Prophylactic colony-stimulating factors in children receiving myelosuppressive chemotherapy: A meta-analysis of randomized controlled trials

Old drug, new use: Recent advances for G-CSF

Granulocyte colony-stimulating factor (G-CSF), also known as colony-stimulating factor 3 (CSF3), is a proinflammatory cytokine that primarily stimulates the survival, proliferation, differentiation and function of neutrophil granulocyte progenitor cells and mature neutrophils. Over the past years, G-CSF has mainly been used to cure patients with neutropenia and as a part of chemotherapy to induct the remission for refractory/relapse leukemia. Recent studies showed that C-CSF can been used as condition regimens and as a part of preventive methods after allogeneic transplantation to improve the survival of patients and also has immunoregulation, and has promote or inhibit the proliferation of solid tumors. Therefore, in this review, we firstly describe the structure for G-CSF. Then its functions and mechanism were reviewed including the neutrophil mobilization, differentiation, migration, and inhibiting apoptosis of neutrophils, and its immunoregulation. Finally, the clinical applications were further discussed.

Efficacy, safety, and cost-effectiveness of pegylated PEG-rhg-CSF in pediatric patients receiving high-intensity chemotherapy: results from a phase II study

Background

High-intensity chemotherapy can cause life-threatening complications in pediatric patients. Therefore, this study investigated safety and efficacy of long-acting pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF; Jinyouli®) in children undergoing high-intensity chemotherapy.

Methods

Treatment-naive patients received post-chemotherapy PEG-rhG-CSF as primary prophylaxis for two cycles. The primary endpoints were drug-related adverse events (AEs) and bone pain scores. Secondary endpoints included grade 3-4 neutropenia, duration of neutropenia recovery, absolute neutrophil count changes, febrile neutropenia (FN), reduced chemotherapy intensity, antibiotic usage, and AE severity. The cost-effectiveness of PEG-rhG-CSF was compared with that of rhG-CSF (Ruibai®).

Results

Here, 307 and 288 patients underwent one and two PEG-rhG-CSF cycles, respectively. Ninety-one patients experienced drug-related AEs, primarily bone pain (12.7%). Moreover, Grade 3-4 neutropenia and FN were observed. Median FN durations were 3.0 days in both cycles. No drug-related delays were observed during chemotherapy. One patient experienced grade 4 neutropenia-induced reduction in chemotherapy intensity during cycle 2. In total, 138 patients received antibiotics. PEG-rhG-CSF exhibited superior cost-effectiveness compared to rhG-CSF.

Conclusion

Our findings indicate that PEG-rhG-CSF is safe, efficient, and cost-effective in pediatric patients undergoing high-intensity chemotherapy, providing preliminary evidence warranting further randomized controlled trials.

The Impact of Prophylactic Post-Chemotherapy G-CSF on the Relapse Rates in Patients with Acute Myeloid Leukemia: A Meta-Analysis

This meta-analysis evaluated the impact of prophylactic post-chemotherapy granulocyte colony-stimulating factor (G-CSF) in patients with acute myeloid leukemia (AML). Overall, the relapse rate, overall survival, event-free survival, and mortality rate were similar in G-CSF (+) compared to G-CSF (-) patients. However, the relative risk (RR) of relapse was higher in children and in secondary AML patients who were treated with G-CSF compared to the G-CSF (-) group [RR, 95% confidence interval: 1.26, 1.04-1.52, and 1.12 (1.02-1.24)]. Treatment with post-chemotherapy G-CSF should be prescribed with caution in pediatric patients with AML and secondary AML as possibly increasing the relapse risk.

Supportive interventions for childhood cancer: An umbrella review of randomized evidence

Therapeutic advancements have improved pediatric cancer prognosis, shifting the interest towards the management of psychosocial burden and treatment-related morbidity. To critically appraise the available evidence, we conducted an umbrella review of meta-analyses of randomized controlled trials on supportive interventions for childhood cancer. Thirty-four publications (92 meta-analyses, 1 network, 14,521 participants) were included. The most concrete data showed a reduction in procedure-related pain and distress through hypnosis. Moreover, exercise improved the functional mobility of the patients. Regarding pharmacological interventions, most of the meta-analyses pertained to the treatment of nausea/vomiting (ondansetron was effective) and infections/febrile neutropenia [granulocyte-(macrophage) colony-stimulating factors showed benefits]. Substantial heterogeneity was detected in 31 associations. Conclusively, supportive interventions for pediatric cancer are being thoroughly evaluated. However, most of the studies are small and of moderate quality, highlighting the need for more randomized evidence in order to increase precision in improving the quality of life of patients, survivors and their families.

Postoperative Rather Than Preoperative Neutropenia Is Associated With Early Catheter-related Bloodstream Infections in Newly Diagnosed Pediatric Cancer Patients

BACKGROUND

The relationship of early catheter-related bloodstream infections (CRBSIs) with perioperative neutropenia and antibiotic prophylaxis is not well established. We sought to evaluate perioperative factors associated with early CRBSIs in newly diagnosed pediatric cancer patients, particularly hematologic indices and antibiotic use.

METHODS

We retrospectively reviewed national registry records of newly diagnosed pediatric cancer patients with port-a-caths inserted using standardized perioperative protocols where only antibiotic use was not regulated. Thirty-day postoperative CRBSI incidence was correlated with preoperative factors using logistic regression and with postoperative blood counts using linear trend analysis.

