A multicenter, prospective, non-interventional real-world study to assess the effectiveness of mecapegfilgrastim in preventing neutropenia in patients with gastrointestinal cancer

BACKGROUND

Mecapegfilgrastim, a long-acting granulocyte-colony stimulating factor has been approved for reducing the incidence of infection, particularly febrile neutropenia (FN), in China.

OBJECTIVE

We conducted a multicenter prospective observational study to examine the safety and effectiveness of mecapegfilgrastim in preventing neutropenia in gastrointestinal patients receiving the chemotherapy, including S-1/capecitabine-based regimens or the fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI)/fluorouracil, leucovorin, and oxaliplatin (FOLFOX)/fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFIRINOX) regimens.

METHOD

Five hundred and sixty-one gastrointestinal patients from 40 sites across China, between May 2019 and November 2021, were included. The administration of mecapegfilgrastim was prescribed at the discretion of local physicians.

RESULTS

The most common adverse drug reactions (ADRs) of any grade for all patients was increased white blood cells (2.9%). Grade 3/4 ADRs were observed for anemia (0.2%), decreased white blood cells (0.2%), and decreased neutrophil count (0.2%). Among the 116 patients who received S-1/capecitabine-based chemotherapy throughout all cycles, ADRs of any grade included anemia (1.7%), myalgia (0.9%), and increased alanine aminotransferase (0.9%). No grade 3/4 ADRs were observed. In 414 cycles of patients who underwent S-1/capecitabine-based regimens, only one (0.2%) cycle experienced grade 4 neutropenia. In the FOLFIRINOX, FOLFOXIRI, and FOLFOX chemotherapy regimens, grade 4 neutropenia occurred in one (2.7%) of 37 cycles, four (4.7%) of 85 cycles, and two (1.2%) of 167 cycles, respectively.

CONCLUSION

In a real-world setting, mecapegfilgrastim has proven effective in preventing severe neutropenia in gastrointestinal patients following chemotherapy. This includes commonly used moderate or high-risk FN regimens or regimens containing S1/capecitabine, all of which have demonstrated favorable efficacy and safety profiles.

Prescription patterns of granulocyte colony-stimulating factors in patients with breast cancer: A real-world study

BACKGROUND AND OBJECTIVES

Myelosuppressive chemotherapy is effective for breast cancer but carries a potential risk of febrile neutropenia (FN). Clinical practice guidelines have recommended prophylaxis with granulocyte colony-stimulating factor (G-CSF) to reduce the incidence of FN in patients receiving chemotherapy. We aimed to examine the use of G-CSFs for primary prophylaxis for FN and to see whether it follows the guidelines. In addition, we examined the changes in the use of long-acting and short-acting G-CSFs in patients with breast cancer over the past ten years.

METHODS

This was a retrospective observational real-world study. The data were obtained from the clinical research database of three hospitals affiliated with Taipei Medical University. Patients with breast cancer who initiated their first chemotherapy regimen between January 1, 2011, and December 31, 2020, were identified by the ICD codes and their use of filgrastim or pegfilgrastim was identified by the Anatomical Therapeutic Chemical codes. Whether and how G-CSF was prescribed during the study patients' first chemotherapy regimen was examined, and the annual change in the total number of short- and long-acting G-CSFs prescribed to the study patients from 2011 to 2020 was analyzed.

RESULTS

Among the 2,444 patients who were prescribed at least one of the examined 15 breast cancer chemotherapy drugs, 1,414 did not use any G-CSFs during their first chemotherapy regimen while 145 used G-CSFs for primary prophylaxis and 185 for treatment. Among the patients receiving high FN risk regimens, only 8.6% used G-CSF for primary prophylaxis. The average (± SD) number of days for short-acting G-CSF use was 2.3 (± 1.5) days with a median of 2 days. In addition, it was found that there was a significant reduction in long-acting G-CSF use (p = 0.03) whereas the changes in short-acting G-CSF use over time were not significant (p = 0.50).

CONCLUSIONS

Our study results show that G-CSFs are used for primary prophylaxis in a small percentage of patients with breast cancer and the duration of short-acting G-CSF use is relatively short. Considering the significant clinical and economic impact of FN, it is hoped that the prescription patterns of G-CSFs observed can provide an important reference for future clinical practice and reimbursement policy.

New insight into strategies used to develop long-acting G-CSF biologics for neutropenia therapy

Over the last 20 years, granulocyte colony-stimulating factors (G-CSFs) have become the major therapeutic option for the treatment of patients with neutropenia. Most of the current G-CSFs require daily injections, which are inconvenient and expensive for patients. Increased understanding of G-CSFs' structure, expression, and mechanism of clearance has been very instrumental in the development of new generations of long-acting G-CSFs with improved efficacy. Several approaches to reducing G-CSF clearance via conjugation techniques have been investigated. PEGylation, glycosylation, polysialylation, or conjugation with immunoglobulins or albumins have successfully increased G-CSFs' half-lives. Pegfilgrastim (Neulasta) has been successfully approved and marketed for the treatment of patients with neutropenia. The rapidly expanding market for G-CSFs has increased demand for G-CSF biosimilars. Therefore, the importance of this review is to highlight the principle, elimination's route, half-life, clearance, safety, benefits, and limitations of different strategies and techniques used to increase the half-life of biotherapeutic G-CSFs. Understanding these strategies will allow for a new treatment with more competitive manufacturing and lower unit costs compared with that of Neulasta.

