Primary Prophylaxis With Biosimilar Filgrastim for Patients at Intermediate Risk for Febrile Neutropenia: A Cost-Effectiveness Analysis

Optimal use of granulocyte colony-stimulating factor prophylaxis to improve survival in cancer patients receiving treatment : An expert view

BACKGROUND

Febrile neutropenia (FN) is a relatively common complication of cytotoxic chemotherapy. Prophylaxis with granulocyte colony-stimulating factor (G-CSF) can prevent FN and chemotherapy dose delays and enable the use of the higher dose intensities associated with a survival benefit; however, G‑CSF is not always used optimally. Five medical oncologists with a special interest in supportive care met to discuss the evidence for prophylaxis with G‑CSF to improve survival in cancer patients, identify reasons why this is not always done, and suggest potential solutions. The dose intensity of chemotherapy is critical for maximizing survival in cancer patients but may be reduced as a result of hematological toxicity, such as FN. Use of G‑CSF has been shown to increase the chances of achieving the planned dose intensity in various cancers, including early-stage breast cancer and non-Hodgkin lymphoma. All physicians treating cancer patients should consider the use of G‑CSF prophylaxis in patients receiving chemotherapy, paying particular attention to patient-related risk factors.

KEY MESSAGES

Strategies to optimize G‑CSF use include educating medical oncologists and pharmacists on the appropriate use of G‑CSF and informing patients about the efficacy of G‑CSF and its potential adverse effects. It is hoped that the evidence and opinions presented will help to encourage appropriate use of G‑CSF to support cancer patients at risk of FN in achieving the best possible outcomes from chemotherapy.

Chemotherapy-induced febrile neutropenia (FN): healthcare resource utilization (HCRU) and costs in commercially insured patients in the US

PURPOSE

Febrile neutropenia (FN) is a known side effect of chemotherapy, often requiring hospitalization. Economic burden increases with an FN episode and estimates of cost per episode should be updated from real-world data.

METHODS

A retrospective claims analysis of FN episodes in patients with non-myeloid malignancies from 2014 to 2021 was performed in IQVIA PharMetrics® Plus database. FN episodes were defined as having same-day claims for neutropenia and fever or infection, plus antibiotic in outpatient settings, following a claim for chemotherapy; index date was defined as the first claim for neutropenia/fever/infection. Patients receiving bone marrow/stem cell transplant and CAR-T therapy were excluded, as were select hematologic malignancies or COVID-19. Healthcare utilization and costs were evaluated and described overall, by episode type (w/wo hospitalization), index year, malignancy type, NCI comorbidity score, and age group.

RESULTS

7,033 FN episodes were identified from 6,825 patients. Most episodes had a hospitalization (91.2%) and 86% of patients had ≥1 risk factor for FN. Overall, FN episodes had a mean (SD) FN-related cost of $25,176 ($39,943). Episodes with hospitalization had higher average FN-related costs versus those without hospitalization ($26,868 vs $7,738), and costs increased with comorbidity score (NCI=0: $23,095; NCI >0-2: $26,084; NCI ≥2: $26,851).

CONCLUSIONS

FN continues to be associated with significant economic burden, and varied by cancer type, comorbidity burden, and age. In this analysis, most FN episodes were not preceded by GCSF prophylaxis. The results of this study highlight the opportunity to utilize GCSF in appropriate oncology scenarios.

Clinical outcomes of coronavirus disease in patients with breast cancer treated with granulocyte colony-stimulating factor following chemotherapy: Triangulation of evidence using population-based cohort and Mendelian randomization analyses