RESULTS

Among 243 patients, 17 CRBSIs (7.0%) occurred at median 14 (range, 8-28) postoperative days. Early CRBSIs were significantly associated with cancer type [acute myeloid leukemia and other leukemias (AML/OLs) vs. solid tumors and lymphomas (STLs): odds ratio (OR), 5.09; P = 0.0036; acute lymphoblastic leukemia vs. STL: OR 0.83; P = 0.0446] but not preoperative antibiotics, absolute neutrophil counts and white blood cell counts. Thirty-day postoperative absolute neutrophil counts and white blood cell trends differed significantly between patients with acute lymphoblastic leukemia and STLs (OR 0.83, P < 0.05) and between AML/OLs and STLs (OR 5.09, P < 0.005), with AML/OL patients having the most protracted neutropenia during this period.

CONCLUSIONS

Contrary to common belief, low preoperative absolute neutrophil counts and lack of preoperative antibiotics were not associated with higher early CRBSI rates. Instead, AML/OL patients, particularly those with prolonged neutropenia during the first 30 postoperative days, were at increased risk. Our findings do not support the use of empirical preoperative antibiotics and instead identify prolonged postoperative neutropenia as a major contributing factor for early CRBSI.

Delayed Granulocyte Colony-Stimulating Factor (G-CSF) Administration after Chemotherapy Reduces Total G-CSF Doses without Affecting Neutrophil Recovery in a Randomized Clinical Study in Children with Solid Tumors

The use of G-CSF after myelotoxic chemotherapy accelerates neutrophil recovery reducing the risk of febrile neutropenia. Current guidelines recommend initiating G-CSF 24 hours after myelotoxic chemotherapy. However, the optimal timing of post-chemotherapy G-CSF administration has not been elucidated. Our previous work in murine models demonstrated that the reappearance of myeloid progenitors does not occur in bone marrow until 3-4 days after completion of chemotherapy suggesting that delayed G-CSF administration may be equally efficacious compared to current practice. We conducted a prospective, randomized, crossover study to compare the absolute neutrophil count (ANC) recovery after chemotherapy and a delayed G-CSF administration to a standard G-CSF administration schedule with early G-CSF start. A total of 21 children with solid tumors who received 2 identical cycles of myelotoxic chemotherapy were randomized to start receiving G-CSF either 24 hours after completion of chemotherapy or on the day that their ANC dropped below 1,000/mm³. There was no significant difference in the time to neutrophil recovery (ANC > 1,000/mm³ post nadir) between the two G-CSF administration schedules: 16.0 ± 0.5 days in the standard group compared to 16.7 ± 0.4 days in the delayed group (p = 0.36). The total number of G-CSF doses given, however, was significantly less in the delayed group: 6.7 ± 0.6 compared to 10.5 ± 0.6 doses in the standard group (p < 0.0001). Our data show that a delayed administration of post chemotherapy G-CSF resulted in a significant reduction in the number of G-CSF injections without compromising the G-CSF effects on neutrophil recovery.

Comparison of Different Doses of Granulocyte Colony-stimulating Factor in the Treatment of High-risk Febrile Neutropenia in Children With Cancer

Febrile neutropenia (FEN) is a significant side effect after chemotherapy, and it is known that using granulocyte colony-stimulating factor (G-CSF) has positive effects on treatment results. In this study, the effects of different G-CSF doses (5 to 10 mcg/kg/day) on treatment results in patients with high-risk FEN were evaluated. A total of 124 high-risk FEN episodes of 62 patients were enrolled in the study between June 2017 and October 2018. The episodes were divided into 2 groups according to G-CSF treatment doses, they received from 5 to 10 mcg/kg/day. The clinical characteristics of the patients, the treatments they received, laboratory findings, microbiologic results, and cost analysis were recorded. No statistically significant difference was found between 2 groups in terms of the mean duration of recovery from neutropenia, duration of fever, total length of hospital stay, duration of FEN episode, duration of G-CSF use, costs, bacteremia frequency, and other treatments. In patients with solid tumors, the cost of filgrastim was significantly higher in the high-dose G-CSF group. Using different doses of G-CSF in high-risk FEN episodes did not show any different effects on clinical and treatment results. The dose of 5 mcg/kg/day would be more appropriate in FEN treatment.

The effect of Absolute Neutrophil Count (ANC) on early surgical site infection in Implanted Central Venous Catheter (ICVC)

PURPOSE

The aim of this study was to evaluate surgical site infection (SSI) rates related to implanted central venous catheters (ICVC) in pediatric hematology and oncology patients with respect to absolute neutrophil count (ANC) levels.

PATIENTS AND METHODS

From January 2004 to December 2015, pediatric patients with ICVC insertion were investigated retrospectively. Patients were divided into four groups according to preoperative ANC levels and Granulocyte-colony stimulating factor (G-CSF) usage. Immediate and early surgical site infections were evaluated 7 and 30 days following surgery.

RESULTS

In total, 1143 patients were enrolled. Patients were placed into 4 groups: 930 patients in group 1 with an ANC≥500/μL without G-CSF, 149 in group 2 with an ANC≥500/μL after G-CSF usage, 36 in group 3 with an ANC<500/μL without G-CSF, and 28 in group 4 with an ANC<500/μL even after G-CSF administration. Rates of immediate and early SSIs were not statistically different between groups. In the two-group analysis (group 1 and 2 vs. 3 and 4), the number of immediate and early SSIs were not also different, respectively.

CONCLUSION

There was no correlation between ANC levels and immediate and early SSI occurrence after ICVC placement.

LEVEL OF EVIDENCE

III.