Phase I/II study to assess the clinical pharmacology and safety of single ascending and multiple subcutaneous doses of PF-06881894 in women with non-distantly metastatic breast cancer

PURPOSE

To evaluate the pharmacodynamics (PD), pharmacokinetics (PK), and safety of single and multiple doses of PF-06881894 (pegfilgrastim-apgf; Nyvepria™), a biosimilar to reference pegfilgrastim (Neulasta®), in women with non-distantly metastatic breast cancer.

METHODS

In Phase I (Cycle 0) of this Phase I/II study, the PD response (absolute neutrophil count [ANC]; CD34 + count), PK profile, and safety of a single 3- or 6-mg subcutaneous dose of PF-06881894 were assessed in chemotherapy-naïve patients before definitive breast surgery. In Phase II (Cycles 1-4), the PD response (duration of severe neutropenia [DSN, Cycle 1], ANC [Cycles 1 and 4]) and PK profile (Cycles 1 and 4) of single and multiple 6-mg doses of PF-06881894 concomitant with chemotherapy and after definitive breast surgery were assessed.

RESULTS

Twenty-five patients (mean age 59 years) were enrolled (Cycle 0, n = 12; Cycles 1-4, n = 13). In Cycle 0, PD responses and PK values were lower with 3-mg versus 6-mg PF-06881894. In Cycles 1 and 4, mean DSN was 0.667 days after single or multiple 6-mg doses of PF-06881894, respectively. In Cycle 4 versus Cycle 1, PD responses were more robust; PK values (mean area under the curve, maximum concentration) were lower; and clearance values were higher. The safety profile of PF-06881894 was similar to that for reference pegfilgrastim.

CONCLUSION

PF-06881894 as a single 3- or 6-mg dose prior to definitive surgery, or multiple 6-mg/cycle doses postoperatively, with/without myelosuppressive chemotherapy, was consistent with the clinical pharmacology and safety profile of reference pegfilgrastim.

TRIAL REGISTRATION

October 2017. ClinicalTrials.gov Identifier: NCT02650193. EudraCT Number: 2015-002057-35.

Febrile neutropenia prophylaxis, G-CSF physician preferences: discrete-choice experiment

OBJECTIVES

Febrile neutropenia (FN) commonly occurs during cancer chemotherapy. Prophylaxis with granulocyte colony-stimulating factors (G-CSFs) is known to reduce the severity and incidence of FN and infections in patients with cancer. Despite the proven efficacy, G-CSFs are not always prescribed as recommended. We performed a discrete-choice experiment (DCE) to determine what factors drive the physician preference for FN prophylaxis in patients with cancer undergoing chemotherapy.

METHODS

Attributes for the DCE were selected based on literature search and on expert focus group discussions and comprised pain at the injection site, presence of bone pain, associated fever/influenza syndrome, efficacy of prophylaxis, biosimilar availability, number of injections per chemotherapy cycle and cost. Oncologists, in a national database, were solicited to participate in an online DCE. The study collected the responses to the choice scenarios, the oncologist characteristics and their usual prescriptions of G-CSFs in the context of breast, lungs and gastrointestinal cancers.

RESULTS

Overall, the responses from 205 physicians were analysed. The physicians were mainly male (61%), with ≤20 years of experience (76%) and working only in public hospitals (73%). The physicians prescribe G-CSF primary prophylaxis for 32% of patients: filgrastim in 46% and pegfilgrastim in 54%. The choice of G-CSF for primary and secondary prophylaxis was driven by cost and number of injections. Biosimilars were well accepted.

CONCLUSION

Cost and convenience of G-CSF drive the physician decision to prescribe or not G-CSF for primary and secondary FN prophylaxes. It is important that these results be incorporated in the optimisation of G-CSF prescription in the clinical setting.

Efficacy and Safety of Filgrastim and Its Biosimilars to Prevent Febrile Neutropenia in Cancer Patients: A Prospective Study and Meta-Analysis

Simple Summary

Febrile neutropenia is the serious side-effect associated with myelosuppressive chemotherapy. Filgrastim, the first granulocyte colony-stimulating factor (G-CSF) was approved by the Food and Drug Administration for the treatment of neutropenia. Subsequently, pegfilgrastim (long-acting G-CSF) and filgrastim biosimilars were developed to have comparable efficacy to filgrastim. Therefore, it is necessary to produce a systematic review and meta-analysis that provides evidence that filgrastim is more efficacious than placebo/no-treatment, as it provides evidence on the comparable efficacy of filgrastim versus pegfilgrastim and biosimilar filgrastim.