Recombinant human granulocyte colony-stimulating factor (G-CSF) administration in patients with cancer and coronavirus disease (COVID-19) remains controversial. Concerns exist that it may worsen COVID-19 outcomes by triggering an inflammatory cytokine storm, despite its common use for managing chemotherapy-induced neutropenia (CIN) or febrile neutropenia post-chemotherapy. Here, we determined whether prophylactic or therapeutic G-CSF administration following chemotherapy exacerbates COVID-19 progression to severe/critical conditions in breast cancer patients with COVID-19. Between December 2022 and February 2023, all 503 enrolled breast cancer patients had concurrent COVID-19 and received G-CSF post-chemotherapy, with most being vaccinated pre-chemotherapy. We prospectively observed COVID-19-related adverse outcomes, conducted association analyses, and subsequently performed Mendelian randomization (MR) analyses to validate the causal effect of genetically predicted G-CSF or its associated granulocyte traits on COVID-19 adverse outcomes. Only 0.99% (5/503) of breast cancer patients experienced COVID-19-related hospitalization following prophylactic or therapeutic G-CSF administration after chemotherapy. No mortality or progression to severe/critical COVID-19 occurred after G-CSF administration. Notably, no significant associations were observed between the application, dosage, or response to G-CSF and COVID-19-related hospitalization (all p >.05). Similarly, the MR analyses showed no evidence of causality of genetically predicted G-CSF or related granulocyte traits on COVID-19-related hospitalization or COVID-19 severity (all p >.05). There is insufficient evidence to substantiate the notion that the prophylactic or therapeutic administration of G-CSF after chemotherapy for managing CIN in patients with breast cancer and COVID-19 would worsen COVID-19 outcomes, leading to severe or critical conditions, or even death, especially considering the context of COVID-19 vaccination.

Filgrastim biosimilar (EP2006): A review of 15 years' post-approval evidence

Filgrastim is approved for several indications, including reduction of the incidence and duration of chemotherapy-induced neutropenia and for stem cell mobilization. The filgrastim biosimilar, EP2006, has been available in Europe since 2009, and in the United States since 2015. In this time, preclinical and clinical data used to support the approval of EP2006 have been published. These data established the biosimilarity of EP2006 to reference filgrastim in terms of structure, pharmacokinetics, pharmacodynamics, efficacy, safety, and immunogenicity. Additional real-world evidence studies have also demonstrated equivalent efficacy and safety of EP2006 compared with reference filgrastim, both in the reduction of neutropenia and in stem cell mobilization in clinical practice. This review summarizes these preclinical, clinical, and real-world data, as well as the available cost-effectiveness data, for EP2006 since its approval 15 years ago.

Impact of primary prophylaxis by pegfilgrastim in diffuse large B-cell lymphoma treated with R-CHOP

Febrile neutropenia (FN) and chemotherapy-induced neutropenia (CIN) are common conditions that lead to dose reduction or delayed chemotherapy in patients with diffuse large B-cell lymphoma (DLBCL). Primary prophylaxis (PP) with long-acting granulocyte colony-stimulating factor (G-CSF) was introduced in South Korea in 2014. We aimed to investigate the effects of PP on FN-related hospitalization and death in patients with DLBCL receiving rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Korean individuals (n = 11,491) with incident DLBCL and receiving R-CHOP during 2010-2016 were followed for FN-related hospitalization and mortality. The PP exposure group (patients during 2014-2015, n = 3599), patients during 2010-2016 (n = 11,491), and patients receiving PP during 2014-2016 (n = 4421) were compared with the non-exposure group (patients during July 2011-June 2013, n = 3017), patients in 2013 (n = 1596), and patients not receiving PP during 2014-2016 (n = 1289), respectively. Multivariable-adjusted hazard ratios (HRs) were calculated using the Cox model. The PP exposure group had 16% lower FN-related hospitalizations than the non-exposure group (HR = 0.84, P < 0.001). PP exposure had no beneficial effect on 1-year (HR = 0.98, P = 0.782) and 5-year mortality (HR = 0.97, P = 0.474). Patients in 2014 (HR = 0.85, P < 0.001), 2015 (HR = 0.88, P = 0.003), and 2016 (HR = 0.80, P < 0.001) had a decreased risk of FN-related hospitalizations compared with those in 2013. Among patients receiving their first R-CHOP cycle during 2014-2016, the HR for FN-related hospitalization was 0.90 (P = 0.014) in PP users compared with non-users. PP with a long-acting G-CSF lowered the FN-related hospitalization risk but did not benefit survival in patients with DLBCL receiving R-CHOP.