A Phase 2, International, Multicenter, Open-label Clinical Trial of Subcutaneous Tbo-Filgrastim in Pediatric Patients With Solid Tumors Undergoing Myelosuppressive Chemotherapy

This phase 2, multicenter, open-label trial investigated the safety and tolerability of tbo-filgrastim in pediatric patients receiving myelosuppressive chemotherapy. In total, 50 patients 1 month to below 16 years of age with solid tumors without bone marrow involvement were stratified into 3 age groups (2 infants, 30 children, 18 adolescents) and prophylactically administered tbo-filgrastim 5 µg/kg body weight once daily subcutaneously. The administration started after the last chemotherapy treatment in week 1 of the first cycle and continued until the expected neutrophil nadir had passed, and the neutrophil count had recovered to 2.0×10/L. The primary endpoint was safety and tolerability of tbo-filgrastim; secondary endpoints included efficacy. The mean (SD) number of doses administered was 9.2 (2.83) in children and 7.3 (1.88) in adolescents. Serious treatment-emergent adverse events were reported in 24% of patients; the most common were febrile neutropenia (FN) (12%), anemia (8%), and thrombocytopenia (8%). Nine patients (18%) experienced mild treatment-related treatment-emergent adverse events; the most common were musculoskeletal and connective tissue disorders (8%). No deaths or withdrawals occurred. The incidence of severe neutropenia (SN) was 52% and the mean (SD) duration of SN was 1.8 (2.21) days; FN incidence was 26%. A daily dose of tbo-filgrastim 5 μg/kg body weight administered to pediatric patients demonstrated a safety profile consistent with the safety profile in adult patients. The incidence of FN was on the lower end of the range reported in the literature and the SN results provide supportive data on the efficacy of tbo-filgrastim in pediatric patients.

Strategies to generate functionally normal neutrophils to reduce infection and infection-related mortality in cancer chemotherapy

Neutrophils form an essential part of innate immunity against infection. Cancer chemotherapy-induced neutropenia (CCIN) is a condition in which the number of neutrophils in a patient's bloodstream is decreased, leading to increased susceptibility to infection. Granulocyte colony-stimulating factor (GCSF) has been the only approved treatment for CCIN over two decades. To date, CCIN-related infection and mortality remain a significant concern, as neutrophils generated in response to administered GCSF are functionally immature and cannot effectively fight infection. This review summarizes the molecular regulatory mechanisms of neutrophil granulocytic differentiation and innate immunity development, dissects the biology of GCSF in myeloid expansion, highlights the shortcomings of GCSF in CCIN treatment, updates the recent advance of a selective retinoid agonist that promotes neutrophil granulocytic differentiation, and evaluates the benefits of developing GCSF biosimilars to increase access to GCSF biologics versus seeking a new mode to fundamentally advance GCSF therapy for treatment of CCIN.

The Comparison of The Efficacy and Safety of Original and Biosimilar Filgrastim in Prevention of Chemotherapy-Induced Neutropenia in Children with Cancer

Objective

In adults and children, the duration of chemotherapy-induced neutropenia and associated complications has decreased because of the prophylactic use of granulocyte colony-stimulating factors (G-CSFs). Biosimilar G-CSFs can play an important role in reducing treatment costs in daily practice. However, some concerns regarding the efficacy and safety of new biosimilar products exist among clinicians. This study compared the efficacy and safety of original and biosimilar filgrastims for the prophylaxis of chemotherapy-induced neutropenia in children.

Materials and Methods

Thirty children receiving myelosuppressive chemotherapy were enrolled in this study. Filgrastims (5 μg/kg/day) were subcutaneously administered in Group A (biosimilar, Leucostim®; Dem İlaç) and Group B (original drug, Neupogen®; Roche). Hemoglobin, white blood cell (WBC) count, platelet count, transfusion requirements, duration of hospitalization, and frequency and duration of adverse events including fever, neutropenia, and mucositis were evaluated following 25 treatment cycles in both groups.

Results

The hemoglobin value, WBC count, and platelet count on days 1, 5, and 10, and the red blood cell and platelet transfusion requirements, frequency, duration, and severity of mucositis, and durations of fever, febrile neutropenia, and hospitalization were similar in both groups. Although the mean WBC counts on days 1 and 5 were lower in Group A, the difference was statistically insignificant.

Conclusion

The biosimilar filgrastim, Leucostim, is as effective and safe as the original drug for prophylaxis of chemotherapy-induced neutropenia in children.

Impact on acute myeloid leukemia relapse in granulocyte colony-stimulating factor application: a meta-analysis

OBJECTIVES

This meta-analysis evaluated the impact of granulocyte colony-stimulating factor (G-CSF) added to chemotherapy on treatment outcomes including survival and disease recurrence in patients with acute myeloid leukemia (AML).

METHODS

Medline, Cochrane, EMBASE, and Google Scholar databases were searched until 19 September 2016 using search terms. Studies that investigated patients with AML who underwent stem-cell transplantation were included.

RESULTS

The overall analysis revealed a significant improvement in overall survival (OS) (P = .019) and disease-free survival (DFS) (P = .002) for patients receiving G-CSF with chemotherapy. Among patients without prior AML treatment, there was a significant improvement in DFS (P = .014) and reduction in incidence of relapse (P = .015) for those who received G-CSF. However, subgroup analyses found no significant difference between G-CSF (+) and G-CSF (-) treatments in rates of OS (P = .104) and complete remission (CR) (P = .572) for patients without prior AML treatment. Among patients with relapsed/refractory AML, there was no significant difference found between G-CSF (+) and G-CSF (-) groups for OS (P = .225), DFS (P = .209), and CR (P = .208).

DISCUSSION

Treatment with chemotherapy plus G-CSF appears to provide better survival and treatment responses compared with chemotherapy alone, particularly for patients with previously untreated AML.