Abstract

Background: The aim of this review and meta-analysis was to identify, assess, meta-analyze and summarize the comparative effectiveness and safety of filgrastim in head-to-head trials with placebo/no treatment, pegfilgrastim (and biosimilar filgrastim to update advances in the field. Methods: The preferred reporting items for systematic reviews and meta-analyses PRISMA statement were applied, and a random-effect model was used. Primary endpoints were the rate and duration of grade 3 or 4 neutropenia, and an incidence rate of febrile neutropenia. Secondary endpoints were time to absolute neutrophil count ANC recovery, depth of ANC nadir (lowest ANC), neutropenia-related hospitalization and other neutropenia-related complications. For filgrastim versus biosimilar filgrastim comparison, the primary efficacy endpoint was the mean difference in duration of severe neutropenia DSN. Results: A total of 56 studies were considered that included data from 13,058 cancer patients. The risk of febrile neutropenia in filgrastim versus placebo/no treatment was not statistically different. The risk ratio for febrile neutropenia was 0.58, a 42% reduction in favor of filgrastim. The most reported adverse event with FIL was bone pain. For pegfilgrastim versus filgrastim, no statistically significant difference was noted. The risk ratio was 0.90 (95% CI 0.67 to 1.12). The overall difference in duration of severe neutropenia between filgrastim and biosimilar filgrastim was not statistically significant. The risk ratio was 1.03 (95% CI 0.93 to 1.13). Conclusions: Filgrastim was effective and safe in reducing febrile neutropenia and related complications, compared to placebo/no treatment. No notable differences were found between pegfilgrastim and filgrastim in terms of efficacy and safety. However, a similar efficacy profile was observed with FIL and its biosimilars.

Long-term patient reported outcomes and hematologic toxicity among patients who received Granulocyte-Colony Stimulating Factors during chemotherapy for early breast cancer

We assessed long-term associations of Granulocyte-Colony Stimulating Factors (G-CSF) use with patient-reported outcomes (PROs) and hematologic toxicity among chemotherapy-treated, early-stage breast cancer patients in CANTO (NCT01993498). Among 2920 patients longitudinally followed-up until year-4 after diagnosis, 49% used G-CSF. In multivariable-adjusted mixed-models, EORTC QLQ-C30 pain and summary score were not substantially different between groups (overall adjusted mean difference, use vs no-use [95%CI]: +1.27 [-0.33 to +2.87] and -1.01 [-1.98 to -0.04], respectively). PROs were slightly worse at year-4 among patients receiving G-CSF, although differences were of trivial clinical significance. No major differences were observed in leukocyte or platelet count over time.

Optimizing Dose-Adjusted EPOCH Chemotherapy with Long-Acting Granulocyte Colony-Stimulating Factor During the COVID-19 Epidemic

Introduction

Febrile neutropenia (FN) is a highly prevalent complication of chemotherapy. In this study, we aimed to evaluate the efficacy of polyethylene glycol recombinant granulocyte colony-stimulating factor (PEG-rhG-CSF) compared with short-acting rhG-CSF in the dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-EPOCH) regimen.

Patients and Methods

A total of 66 patients with newly diagnosed aggressive B-cell lymphomas who received the rituximab combined with DA-EPOCH regimen and G-CSF support after chemotherapy were included in this study, including 33 patients in the PEG-rhG-CSF group during coronavirus disease (COVID-19) epidemic and another 33 matched patients in short-acting rhG-CSF group as historic control.

Results

The incidence of FN and FN-related hospitalization was significantly lower in chemotherapy cycles using PEG-rhG-CSF than in those using short-acting rhG-CSF (FN incidence: 10.4% vs 20.2%, P=0.038; incidence of FN-related hospitalization: 1.7% vs 7.3%, P=0.042). Overall, the incidence of dose-escalation and dose-reduction of the DA-EPOCH regimen was similar between these two groups.

Conclusion

Our findings suggest that PEG-rhG-CSF as a substitute for short-acting rhG-CSF in the DA-EPOCH regimen significantly reduced the incidence of FN and FN-related hospitalization, while simplifying neutropenia management for both patients and healthcare providers.

Advances in the pharmacological management of neutropenia in solid tumors: the advent of biosimilars

Introduction: Severe neutropenia and infections are potentially life-threatening complications of cytotoxic antineoplastic therapies and often require hospitalization with a severe economic impact. Furthermore, hematological toxicity frequently results in chemotherapy dose reductions and delays that could interfere with disease control.Areas covered: This review provides an overview of granulocyte colony-stimulating factors (G-CSFs) including pegylated molecules, as well as more recent biosimilar G-CSFs, focusing on the toxicity, pharmacokinetics, and efficacy of these compounds.Expert opinion: The administration of hematopoietic growth factors in primary and secondary prophylaxis of neutropenia is a standard supportive care measure. Recently, several biosimilars have been developed. The market for biosimilar agents seems to be increasing over time thanks to their similar effectiveness and safety, compared with their originators, but lower costs.

[Pharmacokinetics and pharmacodynamics of pegylated recombinant human granulocyte colony-stimulating factor in children with acute lymphoblastic leukemia: a prospective control trial]

OBJECTIVE

To study the pharmacokinetic characteristics, clinical effect, and safety of pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) in children with acute lymphoblastic leukemia (ALL).

