Pegfilgrastim on febrile neutropenia in pediatric and adolescent cancer patients: a systematic review and meta-analysis

OBJECTIVES

There is no meta-analysis about the effects of pegfilgrastim on the occurrence of febrile neutropenia (FN) in pediatric/adolescent cancer patients. The study explored the efficacy of prophylactic pegfilgrastim in preventing FN in children/adolescents with cancer.

METHODS

PubMed, Embase, and the Cochrane Library were searched for studies published before April 7, 2020. The primary outcome was the rate of FN. Effect size (ES) and odds ratio (OR) with 95% confidence intervals (CIs) were used to evaluate the outcome. The ES represented the rate of FN, and the STATA 'metaprop' command was used to synthesize the rate.

RESULTS

Eight studies were included, comprising 167 patients and 550 courses of treatment. There was no difference between pegfilgrastim and filgrastim for the rate of FN in children receiving chemotherapy (OR = 0.68, 95% CI: 0.20-2.23, P = 0.520). In patients receiving pegfilgrastim, the rate of FN was 25.6% (95% CI: 14.9%-36.3%), the rate of grade 4 FN was 38.3% (95% CI: 19.2%-59.5%), the rate of severe neutropenia (SN) was 40.5% (95% CI: 35.1%-46.1%), and the rate of treatment delays due to FN was 4.8% (95% CI: 0.8%-11.3%).

DISCUSSION

The number of studies that could be included was small; therefore, a specific type of cancer or a specific treatment could be studied. Heterogeneity was high.

CONCLUSION

There was no difference between pegfilgrastim and filgrastim for the rate of FN. The use of pegfilgrastim was still associated with rates of FN, grade 4 FN, severe neutropenia, and treatment delays due to FN in pediatric cancer patients.

Impacts of a Zwitterionic Peptide on its Fusion Protein

Therapeutic proteins frequently need to be modified with high-molecular-weight molecules to improve their pharmacokinetic properties. The genetic linkage of therapeutic proteins to a high-molecular-weight zwitterionic peptide, termed EKP, offers a promising approach. As with any protein modification, EKP could impact the structural behavior and receptor binding properties of the linked therapeutic protein, thereby altering its bioactivity. To evaluate the effects of EKP on therapeutic proteins, we study the receptor binding properties of high-molecular-weight EKP linked to the growth colony-stimulating factor (GCSF) using the genetically based yeast display platform. We find that yeast-displayed EKP-GCSF and GCSF exhibits similar binding to its receptor GCSF-R, suggesting that EKP does not hinder receptor binding. Furthermore, yeast-displayed EKP-GCSF demonstrates protection against thermal denaturation compared to GCSF. Similarly, to study the structural effects of EKP on GCSF, we employ in silico modeling using alphaFold2 in conjunction with molecular dynamics (MD) simulations. Likewise, in silico modeling reveals that EKP does not alter the structural behavior of GCSF. Finally, we demonstrate the functional benefits of EKP, by which the EKP-GCSF fusion protein produced in Escherichia coli exhibits improved pharmacokinetics and prolonged bioactivity in vivo.

Real-world cost-effectiveness of primary prophylaxis with G-CSF biosimilars in patients at intermediate/high risk of febrile neutropenia

Background: Real-world data suggests superiority of pegfilgrastim (PEG) over filgrastim (FIL) in reducing the incidence of chemotherapy-induced febrile neutropenia (FN), probably attributable to underdosed FIL in practice. We used real-world data to assess the cost-effectiveness of primary prophylaxis with PEG versus FIL in cancer patients at intermediate-to-high risk of FN from a US payer perspective. Methods: A Markov model with lifetime horizon. Results: For the high-risk group, PEG (vs FIL) biosimilars resulted in 0.43 FN events prevented (FNp), 0.27 quality-adjusted life-years gained (QALYg) and a cost saving of USD$5703. For the intermediate-risk group, PEG biosimilar led to 0.18 FNp and 0.12 QALYg, at USD$9674/FNp and USD$14,502/QALYg. Conclusion: PEG biosimilars may provide opportunities to optimize FN management in patients with intermediate-to-high FN risk.

Costs associated with febrile neutropenia in Japanese patients with primary breast cancer: post-hoc analysis of a randomized clinical trial

Background

Febrile neutropenia (FN), a decrease in blood neutrophils accompanied by fever, is a major adverse event (AE) associated with cancer chemotherapy. We aimed to estimate the direct medical costs associated with FN management in breast cancer patients within a clinical trial with pegfilgrastim, a pegylated form of recombinant granulocyte colony-stimulating factor (G-CSF).

Methods

We obtained data from 346 Japanese breast cancer patients in a randomized, placebo-controlled clinical trial comparing FN incidence due to TC adjuvant chemotherapy (docetaxel 75 mg/m2, cyclophosphamide 600 mg/m2) between pegfilgrastim-treated and placebo groups. We estimated mean costs for chemotherapy drugs, drugs for all AEs and FN, and hospitalization for all AEs and FN. We also calculated mean costs associated with drugs and hospitalization for FN specifically for patients who developed FN in the placebo group.

Results

For the pegfilgrastim and placebo groups, the total cost during the first cycle of chemotherapy was ¥189 135 and ¥98 106. This difference is associated with prophylactic use of pegfilgrastim. Our analysis clarified in the placebo group that FN incidents of 119/173 (68.6%), the mean drug cost related to all AEs and hospitalization caused by the first cycle of chemotherapy were ¥14 411and ¥11 180, respectively. The cost of each for FN treatment was ¥16 429 for the placebo group. The mean treatment cost for patients who developed FN in placebo group, was ¥11 145 for drugs and ¥28 420 for drugs and hospitalization.

Conclusions

Pegfilgrastim reduced the costs incurred for both drugs and hospitalization for AEs as well as FN, although the total medical cost during the chemotherapy increased. Our study constitutes baseline data for further health economic evaluations of pegfilgrastim.

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.

Pegfilgrastim for the prevention of chemotherapy-induced febrile neutropenia in patients with solid tumors

INTRODUCTION

Neutropenia and febrile neutropenia are the most common and most severe bone marrow toxicities of chemotherapy. Recombinant granulocyte-colony stimulating factors (G-CSFs), both daily (filgrastim and biosimilars, and lenograstim) and long-acting (pegfilgrastim and lipegfilgrastim) formulations, are currently available to counteract the negative consequences of these side effects.

AREAS COVERED

The purpose of this article is to review the physiopathology of chemotherapy-induced febrile neutropenia and its consequences, and the current evidence regarding the pharmacological properties, clinical efficacy and cost-effectiveness of pegfilgrastim as a strategy to prevent chemotherapy-induced febrile neutropenia in patients with solid tumors.

EXPERT OPINION

Chemotherapy-induced febrile neutropenia and its complications are still a major health-care concern, and the inappropriate employment of G-CSFs in clinical practice can partially explain its burden. Pegfilgrastim has pharmacological advantages over daily G-CSFs that makes it easily administrable, thus reducing the chance of incorrect delivery. The once-per-cycle administration might explain the findings derived from observational studies suggesting a possible superior efficacy of pegfilgrastim over daily G-CSFs. For patients at higher risk of failure with daily G-CSF prophylaxis (e.g. risk of non-compliance, difficulties on performing regular hemograms, high risk of developing febrile neutropenia), pegfilgrastim might be the most appropriate option.