ABBREVIATIONS

AML, acute myeloid leukemia; CI, confidence interval; CR, complete remission; DFS, disease-free survival; G-CSF, granulocyte colony-stimulating factor; GM-CSF, granulocyte macrophage colony-stimulating factor; HR, hazard ratio; MDS, myelodysplastic syndrome; OR, odds ratio; OS, overall survival; RCTs, randomized control trials; RR, relative risk.

Effect of Nigella sativa seed administration on prevention of febrile neutropenia during chemotherapy among children with brain tumors

PURPOSE

Seeds of Nigella sativa (NS) are used to combat various disease conditions through their antibacterial effects. To evaluate the seeds' potential, we studied their effect on the prevention of febrile neutropenia (FN) in children with brain tumors.

METHODS

A randomized pretest-post-test control group study including 80 children (2-18 years) with brain tumors undergoing chemotherapy were equally allocated into two groups. Intervention group received 5 g of NS seeds daily throughout treatment while controls received nothing. CBC with differentials, incidence of FN, and LOS were noted on each follow-up.

RESULTS

The majority of children 38/40 (95%), of the intervention group, took the seeds for 3-9 consecutive months. Eight out of 372 (2.2%) FN episodes were experienced by children of intervention group compared to controls 63/327 (19.3%) (p = 0.001) and a shorter LOS (median = 2.5 days) vs 5 days in the control group (p = 0.006). Children in both groups belonged to almost same geographical area with similar socio-economic background. Weights of children were almost equal at diagnosis.

CONCLUSION

NS seeds showed a decrease in incidence of FN in children with brain tumors with shortening of subsequent LOS which may improve their outcome and thereby quality of life. Larger scale studies are needed to further evaluate the seeds' potential.

Risk Factors for Febrile Neutropenia in Children With Solid Tumors Treated With Cisplatin-based Chemotherapy

Febrile neutropenia (FN) is a common and potentially fatal adverse drug reaction of cisplatin-based chemotherapy (CDDPBC) in pediatric patients. Hence, the aim of this study was to determine the incidence and independent risk factors for FN in pediatric patients with solid tumors treated with CDPPBC. Cohort integration was performed in the first cycle of chemotherapy with CDDPBC and patients were followed up to 6 months after the last cycle. FN was defined according to the Common Terminology Criteria for Adverse Events. Relative risks were calculated with confidence intervals at 95% (95% CI) to determine FN risk factors. Multiple logistic regression was performed to identify independent risk factors. One hundred and thirty-nine pediatric patients (median age 7.4 y, range 0.08 to 17 y) were included in the study. FN incidence was 62.5%. Independent risk factors for FN were chemotherapy regimens including anthracyclines (odds ratio [OR]=19.44 [95% CI, 5.40-70.02), hypomagnesaemia (OR=8.20 [95% CI, 1.81-37.14]), and radiotherapy (OR=6.67 [95% CI, 1.24-35.94]). It is therefore concluded that anthracyclines-containing regimens, hypomagnesaemia, and radiotherapy are independent risk factors for FN in patients receiving CDDPBC.

Enhanced and Secretory Expression of Human Granulocyte Colony Stimulating Factor by Bacillus subtilis SCK6

This study describes a simplified approach for enhanced expression and secretion of a pharmaceutically important human cytokine, that is, granulocyte colony stimulating factor (GCSF), in the culture supernatant of Bacillus subtilis SCK6 cells. Codon optimized GCSF and pNWPH vector containing SpymwC signal sequence were amplified by prolonged overlap extension PCR to generate multimeric plasmid DNA, which was used directly to transform B. subtilis SCK6 supercompetent cells. Expression of GCSF was monitored in the culture supernatant for 120 hours. The highest expression, which corresponded to 17% of the total secretory protein, was observed at 72 hours of growth. Following ammonium sulphate precipitation, GCSF was purified to near homogeneity by fast protein liquid chromatography on a QFF anion exchange column. Circular dichroism spectroscopic analysis showed that the secondary structure contents of the purified GCSF are similar to the commercially available GCSF. Biological activity, as revealed by the regeneration of neutrophils in mice treated with ifosfamine, was also similar to the commercial preparation of GCSF. This, to our knowledge, is the first study that reports secretory expression of human GCSF in B. subtilis SCK6 with final recovery of up to 96 mg/L of the culture supernatant, without involvement of any chemical inducer.

Prophylactic antibiotics or G(M)-CSF for the prevention of infections and improvement of survival in cancer patients receiving myelotoxic chemotherapy

BACKGROUND

Febrile neutropenia (FN) and other infectious complications are some of the most serious treatment-related toxicities of chemotherapy for cancer, with a mortality rate of 2% to 21%. The two main types of prophylactic regimens are granulocyte (macrophage) colony-stimulating factors (G(M)-CSF) and antibiotics, frequently quinolones or cotrimoxazole. Current guidelines recommend the use of colony-stimulating factors when the risk of febrile neutropenia is above 20%, but they do not mention the use of antibiotics. However, both regimens have been shown to reduce the incidence of infections. Since no systematic review has compared the two regimens, a systematic review was undertaken.

OBJECTIVES

To compare the efficacy and safety of G(M)-CSF compared to antibiotics in cancer patients receiving myelotoxic chemotherapy.

SEARCH METHODS

We searched The Cochrane Library, MEDLINE, EMBASE, databases of ongoing trials, and conference proceedings of the American Society of Clinical Oncology and the American Society of Hematology (1980 to December 2015). We planned to include both full-text and abstract publications. Two review authors independently screened search results.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing prophylaxis with G(M)-CSF versus antibiotics for the prevention of infection in cancer patients of all ages receiving chemotherapy. All study arms had to receive identical chemotherapy regimes and other supportive care. We included full-text, abstracts, and unpublished data if sufficient information on study design, participant characteristics, interventions and outcomes was available. We excluded cross-over trials, quasi-randomised trials and post-hoc retrospective trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the results of the search strategies, extracted data, assessed risk of bias, and analysed data according to standard Cochrane methods. We did final interpretation together with an experienced clinician.

