Predictive modeling of the outcomes of chemotherapy-induced (febrile) neutropenia prophylaxis with biosimilar filgrastim (MONITOR-GCSF study)

Cost-efficiency analysis of conversion to biosimilar filgrastim for supportive cancer care and resultant expanded access analysis to supportive care and early-stage HER2+ breast cancer treatment in Saudi Arabia: simulation study

AIMS

This study estimated, for Saudi Arabia, the cost-efficiency of converting patients from reference Neupogen and Neulastim to one of two filgrastim biosimilars (Nivestim, Zarzio); the budget-neutral expanded access to supportive care with biosimilar filgrastim and therapeutic care to ado-trastuzumab emtansine thus afforded; and the number-needed-to-convert (NNC) to provide supportive or therapeutic treatment to one patient.

MATERIALS AND METHODS

Replicating prior studies, we modeled the cost-efficiencies gained from converting varying proportions of a hypothetical panel of 4,000 patients undergoing six cycles of cancer treatment from Neupogen or Neulastim to one of the two biosimilar G-CSF formulations, using national cost inputs. Cost-savings in USD were used to estimate the additional doses of biosimilar G-CSF and expanded access to ado-trastuzumab emtansine on a budget-neutral basis, and NNC to purchase one additional dose of supportive or therapeutic treatment.

RESULTS

Savings from conversion from reference to a biosimilar filgrastim were $3,086,400 (Nivestim) and $3,460,800 (Zarzio). With reference pegfilgrastim, savings from conversion were $11,712,240 (Nivestim) and $12,086,640 (Zarzio). Biosimilar conversion from reference to biosimilar filgrastim enabled expanded access to ado-trastuzumab emtansine ranging from 61 patients (5 days, Nivestim) to 191 patients (14 days, Zarzio). For supportive care, biosimilar conversion enabled expanded access ranging from 8,244 patients (5 days, Nivestim) to 25,882 patients (14 days, Zarzio). For biosimilar conversion from daily filgrastim, the NNC for treatment with ado-trastuzumab emtansine decreased as days of injections increased [5 days: 395 (Nivestim), 352 (Zarzio); 14 days: 141(Nivestim), 126 (Zarzio)]. Alternately, for biosimilar conversion from single-injection pegfilgrastim to daily biosimilar filgrastim, the NNC for treatment with ado-trastuzumab emtansine rose as days of injections increased, being highest under the 14-day scenario (146, Nivestim; 130, Zarzio).

CONCLUSION

This simulation study demonstrated significant potential cost-savings from biosimilar conversion. These savings provide budget-neutral increased access to supportive and therapeutic cancer care.

Real-world burden of chemotherapy-induced myelosuppression in patients with small cell lung cancer: a retrospective analysis of electronic medical data from community cancer care providers

AIMS

Chemotherapy-induced myelosuppression, which commonly exhibits as neutropenia, anemia, or thrombocytopenia, represents a substantial burden for patients with cancer that affects health-related quality of life and increases healthcare resource utilization (HCRU). We evaluated the burden of myelosuppression among chemotherapy-treated patients with small cell lung cancer (SCLC) using real-world data from community cancer care providers in the Western United States.

MATERIALS AND METHODS

This was a retrospective, observational analysis of electronic medical records (EMRs) from Providence St. Joseph Health hospital-associated oncology clinics between January 2016 and December 2019. Patient demographics were assessed from the date of first SCLC diagnosis in adult patients with chemotherapy-induced grade ≥3 myelosuppression in first-line (1L) or second-line-and-beyond (2L+) treatment settings. Myelosuppressive adverse events (AEs), treatment patterns, and HCRU were assessed from the date of chemotherapy initiation (index date) until 12 months, date of the last visit, date of death, or study end, whichever occurred earliest.

RESULTS

Of 347 eligible patients with SCLC who had received chemotherapy (mean age 66; 49% female), all had received at least 1L treatment, and 103 (29.7%) had a 2L + treatment recorded within the EMR during the study period. Of 338 evaluable patients with longitudinal laboratory data, 206 (60.9%) experienced grade ≥3 myelosuppressive AEs, most commonly neutropenia, anemia, and thrombocytopenia (44.9, 41.1, and 25.4 per 100 patients, respectively). Rates of granulocyte colony-stimulating factor use and red blood cell transfusions were 47.0 and 41.7 per 100 patients, respectively. There was a trend toward increasing the use of supportive care interventions and visits to inpatient and outpatient facilities in patients with myelosuppressive AEs in more than one cell lineage.

CONCLUSIONS

Chemotherapy-induced myelosuppression places a substantial real-world burden on patients with SCLC in the community cancer care setting. Innovations to protect bone marrow from chemotherapy-induced damage have the potential to reduce this burden.

