytostatic drugs

Use of G-CSF to Sustain Dose Intensity in Breast Cancer Patients Receiving Adjuvant Chemotherapy: A Pilot Study

Background

Adjuvant chemotherapy for breast cancer is frequently accompanied by neutropenia requiring dose reduction or treatment delay that can potentially compromise therapeutic effectiveness. Recombinant granulocyte-colony stimulating factor (G-CSF) reduces the duration and severity of neutropenia.

Methods

Nineteen patients with newly diagnosed breast cancer receiving adjuvant systemic chemotherapy met criteria for dose reduction or treatment delay due to neutropenia. All were treated with G-CSF. The mean duration of G-CSF therapy was five days.

Results

An increase in mean absolute neutrophil count was seen in cycles with G-CSF. Chemotherapy treatment was delayed less often following the use of G-CSF.

Conclusions

Breast cancer patients receiving adjuvant chemotherapy who face treatment delays or dose reductions can continue on full-dose intensity therapy using supportive G-CSF. Prospective trials are needed to accurately measure the impact of G-CSF on dose intensity and long-term disease control.

Pretreatment with Dexamethasone Increases Antitumor Activity of Carboplatin and Gemcitabine in Mice Bearing Human Cancer Xenografts

PURPOSE

The present study was undertaken to determine the effects of dexamethasone (DEX) pretreatment on antitumor activity and pharmacokinetics of the cancer chemotherapeutic agents carboplatin and gemcitabine.

EXPERIMENTAL DESIGN

Antitumor activities of carboplatin and gemcitabine with or without DEX pretreatment were determined in six murine-human cancer xenograft models, including cancers of colon (LS174T), lung (A549 and H1299), and breast (MCF-7 and MDA-MB-468) and glioma (U87-MG). Effects of DEX on plasma and tissue pharmacokinetics of carboplatin and gemcitabine were also determined by using the LS174T, A549, and H1299 models.

RESULTS

Although DEX alone showed minimal antitumor activity, DEX pretreatment significantly increased the efficacy of carboplatin, gemcitabine, or a combination of both drugs by 2-4-fold in all xenograft models tested. Without DEX treatment, the tumor exposure to carboplatin, measured by the area under the curve, was markedly lower than normal tissues. However, DEX pretreatment significantly increased tumor carboplatin levels, including 200% increase in area under the curve, 100% increase in maximum concentration, and 160% decrease in clearance. DEX pretreatment similarly increased gemcitabine uptake in tumors.

CONCLUSIONS

To our knowledge, this is the first report that DEX significantly enhances the antitumor activity of carboplatin and gemcitabine and increases their accumulation in tumors. These results provide a basis for further evaluation of DEX as a chemosensitizer in patients.

Hematopoietic Protection by Dexamethasone or Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) in Patients Treated With Carboplatin and Ifosfamide

Based on preclinical studies, the authors undertook a pilot study to determine the hematologic and biologic effects of pretreatment with dexamethasone (Dex) or granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients receiving carboplatin and ifosfamide. Patients (n = 28) with metastatic solid tumors were randomized to receive pretreatment with Dex or GM-CSF or no pretreatment prior to courses 1 or 2 of carboplatin and ifosfamide. No alteration in dose of chemotherapy was allowed between course 1 and 2. Alterations of hematologic and nonhematologic toxicity and selected biologic parameters were compared between courses 1 and 2. Patients without any pretreatment demonstrated worsening hematologic toxicity in course 2 compared to course 1. In contrast, Dex pretreatment reduced hematopoietic toxicity and improved the absolute granulocyte count (AGC) and platelet count recovery times. For example, course 1 versus course 2 (with Dex pretreatment): AGC nadir (mm3) 153 versus 549 (p = 0.07), days AGC <500/mm3 7.8 versus 4.0 (p = 0.10), days to AGC recovery >1,500/mm3, 26 versus 22 (p = 0.034). Overall comparison between all five cohorts by analyses of variance demonstrated that intervention with Dex improved multiple hematopoietic toxicities, including AGC nadir (p = 0.015), and recovery times to AGC >1,500/mm3 (p = 0.07) and platelet count to >100,000/mm3 (p = 0.05). GM-CSF pretreatment did not worsen hematopoietic parameters after course 2 compared to course 1. Expected biologic effects of Dex and GM-CSF treatment were observed. Patients demonstrated an overall response rate of 32%, 1 complete response, and 8 partial responses. In patients with cancer, pretreatment with Dex or GM-CSF may significantly decrease the hematopoietic toxicity of chemotherapeutic agents.