MAIN RESULTS

In this updated review, we included no new randomised controlled trials. We included two trials in the review, one with 40 breast cancer patients receiving high-dose chemotherapy and G-CSF compared to antibiotics, a second one evaluating 155 patients with small-cell lung cancer receiving GM-CSF or antibiotics.We judge the overall risk of bias as high in the G-CSF trial, as neither patients nor physicians were blinded and not all included patients were analysed as randomised (7 out of 40 patients). We considered the overall risk of bias in the GM-CSF to be moderate, because of the risk of performance bias (neither patients nor personnel were blinded), but low risk of selection and attrition bias.For the trial comparing G-CSF to antibiotics, all cause mortality was not reported. There was no evidence of a difference for infection-related mortality, with zero events in each arm. Microbiologically or clinically documented infections, severe infections, quality of life, and adverse events were not reported. There was no evidence of a difference in frequency of febrile neutropenia (risk ratio (RR) 1.22; 95% confidence interval (CI) 0.53 to 2.84). The quality of the evidence for the two reported outcomes, infection-related mortality and frequency of febrile neutropenia, was very low, due to the low number of patients evaluated (high imprecision) and the high risk of bias.There was no evidence of a difference in terms of median survival time in the trial comparing GM-CSF and antibiotics. Two-year survival times were 6% (0 to 12%) in both arms (high imprecision, low quality of evidence). There were four toxic deaths in the GM-CSF arm and three in the antibiotics arm (3.8%), without evidence of a difference (RR 1.32; 95% CI 0.30 to 5.69; P = 0.71; low quality of evidence). There were 28% grade III or IV infections in the GM-CSF arm and 18% in the antibiotics arm, without any evidence of a difference (RR 1.55; 95% CI 0.86 to 2.80; P = 0.15, low quality of evidence). There were 5 episodes out of 360 cycles of grade IV infections in the GM-CSF arm and 3 episodes out of 334 cycles in the cotrimoxazole arm (0.8%), with no evidence of a difference (RR 1.55; 95% CI 0.37 to 6.42; P = 0.55; low quality of evidence). There was no significant difference between the two arms for non-haematological toxicities like diarrhoea, stomatitis, infections, neurologic, respiratory, or cardiac adverse events. Grade III and IV thrombopenia occurred significantly more frequently in the GM-CSF arm (60.8%) compared to the antibiotics arm (28.9%); (RR 2.10; 95% CI 1.41 to 3.12; P = 0.0002; low quality of evidence). Neither infection-related mortality, incidence of febrile neutropenia, nor quality of life were reported in this trial.

AUTHORS' CONCLUSIONS

As we only found two small trials with 195 patients altogether, no conclusion for clinical practice is possible. More trials are necessary to assess the benefits and harms of G(M)-CSF compared to antibiotics for infection prevention in cancer patients receiving chemotherapy.

Recommendations for the Use of WBC Growth Factors: American Society of Clinical Oncology Clinical Practice Guideline Update

PURPOSE

To update the 2006 American Society of Clinical Oncology guideline on the use of hematopoietic colony-stimulating factors (CSFs).

METHODS

The American Society of Clinical Oncology convened an Update Committee and conducted a systematic review of randomized clinical trials, meta-analyses, and systematic reviews from October 2005 through September 2014. Guideline recommendations were based on the review of the evidence by the Update Committee.

RESULTS

Changes to previous recommendations include the addition of tbo-filgrastim and filgrastim-sndz, moderation of the recommendation regarding routine use of CSFs in older patients with diffuse aggressive lymphoma, and addition of recommendations against routine dose-dense chemotherapy in lymphoma and in favor of high-dose-intensity chemotherapy in urothelial cancer. The Update Committee did not address recommendations regarding use of CSFs in acute myeloid leukemia or myelodysplastic syndromes in adults.

RECOMMENDATIONS

Prophylactic use of CSFs to reduce the risk of febrile neutropenia is warranted when the risk of febrile neutropenia is approximately 20% or higher and no other equally effective and safe regimen that does not require CSFs is available. Primary prophylaxis is recommended for the prevention of febrile neutropenia in patients who are at high risk on the basis of age, medical history, disease characteristics, and myelotoxicity of the chemotherapy regimen. Dose-dense regimens that require CSFs should only be used within an appropriately designed clinical trial or if supported by convincing efficacy data. Current recommendations for the management of patients exposed to lethal doses of total-body radiotherapy, but not doses high enough to lead to certain death as a result of injury to other organs, include the prompt administration of CSFs.

A comparison of international guidelines for the prevention of chemotherapy-induced neutropenia

PURPOSE OF REVIEW

Clinical practice guidelines for the prevention of febrile neutropenia in patients receiving cancer chemotherapy utilizing the myeloid growth factors have been developed by several major international professional organizations. This review provides updates on the current status of these guidelines and summarizes recent reported studies currently under review by guideline panels which may alter guideline recommendations.

RECENT FINDINGS

Whereas the consensus guidelines from the National Comprehensive Cancer Network (NCCN) are updated annually, previous evidence-based recommendations from the American Society of Clinical Oncology (ASCO) and the European Organisation for Research and Treatment of Cancer (EORTC) are currently undergoing an update in their evidence base and recommendations. These updates will consider and base new recommendations on recent important studies related to the efficacy, safety, and cost of these agents in the prevention of neutropenic complications including febrile neutropenia. New information relating to the risk of second malignancies and the ability of the myeloid growth factors to sustain or increase chemotherapy dose intensity and improve overall survival is reviewed.

