Colony-stimulating factors for the management of neutropenia in cancer patients

Clinical predictive models for chemotherapy-induced febrile neutropenia in breast cancer patients: a validation study

Background

Predictive models for febrile neutropenia (FN) would be informative for physicians in clinical decision making. This study aims to validate a predictive model (Jenkin’s model) that comprises pretreatment hematological parameters in early-stage breast cancer patients.

Patients and Methods

A total of 428 breast cancer patients who received neoadjuvant/adjuvant chemotherapy without any prophylactic use of colony-stimulating factor were included. Pretreatment absolute neutrophil counts (ANC) and absolute lymphocyte counts (ALC) were used by the Jenkin’s model to assess the risk of FN. In addition, we modified the threshold of Jenkin’s model and generated Model-A and B. We also developed Model-C by incorporating the absolute monocyte count (AMC) as a predictor into Model-A. The rates of FN in the 1st chemotherapy cycle were calculated. A valid model should be able to significantly identify high-risk subgroup of patients with FN rate >20%.

Results

Jenkin’s model (Predicted as high-risk when ANC≦3.1*10∧9/L;ALC≦1.5*10∧9/L) did not identify any subgroups with significantly high risk (>20%) of FN in our population, even if we used different thresholds in Model-A(ANC≦4.4*10∧9/L;ALC≦2.1*10∧9/L) or B(ANC≦3.8*10∧9/L;ALC≦1.8*10∧9/L). However, with AMC added as an additional predictor, Model-C(ANC≦4.4*10∧9/L;ALC≦2.1*10∧9/L; AMC≦0.28*10∧9/L) identified a subgroup of patients with a significantly high risk of FN (23.1%).

Conclusions

In our population, Jenkin’s model, cannot accurately identify patients with a significant risk of FN. The threshold should be changed and the AMC should be incorporated as a predictor, to have excellent predictive ability.

Study design: two long-term observational studies of the biosimilar filgrastim Nivestim™ (Hospira filgrastim) in the treatment and prevention of chemotherapy-induced neutropenia

Background

Nivestim™ (filgrastim) is a follow-on biologic agent licensed in the EU for the treatment of neutropenia and febrile neutropenia induced by myelosuppressive chemotherapy. Nivestim™ has been studied in phase 2 and 3 clinical trials where its efficacy and safety was found to be similar to its reference product, Neupogen^®. Follow-on biologics continue to be scrutinised for safety. We present a design for two observational phase IV studies that are evaluating the safety profile of Nivestim™ for the prevention and treatment of febrile neutropenia (FN) in patients treated with cytotoxic chemotherapy in general clinical practice.

Methods/Design

The NEXT (Tolérance de Nivestim chez les patiEnts traités par une chimiothérapie anticancéreuse cytotoXique en praTique courante) and VENICE (VErträglichkeit von NIvestim unter zytotoxischer Chemotherapie in der Behandlung malinger Erkrankungen) trials are multicentre, prospective, longitudinal, observational studies evaluating the safety profile of Nivestim™ in 'real-world’ clinical practice. Inclusion criteria include patients undergoing cytotoxic chemotherapy for malignancy and receiving Nivestim as primary or secondary prophylaxis (NEXT and VENICE), or as treatment for ongoing FN (NEXT only). In accordance with European Union pharmacovigilance guidelines, the primary objective is to evaluate the safety of Nivestim™ by gathering data on adverse events in all system organ classes. Secondary objectives include obtaining information on patient characteristics, efficacy of Nivestim™ therapy (including chemotherapy dose intensity), patterns of use of Nivestim™, and physician knowledge regarding filgrastim prescription and the reasons for choosing Nivestim™. Data will be gathered at three visits: 1. At the initial inclusion visit, 2. At a 1-month follow-up visit, and 3. At the end of chemotherapy.

Recruitment for VENICE commenced in July 2011 and in November 2011 for NEXT. VENICE completed recruitment in July 2013 with 407 patients, and NEXT in September 2013 with 2123 patients. Last patient, last visit for each study will be December 2013 and March 2014 respectively.

Discussion

The NEXT and VENICE studies will provide long-term safety, efficacy and practice pattern data in patients receiving Nivestim™ to support myelosuppressive chemotherapy in real world clinical practice. These data will improve our understanding of the performance of Nivestim™ in patients encountered in the general patient population.

Trial registration

NEXT NCT01574235, VENICE NCT01627990

Sequential administration of the high affinity CXCR4 antagonist BKT140 promotes megakaryopoiesis and platelet production

Platelets are the terminal differentiation product of megakaryocytes (MKs). Cytokines, such as thrombopoietin (TPO), are known to influence different steps in MK development; however, the complex differentiation and platelet localization processes are not fully understood. MKs express the receptor CXCR4 and have been shown to migrate in response to CXCL12 and to increase their platelet production. In this study, we studied the role of CXCR4 in platelet production with the high affinity CXCR4 antagonist, BKT140. Single and sequential administration of BKT140 significantly increased the number of MKs and haematopoietic progenitors (HPCs) within the bone marrow (BM). Increased megakaryopoiesis was associated with increased platelet production. Single and sequential administration of BKT140 also increased the number of HPCs in the blood. In a model of 5-fluorouracil-induced thrombocytopenia, BKT140 significantly reduced the severity and duration of thrombocytopenia and cytopenia when administered before and after chemotherapy. Our results demonstrated that the CXCR4 antagonist, BKT140, mediated unique beneficial effects by stimulating megakaryopoiesis and platelet production. These results provide evidence for the possible therapeutic use of BKT140 for modulating platelet numbers in thrombocytopenic conditions.

Water extract of deer bones activates macrophages and alleviates neutropenia

Extracts from deer bones, called nok-gol in Korean, have long been used to invigorate Qi. While neutropenia is not well detected in normal physiological condition, it could be a cause of severe problems to develop diseases such as infectious and cancerous diseases. Thus, a prevention of neutropenia in normal physiology and pathophysiological states is important for maintaining Qi and preventing disease progress. In cell biological aspects, activated macrophages are known to prevent neutropenia. In this study, we demonstrate that water extract of deer bone (herein, NG) prevents neutropenia by activating macrophages. In mouse neutropenia model system in vivo where ICR mice were treated with cyclophosphamide to immunosuppress, an oral administration of NG altered the number of blood cells including lymphocytes, neutrophils, basophils, and eosinophils. This in vivo effect of NG was relevant to that of granulocyte colony stimulating factor (G-CSF) that was known to improve neutropenia. Our in vitro studies further showed that NG treatment increased intracellular reactive oxygen species (ROS) and promoted macrophagic differentiation of mouse monocytic Raw264.7 cells in a dose-dependent manner. In addition, NG enhanced nitric oxide (NO) synthesis and secretions of cytokines including IL-6 and TNF- α . Consistently, NG treatment induced phosphorylation of ERK, JNK, IKK, I κ B α , and NF- κ B in Raw264.7 cells. Thus, our data suggest that NG is helpful for alleviating neutropenia.