A prospective randomized phase II trial of GM-CSF priming to prevent topotecan-induced neutropenia in chemotherapy-naive patients with malignant melanoma or renal cell carcinoma

We conducted a phase II randomized trial of recombinant granculocyte-macrophage colony-stimulating factor (GM-CSF) administered before topotecan chemotherapy to determine whether it could prevent myelosuppression and to determine the antitumor activity of this topoisomerase I inhibitor in 53 patients with metastatic malignant melanoma and renal cell cancer. All patients received GM-CSF after topotecan at a dose of 250 microg/m(2) daily for at least 8 days. Patients randomly assigned to receive GM-CSF priming were treated with GM-CSF at 250 microg/m(2) twice daily for 5 days before treatment. Twenty-five patients were randomly assigned to receive GM-CSF priming and 28 to receive topotecan without priming. The primary analysis was restricted to the protective effects seen during the first cycle of therapy. Grade 4 neutropenia occurred in 8 of 23 patients (35%) and grade 3 neutropenia in 5 of 23 patients (22%) randomized to GM-CSF priming, whereas 18 of 26 (69%) and 5 of 26 (19%) patients experienced grade 4 or 3 neutropenia, respectively, without GM-CSF priming (P =.0074). The mean duration of neutropenia was reduced by GM-CSF priming: grade 3 neutropenia from 5.2 +/- 0.7 to 2.8 +/- 0.7 days (P =.0232) and grade 4 neutropenia from 2.7 +/- 0.6 to 1.1 +/- 0.4 days (P = 0.0332). The protective effects of GM-CSF extended to the second cycle of treatment. The incidence of febrile neutropenia was also reduced. Chemotherapy-induced anemia and thrombocytopenia were similar in both groups. One partial response was seen in a patient with melanoma, and one patient with renal cell cancer had complete regression of pulmonary metastases and was rendered disease-free by nephrectomy. (Blood. 2001;97:1942-1946)

Minute quantities of granulocyte-macrophage colony-stimulating factor prolong eosinophil survival

Allergic asthma is characterized by pulmonary infiltration and accumulation of eosinophils, which is enhanced by granulocyte-macrophage colony-stimulating factor (GM-CSF). T cells, fibroblasts, and eosinophils themselves produce GM-CSF, suggesting it functions in the lung microenvironment as a survival factor. However, the amounts and the mechanism by which GM-CSF supports eosinophil survival remain poorly understood. We have previously reported that human peripheral blood eosinophils (PBEo) can be transfected with GM-CSF mRNA using particle-mediated gene transfer (PMGT). Using this technology, GM-CSF mRNA was introduced into resting PBEo, and GM-CSF production and cell survival were assessed. GM-CSF protein was undetectable (< 1 pg/ml) in the supernatant but present intracellularly at very low levels. Unexpectedly, the in vitro survival of transfected PBEo was 4-fold greater than that of controls. Neutralizing anti-GM-CSF but not anti-interleukin-5 (anti-IL-5) antibody added up to 24 h after transfection abolished enhanced survival, demonstrating that the continuous presence of GM-CSF was required. Conditioned medium prepared from transfected PBEo prolonged the survival of naive cells. Comparable survival activity was mimicked by a single dose of 100-500 pg/ml or multiple administrations of 0.1 pg/ml recombinant human GM-CSF (rHuGM-CSF). Survival was completely inhibited by a Jak2 inhibitor, suggesting that GM-CSF-mediated survival involved signaling through the Jak-Stat pathway. Thus, autocrine production of low levels of GM-CSF by a minority of PBEo can block apoptosis of the entire culture by a minute but sustained GM-CSF release.