SUMMARY

Current guideline recommendations for the prevention of febrile neutropenia are reviewed along with recent published results likely to alter future guideline recommendations on the use of these agents.

Controlled release of granulocyte colony-stimulating factor enhances osteoconductive and biodegradable properties of Beta-tricalcium phosphate in a rat calvarial defect model

Autologous bone grafts remain the gold standard for the treatment of congenital craniofacial disorders; however, there are potential problems including donor site morbidity and limitations to the amount of bone that can be harvested. Recent studies suggest that granulocyte colony-stimulating factor (G-CSF) promotes fracture healing or osteogenesis. The purpose of the present study was to investigate whether topically applied G-CSF can stimulate the osteoconductive properties of beta-tricalcium phosphate (β-TCP) in a rat calvarial defect model. A total of 27 calvarial defects 5 mm in diameter were randomly divided into nine groups, which were treated with various combinations of a β-TCP disc and G-CSF in solution form or controlled release system using gelatin hydrogel. Histologic and histomorphometric analyses were performed at eight weeks postoperatively. The controlled release of low-dose (1 μg and 5 μg) G-CSF significantly enhanced new bone formation when combined with a β-TCP disc. Moreover, administration of 5 μg G-CSF using a controlled release system significantly promoted the biodegradable properties of β-TCP. In conclusion, the controlled release of 5 μg G-CSF significantly enhanced the osteoconductive and biodegradable properties of β-TCP. The combination of G-CSF slow-release and β-TCP is a novel and promising approach for treating pediatric craniofacial bone defects.

Expression and purification of recombinant human granulocyte colony-stimulating factor in fed-batch culture of Escherichia coli

Granulocyte colony-stimulating factor (G-CSF) is a cytokine that has multiple roles in hematopoietic cells such as the regulation of proliferation and differentiation. Here, we describe fed-batch culture, refolding, and purification of rhG-CSF. The suitability of urea or sarcosine for solubilizing inclusion bodies (IBs) was tested. It was observed that urea is more efficient for solubilizing and refolding IBs than sarcosine is. The purity of rhG-CSF and the removal percentage of the rhG-CSF isoforms during purification were increased by pH 5.5 precipitation. The purity and the yield of purified rhG-CSF were 99% and 0.5 g of protein per liter culture broth, respectively. Our protocols of recombinant protein purification using ion exchange chromatography and semipreparative high performance liquid chromatography of pH-precipitated refolded solution may be informative to the industrial scale production of biopharmaceuticals.

Simplified large-scale refolding, purification, and characterization of recombinant human granulocyte-colony stimulating factor in Escherichia coli

Granulocyte-colony stimulating factor (G-CSF) is a pleiotropic cytokine that stimulates the development of committed hematopoietic progenitor cells and enhances the functional activity of mature cells. Here, we report a simplified method for fed-batch culture as well as the purification of recombinant human (rh) G-CSF. The new system for rhG-CSF purification was performed using not only temperature shift strategy without isopropyl-l-thio-β-d-galactoside (IPTG) induction but also the purification method by a single step of prep-HPLC after the pH precipitation of the refolded samples. Through these processes, the final cell density and overall yield of homogenous rhG-CSF were obtained 42.8 g as dry cell weights, 1.75 g as purified active proteins, from 1 L culture broth, respectively. The purity of rhG-CSF was finally 99% since the isoforms of rhG-CSF could be separated through the prep-HPLC step. The result of biological activity indicated that purified rhG-CSF has a similar profile to the World Health Organization (WHO) 2^nd International Standard for G-CSF. Taken together, our results demonstrate that the simple purification through a single step of prep-HPLC may be valuable for the industrial-scale production of biologically active proteins.

Comparison of filgrastim and lenograstim in pediatric solid tumors

PURPOSE

Chemotherapy-induced febrile neutropenia (FEN), which causes treatment delays or chemotherapy dose reductions, is a serious side effect of cancer treatment. In Turkey, recombinant G-CSF (rG-CSF) has been used since 2000 to control neutropenia. The purpose of this prospective randomized study is to compare the effectiveness, toxicities and the cost of these two drugs in children.

METHODS

Between April and December 2008, 29 patients were administered 40 courses of chemotherapy in each arm. A randomized crossover study was designed. All patients were administered rG-CSF 24 hours after the last day of chemotherapy as a secondary prophylaxis. Complete blood counts as well as peripheral blood progenitor (CD34+) cell levels were measured before G-CSF treatment and on the fifth and the seventh day of treatment.

RESULTS

The median duration of neutropenia, FEN, the length of hospitalization, the incidence of FEN, and documented infection was not different between the two rG-CSF treatment groups. Erythrocyte and platelet transfusion rates were also similar. After 7 days, the mean leukocyte (WBC [white blood cell]) and neutrophil count (ANC [absolute neutrophil count]), hemoglobin and platelet levels were not significantly different. However, the CD34+ cell level was significantly higher in the lenograstim group. Lenograstim was also more expensive than filgrastim. No serious side effects were reported for either rG-CSF treatment.

CONCLUSIONS

There is no difference following the administration of either lenograstim or filgrastim for the duration of neutropenia, FEN or hospitalization for pediatric cancer patients. For stem cell mobilization, lenograstim was superior to filgrastim.

Serious medical complications in children with cancer and fever in chemotherapy-induced neutropenia: results of the prospective multicenter SPOG 2003 FN study

BACKGROUND

Fever and chemotherapy-induced neutropenia (FN) is the most frequent potentially lethal complication of therapy in children with cancer. This study aimed to describe serious medical complications (SMC) in children with FN regarding incidence, clinical spectrum, and associated characteristics.