Cost-effectiveness of granulocyte colony-stimulating factors (G-CSFs) for the prevention of febrile neutropenia (FN) in patients with cancer

PURPOSE

Clinical practice guidelines recommend the use of all approved granulocyte colony-stimulating factors (G-CSFs), including filgrastim and pegfilgrastim, as primary febrile neutropenia (FN) prophylaxis in patients receiving high- or intermediate-risk regimens (in those with additional patient risk factors). Previous studies have examined G-CSF cost-effectiveness by cancer type in patients with a high baseline risk of FN. This study evaluated patients with breast cancer (BC), non-small cell lung cancer (NSCLC), or non-Hodgkin's lymphoma (NHL) receiving therapy who were at intermediate risk for FN and compared primary prophylaxis (PP) and secondary prophylaxis (SP) using biosimilar filgrastim or biosimilar pegfilgrastim in Austria, France, and Germany.

METHODS

A Markov cycle tree-based model was constructed to evaluate PP versus SP in patients with BC, NSCLC, or NHL receiving therapy over a lifetime horizon. Cost-effectiveness was evaluated over a range of willingness-to-pay (WTP) thresholds for incremental cost per quality-adjusted life year (QALY) gained. Sensitivity analyses evaluated uncertainty.

RESULTS

Results demonstrated that using biosimilar filgrastim as PP compared to SP resulted in incremental cost-effectiveness ratios (ICERs) well below the most commonly accepted WTP threshold of €30,000. Across all three countries, PP in NSCLC had the lowest cost per QALY, and in France, PP was both cheaper and more effective than SP. Similar results were found using biosimilar pegfilgrastim, with ICERs generally higher than those for filgrastim.

CONCLUSIONS

Biosimilar filgrastim and pegfilgrastim as primary prophylaxis are cost-effective approaches to avoid FN events in patients with BC, NSCLC, or NHL at intermediate risk for FN in Austria, France, and Germany.

Real-World Use of Granulocyte-Colony Stimulating Factor in Patients with Breast Cancer from Alberta, Canada

BACKGROUND

There are limited published data in the Canadian healthcare system on the use of granulocyte colony-stimulating factor (G-CSF) among patients with breast cancer. This study characterized real-world G-CSF use during the period surrounding the introduction of filgrastim biosimilar.

METHODS

Electronic medical records were reviewed retrospectively for patients with breast cancer who received moderately or highly myelosuppressive (neo)adjuvant chemotherapy from 2008 to 2019 in Alberta, Canada. Trends in G-CSF usage were plotted to elucidate temporal variations and multivariable regression models were constructed to identify clinical factors associated with G-CSF use.

RESULTS

We included 6662 patients in our analyses. G-CSF was used in 57.1% of patients during their treatment trajectory. Among the 3801 patients who were treated with G-CSF, the majority received pegfilgrastim only (91.5%; n = 3477) versus filgrastim only (5.7%; n = 217). G-CSF use increased linearly more than two-fold over the 11-year study period. Predictors of G-CSF use included younger age, south zone of residence, higher neighborhood education, inferior disease stage, highly neutropenic risk chemotherapy, and more recent chemotherapy initiation.

CONCLUSIONS

Despite increasing G-CSF usage over time, an appreciable proportion of patients for whom G-CSF prophylaxis is recommended did not receive it. G-CSF use could be further optimized to align with supportive care clinical guidelines and reduce the impact of neutropenia and its associated complications.

Colony stimulating factors for prophylaxis of chemotherapy-induced neutropenia in children

INTRODUCTION

Febrile neutropenia (FN) is one of the complications of chemotherapy that can increase the risk of infection and mortality. Granulocyte colony-stimulating factors (G-CSFs) are used in practice to prevent and treat episodes of neutropenia. The use of G-CSFs in children with cancer has not been studied much for primary prophylaxis of FN.

AREAS COVERED

Current data suggest that G-CSFs have a similar pharmacokinetic profile in children and adults. Clinical trials published from 2002 to 2021 using G-CSFs in pediatric cancer patients were reviewed. All evaluated clinical trials used a dosage of 5 mcg/kg of filgrastim daily until neutrophil recovery or a single dose of 100 mcg/kg pegfilgrastim. Filgrastim demonstrated the benefit in decreasing the duration of fever, hospital stay, and antibiotic use in high-risk neuroblastoma patients. Pegfilgrastim showed similar efficacy in reducing the occurrence of FN and infections, with bone pain as an adverse effect.