Synergistic radioprotection by gamma-tocotrienol and pentoxifylline: role of cAMP signaling

Purpose. This study was designed to determine the efficacy and mechanisms of radioprotection by the combination of gamma-tocotrienol (GT3) and pentoxifylline (PTX) against acute radiation injury. Materials and Methods. Post-irradiation survival was monitored to determine the most efficacious dose and time of administration of PTX. Dose reduction factor (DRF) was calculated to compare the radioprotective efficacy of the combination. To determine the mechanism of synergistic radioprotection by the combination, mevalonate or calmodulin were coadministered with the GT3-PTX combination. Mevalonate was used to reverse the inhibitory effect of GT3 on 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR), and calmodulin was used to reverse the inhibition of phosphodiesterase (PDE) by PTX. Results. The combination was most effective when 200 mg/kg of PTX was administered 15 min before irradiation along with 200 mg/kg of GT3 (-24 h) and resulted in a DRF of 1.5. White blood cells and neutrophil counts showed accelerated recovery in GT3-PTX-treated groups compared to GT3. Mevalonate had no effect on the radioprotection of GT3-PTX; calmodulin abrogated the synergistic radioprotection by GT3-PTX. Conclusion. The mechanism of radioprotection by GT3-PTX may involve PDE inhibition.

Top-down MS for rapid methionine oxidation site assignment in filgrastim

Protein therapeutics have emerged as a major new class of pharmaceuticals. One important shelf-life-limiting factor of biopharmaceuticals is methionine oxidation, and therefore, it is important that analytical methods are able to thoroughly characterize all possible oxidized variants. Here, we present a fast and sensitive method to perform online methionine oxidation site assignment using granulocyte colony-stimulating factor (filgrastim) as a model. The method is based on top-down MS using the all-ion fragmentation mode of the Exactive benchtop mass spectrometer. Conditions that provide information on the intact mass of the protein as well as on fragment ions that allow unambiguous site assignment of methionine oxidation in filgrastim variants as low as 0.12 % of total peak area in a chromatographic time scale were identified. Using this method, we performed methionine oxidation site assignment in H₂O₂-stressed filgrastim and in filgrastim which was stored at intended conditions, respectively. We show that the relative abundance of oxidation species observed in filgrastim stored under intended conditions differs strikingly from the oxidized species observed after H₂O₂ stress. Additionally, we report an oxidized filgrastim variant that has not been previously described in the literature.

Figure

In vitro and in vivo protective effects of granulocyte colony-stimulating factor against radiation-induced intestinal injury

Intestinal injury is a major cause of death after high-dose radiation exposure. The use of granulocyte-colony stimulating factor (G-CSF) to treat radiation injury has focused on enhancing recovery from hematopoietic radiation syndrome. We evaluated G-CSF for its ability to protect against radiation-induced intestinal injury in rat intestinal epithelial cells (IEC-6) and BALB/c mouse models. For in vitro tests, pre-radiation addition of G-CSF to IEC-6 prevented cytotoxicity and the loss of cell viability. Pre-radiation G-CSF treatment also reduced radiation-induced cleavage of caspase-3 and p53 in IEC-6. For in vivo tests, examination 12 h after abdominal irradiation showed that G-CSF-treated mice were protected against apoptosis of the jejunal crypts. G-CSF-treated mice also showed attenuated intestinal morphological changes 3.5 days after abdominal radiation (10 Gy). G-CSF also reduced the levels of proinflammatory cytokines interleukin-6 and tumor necrosis factor-α after radiation. This study showed that G-CSF may protect against radiation-induced intestinal damage through its anti-apoptotic and anti-inflammatory effects. These results suggest that G-CSF is promising candidate for protection against intestinal mucosal injury following irradiation.

Extracellular signal-regulated kinase 2 mediates the expression of granulocyte colony-stimulating factor in invasive cancer cells

Granulocyte colony-stimulating factor (G-CSF) affects granulopoiesis and is important for mobilizing neutrophils into blood circulation. Due to the hematopoietic properties of G-CSF, it has been widely used to clinically treat chemotherapy-induced neutropenia. However, G-CSF can promote tumors by inhibiting innate and adaptive immunity and enhancing angiogenesis and neoplastic growth. Most G-CSF-producing tumors are associated with a poor prognosis. This indicates that G-CSF promotes cancer progression. Thus, identifying regulatory molecules involved in tumor-derived G-CSF expression may provide therapeutic targets for cancer treatment. This study identified considerable G-CSF expression in malignant breast, lung and oral cancer cells. However, G-CSF expression was barely detectable in non-invasive cell lines. Expression of G-CSF mRNA and protein increased during exposure to tumor necrosis factor-α (TNF-α). Treatment with U0126 (a mitogen-activated protein kinase inhibitor) drastically reduced basal levels of G-CSF and TNF-α-induced G-CSF in aggressive cancer cells. This study also showed that knockdown of extracellular signal-regulated kinase (ERK) 2 by shRNA was necessary and sufficient to eliminate the expression of tumor-derived G-CSF. This did not apply to ERK1. Therefore, ERK2 (but not ERK1) is responsible for the transcriptional regulation of tumor-derived G-CSF. The results indicate the pharmaceutical value of specific ERK2 inhibitors in treating patients with G-CSF-producing tumors.

Optimization of auto-induction medium for G-CSF production by Escherichia coli using artificial neural networks coupled with genetic algorithm

Granulocyte colony-stimulating factor (G-CSF) is a cytokine widely used in cancer patients receiving high doses of chemotherapeutic drugs to prevent the chemotherapy-induced suppression of white blood cells. The production of recombinant G-CSF should be increased to meet the increasing market demand. This study aims to model and optimize the carbon source of auto-induction medium to enhance G-CSF production using artificial neural networks coupled with genetic algorithm. In this approach, artificial neural networks served as bioprocess modeling tools, and genetic algorithm (GA) was applied to optimize the established artificial neural network models. Two artificial neural network models were constructed: the back-propagation (BP) network and the radial basis function (RBF) network. The root mean square error, coefficient of determination, and standard error of prediction of the BP model were 0.0375, 0.959, and 8.49 %, respectively, whereas those of the RBF model were 0.0257, 0.980, and 5.82 %, respectively. These values indicated that the RBF model possessed higher fitness and prediction accuracy than the BP model. Under the optimized auto-induction medium, the predicted maximum G-CSF yield by the BP-GA approach was 71.66 %, whereas that by the RBF-GA approach was 75.17 %. These predicted values are in agreement with the experimental results, with 72.4 and 76.014 % for the BP-GA and RBF-GA models, respectively. These results suggest that RBF-GA is superior to BP-GA. The developed approach in this study may be helpful in modeling and optimizing other multivariable, non-linear, and time-variant bioprocesses.