PROCEDURE

Pediatric patients presenting with FN induced by non-myeloablative chemotherapy were observed in a prospective multicenter study. SMC was defined as potentially life-threatening complication (PLTC), transfer to the pediatric intensive care unit (PICU), or death.

RESULTS

A total of 443 FN episodes were reported from 8 centers. Of these, 411 episodes were reported from 4 centers recruiting consecutively and without bias regarding the risk of complications. They were used for calculation of proportions. An SMC was reported in 23 episodes [5.6%; 95% confidence interval (CI): 3.7-8.1], usually defined by more than one criterion. These were PLTC in 13 episodes, PICU in 22, and death in 3 (mortality, 0.7%; 95% CI: 0.2-2.1). Both a delayed onset of SMC (14 of 23 episodes, 61%) and a biphasic clinical course (11 of 23, 48%) were frequently observed. In a multivariate logistic regression analysis, 4 characteristics were significantly and independently associated with the risk of SMC: diagnosis of acute myeloid leukemia, interval since chemotherapy ≤7 days, severely reduced general condition, and hemoglobin ≥9.0 g/dl at presentation.

CONCLUSIONS

In children with FN, SMC were rare, and mortality was very low. Those with SMC often had a delayed onset and biphasic clinical course with secondary deterioration.

ICRP publication 118: ICRP statement on tissue reactions and early and late effects of radiation in normal tissues and organs--threshold doses for tissue reactions in a radiation protection context

This report provides a review of early and late effects of radiation in normal tissues and organs with respect to radiation protection. It was instigated following a recommendation in Publication 103 (ICRP, 2007), and it provides updated estimates of 'practical' threshold doses for tissue injury defined at the level of 1% incidence. Estimates are given for morbidity and mortality endpoints in all organ systems following acute, fractionated, or chronic exposure. The organ systems comprise the haematopoietic, immune, reproductive, circulatory, respiratory, musculoskeletal, endocrine, and nervous systems; the digestive and urinary tracts; the skin; and the eye. Particular attention is paid to circulatory disease and cataracts because of recent evidence of higher incidences of injury than expected after lower doses; hence, threshold doses appear to be lower than previously considered. This is largely because of the increasing incidences with increasing times after exposure. In the context of protection, it is the threshold doses for very long follow-up times that are the most relevant for workers and the public; for example, the atomic bomb survivors with 40-50years of follow-up. Radiotherapy data generally apply for shorter follow-up times because of competing causes of death in cancer patients, and hence the risks of radiation-induced circulatory disease at those earlier times are lower. A variety of biological response modifiers have been used to help reduce late reactions in many tissues. These include antioxidants, radical scavengers, inhibitors of apoptosis, anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, growth factors, and cytokines. In many cases, these give dose modification factors of 1.1-1.2, and in a few cases 1.5-2, indicating the potential for increasing threshold doses in known exposure cases. In contrast, there are agents that enhance radiation responses, notably other cytotoxic agents such as antimetabolites, alkylating agents, anti-angiogenic drugs, and antibiotics, as well as genetic and comorbidity factors. Most tissues show a sparing effect of dose fractionation, so that total doses for a given endpoint are higher if the dose is fractionated rather than when given as a single dose. However, for reactions manifesting very late after low total doses, particularly for cataracts and circulatory disease, it appears that the rate of dose delivery does not modify the low incidence. This implies that the injury in these cases and at these low dose levels is caused by single-hit irreparable-type events. For these two tissues, a threshold dose of 0.5Gy is proposed herein for practical purposes, irrespective of the rate of dose delivery, and future studies may elucidate this judgement further.

Soluble periplasmic production of human granulocyte colony-stimulating factor (G-CSF) in Pseudomonas fluorescens

Cost-effective production of soluble recombinant protein in a bacterial system remains problematic with respect to expression levels and quality of the expressed target protein. These constraints have particular meaning today as "biosimilar" versions of innovator protein drugs are entering the clinic and the marketplace. A high throughput, parallel processing approach to expression strain engineering was used to evaluate soluble expression of human granulocyte colony-stimulating factor (G-CSF) in Pseudomonas fluorescens. The human g-csf gene was optimized for expression in P. fluorescens and cloned into a set of periplasmic expression vectors. These plasmids were transformed into a variety of P. fluorescens host strains each having a unique phenotype, to evaluate soluble expression in a 96-well growth and protein expression format. To identify a strain producing high levels of intact, soluble Met-G-CSF product, more than 150 protease defective host strains from the Pfēnex Expression Technology™ toolbox were screened in parallel using biolayer interferometry (BLI) to quantify active G-CSF binding to its receptor. A subset of these strains was screened by LC-MS analysis to assess the quality of the expressed G-CSF protein. A single strain with an antibiotic resistance marker insertion in the pfaI gene was identified that produced>99% Met-GCSF. A host with a complete deletion of the autotransporter-coding gene pfaI from the genome was constructed, and expression of soluble, active Met-GSCF in this strain was observed to be 350mg/L at the 1 liter fermentation scale.

Acute myeloid leukemia or myelodysplastic syndrome in randomized controlled clinical trials of cancer chemotherapy with granulocyte colony-stimulating factor: a systematic review

PURPOSE

To evaluate the risk of acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) and overall mortality in patients receiving chemotherapy with or without granulocyte colony-stimulating factor (G-CSF), a systematic review of randomized controlled trials (RCTs) was conducted.