EXPERT OPINION

Filgrastim 5 mcg/kg/day or pegfilgrastim 100 mcg/kg single dose is appropriate when given at least 24 hours or after the chemotherapy in pediatric patients who weigh 45 kg or more. More prospective randomized trials are necessary to further investigate the efficacy and safety of G-CSFs in children with different types of cancer.

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.

Trends in Use of Granulocyte Colony-Stimulating Factor Following Introduction of Biosimilars Among Adults With Cancer and Commercial or Medicare Insurance From 2014 to 2019

IMPORTANCE

The introduction of biosimilars and novel delivery devices between 2014 and 2019 may have changed the utilization of granulocyte colony-stimulating factors (G-CSF).

OBJECTIVE

To assess utilization trends of G-CSFs for primary prophylaxis of febrile neutropenia (FN) among patients with cancer receiving myelosuppressive chemotherapy with commercial or Medicare insurance.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study assessed G-CSF utilization trends overall and stratified by regimen febrile neutropenia risk level. Associations between patient characteristics and G-CSF use were evaluated. Patients with cancer, including breast, lung, colorectal, esophageal and gastric, pancreatic, prostate, ovarian, and non-Hodgkin lymphomas, initiating myelosuppressive chemotherapy courses were included from the 2014 to 2019 commercial insurance and 2014 to 2018 Medicare fee-for-service claims databases. Data were analyzed from March to June 2021.

EXPOSURES

Year of chemotherapy initiation.

MAIN OUTCOMES AND MEASURES

The main outcomes were use and trends of G-CSFs for primary prophylaxis, from completion to 3 days after in the first chemotherapy cycle.

RESULTS

In total, 86 731 chemotherapy courses (mean [SD] age, 57.7 [11.5] years; 57 838 [66.7%] women and 28 893 [33.3%] men) were identified from 82 410 patients in the commercial insurance database and 32 398 chemotherapy courses (mean [SD] age, 71.8 [8.3] years; 18 468 [57.0%] women and 13 930 [43.0%] men) were identified from 30 279 patients in the Medicare database. Among the commercially insured population, 39 639 patients (45.7%) received G-CSFs, and 12 562 patients (38.8%) received G-CSFs among Medicare insured patients. Overall G-CSF use increased significantly throughout the study period in both populations, from 45.1% (95% CI, 44.4%-45.7%) of patients in 2014 to 47.5% (95% CI, 46.5%-48.5%) of patients in 2019 (P = .001) in the commercially insured population and from 36.0% (95% CI, 34.2%-38.0%) of patients in 2014 to 39.1% (95% CI, 38.1%-40.1%) of patients in 2018 (P < .001) in the Medicare population. The greatest increases in G-CSF use were observed among patients with high FN risk, from 75.0% (95% CI, 74.1%-76.0%) of patients to 83.2% (95% CI, 82.0%-84.2%) of patients (P < .001) among the commercially insured population and 75.3% (95% CI, 71.8%-78.6%) of patients to 86.2% (95% CI, 84.7%-87.6%) of patients (P < .001) among the Medicare population. Use of G-CSFs decreased in the commercially insured population among patients with intermediate FN risk (from 27.5% [95% CI, 26.4%-28.5%] of patients to 20.4% [95% CI, 19.1%-21.7%] of patients; P < .001) or low FN risk (from 19.3% [95% CI, 18.3%-20.4%] of patients to 16.3% [95% CI, 14.7%-18.0%] of patients; P < .001) and remained stable in the Medicare population (intermediate risk: from 26.4% [95% CI, 23.8%-29.2%] of patients to 28.4% [95% CI, 27.0%-29.8%] of patients; P = .35; low risk: from 19.6% [95% CI, 17.0%-22.4%] of patients to 20.9% [95% CI, 19.6%-22.3%] of patients; P = .58). Factors associated with increased odds of G-CSF use included older age (commercial insurance: adjusted odds ratio [aOR], 1.50 [95% CI, 1.41-1.59]; Medicare: aOR, 1.36 [95% CI, 1.08-1.71]), receiving a regimen with high FN risk (commercial insurance: aOR, 16.01 [95% CI, 15.17-16.90]; Medicare: aOR, 17.17 [95% CI, 15.76-18.71]), and history of neutropenia (commercial insurance: 3.90 (3.67-4.15); Medicare: 3.82 (3.50-4.18).