Elevating body temperature enhances hematopoiesis and neutrophil recovery after total body irradiation in an IL-1-, IL-17-, and G-CSF-dependent manner

Neutropenia is a common side effect of cytotoxic chemotherapy and radiation, increasing the risk of infection in these patients. Here we examined the impact of body temperature on neutrophil recovery in the blood and bone marrow after total body irradiation (TBI). Mice were exposed to either 3 or 6 Gy TBI followed by a mild heat treatment that temporarily raised core body temperature to approximately 39.5°C. Neutrophil recovery was then compared with control mice that received either TBI alone heat treatment alone. Mice that received both TBI and heat treatment exhibited a significant increase in the rate of neutrophil recovery in the blood and an increase in the number of marrow hematopoietic stem cells and neutrophil progenitors compared with that seen in mice that received either TBI or heat alone. The combination treatment also increased G-CSF concentrations in the serum, bone marrow, and intestinal tissue and IL-17, IL-1β, and IL-1α concentrations in the intestinal tissue after TBI. Neutralizing G-CSF or inhibiting IL-17 or IL-1 signaling significantly blocked the thermally mediated increase in neutrophil numbers. These findings suggest that a physiologically relevant increase in body temperature can accelerate recovery from neutropenia after TBI through a G-CSF-, IL-17-, and IL-1-dependent mechanism.

Role of radiation-induced granulocyte colony-stimulating factor in recovery from whole body gamma-irradiation

The purpose of this study was to further elucidate the radioprotective role of granulocyte colony-stimulating factor (G-CSF) induced in response to irradiation. The induction of G-CSF and interleukin-6 (IL-6) in response to radiation exposure was evaluated in mice. The level of cytokine in serum was determined by multiplex Luminex. The role of G-CSF on survival and tissue injury after total body gamma-irradiation was evaluated by administration of neutralizing antibody to G-CSF before radiation exposure. An isotype control was used for comparison and survival was monitored for 30 d after irradiation. Jejunum samples were used for immunohistochemistry. Ionizing radiation exposure induced significant levels of the hematopoietic cytokines G-CSF and IL-6, in mice receiving 9.2 Gy radiation. Maximal levels of G-CSF were observed in peripheral blood of mice 8h after irradiation. IL-6 levels were maximum at 12h after irradiation. Administration of G-CSF antibody significantly enhanced mortality in irradiated mice. G-CSF antibody-treated mice had higher numbers of CD68(+) cells and apoptotic cells in intestinal villi. Our results confirm that radiation exposure induces elevations of circulating G-CSF and IL-6. Neutralizing antibody to G-CSF exacerbates the deleterious effects of radiation, indicating that G-CSF induced in response to irradiation plays an important role in recovery.

CBLB613: a TLR 2/6 agonist, natural lipopeptide of Mycoplasma arginini , as a novel radiation countermeasure

To date, there are no safe and effective drugs available for protection against ionizing radiation damage. Therefore, a great need exists to identify and develop non-toxic agents that will be useful as radioprotectors or postirradiation therapies under a variety of operational scenarios. We have developed a new pharmacological agent, CBLB613 (a naturally occurring Mycoplasma-derived lipopeptide ligand for Toll-like receptor 2/6), as a novel radiation countermeasure. Using CD2F1 mice, we investigated CBLB613 for toxicity, immunogenicity, radioprotection, radiomitigation and pharmacokinetics. We also evaluated CBLB613 for its effects on cytokine induction and radiation-induced cytopenia in unirradiated and irradiated mice. The no-observable-adverse-effect level of CBLB613 was 1.79 mg/kg and 1 mg/kg for single and repeated doses, respectively. CBLB613 significantly protected mice against a lethal dose of (60)Co γ radiation. The dose reduction factor of CBLB613 as a radioprotector was 1.25. CBLB613 also mitigated the effects of (60)Co γ radiation on survival in mice. In both irradiated and unirradiated mice, the drug stimulated induction of interleukin-1β (IL-1β), IL-6, IL-10, IL-12, keratinocyte-derived chemokine, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor-1α. CBLB613 also reduced radiation-induced cytopenia and increased bone marrow cellularity in irradiated mice. Our immunogenicity study demonstrated that CBLB613 is not immunogenic in mice, indicating that it could be developed as a radioprotector and radiomitigator for humans against the potentially lethal effects of radiation exposure.

Pharmacokinetic profiles of a biosimilar filgrastim and Amgen filgrastim: results from a randomized, phase I trial

Recombinant human granulocyte colony-stimulating factor (filgrastim) has multiple hematologic and oncologic indications as Neupogen (Amgen filgrastim). Hospira has developed a biosimilar filgrastim (Nivestim). Here, results are reported from a phase I trial, primarily designed to compare the pharmacokinetic profiles of Hospira filgrastim and Amgen filgrastim. A phase I, single-center, open-label, randomized trial was undertaken to demonstrate equivalence of the pharmacokinetic characteristics of Hospira filgrastim and Amgen filgrastim. Forty-eight healthy volunteers were randomized to receive intravenous (i.v.) or subcutaneous (s.c.) dosing and then further randomized to order of treatment. Volunteers in each of the two dosing groups received a single 10microg/kg dose of Hospira filgrastim or Amgen filgrastim, with subsequent crossover. Bioequivalence was evaluated by analysis of variance; if the estimated 90% confidence intervals (CIs) for the ratio of 'test' to 'reference' treatment means were within the conventional equivalence limits of 0.80-1.25, then bioequivalence was concluded. Forty-six volunteers completed the study. Geometric mean area under the curve from time 0 to the last time point (primary endpoint) was similar in volunteers given Hospira filgrastim or Amgen filgrastim following i.v. (ratio of means: 0.96; 90% CI: 0.90-1.02) or s.c. (ratio of means: 1.02; 90% CI: 0.95-1.09) dosing; 90% CIs were within the predefined range necessary to demonstrate bioequivalence. Hospira filgrastim was well tolerated with no additional safety concerns over Amgen filgrastim. Hospira filgrastim is bioequivalent with Amgen filgrastim in terms of its pharmacokinetic properties and may provide a clinically effective alternative.