OUP accepted manuscript

Background

The FEbrile Neutropenia after ChEmotherapy (FENCE) score was developed to estimate the risk of febrile neutropenia (FN) at first cycle of chemotherapy but has not been externally validated. We aimed to validate the FENCE score based on its risk groups in patients treated at a comprehensive cancer center.

Methods

We conducted a retrospective study of treatment-naïve adult patients with solid tumors and diffuse large B-cell lymphoma who received first-cycle chemotherapy between January and November 2019. Patients were followed until the second cycle of chemotherapy to identify any FN events (neutrophil count <0.5 × 10⁹/L with fever ≥38.2°C). The FENCE score was determined and patients classified as low, intermediate, high, and very high risk. The discriminatory ability of classifying patients into FENCE risk groups was calculated as the area under the receiver operating characteristics curve and incidence rate ratios within each FENCE risk group.

Results

FN was documented during the first cycle of chemotherapy in 45 of the 918 patients included (5%). The area under the receiver operating characteristics curve was 0.66 (95% confidence interval [CI] = 0.58 to 0.73). Compared with the low-risk group (n = 285), the incidence rate ratio of developing FN was 1.58 (95% CI = 0.54 to 5.21), 3.16 (95% CI = 1.09 to 10.25), and 3.93 (95% CI = 1.46 to 12.27) in the intermediate (n = 293), high (n = 162), and very high (n = 178) risk groups, respectively.

Conclusions

In this study, classifying patients into FENCE risk groups demonstrated moderate discriminatory ability for predicting FN. Further validation in multicenter studies is necessary to determine its generalizability.

Improved risk prediction of chemotherapy-induced neutropenia-model development and validation with real-world data

BACKGROUND

The existing risk prediction models for chemotherapy-induced febrile neutropenia (FN) do not necessarily apply to real-life patients in different healthcare systems and the external validation of these models are often lacking. Our study evaluates whether a machine learning-based risk prediction model could outperform the previously introduced models, especially when validated against real-world patient data from another institution not used for model training.

METHODS

Using Turku University Hospital electronic medical records, we identified all patients who received chemotherapy for non-hematological cancer between the years 2010 and 2017 (N = 5879). An experimental surrogate endpoint was first-cycle neutropenic infection (NI), defined as grade IV neutropenia with serum C-reactive protein >10 mg/l. For predicting the risk of NI, a penalized regression model (Lasso) was developed. The model was externally validated in an independent dataset (N = 4594) from Tampere University Hospital.

RESULTS

Lasso model accurately predicted NI risk with good accuracy (AUROC 0.84). In the validation cohort, the Lasso model outperformed two previously introduced, widely approved models, with AUROC 0.75. The variables selected by Lasso included granulocyte colony-stimulating factor (G-CSF) use, cancer type, pre-treatment neutrophil and thrombocyte count, intravenous treatment regimen, and the planned dose intensity. The same model predicted also FN, with AUROC 0.77, supporting the validity of NI as an endpoint.

CONCLUSIONS

Our study demonstrates that real-world NI risk prediction can be improved with machine learning and that every difference in patient or treatment characteristics can have a significant impact on model performance. Here we outline a novel, externally validated approach which may hold potential to facilitate more targeted use of G-CSFs in the future.

Use of prophylactic pegfilgrastim for chemotherapy-induced neutropenia in the US: A review of adherence to present guidelines for usage

Evidence-based US guidelines provide recommendations for the use of granulocyte colony-stimulating factor (G-CSF) as supportive therapy in patients with cancer receiving chemotherapy. Pegfilgrastim is recommended for FN prophylaxis in patients with non-myeloid malignancies receiving a high-risk chemotherapy regimen, or an intermediate-risk regimen if one or more risk factors are present. The guidelines highlight the patient characteristics and chemotherapy regimens for solid tumors and hematologic malignancies that may influence a patient's overall risk of FN and may benefit from pegfilgrastim support. This review aimed to evaluate how pegfilgrastim use in patients with cancer receiving myelosuppressive chemotherapy in routine clinical practice aligns with evidence-based US guidelines. Examination of the literature revealed widespread deviation in relation to under- and over-prescribing, and timing of administration in US clinical practice. Pegfilgrastim is often over-prescribed in patients receiving palliative chemotherapy and those at low risk of FN. Potential under-prescribing of pegfilgrastim was also observed. In this literature search, data that appear to support same-day administration of pegfilgrastim were from uncontrolled studies that were limited in size. Analyses of healthcare claims data clearly favored next-day use, with statistically significant increases in FN incidence among patients receiving same-day pegfilgrastim versus those treated 1-4 days post-chemotherapy. Earlier-than-recommended administration typically occurs at the physician's discretion where next-day administration might present barriers to the patient receiving supportive therapy.There is a need to ensure appropriate prescribing to optimize patient outcomes, as deviation from the guideline recommendations was associated with increased incidence of FN and hospitalization.