CONCLUSIONS AND RELEVANCE

This cross-sectional study found that utilization of G-CSFs increased among patients with cancer with high FN risk in both a commercially and Medicare-insured population, but 14% to 17% of patients still did not receive preventive treatment.

Prediction of Neutropenic Events in Chemotherapy Patients: A Machine Learning Approach

PURPOSE

Severe and febrile neutropenia present serious hazards to patients with cancer undergoing chemotherapy. We seek to develop a machine learning-based neutropenia prediction model that can be used to assess risk at the initiation of a chemotherapy cycle.

MATERIALS AND METHODS

We leverage rich electronic medical records (EMRs) data from a large health care system and apply machine learning methods to predict severe and febrile neutropenic events. We outline the data curation process and challenges posed by EMRs data. We explore a range of algorithms with an emphasis on model interpretability and ease of use in a clinical setting.

RESULTS

Our final proposed model demonstrates an out-of-sample area under the receiver operating characteristic curve of 0.865 (95% CI, 0.830 to 0.891) in the prediction of neutropenic events on the basis of only 20 clinical features. The model validates known risk factors and offers insight into potential novel clinical indicators and treatment characteristics that elevate risk. It relies on factors that are directly extractable from EMRs, provided a tool can be easily integrated into existing workflows. A cost-based analysis provides insight into optimal risk thresholds and offers a framework for tailoring algorithms to individual hospital needs.

CONCLUSION

A better understanding of neutropenic risk on an individual level enables a more informed approach to patient monitoring and treatment decisions.

The Impact of Baseline Risk Factors on the Incidence of Febrile Neutropenia in Breast Cancer Patients Receiving Chemotherapy with Pegfilgrastim Prophylaxis: A Real-World Data Analysis

Background: There are sparse data addressing whether standard risk factors for febrile neutropenia (FN) are relevant in patients receiving myelosuppressive chemotherapy and primary prophylaxis for FN, which would have implications for variables to consider during real-world comparative analyses of FN incidence. Objective: To assess the impact of baseline patient-specific risk factors and regimen risk on the incidence of FN in patients receiving pegfilgrastim primary prophylaxis. Methods: This was a retrospective observational study in patients with breast cancer (BC) who received myelosuppressive chemotherapy and prophylactic pegfilgrastim identified January 1, 2017-May 31, 2018 from MarketScan® research databases. The outcomes were defined as incidence of FN in the first cycle and among all cycles of chemotherapy using three different definitions for FN. Logistic regression and generalized estimating equations models were used to compare outcomes among patients with and without patient-specific risk factors and among those receiving regimens categorized as high-, intermediate-, or other-risk for FN (low-risk or undefinable by clinical practice guidelines). Results: A total of 4460 patients were identified. In the first cycle of therapy, patients receiving intermediate-risk regimens were at up to 2 times higher risk for FN across all definitions than those receiving high-risk regimens (P<0.01). The odds ratio for main FN among patients with ≥4 versus 0 risk factors was 15.8 (95% confidence interval [CI]: 1.5, 169.4; P<0.01). Patients with ≥3 FN risk factors had significantly greater risks for FN across all cycles of treatment than those with no risk factors; this was true for all FN definitions. Discussion: The choice of FN definition significantly changed the impact of risk factors on the FN outcomes in our study, demonstrating the importance of evaluating all proxies for true FN events in a database study. This is particularly important during real-world study planning where potential missteps may lead to bias or confounding effects that render a study meaningless. Conclusions: In patients with BC receiving chemotherapy with pegfilgrastim prophylaxis, patient-specific risk factors and regimen risk levels are determinants of FN risk. In real-world studies evaluating FN incidence, it is imperative to consider and control for these risk factors when conducting comparative analyses.