Late-onset neutropenia after rituximab treatment: case series and comprehensive review of the literature

Rituximab is a chimeric monoclonal antibody against CD20 that is used mainly for the treatment of CD20-positive lymphoma. Recently, its use has been expanded to include treatment of other nonmalignant diseases such as rheumatologic diseases and autoimmune cytopenia. Correlating with the increased use of rituximab has been an increased number of reports of its late adverse effects. One of these is late-onset neutropenia (LON). Most investigators define LON as grade III-IV neutropenia occurring 3-4 weeks after the last treatment with rituximab, in the absence of an alternative explanation for the neutropenia.We report 6 cases of LON identified in our institution. Four patients were treated for diffuse large B-cell lymphoma, and 2 patients for follicular lymphoma. Median patient age was 68 years (range, 33-83 yr); LON appeared after a median interval of 77 days (range, 42-153 d) and lasted for a median of 5 days (range, 1-45 d). Five of the 6 patients presented with infectious complications, and 4 patients experienced recurrent episodes of neutropenia. One patient presented with LON and concomitant subacute pulmonary disease that was attributed to rituximab therapy.In addition to our own case series we present a systematic review of the literature, which we performed to compile data to describe better the syndrome of LON. Systematic studies, case series, and case reports were extracted. Most studies dealing with LON are retrospective by design and are limited by the heterogeneous populations included in the analysis. The incidence of LON is generally reported to be in the range of 3%-27%. Data regarding populations at risk are not consistent, and in some instances are conflicting.Patients considered at increased risk of LON include patients after autologous stem cell transplantation, patients treated for acquired immunodeficiency syndrome (AIDS)-related lymphoma, and patients treated with purine analogues. Patients who received previous cytotoxic treatment as well as those treated with more intensive chemotherapy or with chemotherapy in combination with radiotherapy are also considered to be at risk of LON. In addition, advanced stages of disease and having received multiple doses of rituximab are risk factors for LON.The mechanism of LON is poorly understood. Direct toxicity is very unlikely. Some speculate that there may be an infectious etiology involved, as well as an antibody-mediated process, but these ideas have not been substantiated. The concept of a lymphocyte subpopulation imbalance leading to LON has been presented based on the demonstration of T-LGL in peripheral blood and bone marrow of patients with LON. Perturbations in stromal-derived factor-1 and in the BAFF cytokine have also been discussed as potential players in the pathogenesis of LON. A recent study correlated specific polymorphism in the immunoglobulin G Fc receptor FCγRIIIa 158 V/F with increased rates of LON.The clinical significance of LON is important because it may affect treatment strategies. Of note, infectious complications are not very frequent and not very severe. Pooling data from the major retrospective studies reveals an infection rate of 16.9%. Most infections were mild and resolved promptly. One death occurred from infection during neutropenia. Repeated episodes of LON are not uncommon, but it is so far impossible to identify those patients at risk of these relapsing episodes of LON. Re-treatment with rituximab after LON may result in recurrent episodes, but the implications and risks are uncertain at the present time. The role of growth factors once LON appears is ill defined, and the decision to use them should be made on a case-by-case basis.

Comparison of the pharmacodynamic profiles of a biosimilar filgrastim and Amgen filgrastim: results from a randomized, phase I trial

Further to the patent expiry of Neupogen (Amgen filgrastim), Hospira has developed a biosimilar filgrastim (Nivestim) that may offer a clinically effective alternative for multiple hematologic and oncologic indications. Here results are reported from a phase I trial, primarily designed to compare the pharmacodynamic profiles of Hospira filgrastim and Amgen filgrastim. A phase I, single-center, double-blind, randomized trial was undertaken to demonstrate equivalence of the pharmacodynamic characteristics of Hospira filgrastim and Amgen filgrastim. Fifty healthy volunteers were randomized to receive 5 or 10 microg/kg dosing, before further randomization to treatment sequence. All volunteers received five daily subcutaneous doses of Hospira filgrastim or Neupogen, with subsequent crossover to the alternative treatment. Bioequivalence was evaluated by analysis of variance; if the estimated 90% confidence intervals (CIs) for the ratio of 'test' to 'reference' treatment means were within the conventional equivalence limits of 0.80-1.25, then bioequivalence was concluded. Forty-eight volunteers completed the study. Geometric mean absolute neutrophil count area under the curve from time 0 to the last time point at day 5 (primary endpoint) was comparable in volunteers given Hospira filgrastim or Amgen filgrastim at 5 microg/kg (ratio of means, 0.98; 90% CI, 0.92-1.05) or 10 microg/kg (ratio, 0.97; 90% CI, 0.93-1.01); 90% CIs were within the predefined range necessary to demonstrate bioequivalence. Hospira filgrastim was well tolerated with no additional safety concerns over Amgen filgrastim. Hospira filgrastim is bioequivalent with Amgen filgrastim with regard to its pharmacodynamic characteristics.

Macrophages as mediators of tumor immunosurveillance

Tumor immunosurveillance is a well-established mechanism for regulation of tumor growth. In this regard, most studies have focused on the role of T- and NK-cells as the critical immune effector cells. However, macrophages play a major role in the recognition and clearance of foreign, aged, and damaged cells. Macrophage phagocytosis is negatively regulated via the receptor SIRPalpha upon binding to CD47, a ubiquitously expressed protein. We recently showed that CD47 is up-regulated in myeloid leukemia and migrating hematopoietic progenitors, and that the level of protein expression correlates with the ability to evade phagocytosis. These results implicate macrophages in the immunosurveillance of hematopoietic cells and leukemias. The ability of macrophages to phagocytose tumor cells might be exploited therapeutically by blocking the CD47-SIRPalpha interaction.

Comparison of hospitalization risk and associated costs among patients receiving sargramostim, filgrastim, and pegfilgrastim for chemotherapy-induced neutropenia

BACKGROUND

Sargramostim is a granulocyte-macrophage-colony-stimulating factor (GM-CSF). Unlike filgrastim and pegfilgrastim, which are granulocyte-colony-stimulating factors (G-CSFs), sargramostim activates a broader range of myeloid lineage-derived cells. Therefore, GM-CSF might reduce infection risk more than the G-CSFs. This study compared real-world infection-related hospitalization rates and costs in patients using G/GM-CSF for chemotherapy-induced neutropenia.

METHODS

This retrospective matched-cohort study analyzed nationally representative health insurance claims in the United States from 2000 through 2007. The sample population included patients who received chemotherapy and G/GM-CSF. G/GM-CSF treatment episodes began with the first administration of G/GM-CSF and ended when a subsequent administration was >28 days after a prior administration. Sargramostim patients were matched 1:1 with filgrastim and pegfilgrastim patients based on gender and birth year. Outcomes included infection-related hospitalization rates and the associated costs. Hospitalization rates were analyzed using univariate and multivariate Poisson methods; covariates included myelosuppressive agents received, tumor type, anemia, and comorbidities.