Prophylaxis and treatment strategies for optimizing chemotherapy relative dose intensity

INTRODUCTION

A decrease in relative-dose intensity (RDI) of chemotherapy has been shown to be associated with poor patient outcomes in solid tumors and non-Hodgkin's lymphoma. The actual delivered chemotherapy dose received by patients can be influenced by dose reductions and treatment delays, often due to toxicities, most commonly chemotherapy-induced neutropenia (CIN).

AREAS COVERED

We review seminal evidence and more recent studies that have shown an association between higher RDI and improved patient survival. A smaller number of studies has shown no association between RDI and outcomes. These differences may be due to study limitations, including low power, differences in patient and disease characteristics, or the chemotherapeutic regimen. We describe guidelines recommendations to prevent and treat CIN with granulocyte-colony stimulating factor (G-CSF) and describe novel approaches to prevent neutropenia that are being developed that may provide greater value and be associated with fewer adverse events than standard G-CSF options.

EXPERT OPINION

Maintaining RDI is important to ensure optimal patient outcomes. This can be achieved through the proper administration of G-CSF prophylaxis and treatment. Newer agents in development to treat and/or prevent CIN are entering regulatory review and may potentially change the treatment landscape for CIN in the future.

Assessment of Chemotherapy-Induced Febrile Neutropenia in Cancer Patients

Purpose: Chemotherapy-induced febrile neutropenia (CIFN) is an adverse drug reaction which needs medical attention. The treatment options for the CIFN are mandatory to improve treatment outcomes and quality of life. Methods: A prospective observational study was conducted in the in-patients and out-patients of oncology department who received chemotherapy from October 2016 to March 2017. The information such as demographics (age, gender, and comorbidities), complaints on admission, hematological investigations (neutrophil counts, platelet counts, hemoglobin levels, erythrocyte sedimentation rate, and white blood cells), type of tumor, stage of cancer, prophylaxis, cycle of antineoplastic chemotherapy that cause febrile neutropenia, treatment history, and outcome data were obtained from the patient's clinical record. The Multinational Association for Supportive Care in Cancer score and Absolute Neutrophil Count grading was used to predict the patient's risk of developing CIFN. Results: Out of 200 patients, 19 patients developed 22 episodes of CIFN. The overall occurrence of CIFN during the study was 9.5%. The higher incidence of CIFN has been observed among male gender (57.89%), stage III patients (42.10%), solid tumor (73.68%), and double chemotherapy regimen (59.1%). The higher incidence of CIFN was developed in I cycle (36.36%) followed by II cycle (22.72%) and VI cycle (18.18%). Conclusions: The incidence of CIFN during the study was 9.5%. In the 19 chemotherapy-induced FN patients, there has no significant effect of prophylaxis to prevent the febrile neutropenia.

Economic modeling for the US of the cost-efficiency and associated expanded treatment access of conversion to biosimilar pegfilgrastim-bmez from reference pegfilgrastim

Aims: For this economic analysis, we aimed to model: (1) the cost-efficiency of prophylaxis with biosimilar pegfilgrastim-bmez for chemotherapy-induced (febrile) neutropenia (CIN/FN) compared to reference pegfilgrastim, and (2) the expanded access to CIN/FN prophylaxis and anti-neoplastic treatment that could be achieved with biosimilar cost-savings on a budget-neutral basis.Methods: In a hypothetical panel of 20,000 cancer patients receiving CIN/FN prophylaxis and using the average sales price (ASP) for the second quarter of 2019 for reference pegfilgrastim, we: conducted an ex ante simulation from the payer perspective of the cost-savings of 10-100% conversion from reference to biosimilar pegfilgrastim-bmez using drug price discounting ranging from 10-35%; estimated the budget-neutral expanded access to biosimilar pegfilgrastim-bmez enabled by these cost-savings; and estimated the budget-neutral expanded access to anti-neoplastic treatment with pembrolizumab. The simulations were replicated using fourth quarter 2019 wholesale acquisition cost (WAC) for reference pegfilgrastim and biosimilar pegfilgrastim-bmez in a post facto analysis.Results: In ASP simulations, cost-savings of using pegfilgrastim-bmez over reference pegfilgrastim in a 20,000 patient panel range from $1.3 M (at 15% price discount) to $3 M (35%) at 10% conversion rate and from $6.4 M to $14.9 M, respectively, at 50% conversion. These savings could provide prophylaxis with pegfilgrastim-bmez to an additional 352 (15% discount) to 1,076 patients (35%) at 10% conversion or 1,764-5,384, respectively, at 50% conversion. Alternatively, savings could be reallocated for anti-neoplastic treatment with pembrolizumab to 3 (15% discount) to 9 (35%) patients at 10% conversion or 19-45, respectively, at 50% conversion. When utilizing WAC, cost-savings range from $4.6 M (10% conversion) to $23.1 M (50%) which could provide pegfilgrastim-bmez to an additional 1,174 (10% conversion) to 5,873 patients (50%).Conclusions: Prophylaxis with biosimilar pegfilgrastim-bmez increases the value of cancer care by generating significant cost-savings that could be reallocated to provide expanded access to CIN/FN prevention and anti-neoplastic therapy on a budget-neutral basis.