METHODS

Electronic databases searched through October 2008 identified 3,794 articles for initial screening. Eligibility included solid tumor or lymphoma patients randomly assigned to chemotherapy with or without G-CSF support, > or = 2 years of follow-up, and reporting AML/MDS or all second malignancies. Dual blinded data extraction was performed. Relative risk (RR) and absolute risk (AR) estimates +/- 95% CIs were calculated by the Mantel-Haenszel method.

RESULTS

In the 25 eligible RCTs, 6,058 and 6,746 patients were randomly assigned to receive chemotherapy with and without initial G-CSF support, respectively. At mean and median follow-up across studies of 60 and 53 months, respectively, AML/MDS was reported in 22 control patients and 43 G-CSF-treated patients, with an estimated RR of 1.92 (95% CI, 1.19 to 3.07; P = .007) and AR increase of 0.41% (95% CI, 0.10% to 0.72%; P = .009). Deaths were reported in 1,845 patients randomly assigned to G-CSF and in 2,099 controls, for estimates of RR and AR decrease of 0.897 (95% CI, 0.857 to 0.938; P < .001) and 3.40% (95% CI, 2.01% to 4.80%; P < .001), respectively. Greater RR reduction for mortality was seen for both larger studies (P = .05) and greater chemotherapy dose-intensity (P = .012).

CONCLUSION

Delivered chemotherapy dose-intensity and risk of AML/MDS are increased but all-cause mortality is decreased in patients receiving chemotherapy with G-CSF support. Greater reductions in mortality were observed with greater chemotherapy dose-intensity.

Prophylactic antibiotics or G-CSF for the prevention of infections and improvement of survival in cancer patients undergoing chemotherapy

BACKGROUND

Febrile neutropenia (FN) and other infectious complications are some of the most serious treatment-related toxicities of chemotherapy for cancer, with a mortality rate of 2% to 21%. The two main types of prophylactic regimens are granulocyte (G-CSF) or granulocyte-macrophage colony stimulating factors (GM-CSF); and antibiotics, frequently quinolones or cotrimoxazole. Important current guidelines recommend the use of colony stimulating factors when the risk of febrile neutropenia is above 20% but they do not mention the use of antibiotics. However, both regimens have been shown to reduce the incidence of infections. Since no systematic review has compared the two regimens, a systematic review was undertaken.

OBJECTIVES

To compare the effectiveness of G-CSF or GM-CSF with antibiotics in cancer patients receiving myeloablative chemotherapy with respect to preventing fever, febrile neutropenia, infection, infection-related mortality, early mortality and improving quality of life.

SEARCH STRATEGY

We searched The Cochrane Library, MEDLINE, EMBASE, databases of ongoing trials, and conference proceedings of the American Society of Clinical Oncology and the American Society of Hematology (1980 to 2007). We planned to include both full-text and abstract publications.

SELECTION CRITERIA

Randomised controlled trials comparing prophylaxis with G-CSF or GM-CSF versus antibiotics in cancer patients of all ages receiving chemotherapy or bone marrow or stem cell transplantation were included for review. Both study arms had to receive identical chemotherapy regimes and other supportive care.

DATA COLLECTION AND ANALYSIS

Trial eligibility and quality assessment, data extraction and analysis were done in duplicate. Authors were contacted to obtain missing data.

MAIN RESULTS

We included two eligible randomised controlled trials with 195 patients. Due to differences in the outcomes reported, the trials could not be pooled for meta-analysis. Both trials showed non-significant results favouring antibiotics for the prevention of fever or hospitalisation for febrile neutropenia.

AUTHORS' CONCLUSIONS

There is no evidence for or against antibiotics compared to G(M)-CSFs for the prevention of infections in cancer patients.

Human granulocyte colony stimulating factor (hG-CSF): cloning, overexpression, purification and characterization

Background

Biopharmaceutical drugs are mainly recombinant proteins produced by biotechnological tools. The patents of many biopharmaceuticals have expired, and biosimilars are thus currently being developed. Human granulocyte colony stimulating factor (hG-CSF) is a hematopoietic cytokine that acts on cells of the neutrophil lineage causing proliferation and differentiation of committed precursor cells and activation of mature neutrophils. Recombinant hG-CSF has been produced in genetically engineered Escherichia coli (Filgrastim) and successfully used to treat cancer patients suffering from chemotherapy-induced neutropenia. Filgrastim is a 175 amino acid protein, containing an extra N-terminal methionine, which is needed for expression in E. coli. Here we describe a simple and low-cost process that is amenable to scaling-up for the production and purification of homogeneous and active recombinant hG-CSF expressed in E. coli cells.

Results

Here we describe cloning of the human granulocyte colony-stimulating factor coding DNA sequence, protein expression in E. coli BL21(DE3) host cells in the absence of isopropyl-β-D-thiogalactopyranoside (IPTG) induction, efficient isolation and solubilization of inclusion bodies by a multi-step washing procedure, and a purification protocol using a single cationic exchange column. Characterization of homogeneous rhG-CSF by size exclusion and reverse phase chromatography showed similar yields to the standard. The immunoassay and N-terminal sequencing confirmed the identity of rhG-CSF. The biological activity assay, in vivo, showed an equivalent biological effect (109.4%) to the standard reference rhG-CSF. The homogeneous rhG-CSF protein yield was 3.2 mg of bioactive protein per liter of cell culture.

Conclusion

The recombinant protein expression in the absence of IPTG induction is advantageous since cost is reduced, and the protein purification protocol using a single chromatographic step should reduce cost even further for large scale production. The physicochemical, immunological and biological analyses showed that this protocol can be useful to develop therapeutic bioproducts. In summary, the combination of different experimental strategies presented here allowed an efficient and cost-effective protocol for rhG-CSF production. These data may be of interest to biopharmaceutical companies interested in developing biosimilars and healthcare community.

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.