Short term treatment with Escherichia coli recombinant human granulocyte-macrophage-colony stimulating factor prior to chemotherapy for Hodgkin disease

BACKGROUND

Granulocyte-macrophage-colony stimulating factor (GM-CSF) administration stimulates the proliferation of hemopoietic progenitors. Shortly (48-96 hours) after its discontinuation, feedback phenomena occur and the progenitor proliferation rate drops below baseline levels. As the quiescence of hyperplastic bone marrow suggests that hemopoietic cells may be refractory to the toxic effects of cytostatic drugs, the decision was made to test the hypothesis that GM-CSF given before chemotherapy may be myeloprotective.

METHODS

Fifty-six patients with newly diagnosed Stage II-IV Hodgkin disease, ages 18-77 years, were randomized to receive GM-CSF (5 microg/kg subcutaneously) or placebo from Day 7 to Day 4 before each chemotherapy administration (6 cycles of a hybrid of mechlorethamine, vincristine, procarbazine, and prednisone with doxorubicin, bleomycin, vinblastine, and dacarbazine). The treatment was considered a success if the delivery rate of chemotherapy was >90% after 3 cycles and >80% after 6 cycles.

RESULTS

Thirty patients received GM-CSF and 26 placebo. The dose intensity (85.2% vs. 79.6%) and the overall success in terms of delivery rate (56.7% vs. 50%) were higher in the GM-CSF group, although these differences were not statistically significant. The neutrophil nadirs were higher in the GM-CSF group during the first three cycles and subsequently similar in both groups.

CONCLUSIONS

No significant differences in terms of myelotoxicity or drug delivery were observed between the two treatment arms. Although the myeloprotective effect of the prechemotherapy administration of GM-CSF seems to be minimal, the data indicate a safe timing between GM-CSF discontinuation and further chemotherapy. Because cumulative myelotoxicity has been observed with other growth factors, given in the interval between the chemotherapy cycles, this may be relevant to the planning of rapid cycling.

Granulocyte-macrophage colony-stimulating factor treatment before doxorubicin and cyclophosphamide chemotherapy priming in women with early-stage breast cancer

PURPOSE

To determine if inhibition of stem-cell activity induced by granulocyte-macrophage colony-stimulating factor ([GM-CSF]; Sargramostim; Immunex Corporation, Seattle, WA) withdrawal or priming protects hematopoietic stem cells from the cytotoxic effects of adjuvant chemotherapy for early-stage breast cancer.

PATIENTS AND METHODS

Serial blood counts were performed in 20 women with early-stage breast cancer receiving four courses of cyclophosphamide and doxorubicin chemotherapy. By a double-blind, placebo-controlled, balanced randomization, subjects received GM-CSF priming on days 5 to 1 for courses 1 and 3 or courses 2 and 4.

RESULTS

Compared with before priming, after priming the times to neutrophil nadir (12.8 +/- 2.5 days v 14.8 +/- 1.5 days, respectively; P =.0001) and platelet nadir (mean +/- SD, 10.1 +/- 1.9 days v 11.1 +/- 2.2 days, P <.05) were shorter, indicating a shift of cytotoxicity to later progenitors. The neutrophil nadir was similar with and without priming (mean +/- SD, 490 +/- 310/microL v 550 +/- 350/microL, respectively; P =.2); however, on day 16 the mean neutrophil count was higher (mean +/- SD, 1030 +/- 580/microL v 690 +/- 370/microL, P =.004), and the proportion of patients with a neutrophil count less than 500/microL was lower after priming than before (six of 35 or 17. 1% v 12 of 34 or 35.3%, respectively; P =.04). The platelet nadir was higher (mean +/- SD, 166,000 +/- 51,000/microL after priming v 151,000 +/- 45,000/microL before priming, P =.007), and the duration of thrombocytopenia, ie, a platelet count less than 150,000/microL, was shorter (1.5 +/- 2.1 days v 2.8 +/- 2.9 days, P =.0025) after priming. Episodes of fever and neutropenia were not observed.

CONCLUSIONS

GM-CSF priming from days 5 to 1 before doxorubicin and cyclophosphamide chemotherapy was associated with an earlier neutrophil and platelet nadir. On day 16, a higher mean neutrophil count and a lower proportion of patients with severe (< 500/microL) neutropenia were observed. Beneficial effects on the severity and duration of thrombocytopenia were also noted. These observations support the hypothesis that GM-CSF priming protects hematopoietic progenitors from the cytotoxic effects of chemotherapy.