Febrile neutropenia hospitalization due to pegfilgrastim on-body injector failure compared to single-injection pegfilgrastim and daily injections with reference and biosimilar filgrastim: US cost simulation for lung cancer and non-Hodgkin lymphoma

Background: Guidelines recommend febrile neutropenia (FN) prophylaxis following myelotoxic chemotherapy with either daily injections of filgrastim (Neupogen^®) or biosimilar filgrastim-sndz (Zarzio/Zarxio^®), single-injection pegfilgrastim (Neulasta^®), or pegfilgrastim administered through an on-body injector (PEG-OBI; Neulasta^® Onpro^®). PEG-OBI failure rates up to 6.9% have been reported, putting patients at incremental risk for FN and FN-related hospitalization. Our objective was to estimate, from a US payer perspective, the incremental costs of FN hospitalizations and the total incremental costs associated with PEG-OBI prophylaxis at varying device failure rates over assured FN prophylaxis with daily injections of filgrastim or filgrastim-sndz or a single injection of pegfilgrastim.Methods: Cost simulations comparing prophylaxis with PEG-OBI at failure rates of 1-10% versus assured prophylaxis in cycle 1 of chemotherapy were performed for panels of 10,000 patients with lung cancer treated with cyclophosphamide, doxorubicin, and etoposide (1 analysis) or non-Hodgkin lymphoma (NHL) treated with CHOP or CNOP (2 analyses). Daily injection scenarios were 4.3, 5, and 11 injections for lung cancer and 5, 6.5, and 11 for NHL. The analyses are from the US payer perspective.Results: For lung cancer, the total incremental cost of PEG-OBI prophylaxis at varying failure rates and durations ranged from $6,691,969‒$31,765,299 over filgrastim and $18,901,969‒$36,538,299 over filgrastim-sndz. For NHL, in scenario 1, the total incremental costs ranged from $6,794,984‒$30,361,345 over filgrastim and $19,004,984‒$35,911,345 over filgrastim-sndz; in scenario 2, the incremental costs ranged from $7,003,657‒$32,448,067 over filgrastim and $19,213,657‒$37,998,067 over filgrastim-sndz.Conclusions: In this simulation, the incremental costs of FN-related hospitalization due to PEG-OBI failure in cycle 1 compared to assured prophylaxis with reference pegfilgrastim, reference filgrastim, and biosimilar filgrastim-sndz varied depending upon the PEG-OBI failure rate and the alternative G-CSF prophylaxis option. Biosimilar filgrastim-sndz offers the greatest cost-efficiency.

Treatment patterns and outcomes in patients with non-small cell lung cancer receiving biosimilar filgrastim for prophylaxis of chemotherapy-induced/febrile neutropaenia: Results from the MONITOR-GCSF study

Objective

Real‐world evidence data on the use of granulocyte colony‐stimulating factor (G‐CSF) in patients with non‐small cell lung cancer (NSCLC) are limited. MONITOR‐GCSF is a pan‐European, multicentre, prospective, non‐interventional study designed to describe patient characteristics, treatment patterns and clinical outcomes in patients receiving biosimilar filgrastim in the prophylaxis of chemotherapy‐induced neutropaenia (CIN) and febrile neutropaenia (FN).

Methods

In this subanalysis, patient characteristics, treatment patterns, and outcomes are described for 345 patients with stage 3 or 4 NSCLC, receiving up to six chemotherapy cycles. Patients were treated with biosimilar filgrastim as per their treating physician's best judgement.

Results

CIN (any grade) occurred in 13.6% of patients in Cycle 1 and in 36.5% of patients in all cycles. FN occurred in 1.4% of patients in Cycle 1 and in 5.2% of patients in all cycles. Grade 3–4 FN occurred in 1.2% of patients in Cycle 1 and in 3.8% of patients in all cycles.

Conclusion

Results show that in real‐life practice in patients with NSCLC, biosimilar filgrastim has similar effectiveness and safety to the known effectiveness and safety profile of reference filgrastim, supporting the use of biosimilar filgrastim for the real‐world treatment of neutropaenia in patients with NSCLC.