METHODS

A prospective study was performed on children with ALL who cyclophosphamide, cytarabine, and 6-mercaptopurine were used for consolidation therapy. PEG-rhG-CSF (PEG-rhG-CSF group) or rhG-CSF (rhG-CSF group) was injected after chemotherapy. The plasma concentration of PEG-rhG-CSF was measured, and clinical outcome and safety were observed for both groups.

RESULTS

A total of 17 children with ALL were enrolled, with 9 children in the PEG-rhG-CSF group and 8 children in the rhG-CSF group. In the PEG-rhG-CSF group, the peak concentration of PEG-rhG-CSF was 348.2 ng/mL (range 114.7-552.0 ng/mL), the time to peak was 48 hours (range 12-72 hours), and the half life was 14.1 hours (range 11.1-18.1 hours). The plasma concentration curve of PEG-rhG-CSF was consistent with the mechanism of neutrophil-mediated clearance. Compared with the rhG-CSF group, the PEG-rhG-CSF group had a significantly shorter median time to absolute neutrophil count (ANC) recovery (P<0.05). There were no significant differences between the two groups in ANC nadir, incidence rate of febrile neutropenia, duration of grade IV neutropenia, incidence rate of infection, and length of hospital stay. No bone pain or muscle soreness was observed in either group (P>0.05).

CONCLUSIONS

The pharmacokinetic characteristics of PEG-rhG-CSF in children with ALL receiving consolidation chemotherapy are consistent with the mechanism of neutrophil-mediated clearance, with a short half life and fast recovery of ANC, and there are no significant differences in safety between PEG-rhG-CSF and rhG-CSF.

Retrospective study evaluating the safety of administering pegfilgrastim on the final day of 5-fluorouracil continuous intravenous infusion

BACKGROUND

Pegfilgrastim, a long-acting granulocyte-colony-stimulating factor used to prevent neutropenia, is not indicated for administration within 24 h of completion of chemotherapy. The safety of administering pegfilgrastim in gastrointestinal cancer chemotherapy regimens containing continuous intravenous infusion of 5-fluorouracil (5-FUCI) on the day of completion of 5-fluorouracil has not been adequately studied.

METHODS

An institutional review board-approved retrospective analysis of patients with a gastrointestinal malignancy receiving pegfilgrastim on the final day of 5-FUCI was conducted. The primary end point was to determine the incidence of grade 3 and grade 4 neutropenia and febrile neutropenia when pegfilgrastim was administered on the final day of 5-FUCI. The secondary endpoint was to determine rate of dose reductions and treatment delays.

RESULTS

A total of 300 patients were reviewed from January 2010 to May 2017. The most common cancers were colorectal (25%) and pancreatic (60%), with 77% of patients having late stage disease. The risk of a patient developing grade 3 neutropenia was 0.010 (95% CI 0.002-0.029) and grade 4 neutropenia was 0.007 (95% CI 0.001-0.024). The risk of febrile neutropenia was 0.007 (95% CI 0.001-0.024). The risks of treatment delay and treatment reduction were 0.013 (95% CI 0.004-0.034) and 0.010 (95% CI 0.002-0.029), respectively.

CONCLUSION

The low risk of grade 3 and grade 4 neutropenia, febrile neutropenia, as well as dose delays and/or reduction suggests that pegfilgrastim can be administered on the final day of 5-FUCI. Limitations of this study were that it was retrospective in nature and was conducted at a single institution.

Pharmacokinetics and Pharmacodynamics of Two Formulations of Pegylated Recombinant Human Granulocyte Colony-Stimulating Factor in Healthy Chinese Subjects: An Open-Label, Randomized, Parallel-Design Bioavailability Study

Pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF, pegfilgrastim) is a long-acting derivative of recombinant human granulocyte colony-stimulating factor with limited renal clearance and a longer half-life. It is used for the prevention of febrile neutropenia, owing to its capacity to promote neutrophil recovery. In this study, the pharmacokinetics, pharmacodynamics, safety, and immunogenicity of 2 formulations of PEG-rhG-CSF were evaluated in healthy Chinese subjects. Twenty-four male subjects who received a single dose of subcutaneous PEG-rhG-CSF 100 µg/kg were randomized to either treatment A (3 mg/mL) or treatment B (1 mg/mL). Noncompartmental pharmacokinetic parameters of PEG-rhG-CSF were derived from serum concentration-time data. In addition, absolute neutrophil count (ANC) as a pharmacodynamic maker, immunogenicity through antidrug antibody testing, and safety were evaluated. The mean area under the concentration-time curve from time zero to the last quantifiable concentration (AUC_0-t ) and the mean maximum concentration (C_max ) of PEG-rhG-CSF after treatment A were 5070 ng·h/mL and 125 ng/mL, respectively; these values were comparable to those measured after treatment B (5340 ng·h/mL and 123 ng/mL, respectively). The mean value of area under the △ANC (baseline-adjusted ANC)-time curve and the maximum △ANC values were 4380 × 10⁹  h/L and 33.1 × 10⁹ /L, respectively, in the treatment A group, and 5170 × 10⁹  h/L and 38.6 × 10⁹ /L, respectively, in the treatment B group. The pharmacokinetic and pharmacodynamic profiles were similar for the 2 PEG-rhG-CSF formulations following a single dose of 100 µg/kg. The safety and immunogenicity profiles were also similar, with no significant differences. The dose adjustment of PEG-rhG-CSF was not considered necessary for formulation transformation.