RESULTS

A total of 990 sargramostim-filgrastim and 982 sargramostim-pegfilgrastim matched pairs were analyzed. Cohorts were similar with regard to age, gender, and comorbid conditions. Several differences were observed with regard to tumor type, anemia, and chemotherapy, but no systematic trends were apparent. Sargramostim patients experienced a 56% lower risk of infection-related hospitalizations compared with filgrastim and pegfilgrastim patients. Infection-related hospitalization costs were 84% and 62% lower for sargramostim patients compared with patients treated with filgrastim and pegfilgrastim, respectively.

CONCLUSIONS

Among patients with or at risk for chemotherapy-induced neutropenia, these data indicated that use of sargramostim was associated with a reduced risk of infection-related hospitalization and lower associated costs compared with filgrastim or pegfilgrastim.

Pharmacokinetic and pharmacodynamic modelling of the novel human granulocyte colony-stimulating factor derivative Maxy-G34 and pegfilgrastim in rats

OBJECTIVES

This study aims to compare pharmacokinetics and pharmacodynamics of pegfilgrastim, a pharmaceutical recombinant human granulocyte colony-stimulating factor (rhG-CSF), with that of a newly developed reagent, Maxy-G34. This comparison was performed using rat experiments and biomathematical modelling of granulopoiesis.

METHODS

Healthy rats and those with cyclophosphamide-induced neutropenia were treated with either pegfilgrastim or Maxy-G34 under various schedules. Time courses of absolute neutrophil count (ANC) and G-CSF serum level were measured and we constructed a combined pharmacokinetic/pharmacodynamic model of both drugs. Neutropenic episodes were assessed by experimental data and model simulations.

RESULTS

Both Pegfilgrastim and Maxy-G34 showed strong dose-dependent efficacy in reducing neutropenic episodes. However, time courses of ANC and G-CSF serum levels were markedly different. The biomathematical model showed good agreement with these data. We estimated that differences between the two drugs could be explained by lower bioavailability and reduced elimination of Maxy-G34. Based on the data and model interpolations, we estimated that Maxy-G34 is superior in reducing neutropenic episodes. Also, we predicted that G-CSF administration 48 h after cyclophosphamide would be superior to its administration after 2 or 24 h, for both derivatives.

CONCLUSION

Maxy-G34 is a highly potent drug for stimulation of neutrophil production in rats. By our modelling approach, we quantified differences between Maxy-G34 and pegfilgrastim, related to pharmacokinetic parameters. Model simulations can be used to estimate optimal dosing and timing options in the present preclinical rat model.

XM02, the first granulocyte colony-stimulating factor biosimilar, is safe and effective in reducing the duration of severe neutropenia and incidence of febrile neutropenia in patients with non-Hodgkin lymphoma receiving chemotherapy

Recombinant granulocyte colony-stimulating factors (G-CSFs) such as filgrastim or lenograstim are being used to treat chemotherapy-induced neutropenia. The aim of the present study was to investigate a new G-CSF, XM02, in comparison to filgrastim in terms of safety and efficacy in the prevention of chemotherapy-induced neutropenia in non-Hodgkin-lymphoma (NHL). A total of 92 patients receiving chemotherapy were randomised in cycle 1 to treatment with daily injections (subcutaneous 5 microg/kg/day) of XM02 (n = 63) or filgrastim (n = 29) for at least 5 days and a maximum of 14 days. In subsequent cycles, all patients received XM02. The mean duration of severe neutropenia (DSN) was 0.5 and 0.9 days in cycle 1 for XM02 and filgrastim, respectively (p = 0.1055). In cycle 1, the incidence of febrile neutropenia (FN) was 11.1% for XM02 and 20.7% for filgrastim (p = 0.1232). The adverse event profile was similar between XM02 and filgrastim. XM02 demonstrated equivalent efficacy and similar safety profile as the reference medication filgrastim. Treatment with XM02 is as beneficial as filgrastim in ameliorating severe neutropenia and FN in patients with NHL receiving chemotherapy. XM02 is safe and well tolerated in the doses applied in this study.

XM02, the first biosimilar G-CSF, is safe and effective in reducing the duration of severe neutropenia and incidence of febrile neutropenia in patients with small cell or non-small cell lung cancer receiving platinum-based chemotherapy

BACKGROUND

Recombinant granulocyte colony-stimulating factors such as Neupogen are used to treat chemotherapy-induced neutropenia. The aim of the study was to show that a new granulocyte colony-stimulating factor, XM02, is as safe and effective as Neupogen in the treatment of chemotherapy-induced neutropenia in patients with small cell or non-small cell lung cancer.

PATIENTS AND METHODS

A total of 240 patients receiving platinum-based chemotherapy were randomized in cycle 1 to treatment with daily injections (subcutaneous 5 microg/kg/d) of XM02 (n = 160) or Filgrastim Neupogen (n = 80) for at least 5 days and a maximum of 14 days. In subsequent cycles, all patients received XM02.

RESULTS

The mean duration of severe neutropenia was 0.5 and 0.3 days in cycle 1 for XM02 and Filgrastim, respectively. In the analysis of covariance for duration of severe neutropenia in cycle 1, the estimated treatment difference "XM02 minus Filgrastim" was 0.157 days, with 95% confidence level (-0.114 days, 0.428 days), which was included in the prespecified equivalence range (-1, 1). There was no statistically significant difference of the end point incidence of febrile neutropenia in cycle 1 between XM02 and Filgrastim (p = 0.2347). The adverse event profile was similar between XM02 and Filgrastim.

CONCLUSION

XM02 demonstrated similar efficacy and safety profile as the reference medication Filgrastim in cycle 1. In conclusion, treatment with XM02 is beneficial in ameliorating severe neutropenia and febrile neutropenia in lung cancer patients receiving myelosuppressive chemotherapy. XM02 is safe and well tolerated in the doses applied in this study.

XM02 is superior to placebo and equivalent to Neupogen in reducing the duration of severe neutropenia and the incidence of febrile neutropenia in cycle 1 in breast cancer patients receiving docetaxel/doxorubicin chemotherapy

Background

Recombinant granulocyte colony-stimulating factors (G-CSFs) such as Filgrastim are used to treat chemotherapy-induced neutropenia. We investigated a new G-CSF, XM02, and compared it to Neupogen™ after myelotoxic chemotherapy in breast cancer (BC) patients.

Methods

A total of 348 patients with BC receiving docetaxel/doxorubicin chemotherapy were randomised to treatment with daily injections (subcutaneous 5 μg/kg/day) for at least 5 days and a maximum of 14 days in each cycle of XM02 (n = 140), Neupogen™ (n = 136) or placebo (n = 72). The primary endpoint was the duration of severe neutropenia (DSN) in cycle 1.

Results

The mean DSN in cycle 1 was 1.1, 1.1, and 3.9 days in the XM02, Neupogen™, and placebo group, respectively. Superiority of XM02 over placebo and equivalence of XM02 with Neupogen™ could be demonstrated. Toxicities were similar between XM02 and Neupogen™.