Safety and efficacy of alternating treatment with EP2006, a filgrastim biosimilar, and reference filgrastim: a phase III, randomised, double-blind clinical study in the prevention of severe neutropenia in patients with breast cancer receiving myelosuppressive chemotherapy

Background

In 2015, the biosimilar filgrastim EP2006 became the first biosimilar approved by the US Food and Drug Administration for commercial use in the United States, marketed as Zarxio® (Sandoz). This phase III randomised, double-blind registration study in patients with breast cancer receiving (neo)adjuvant myelosuppressive chemotherapy (TAC; docetaxel + doxorubicin + cyclophosphamide) compares reference filgrastim, Neupogen® (Amgen), with two groups receiving alternating treatment with reference and biosimilar every other cycle.

Patients and methods

A total of 218 patients receiving 5 µg/kg/day filgrastim over six chemotherapy cycles were randomised 1: 1: 1: 1 into four arms. Two arms received only one product, biosimilar or reference (unswitched), and two arms (switched) received alternating treatments every other cycle (biosimilar then reference or vice versa over six cycles). Since the switch occurred from cycle 2 onwards, this analysis compared pooled switched groups to the unswitched reference group for efficacy during cycles 2-6. Safety was also assessed. Non-inferiority in febrile neutropenia (FN) rates between groups for cycles 2-6 was shown if 95% were within a pre-defined margin of - 15%.

Results

A total of 109 patients switched treatment, and 52 patients received reference in all cycles. Baseline characteristics were similar between groups. The incidence of FN was 0% (reference) versus 3.4% (n = 3, switched) across cycles 2-6, with a difference of - 3.4% (95% confidence interval: -9.65% to 4.96%), showing non-inferiority. Infections occurred in 9.3% (switched) versus 9.9% (reference). Hospitalisation due to FN was low (one patient in cycle 6; switched). Adverse events related to filgrastim were reported in 42.1% (switched) versus 39.2% (reference) (all cycles). Musculoskeletal/connective tissue disorders related to filgrastim occurred in 35.5% (switched) versus 39.2% (reference) (all cycles), including bone pain (30.8% versus 33.3%). No neutralising antibodies were detected.

Conclusions

There were no clinically meaningful results regarding efficacy, safety or immunogenicity when switching from reference to biosimilar filgrastim/EP2006, or vice versa.

Development and validation of a cycle-specific risk score for febrile neutropenia during chemotherapy cycles 2-6 in patients with solid cancers: The CSR FENCE score

The absolute risk reduction by prophylaxis in chemotherapy-induced febrile neutropenia (FN) is largest in patients at highest underlying risk. Therefore, reliable predictive models are needed. Here, we develop and validate such a model for risk of FN during chemotherapy cycles 2-6. A prediction score for risk of FN during the first cycle has recently been published. Patients with solid cancers initiating first-line chemotherapy in 2010-2016 were included. Cycle-specific risk factors were assessed by Poisson regression using generalized estimating equations and random split sampling. The derivation cohort included 4,590 patients treated with 15,419 cycles, wherein 326 (2.1%) FN events occurred. Predictors of FN in multivariable analyses were: higher predicted risk of FN in the first cycle, platinum- or taxane-containing therapies, concurrent radiotherapy, treatment in cycle 2 compared to later cycles, previous FN or neutropenia and not receiving granulocyte colony-stimulating factors. Each predictor added between -2 and 8 points to each patient's score (median score 4; interquartile range, 1-6). The incidence rate ratios for developing FN in the intermediate (score 1-4), high (score 5-6) and very high risk groups (score ≥7) were 7.8 (95% CI, 2.4-24.9), 18.6 (95% CI, 5.9-58.8) and 51.7 (95% CI, 16.5-162.3) compared to the low risk group (score ≤0), respectively. The score had good discriminatory ability with a Harrell's C-statistic of 0.78 (95% CI, 0.76-0.80) in the derivation and 0.75 (95% CI, 0.72-0.78) in the validation cohort (patient n = 2,295, cycle n = 7,670). The Cycle-Specific Risk of FEbrile Neutropenia after ChEmotherapy score is the first published method to estimate cycle-specific risk of FN.

Chemotherapy-induced neutropenia/febrile neutropenia prophylaxis with biosimilar filgrastim in solid tumors versus hematological malignancies: MONITOR-GCSF study

Aim: This study aimed to report patterns of biosimilar filgrastim prophylaxis and outcomes of chemotherapy-induced neutropenia (CIN)/febrile neutropenia (FN) in patients with hematological malignancies or solid tumors. Patients & methods: MONITOR-GCSF is a real-world study of 1447 cancer patients receiving CIN/FN prophylaxis with biosimilar filgrastim (solid tumors: 77.2%; hematological malignancies: 22.8%). Results: Differences in prophylaxis intensity and day of initiation relative to guideline recommendations were observed. In hematology patients, higher rates of CIN and FN occurred at cycle level, and rate of FN was higher at patient level (9.1 vs 5.0% in solid tumor patients). Conclusion: Adequate GCSF support in hematology and solid tumor patients is important to prevent CIN/FN and related hospitalizations and chemotherapy disturbances.