Pulmonary Kaposi's sarcoma in AIDS patients treated with combined chemotherapy and recombinant human granulocyte colony-stimulating factor

Optimal delivery of chemotherapy in AIDS patients with Kaposi's sarcoma (KS) is frequently limited by hematological toxicity, mainly neutropenia. We have conducted an open-label study to investigate the safety and efficacy of recombinant human granulocyte colony-stimulating factor (filgrastim, r-metHuG-CSF) administration in 25 AIDS patients with pulmonary KS treated with Adriamycin, bleomycin, and vincristine (ABV) combination. The patients were assigned to receive r-metHuG-CSF (Neupogen, Dompé, Biotec, 5 mg/kg of body weight per day) injected subcutaneously for 3-5 days before chemotherapy until the absolute neutrophil count was higher than 25 x 10(9); r-metHuG-CSF was then discontinued 5 days before chemotherapy. Patients were eligible to resume r-metHuG-CSF 3 days after completing the anticancer regimen until normalization of the absolute neutrophil count occurred, for a maximum of 10 days. The cytotoxic regimen included vincristine 1.4 mg/m2, bleomycin 10 mg/m2, and doxorubicin 20 mg/m2, every 2 weeks. The overall response rate was 58% with a complete response rate of 18%. Median survival was 11 months and median response duration was 6 months. Adverse effects consisted of transient nausea and vomiting in 48% of patients, and moderate headache in 43%. Hematologic toxicities included anemia in 27%, and mild to moderate neutropenia (grade II-III) in 38%. The mean leukocyte and neutrophil nadirs were 1920 and 850 mm3. The mean duration of neutropenia was 3.2 days. The combination of r-metHuG-CSF and ABV chemotherapy was well tolerated. Administration of r-metHuG-CSF within 5 days before chemotherapy appears to be an acceptable treatment with important clinical implications. We stress that further studies are needed to determine the maximum tolerable doses of combination chemotherapy supported by G-CSF in AIDS-associated KS patients.

Optimal scheduling of interleukin-12 and fractionated radiation therapy in the murine Lewis lung carcinoma

Interleukin-12 (IL-12), a naturally occurring cytokine, has demonstrated antitumor activity in several murine solid tumors. The Lewis lung carcinoma was used to study the most effective scheduling of recombinant murine interleukin-12 (rmIL-12) administration with fractionated radiation therapy. The effect of the schedule of rmIL-12 administration alone or along with a 1- or 2-week fractionated radiation therapy regimen was examined. Beginning rmIL-12 prior to or at the same time as radiation therapy and extending rmIL-12 through the radiation regimen and beyond produced the longest tumor growth delays. Those treatment regimens which were most effective against the primary tumor were also most effective in decreasing the number of lung metastases on day 20. To further assess the immunotherapeutic effects from rmIL-12 administration, the efficacy of rmIL-12 with fractionated radiation therapy delivered to a right hind-limb tumor was measured as tumor growth delay in an unirradiated left hind-limb tumor. There was some difference in the tumor growth delay between the unirradiated tumor in the animals bearing an irradiated tumor in the contralateral leg, and the tumors in animals receiving rmIL-12 only. Recombinant murine granulocyte-macrophage-colony stimulating factor (rmGM-CSF) was also an antitumor agent active against the Lewis lung carcinoma and produced an additive effect in combination with fractionated radiation therapy in this tumor. rmIL-12 was a radiation sensitizer in the Lewis lung carcinoma. When rmIL-12 (45-microg/kg) and rmGM-CSF (45 microg/kg) were administered together with fractionated radiation therapy, a marked increase in tumor growth delay resulted. This treatment combination also nearly ablated lung metastases on day 20 in these animals. These results may serve as a useful guide in developing clinical protocols, including rmIL-12 and fractionated radiation therapy.