Conclusion

XM02 was superior to placebo and equivalent to Neupogen™ in reducing DSN after myelotoxic chemotherapy.

Trial Registration

Current Controlled Trials ISRCTN02270769

Patients' Perceptions of Physician-Patient Discussions and Adverse Events with Cancer Therapy

Objectives

Patients with cancer who are treated with chemotherapy report adverse events during their treatment, which can affect their quality of life and increase the likelihood that their treatment will not be completed. In this study, patients' perceptions of the physician-patient relationship and communication about cancer-related issues, particularly adverse events were examined.

Methods

We surveyed 508 patients with cancer concerning the occurrence of adverse events and their relationship and communication with their physicians regarding cancer, treatment, and adverse events.

Results

Most individuals surveyed (>90%) discussed diagnosis, treatment plan, goals, and schedule, and potential adverse events with their physicians before initiating chemotherapy; approximately 75% of these individuals understood these topics completely or very well. Physician-patient discussions of adverse events were common, with tiredness, nausea and vomiting, and loss of appetite discussed prior to chemotherapy in over 80% of communications. These events were also the most often experienced (ranging in 95% to 64% of the respondents) along with low white blood cell counts (WBCs), which were experienced in 67% of respondents. Approximately 75% of the individuals reported that their overall quality of life was affected by adverse events.

Conclusions

These findings suggest that discussions alone do not provide patients with sufficient understanding of the events, nor do they appear to adequately equip patients to cope with them. Therefore, efforts to improve cancer care should focus on developing tools to improve patients' understanding of the toxicities of chemotherapy, as well as providing resources to reduce the effects of adverse events.

Management of Chemotherapy-Induced Neutropenia: Opportunities for Pharmacist Involvement

Purpose

This article highlights the clinical impact of chemotherapy-induced neutropenia (CIN) and reviews the clinical evidence supporting the updated guideline recommendations from leading scientific organizations that focus on cancer care regarding the use of myeloid growth factors to reduce the incidence of febrile neutropenia (FN) from chemotherapy. The aim is to provide insight for practicing pharmacists regarding how they can be more proactive in developing best-practice strategies for the management of CIN as well as the prevention of FN.

Summary

CIN, the primary dose-limiting toxicity of chemotherapy, is common in many tumor types that are treated with myelosuppressive chemotherapy and occurs with the greatest frequency in the first cycle of treatment. Treatment with myeloid growth factors, or colony-stimulating factors (CSFs), has shown to be effective in reducing the risk, severity, and duration of FN from chemotherapy. Despite recent revisions to various clinical guidelines that have resulted in alignment on the recommendation for prophylactic CSF use in patients with a greater than or equal to 20% risk of developing FN, a gap remains between actual clinical usage and best practice. Pharmacists are key members of multidisciplinary health care teams and are uniquely positioned to evaluate current practice and develop strategies that ensure appropriate CSF use. This paper summarizes the recent changes to CSF guidelines, reviews clinical data that support those changes, and discusses strategies for pharmacist involvement in the management of CIN and FN prevention using real-world examples of improvement initiatives.

Conclusion

Neutropenia is a dose-limiting toxicity of chemotherapy that has significant implications for effective cancer treatment and patient health outcomes. Pharmacists are uniquely positioned to perform various interventions, which help ensure appropriate CSF use and improve the management of CIN.

An agonist of toll-like receptor 5 has radioprotective activity in mouse and primate models

The toxicity of ionizing radiation is associated with massive apoptosis in radiosensitive organs. Here, we investigate whether a drug that activates a signaling mechanism used by tumor cells to suppress apoptosis can protect healthy cells from the harmful effects of radiation. We studied CBLB502, a polypeptide drug derived from Salmonella flagellin that binds to Toll-like receptor 5 (TLR5) and activates nuclear factor-kappaB signaling. A single injection of CBLB502 before lethal total-body irradiation protected mice from both gastrointestinal and hematopoietic acute radiation syndromes and resulted in improved survival. CBLB502 injected after irradiation also enhanced survival, but at lower radiation doses. It is noteworthy that the drug did not decrease tumor radiosensitivity in mouse models. CBLB502 also showed radioprotective activity in lethally irradiated rhesus monkeys. Thus, TLR5 agonists could potentially improve the therapeutic index of cancer radiotherapy and serve as biological protectants in radiation emergencies.

Granulocyte-macrophage colony stimulating factor induces endothelial capillary formation through induction of membrane-type 1 matrix metalloproteinase expression in vitro

In our study, we examined the mechanism by which granulocyte-macrophage colony stimulating factor (GM-CSF) regulates angiogenesis using in vitro models. GM-CSF significantly increased precapillary sprout-like formation from endothelial cell spheroids seeded in type-I collagen gels and tubule formation on coculture of endothelial cells with fibroblasts. In both cases, sprout and tubule formation was highly dependent on metalloproteinase activity. Tissue Inhibitor of metalloproteinase (TIMP) profiling in the spheroid and coculture models showed inhibition by TIMP-2 but not by TIMP-1, indicative of activity of membrane-type matrix metalloproteinases (MT-MMPs). GM-CSF induced sprout formation in spheroids was found to be potently inhibited by siRNA specific for MT1-MMP. Subsequent analysis showed that GM-CSF transiently increased MT1-MMP mRNA in endothelial cells in a MEK-dependent mechanism, which led to increased surface levels of MT1-MMP. This was accompanied by an increase in MT1-MMP-dependent degradation of DQ-collagen by lysates of GM-CSF stimulated endothelial cells. GM-CSF did not increase MT1-MMP levels in fibroblasts. The effect of GM-CSF on endothelial cell sprout formation could be mimicked by adenoviral transduction of intact spheroids with virus expressing MT1-MMP, but not by transduction of endothelial cells before spheroid formation, suggesting that upregulation of MT1-MMP must only occur in cells directly involved in tubule formation.

A neuroprotective function for the hematopoietic protein granulocyte-macrophage colony stimulating factor (GM-CSF)

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic cytokine responsible for the proliferation, differentiation, and maturation of cells of the myeloid lineage, which was cloned more than 20 years ago. Here we uncovered a novel function of GM-CSF in the central nervous system (CNS). We identified the GM-CSF alpha-receptor as an upregulated gene in a screen for ischemia-induced genes in the cortex. This receptor is broadly expressed on neurons throughout the brain together with its ligand and induced by ischemic insults. In primary cortical neurons and human neuroblastoma cells, GM-CSF counteracts programmed cell death and induces BCL-2 and BCL-Xl expression in a dose- and time-dependent manner. Of the signaling pathways studied, GM-CSF most prominently induced the PI3K-Akt pathway, and inhibition of Akt strongly decreased antiapoptotic activity. Intravenously given GM-CSF passes the blood-brain barrier, and decreases infarct damage in two different experimental stroke models (middle cerebral artery occlusion (MCAO), and combined common carotid/distal MCA occlusion) concomitant with induction of BCL-Xl expression. Thus, GM-CSF acts as a neuroprotective protein in the CNS. This finding is remarkably reminiscent of the recently discovered functionality of two other hematopoietic factors, erythropoietin and granulocyte colony-stimulating factor in the CNS. The identification of a third hematopoietic factor acting as a neurotrophic factor in the CNS suggests a common principle in the functional evolution of these factors. Clinically, GM-CSF now broadens the repertoire of hematopoietic factors available as novel drug candidates for stroke and neurodegenerative diseases.

Granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor promote malignant growth of cells from head and neck squamous cell carcinomas in vivo

Granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) are used to ameliorate cancer therapy-induced neutropenia and mucositis. Yet, first data in head and neck squamous cell carcinoma (HNSCC) indicate an impaired long-term prognosis on G-CSF treatment, and previous studies showed a contribution of both factors to the progression of human epithelial tumors. Therefore, we investigate the role of G-CSF and GM-CSF in progression of tumor cells from human HNSCC. Both factors stimulated proliferation and migration of tumor cell lines established from patient tumors expressing G-CSF and GM-CSF and/or their receptors. Blockade of G-CSF and GM-CSF inhibited tumor cell invasion in a three-dimensional organotypic culture model. The contribution of both factors to tumor malignancy was further confirmed in nude mouse transplants in vivo. Invasive and malignant growth yielding a similar tumor phenotype as the original patient tumor was exclusively observed in G-CSF- and GM-CSF-expressing tumors and was associated with enhanced and persistent angiogenesis and enhanced inflammatory cell recruitment. Although factor-negative tumors grew somewhat faster, they were characterized by lack of invasion, reduced and transient angiogenesis, and large necrotic areas. These data provide evidence for a progression-promoting effect of G-CSF and GM-CSF in human HNSCC and suggest further detailed evaluation of their use in the therapy of these tumors.

The hematopoietic factor GM-CSF (granulocyte-macrophage colony-stimulating factor) promotes neuronal differentiation of adult neural stem cells in vitro

Background

Granulocyte-macrophage colony stimulating factor (GM-CSF) is a hematopoietic growth factor involved in the generation of granulocytes, macrophages, and dendritic cells from hematopoietic progenitor cells. We have recently demonstrated that GM-CSF has anti-apoptotic functions on neurons, and is neuroprotective in animal stroke models.

Results

The GM-CSF receptor α is expressed on adult neural stem cells in the rodent brain, and in culture. Addition of GM-CSF to NSCs in vitro increased neuronal differentiation in a dose-dependent manner as determined by quantitative PCR, reporter gene assays, and FACS analysis.

Conclusion

Similar to the hematopoietic factor Granulocyte-colony stimulating factor (G-CSF), GM-CSF stimulates neuronal differentiation of adult NSCs. These data highlight the astonishingly similar functions of major hematopoietic factors in the brain, and raise the clinical attractiveness of GM-CSF as a novel drug for neurological disorders.

Granulocyte colony-stimulating factors in the management of chemotherapy-induced neutropenia: evidence based review

(1) Neutropenia is a frequent complication of chemotherapy associated with life-threatening infections, hospitalisation, and chemotherapy dose reductions and delays.(2) Primary prophylaxis with granulocyte colony-stimulating factors has been shown to reduce the incidence and duration of neutropenia, febrile neutropenia, infections, hospitalisation and antibiotic use.(3) Recent randomised clinical trials of filgrastim, lenograstim and pegfilgrastim showed variable results across patient groups at different risks of febrile neutropenia.(4) Pegfilgrastim is at least as effective as filgrastim in the prophylaxis of chemotherapy-induced neutropenia and has improved pharmacokinetics requiring reduced administration.

Enhanced unique pattern of hematopoietic cell mobilization induced by the CXCR4 antagonist 4F-benzoyl-TN14003

An increase in the number of stem cells in blood following mobilization is required to enhance engraftment after high-dose chemotherapy and improve transplantation outcome. Therefore, an approach that improves stem cell mobilization is essential. The interaction between CXCL12 and its receptor, CXCR4, is involved in the retention of stem cells in the bone marrow. Therefore, blocking CXCR4 may result in mobilization of hematopoietic progenitor and stem cells. We have found that the CXCR4 antagonist known as 4F-benzoyl-TN14003 (T-140) can induce mobilization of hematopoietic stem cells and progenitors within a few hours post-treatment in a dose-dependent manner. Furthermore, although T-140 can also increase the number of white blood cells (WBC) in blood, including monocytes, B cells, and T cells, it had no effect on mobilizing natural killer cells. T-140 was found to efficiently synergize with granulocyte colony-stimulating factor (G-CSF) in its ability to mobilize WBC and progenitors, as well as to induce a 660-fold increase in the number of erythroblasts in peripheral blood. Comparison between the CXCR4 antagonists T-140 and AMD3100 showed that T-140 with or without G-CSF was significantly more potent in its ability to mobilize hematopoietic stem cells and progenitors into blood. These results demonstrate that different CXCR4 antagonists may have different therapeutic potentials.

Biologically active human GM-CSF produced in the seeds of transgenic rice plants

Rice flour is a well-known and characterized source of pharmaceutical ingredients, which are gluten-free and incorporated in many drug delivery applications such as excipient starch. To further exploit this uniqueness, the synthetic capacity of rice endosperm tissue, the basis of rice flour, was extended by genetic transformation. Recombinant human GM-CSF, a cytokine used in treating neutropenia and with other potential clinical applications, has been expressed in transgenic rice seeds using a rice glutelin promoter. Rice seeds accumulated human GM-CSF to a level of 1.3% of total soluble protein. The rice seed-produced human GM-CSF was found to be biologically active when tested using a human cell line TF-1. Use of rice as a host plant offers not only attractive features of safe production in seeds but also self-containment of foreign genes, as rice is primarily a self-pollinated crop plant.

Putting Evidence Into Practice: Prevention of Infection

The prevention of infection is an important outcome to measure in patients with cancer because infectious complications are a significant cause of morbidity and mortality. Nurses play a vital role in the prevention of infection in patients with cancer through nursing practice, research, and patient education. However, many common nursing interventions to prevent infection are based on tradition or expert opinion and have not been subjected to scientific examination. The 2005 Oncology Nursing Society Prevention of Infection Outcomes Intervention Project Team reviewed, critiqued, and summarized the research evidence for nursing interventions to prevent infections in patients with cancer. Pharmacologic and nonpharmacologic interventions were included because many advanced practice nurses prescribe medications. This article is an evidence-based review of nursing interventions to prevent infection in patients with cancer.