Febrile neutropenia (FN) occurrence outside of clinical trials: occurrence and predictive factors in adult patients treated with chemotherapy and an expected moderate FN risk. Rationale and design of a real-world prospective, observational, multinational study

Background

Febrile neutropenia (FN) is a common occurrence during chemotherapy. Granulocyte colony-stimulating factors (G-CSFs) can significantly reduce the risk of FN. International guidelines recommend G-CSF for patients receiving chemotherapy with FN risk of ≥20% or 10% to 20% with defined risk factors. Prophylaxis is not typically recommended for FN risk of < 10%; however, few studies have investigated FN incidence in lower-risk patients in real-world settings and tried to identify higher-risk subgroups.

Methods

This real-world prospective, observational, multinational study aims to estimate the rate of development of FN with a chemotherapy line expected to be associated with a 10% to 20% risk of FN. Eligible patients (> 18 years of age) will have a solid tumour or Hodgkin/non-Hodgkin lymphoma and a planned chemotherapy regimen with expected risk of FN of 10% to 20% (according to published guidelines). Patients will be observed for the duration of the chemotherapy line (first cycle administered without FN prophylaxis). Primary endpoint is incidence of FN after the first chemotherapy cycle. Secondary outcomes include: FN-associated morbidity and mortality; time to first FN occurrence; other FN risk factors and impact of FN on quality of life. A risk model using occurrence of FN as a binary outcome will be developed. Data will be stratified by age, comorbidities and other risk factors.

Discussion

This study will provide insight into the real FN risk for common chemotherapy regimens and predictive factors for FN, including patients generally excluded from randomised clinical trials, from which reported FN rates have been variable. This study builds on knowledge of predictive factors from other research and will provide information on patients with 10% to 20% FN risk.

Development of a simplified multivariable model to predict neutropenic complications in cancer patients undergoing chemotherapy

PURPOSE

Neutropenic complications remain the major dose-limiting toxicities of cancer chemotherapy. The aim of this study was to develop and internally validate a comprehensive and easily measurable scoring system for prediction of severe or febrile neutropenia in the first chemotherapy cycle of patients with solid tumors or lymphoma.

METHODS

This prospective cohort study included consecutive patients at a tertiary referral hospital. Many clinical and laboratory-independent variables were measured at baseline. A multivariable logistic regression analysis was applied after unadjusted analysis, and the multivariable model was transformed into a simplified risk score based on 6 bootstrapped regression coefficients. The simplified scoring system was internally validated using cross-validation. All statistical tests were two-sided.

RESULTS

A total of 305 patients were enrolled and followed during 1732 chemotherapy cycles. Of these, 259 were eligible for analysis. The multivariable model revealed 6 predictive factors for severe or febrile neutropenia (scores in parentheses): high-risk regimen without colony-stimulating factor (4 points), intermediate-risk regimen without colony-stimulating factor (3 points), age > 65 years and elevated ferritin (3 points), body mass index < 23 kg/m² and body surface area < 2 m² (2 points), estimated glomerular filtration rate < 60 mL/min/1.73m² (2 points), and elevated C-reactive protein (1 point). The receiver operating characteristic curve was 0.832 (95% confidence interval [Cl], 0.767-0.897) for the simplified model and 0.816 (95% Cl, 0.771-0.860) for the cross-validation.

CONCLUSIONS

We developed and internally validated a user-friendly prediction model to guide personalized decision-making using available clinical data and few cost-effective laboratory tests. External validation in other centers with different patients is required.

Safety Profile of Biosimilar Filgrastim (Zarzio/Zarxio): A Combined Analysis of Phase III Studies

BACKGROUND

Evaluation of adverse events (AEs) in pivotal registration trials and ongoing postmarketing surveillance is important for all biologics, including biosimilars. A combined analysis of two pivotal registration studies was performed to strengthen evidence on safety for biosimilar filgrastim EP2006 in patients with breast cancer receiving myelosuppressive chemotherapy, a sensitive clinical setting to confirm biosimilarity of filgrastim.

MATERIALS AND METHODS

Data were combined from two phase III studies of biosimilar filgrastim EP2006. The U.S. registration study was a randomized, double-blind comparison of biosimilar and reference filgrastim in women aged ≥18 years with breast cancer, receiving (neo)adjuvant treatment with TAC (docetaxel + doxorubicin + cyclophosphamide). The European Union registration study was a single-arm, open-label study of biosimilar filgrastim in women aged ≥18 years with breast cancer receiving doxorubicin + docetaxel. Patients received filgrastim as a subcutaneous injection on day 2 of each cycle for <14 days or until the absolute neutrophil count reached 10 × 10⁹/L after the expected nadir. Results were combined for cycles 1-4.