Interaction of interleukin-11 with cytotoxic therapies in vitro against CEM cells and in vivo against EMT-6 murine mammary carcinoma

Interleukin-11(rhIL-11) is a cytokine that has been shown to enhance the recovery of bone marrow and intestinal crypt cells after cytotoxic insult with radiation or anticancer drugs. The current study examined the effects of rhIL-11 on the response of CEM human lymphoblastic leukemia cells and on the EMT-6 murine mammary carcinoma in vivo to cytotoxic anticancer therapies. Exposure of CEM cells to rhIL-11 for 24 hr did not alter the cytotoxicity of melphalan or radiation, increased the cytotoxicity of CDDP (100 muM) and 4-hydroperoxycyclophosphamide (50 betaM) and decreased the cytotoxicity of 5-fluorouracil and ara-C toward the cells. Treatment of mice bearing the EMT-6 tumor with rhIL-11 twice daily for 4 days prior to and the day of cytotoxic therapy resulted in no significant change in the tumor cell killing or bone marrow CFU-GM killing by melphalan, cyclophosphamide, thiotepa, CDDP, radiation, 5-fluorouracil or ara-C. Administration of rhIL-11 twice per day on days 7-18 to EMT-6 tumor bearing animals receiving high dose chemotherapy (melphalan, thiotepa or cyclophosphamide) as a single dose on day 7 followed by mobilized peripheral blood cells on day 8 and rhG-CSF on days 8-20, tended to prolong the tumor growth delay produced by the drugs. This rhIL-11 treatment also resulted in a more rapid recovery of white blood cells and granulocytes in the animals. Furthermore, animals treated with rhIL-11 had improved survival rates compared with animals receiving all other normal tissue support without rhIL-11.

Cell kinetics of CD34-positive hematopoietic cells following chemotherapy plus colony-stimulating factors in advanced breast cancer

Bone-marrow (BM) hematopoietic precursors are recruited into proliferative activity when colony-stimulating factors (CSF) are sequenced with chemotherapy (CT). Previous studies suggested that further CT can be safely administered only when the increased proliferative activity of these cells has subsided, because most cytostatic drugs selectively damage cycling cells. The safest interval between CSF discontinuation and the start of the next CT course needs to be ascertained in vivo. Thirty patients with advanced breast cancer were treated with an intensified FEC regimen, planned at 21-day intervals, sequenced with granulocyte-macrophage (GM)-CSF (15 patients) or granulocyte (G)-CSF (15 patients). Using flow cytometry (FCM) we evaluated the proliferation kinetics of CD34+ BM hematopoietic progenitors before CT+CSF and at different times after CSF administration was stopped. FEC+GM- and FEC+G-CSF sequences both induced a rapid and sustained increase in the percentage of BM myeloid precursors (BMMP%) and in the cycling status of CD34+BM cells. However, while the BMMP% remained elevated in both cases after CSF were stopped, the enhanced proliferative activity of CD34+ cells decreased more rapidly after GM- than after G-CSF. Using FCM, CD34+ BM-derived hematopoietic presursor cell kinetics is readily evaluated in the clinical setting. The administration of CSF following CT increases both the proliferative activity of CD34+ BM cells and the BMMP%. After CSF were discontinued a kinetic refractoriness of hematopoietic progenitors was more evident after GM-CSF than after G-CSF. These data may be of value in designing clinical trials to avoid cytostatic damage to the BM hematopoietic stem-cell compartment.

The cell cycle as therapeutic target

Approved by the FDA in 1991 with indications for acceleration of neutrophil recovery in several clinical settings, CSFs may prove clinically useful in ways beyond hemorestoration. Myeloprotection conferred by GM-CSF may enable higher doses of chemotherapy to be given with only short intervals between cycles. Priming may make resting AML blasts more chemosensitive. Mobilization of peripheral blood stem cells may facilitate and even improve autologous stem cell transplantation.

Optimizing the effectiveness of hematopoietic growth factors

Hematopoiesis is regulated in a very precise fashion by a balance between both positive and negative growth factor signals in the hematopoietic microenvironment. Many of these growth factor signals have been identified and are available as recombinant proteins. At the present time, the approved uses for hematopoietic growth factors involve their use to facilitate blood cell production in situations of hematopoietic suppression or in cases where endogenous growth factor production is inappropriately low. Recent studies with the hematopoietic growth factors are looking at innovative strategies for their use and new clinical situations in which to evaluate their effectiveness. This review looks at some of these new uses for hematopoietic growth factors.