Neutropenic complications in the PANTHER phase III study of adjuvant tailored dose-dense chemotherapy in early breast cancer

Introduction: Myelosuppresion is a common side effect of chemotherapy and granulocyte-colony stimulating factor (G-CSF) is often used to reduce the risk of neutropenic events. The purpose of this exploratory analysis was to investigate neutropenic complications in the phase III PANTHER trial of standard 3-weekly chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide plus docetaxel (FEC/D) versus bi-weekly tailored dose-dense EC/D adjuvant chemotherapy in breast cancer.Patients and methods: Febrile neutropenia, neutropenic infection and infection grade 3-4 according to CTC AE 3.0, were explored in relation to G-CSF use. Per cycle analysis was performed concerning dose reduction and dose delays in conjunction with G-CSF administration.Results: In the experimental group, 98.9% of patients received primary G-CSF support during EC and 97.4% during docetaxel, compared with 49.7% during FEC and 63.88% during docetaxel in the standard group. Overall, the use of G-CSF was associated with a lower risk for developing neutropenic events (OR 0.44, 95% CI 0.35-0.55, p < .001). Chemotherapy delays due to neutropenia and leukopenia were significantly decreased among patients that received G-CSF (OR 0.098, 95% CI 0.06-0.15 and OR 0.32, 95% CI 0.18-0.58, respectively).Discussion: In conclusion, G-CSF support reduces neutropenic events and permits increased relative dose intensity, which is essential for improved survival outcomes.

The prophylactic effects of long-acting granulocyte colony-stimulating factor for febrile neutropenia in newly diagnosed patients with epithelial ovarian cancer: a randomised controlled study

Objective

This study explored the prophylactic effects of long-acting granulocyte colony-stimulating factor (G-CSF) for febrile neutropenia (FN) in newly diagnosed patients with epithelial ovarian cancer (EOC).

Methods

Patients were randomised into a study group (long-acting G-CSF for all chemotherapy cycles) and a control group (short-acting G-CSF for first cycle and treatment per physician discretion for subsequent cycles) at a ratio of 1:2. The incidences of FN and myelosuppression and the number of clinical visits, medication doses, complete blood count (CBC) tests and adverse events were compared between the two groups. A regression model was used to determine the risk factors for FN.

Results

From 30 November 2018 to 1 April 2019, 84 cases were included in the final analysis; there were 24 (28.6%) and 60 (71.4%) patients in the study and control groups, respectively, and 605 chemotherapy cycles. The study group or chemotherapy cycles utilising long-acting G-CSF had significantly fewer utilisations and doses of short-acting G-CSF; clinical visits; CBC tests; and incidences of FN and myelosuppression; and less G-CSF-associated pain. The utilisation of G-CSF was the only independent factor for FN in a binary regression model.

Conclusion

Long-acting G-CSF could effectively reduce the incidences of FN and myelosuppression and had mild adverse effects in newly diagnosed patients with EOC receiving chemotherapy.

Trial registration number

NCT03740464.

Sensitivity of Pegfilgrastim Pharmacokinetic and Pharmacodynamic Parameters to Product Differences in Similarity Studies

In this work, a previously developed pegfilgrastim (PG) population pharmacokinetic-pharmacodynamic (PKPD) model was used to evaluate potential factors of importance in the assessment of PG PK and PD similarity. Absolute neutrophil count (ANC) was the modelled PD variable. A two-way cross-over study was simulated where a reference PG and a potentially biosimilar test product were administered to healthy volunteers. Differences in delivered dose amounts or potency between the products were simulated. A different baseline absolute neutrophil count (ANC) was also considered. Additionally, the power to conclude PK or PD similarity based on areas under the PG concentration-time curve (AUC) and ANC-time curve (AUEC) were calculated. Delivered dose differences between the products led to a greater than dose proportional differences in AUC but not in AUEC, respectively. A 10% dose difference from a 6 mg dose resulted in 51% and 7% differences in AUC and AUEC, respectively. These differences were more pronounced with low baseline ANC. Potency differences up to 50% were not associated with large differences in either AUCs or AUECs. The power to conclude PK similarity was affected by the simulated dose difference; with a 4% dose difference from 6 mg the power was approximately 29% with 250 subjects. The power to conclude PD similarity was high for all delivered dose differences and sample sizes.

Lenograstim and filgrastim in the febrile neutropenia prophylaxis of hospitalized patients: efficacy and cost of the prophylaxis in a retrospective survey

Purpose

We conducted a retrospective study to evaluate the efficacy and related costs of using two different molecules of granulocyte-colony stimulating factor (G-CSF) (lenograstim - LENO or filgrastim - FIL) as primary prophylaxis of chemotherapy-induced neutropenia in a hematological inpatient setting.