RESULTS

A total of 277 patients received biosimilar filgrastim EP2006. Patients had a mean (± standard deviation) age of 51.1 (± 10.8) years, and 78.7% of patients had stage II or III breast cancer. A total of 46 (20.6%) patients receiving biosimilar filgrastim had AEs considered filgrastim-related. The most frequently reported filgrastim-related AEs were musculoskeletal or connective tissue disorders (15.2%), including bone pain (7.2%). One death (due to pulmonary embolism) occurred of a patient receiving biosimilar filgrastim (not considered filgrastim-related). No patient developed antidrug antibodies during the study.

CONCLUSION

Biosimilar filgrastim has a safety profile consistent with previous filgrastim studies and is effective in preventing febrile neutropenia in patients with breast cancer.

IMPLICATIONS FOR PRACTICE

The biosimilar filgrastim EP2006 (Zarzio, Zarxio, biosimilar filgrastim-sndz) has been approved in Europe since 2009 and in the U.S. since 2015. This combined analysis of two phase III studies provides additional clinical evidence that the biosimilar filgrastim EP2006 has a safety profile consistent with previous studies of reference filgrastim and supports large postmarketing studies of EP2006 in Europe. Strengthening the evidence for biosimilar filgrastim can help improve acceptance of biosimilars and increase patient access to biologics.

Cost-efficiency analyses for the US of biosimilar filgrastim-sndz, reference filgrastim, pegfilgrastim, and pegfilgrastim with on-body injector in the prophylaxis of chemotherapy-induced (febrile) neutropenia

AIMS

Guidelines recommend prophylaxis with granulocyte colony-stimulating factor for chemotherapy-induced (febrile) neutropenia (CIN/FN) based on regimen myelotoxicity and patient-related risk factors. The aim was to conduct a cost-efficiency analysis for the US of the direct acquisition and administration costs of the recently approved biosimilar filgrastim-sndz (Zarxio EP2006) with reference to filgrastim (Neupogen), pegfilgrastim (Neulasta), and a pegfilgrastim injection device (Neulasta Onpro; hereafter pegfilgrastim-injector) for CIN/FN prophylaxis.

METHODS

A cost-efficiency analysis of the prophylaxis of one patient during one chemotherapy cycle under 1-14 days' time horizon was conducted using the unit dose average selling price (ASP) and Current Procedural Terminology (CPT) codes for subcutaneous prophylactic injection under four scenarios: cost of medication only (COSTMED), patient self-administration (SELFADMIN), healthcare provider (HCP) initiating administration followed by self-administration (HCPSTART), and HCP providing full administration (HCPALL). Two case studies were created to illustrate real-world clinical implications. The analyses were replicated using wholesale acquisition cost (WAC).

RESULTS

Using ASP + CPT, cost savings achieved with filgrastim-sndz relative to reference filgrastim ranged from $65 (1 day) to $916 (14 days) across all scenarios. Relative to pegfilgrastim, savings with filgrastim-sndz ranged from $834 (14 days) up to $3,666 (1 day) under the COSTMED, SELFADMIN, and HPOSTART scenarios; and from $284 (14 days) up to $3,666 (1 day) under the HPOALL scenario. Similar to the cost-savings compared to pegfilgrastim, filgrastim-sndz achieved savings relative to pegfilgrastim-injector: from $834 (14 days) to $3,666 (1 day) under the COSTMED scenario, from $859 (14 days) to $3,692 (1 day) under SELFADMIN, from $817 (14 days) to $3,649 (1 day) under HPOSTART, and from $267 (14 days) to $3,649 (1 day) under HPOALL. Cost savings of filgrastim-sndz using WAC + CPT were even greater under all scenarios.

CONCLUSIONS

Prophylaxis with filgrastim-sndz, a biosimilar filgrastim, was associated consistently with significant cost-savings over prophylaxis with reference filgrastim, pegfilgrastim, and pegfilgrastim-injector, and this across various administration scenarios.

Expanded access to cancer treatments from conversion to neutropenia prophylaxis with biosimilar filgrastim-sndz

Aim: Biosimilar medicines offer significant cost-savings potential over their reference products, which can be re-allocated to provide access to other cancer treatments on a budget-neutral basis. Methods: Simulation study using cost data for the USA under consideration of several prophylaxis patterns. Results: Potential savings from conversion from reference filgrastim to biosimilar filgrastim-sndz are significant. These savings expand budget-neutral access to novel immunotherapies (obinutuzumab; pembrolizumab) or supportive care (filgrastim-sndz). Conclusion: The combination of biosimilar savings and expanded access increases the value of cancer care as the same supportive care is provided at lower cost, additional cancer care is enabled at no additional cost, and more patients will have access to cancer care.