Granulocyte and granulocyte macrophage colony-stimulating factors as therapy in human and veterinary medicine

Granulocyte colony-stimulating factors (G-CSFs) and granulocyte macrophage colony-stimulating factors (GM-CSFs) are endogenous cytokines that regulate granulocyte colonies and play a major role in the stimulation of granulopoiesis (neutrophils, basophils and eosinophils) and in the regulation of microbicidal functions. There are numerous pathological conditions in which neutrophils are decreased, the most common being neutropenia associated with cancer chemotherapy, which increases the risk of serious microbial infections developing with the potential for high morbidity and mortality. New methods in molecular biology have led to the identification and cloning of CSF genes and biopharmaceutical production. Since then, CSFs have been widely used for the prevention and treatment of neutropenia associated with cancer chemotherapy, for mobilising haematopoietic cell precursors, and for other neutropenia-related pathologies. This review focuses on the use of CSFs within both human and veterinary medicine. Clinical applications, pharmacology, tolerability and the potential role of these factors in veterinary medicine are considered.

Effects of whole-body gamma irradiation and 5-androstenediol administration on serum G-CSF

5-Androstenediol (5-AED) is a natural circulating adrenocortical steroid hormone that interconverts in vivo with other members of the 5-androstene family of steroids: dehydroepiandrosterone and 5-androstenetriol. These steroids stimulate immune responses and resistance to infection. 5-AED has been identified as a systemic radiation countermeasure that enhances survival in mice exposed to gamma irradiation and ameliorates radiation-induced neutropenia in mice and nonhuman primates. 5-AED mitigates radiation-induced decreases in platelets, natural killer (NK) cells, red blood cells, and monocytes. Administration of 5-AED causes functional activation of circulating granulocytes (phagocytic ability), monocytes (oxidative burst), and NK cells (surface CD11b expression). The effects of 5-AED on survival and hematological parameters are consistent with induction of hematopoietic cytokines. To test this hypothesis, we measured serum cytokines by ELISA, Luminex, and a cytokine array. A cytokine array was used for 62 different cytokines, chemokines, growth factors, and soluble receptors. 5-AED caused significant increases in circulating granulocyte colony-stimulating factor (G-CSF) in irradiated and unirradiated animals as observed with ELISA and Luminex. The cytokine array results suggest induction of G-CSF and additional cytokines, and related molecules. Since G-CSF is an important hematopoietic cytokine, the results support our hypothesis that the previously observed increases in numbers of hematopoietic progenitors, circulating innate immune cells and platelets, and functional activation of granulocytes, monocytes, and NK cells result from a cytokine cascade induced by 5-AED.

Sensitivity analysis of cost factors for various therapy options in the treatment of follicular lymphoma

BACKGROUND

In Germany, patients with relapsed follicular non-Hodgkin's lymphoma do not all receive the same treatment. In this study, 3 therapy regimens were analyzed which were considered to be similar. With the goal of determining the treatment option with the lowest direct costs whilst maintaining the same degree of effectiveness, a cost analysis model was established and applied by way of example to the existing illness constellation.

METHODS

The German doctors' fee scale (Einheitlicher Bewertungsmassstab, EBM) valid until 2005 served as the basis for the calculation of medical services within the scope of the present statutory health insurance guidelines. A virtual standard patient was constructed for the cost model and treated with the different therapy regimens. The incidences of individual adverse events described in literature served as the basis for the characterization of the average toxicity of the respective treatment methods.

RESULT

The overall costs result from the sum of the treatment costs and the toxicity-related costs. The effect of additional interventions on the overall cost was also examined.

CONCLUSION

Whereas the accompanying documentation of costs in clinical studies is organizationally complex and very tedious, the model applied here offers a reliable method of quantifying the costs of the different therapy regimens. It permits the comparison of different treatment alternatives, and it enables, by means of a cost variance analysis, the identification of cost drivers and less expensive measures within a therapy method.

Neutropenic event risk and impaired chemotherapy delivery in six European audits of breast cancer treatment

GOALS OF WORK

The aims of this study were to assess chemotherapy treatment characteristics, neutropenic event (NE) occurrence and related risk factors in breast cancer patients in Western Europe.

MATERIALS AND METHODS

Six retrospective audits of breast cancer chemotherapy were combined into a dataset of 2,860 individuals. NEs were defined as neutropenia-related hospitalisation, dose reduction > or = 15% or dose delay > or = 7 days. Summation dose intensity (SDI) was calculated to compare different types of chemotherapy regimens on a single scale. Risk factors of NE occurrence and of low relative dose intensity (RDI) < or = 85% were identified by multiple logistic regression.

MAIN RESULTS

Patient populations were comparable between audits. Until 1998, cyclophosphamide, methotrexate and fluorouracil regimens were most frequently used, but thereafter, anthracycline-based regimens were most common. NEs occurred in 20% of the patients and low RDI in 16%. NE occurrence predicted low RDI and was associated with higher age, bigger body surface area, lower body mass index, regimen type, more chemotherapy cycles planned, normal to high SDI, concomitant radiotherapy and year of treatment. First cycle NE occurrence predicted NEs from cycle 2 onwards. A risk score using age, SDI, number of planned chemotherapy cycles and concomitant radiotherapy differentiated patients with increasing NE risk (9-37%). An alternative score version not using concomitant radiotherapy performed moderately less well.

CONCLUSIONS

NEs occurred frequently in this combined dataset and they affected treatment delivery. Identifying patients at high NE risk enables targeted prophylaxis and may avoid dose limitations.

G-CSF in the Prevention of Febrile Neutropenia in Chemotherapy in Breast Cancer Patients

The most common chemotherapeutic agents in the treatment of breast cancer are anthracyclines and taxanes. The major dose-limiting toxicities associated with these agents are myelosuppression and associated febrile neutropenia (FN). FN can significantly impact the ability to deliver full-dose chemotherapy on schedule and as a result may increase the risk of disease recurrence and eventual disease-related mortality. The use of granulocyte colony stimulating factors (G-CSFs) significantly improves the management of FN, both in a therapeutic and in a prophylactic approach. Nevertheless, the high cost of these agents limits their widespread prophylactic use. Therefore, the identification of patients who are at a higher risk of developing FN and who will benefit from the prophylactic use of G-CSFs has become the subject of several clinical and cost-effectiveness studies. Recently, new data have been accumulated concerning the risk of FN in different chemotherapy regimens, and different risk models have been developed to assess the neutropenic risk with all its complications. This article reviews and summarizes cutting-edge, disease-specific data as well as national and international guidelines regarding the use of G-CSFs to prevent chemotherapy-induced FN, with focus on the treatment of breast cancer.