Methods

The primary endpoints of the analysis were the efficacy of the two G-CSFs in terms of the level of white blood cells, hemoglobin and platelets at the end of the treatment and the per capita direct medical costs related to G-CSF prophylaxis.

Results

Two hundred twelve patients (96 LENO, 116 FIL) have been evaluated. The following statistically significant differences have been observed between FIL and LENO: the use of a higher number of vials (11 vs 7; P<0.03) to fully recover bone marrow, a higher grade 3-4 neutropenia at the time of G-CSF discontinuation (29.3% vs 16.7%; P=0.031) and an increased number of days of hospitalization (8 vs 5; P<0.005). A longer hospital stay before discharge was necessary (12 vs 10), which reflects the higher final costs per patient (median treatment cost per cycle 10.706 € for LENO, compared to 12.623 € for FIL).

Conclusion

The use of LENO has been associated with a lower number of days of hospitalization, number of vials and less incidence of grade 3-4 neutropenia at the time of G-CSF discontinuation. LENO seems to be cost-saving when compared with FIL (-15.2%).

Pharmacological inhibition of AKT activity in human CD34+ cells enhances their ability to engraft immunodeficient mice

Although practiced clinically for more than 40 years, the use of hematopoietic stem cell (HSC) transplantation remains limited by the inability to expand functional HSCs ex vivo. To determine the role of phosphoinositide 3-kinase (PI3K)/AKT signaling in human hematopoietic stem and progenitor cell (HSPC) maintenance, we examined the effect of genetic and pharmacological inhibition of AKT on human umbilical cord blood (UCB) CD34⁺ cells. We found that knock-down of AKT1 in human UCB CD34⁺ cells using short interfering RNAs targeting AKT1 enhances their quiescence and colony formation potential in vitro. We treated human UCB CD34⁺ cells with an AKT-specific inhibitor (AKTi) and performed both in vitro and in vivo stem and progenitor cell assays. We found that ex vivo treatment of human HSPCs maintains CD34 expression and enhances colony formation in serial replating assays. Moreover, pharmacological inhibition of AKT enhances the short-term repopulating potential of human UCB CD34⁺ cells in immunodeficient mice. Mechanistically, genetic and pharmacological inhibition of AKT activity promotes human HSPC quiescence. These preclinical results suggest a positive role for AKTi during ex vivo culture of human UCB HSPCs.

Comparative effectiveness of granulocyte colony-stimulating factors to prevent febrile neutropenia and related complications in cancer patients in clinical practice: A systematic review

Introduction

Febrile neutropenia (FN) is a serious side-effect of myelosuppressive chemotherapy. Several clinical trials and observational studies have evaluated the effects of prophylactic granulocyte colony-stimulating factors (G-CSFs) on risk of FN and related complications; however, no systematic reviews have focused on effectiveness in routine clinical practice. Here, we perform a systematic review assessing the comparative effectiveness of prophylaxis with a long-acting G-CSF (pegfilgrastim) versus short-acting G-CSFs (filgrastim, lenograstim, and filgrastim biosimilars) in cancer patients in real-world clinical settings.

Methods

A systematic review was performed based on a pre-specified protocol and was consistent with the Cochrane Collaboration Handbook (2009) and the Centre for Reviews and Dissemination’s Guidance for Undertaking Reviews in Health Care (2011). MEDLINE, Embase, BIOSIS, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Library databases were searched for articles published from January 2002 to June 2014. Congress databases (MASCC/ASCO/ESMO) and Google Scholar were searched for abstracts published from January 2012 to August 2014. Filgrastim (NEUPOGEN®), lenograstim and nivestim (a filgrastim biosimilar) were the only short-acting G-CSFs and pegfilgrastim (Neulasta®) was the only long-acting G-CSF described in eligible studies. Outcomes of interest were FN, FN-related hospitalisation and other FN-related complications (death, chemotherapy dose delays and reductions, antimicrobial treatment, severe neutropenia and costs and resource use).

Results

Of 1259 unique records identified, 18 real-world observational studies met predefined inclusion criteria; 15 were retrospective studies, and 3 were prospective studies. Multiple tumour types, chemotherapy regimens and geographical regions were included. Seven studies provided statistical comparisons of the risk of FN; risk of FN among patients receiving prophylaxis with pegfilgrastim versus short-acting G-CSF was significantly lower in three studies, numerically lower in three studies, and numerically higher in one study. Six studies provided statistical comparisons of the risk of FN-related hospitalisation; risk of FN-related hospitalisation among patients receiving prophylaxis with pegfilgrastim versus short-acting G-CSF was significantly lower in all six studies, though some variation was seen in subanalyses. Data for other outcomes were sparse with available results being generally consistent with the results seen for risk of FN and FN-related hospitalisation.

Conclusions

Based on the findings from this review of real-world comparative effectiveness studies, risks of FN and FN-related complications were generally lower for prophylaxis with pegfilgrastim versus prophylaxis with short-acting G-CSFs.

Enhancing Conjugation Yield of Brush Polymer-Protein Conjugates by Increasing Linker Length at the Polymer End-Group

Polymers with oligoethylene glycol side chains are promising in therapeutic protein-polymer conjugates as replacements for linear polyethylene glycol (PEG). Branched PEG polymers can confer additional stability and advantageous properties compared to linear PEGs. However, branched PEG polymers suffer from low conjugation yields to proteins, likely due to steric interactions between bulky side chains of the polymer and the protein. In an effort to increase yields, the linker length between the protein-reactive functional end-group of the polymer chain and branched PEG side chain was systematically increased. This was accomplished by synthesizing four well-defined poly(poly(ethylene glycol methyl ether) acrylates) (pPEGA) with pyridyl disulfide end-groups by reversible addition-fragmentation chain transfer (RAFT) polymerization mediated by chain transfer agents (CTAs) with different linker lengths. These, along with linear PEG and poly(N-isopropylacrylamide) (pNIPAAm), were conjugated to two model proteins, bovine serum albumin (BSA) and beta-lactoglobulin (βLG). The conjugation yields were determined by gel electrophoresis. The length of the linker affected conjugation yield for both proteins. For BSA, the conjugation yield step increased from 10% to 24% when the linker was altered from 1 ethylene glycol (EG) unit to 3, with no additional increase for 4 and 6 EG units. In the case of βLG, the yield gradually increased from 9% to the 33% when the linker length was increased from 1 to 6. PEG and pNIPAAm reacted with yields as high as 75% further emphasizing the effect of steric hindrance in lowering conjugation yields.

Design Rationale and Development Approach for Pegfilgrastim as a Long-Acting Granulocyte Colony-Stimulating Factor

Filgrastim, a recombinant methionyl human granulocyte colony-stimulating factor (G-CSF) (r-metHuG-CSF), is efficacious in stimulating neutrophil production and maturation to prevent febrile neutropenia (FN) in response to chemotherapy. Because of its relatively short circulating half-life, daily filgrastim injections are required to stimulate neutrophil recovery. In an effort to develop a long-acting form of filgrastim that was as safe and efficacious as filgrastim but had a longer in vivo residence time, a number of strategies were considered. Ultimately, fusion of filgrastim to polyethylene glycol (PEG) was selected. Following extensive analysis of conjugation chemistries as well as in vitro and in vivo characterization of a panel of PEGylated proteins, a construct containing a 20 kDa PEG moiety covalently conjugated to the N-terminus of filgrastim was chosen for advancement as pegfilgrastim. Pegfilgrastim is primarily cleared by neutrophils and neutrophil precursors (rather than the kidneys), meaning that clearance from the circulation is self-regulating and pegfilgrastim is eliminated only after neutrophils start to recover. Importantly, addition of PEG did not alter the mechanism of action and safety profile compared to filgrastim. Clinical evaluation revealed that a single 6 mg dose effectively reduces the duration of neutropenia and risk of FN in patients receiving chemotherapy. This work demonstrates the benefit of using PEGylation to generate pegfilgrastim, which allows for once-per-chemotherapy cycle administration while maintaining similar safety and efficacy profiles as those for multiple daily administration of filgrastim. Approaches that may provide advances for therapeutic agonists of G-CSF receptor are also discussed.

Gene expression changes in spinal motoneurons of the SOD1(G93A) transgenic model for ALS after treatment with G-CSF

Background: Amyotrophic lateral sclerosis (ALS) is an incurable fatal motoneuron disease with a lifetime risk of approximately 1:400. It is characterized by progressive weakness, muscle wasting, and death ensuing 3–5 years after diagnosis. Granulocyte-colony stimulating factor (G-CSF) is a drug candidate for ALS, with evidence for efficacy from animal studies and interesting data from pilot clinical trials. To gain insight into the disease mechanisms and mode of action of G-CSF, we performed gene expression profiling on isolated lumbar motoneurons from SOD1^G93A mice, the most frequently studied animal model for ALS, with and without G-CSF treatment.

Results: Motoneurons from SOD1^G93A mice present a distinct gene expression profile in comparison to controls already at an early disease stage (11 weeks of age), when treatment was initiated. The degree of deregulation increases at a time where motor symptoms are obvious (15 weeks of age). Upon G-CSF treatment, transcriptomic deregulations of SOD1^G93A motoneurons were notably restored. Discriminant analysis revealed that SOD1 mice treated with G-CSF has a transcriptom close to presymptomatic SOD1 mice or wild type mice. Some interesting genes modulated by G-CSF treatment relate to neuromuscular function such as CCR4-NOT or Prss12.

Conclusions: Our data suggest that G-CSF is able to re-adjust gene expression in symptomatic SOD1^G93A motoneurons. This provides further arguments for G-CSF as a promising drug candidate for ALS.

Efficacy, effectiveness and safety of long-acting granulocyte colony-stimulating factors for prophylaxis of chemotherapy-induced neutropenia in patients with cancer: a systematic review

PURPOSE

Pegfilgrastim was introduced over a decade ago. Other long-acting granulocyte colony-stimulating factors (G-CSFs) have recently been developed. We systematically reviewed the efficacy, effectiveness and safety of neutropenia prophylaxis with long-acting G-CSFs in cancer patients receiving chemotherapy.

METHODS

We performed a systematic literature search of the MEDLINE, EMBASE and Cochrane Library databases, and abstracts from key congresses. Studies of long-acting G-CSFs for prophylaxis of chemotherapy-induced neutropenia (CIN) and febrile neutropenia (FN) were identified by two independent reviewers. Abstracts and full texts were assessed for final inclusion; risk of bias was evaluated using the Cochrane's tool. Effectiveness and safety results were extracted according to study type and G-CSF used.

RESULTS

Of the 839 articles identified, 41 articles representing different studies met the eligibility criteria. In five randomised controlled trials, 11 clinical trials and 17 observational studies across several tumour types and chemotherapy regimens, pegfilgrastim was used alone or compared with daily G-CSF, no G-CSF, no upfront pegfilgrastim or placebo. Studies generally reported lower incidence of CIN (4/7 studies), FN (11/14 studies), hospitalisations (9/13 studies), antibiotic use (6/7 studies) and adverse events (2/5 studies) with pegfilgrastim than filgrastim, no upfront pegfilgrastim or no G-CSF. Eight studies evaluated other long-acting G-CSFs; most (5/8) were compared to pegfilgrastim and involved patients with breast cancer receiving docetaxel-based therapy. Efficacy and safety profiles of balugrastim and lipegfilgrastim were comparable to pegfilgrastim in phase 3 studies. Efficacy and safety of other long-acting G-CSFs were mixed.

CONCLUSIONS

Pegfilgrastim reduced the incidence of FN and CIN compared with no prophylaxis. Most studies showed better efficacy and effectiveness for pegfilgrastim than filgrastim. Efficacy and safety profiles of lipegfilgrastim and balugrastim were similar to pegfilgrastim.

First-line combination chemotherapy with cisplatin, etoposide and ifosfamide for the treatment of disseminated germ cell cancer: re-evaluation in the granulocyte colony-stimulating factor era

BACKGROUND

This study re-evaluated the efficacy and tolerability of cisplatin, etoposide, and ifosfamide (VIP) combination chemotherapy as an alternative first-line regimen for patients with disseminated germ cell cancer (GCC) in this granulocyte colony-stimulating factor (G-CSF) era.

METHODS

The medical records of 91 consecutive patients with previously untreated disseminated GCC who received first-line VIP between 1995 and 2011 were retrospectively reviewed.

RESULTS

The 5-year overall survival rates for patients with good (n = 49), intermediate (n = 22) and poor (n = 20) prognoses according to the International Germ Cell Cancer Collaborative Group classification were 100, 79 and 83%, respectively. G-CSF was given to all patients, and no treatment-related deaths due to myelosuppression occurred.

CONCLUSION

The present study is the first to examine the therapeutic outcomes and safety profile of first-line VIP after routine G-CSF use. VIP might be an alternative first-line regimen for patients with disseminated GCC in this G-CSF era.

Low temperature thermal dependent Filgrastim adsorption behavior detected with ToF-SIMS

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) detected changes in Filgrastim (granulocyte colony stimulating growth factor, G-CSF) adsorption behavior at a solid interface when exposed to temperatures as low as 35 °C, i.e., before thermal denaturation, was detected by circular dichroism (CD) or dynamic light scattering (DLS). Biopharmaceuticals rely on maintaining sufficient conformation to impart correct biological function in vivo. Stability of such molecules is critical during synthesis, storage, transport, and administration. CD analysis indicated loss of structure at temperatures greater than ~60 °C, while DLS detected aggregation at ~42 °C. Furthermore, we demonstrate the nature of G-CSF interaction with a surface was altered rapidly and at relatively low temperatures. Specifically, after 10 min thermal treatment, changes in adsorption behavior occurred at 35 °C indicated by principal component analysis of spectra as primarily due to increasing yields of methionine fragments. This was likely to be due to either altering the preferential protein orientation upon adsorption or greater denaturation exposing the hydrophobic core. This investigation demonstrates the sensitivity of ToF-SIMS in studying biopharmaceutical adsorption and conformational change and can assist with studies into promoting their stability.

Efficacy of oral cytarabine ocfosfate and etoposide in the treatment of elderly patients with higher-risk myelodysplastic syndromes compared to that in elderly acute myeloid leukemia patients

BACKGROUND

Elderly acute myeloid leukemia (AML) patients and patients with higher-risk myelodysplastic syndromes (MDS) have a much poorer prognosis than younger patients despite intensive chemotherapy.

METHODS

Ten patients with higher-risk MDS and 12 patients with AML over 65 years of age were enrolled into this study and received oral induction therapy with cytarabine ocfosfate and etoposide.

RESULTS

The therapy response rates were 60% in the MDS group and 41.7% in the AML group. The difference in overall survival among MDS and AML patients was not statistically significant. The difference in the median survival times of the responsive and nonresponsive groups, which included MDS and AML patients, was statistically significant (790 and 174 days, respectively).

CONCLUSIONS

Based on a comparison of the data of this therapy in elderly higher-risk MDS patients versus elderly AML patients, we conclude that this therapy is well tolerated and can be cost-effective and useful for higher-risk MDS in elderly patients.