Comparative study of the number of report and time-to-onset of the reported adverse event between the biosimilars and the originator of filgrastim

PURPOSE

The objective of this study is to specify the most reported adverse events as preferred terms (PTs) and to compare the reported adverse events about some properties including the number of report and time-to-onset (TTO) distribution of the originator of filgrastim Neupogen® and its biosimilars in Europe, using VigiBase®.

METHODS

We identified the biosimilar which was reported as the suspected drug in more than 100 individual case safety reports in Europe. Then, we specified the top ranking 10 PTs in the cases reported with Neupogen® or each biosimilar as the suspected drug. We also compared the TTO of the most reported PTs using the data about the onset date of the PT and the start date of filgrastim. We used Kolmogorov-Smirnov method to detect significant difference.

RESULTS

The total ICSR numbers with Neupogen® and 3 biosimilars, Zarzio®, Nivestim®, and Tevagrastim® were 1,301, 295, 156, and 127, respectively, in Europe. The most reported PTs with Neupogen® were bone pain, pyrexia, and dyspnoea. The TTO of bone pain and pyrexia with Zarzio® (N: 22 and 16, median: 1 and 0.5 days) were significantly shorter than those with Neupogen® (P < 0.01, N: 72 and 33, median: 3.5 and 3 days), respectively. The most reported PTs with biosimilars were drug ineffective and neutropenia.

CONCLUSION

The difference in the TTO was identified between originator filgrastim Neupogen and its biosimilar regarding some PTs, which may suggest the difference in their safety profile. Copyright © 2017 John Wiley & Sons, Ltd.

Over- and under-prophylaxis for chemotherapy-induced (febrile) neutropenia relative to evidence-based guidelines is associated with differences in outcomes: findings from the MONITOR-GCSF study

PURPOSE

In the MONITOR-GCSF study of chemotherapy-induced (febrile) neutropenia with biosimilar filgrastim, 56.6% of patients were prophylacted according to amended EORTC guidelines, but 17.4% were prophylacted below and 26.0% above guideline recommendations.

METHODS

MONITOR-GCSF is a prospective, observational study of 1447 evaluable patients from 140 cancers centers in 12 European countries treated with myelosuppressive chemotherapy for up to 6 cycles receiving biosimilar GCSF prophylaxis. Patients were classified as under-, correctly-, or over-prophylacted with GCSF relative to guideline recommendations based on their chemotherapy risk, individual risk factors, and type of GCSF prophylaxis (primary versus secondary).

RESULTS

Differences between under- (17.4%), correctly- (56.6%), or over-prophylacted (26.0%) groups were found in terms of patient risk factors (age, performance status, history of FN, comorbid conditions) as well as prophylaxis patterns (type of prophylaxis, day of GCSF initiation, and GCSF duration). Rates of chemotherapy-induced neutropenia (CIN) (all grades), FN, and CIN-related hospitalizations were consistently lower in over-prophylacted patients relative to under- and correctly-prophylacted patients. No differences were observed between under- and correctly-prophylacted patients except for CIN/FN-related chemotherapy disturbances. No GCSF safety differences were found between groups (except for headaches).

CONCLUSIONS

The real-world evidence provided by the MONITOR-GCSF study indicates that providing GCSF support may yield better CIN, FN, and CIN/FN-related hospitalization outcomes if patients are prophylacted at levels above guideline recommendations. Patients who are under-prophylacted are at higher risk for disturbances to their chemotherapy regimens. Our findings support the guideline recommendation that CIN/FN risk be assessed at the beginning of each chemotherapy cycle.

Chemotherapy-induced (febrile) neutropenia prophylaxis with biosimilar filgrastim in elderly versus non-elderly cancer patients: Patterns, outcomes, and determinants (MONITOR-GCSF study)

BACKGROUND

Myelotoxic chemotherapy is associated with chemotherapy-induced (febrile) neutropenia (CIN/FN). The MONITOR-GCSF study evaluated biosimilar filgrastim (Zarzio®) prophylaxis patterns, associated outcomes, and determinants. We performed stratified analyses comparing elderly and non-elderly patients.

METHODS

Comparative (elderly/non-elderly) analysis of demographics and clinical status, prophylaxis, associated CIN/FN outcomes (CIN grade 4 [CIN4], FN, CIN/FN-related hospitalizations and chemodisturbances, composite), and, per hierarchical modeling, determinants thereof evaluated at the patient- and cycle-level.

RESULTS

There were no significant differences between both cohorts in prophylaxis initiation/duration and associated outcomes, but proportionately more elderly patients were correctly-prophylacted and fewer over-prophylacted. Common determinants of poor CIN/FN outcomes included concomitant antibiotic prophylaxis, impaired performance status, and any grade CIN in a previous cycle, whereas common determinants of good outcomes included over-prophylaxis and prophylaxis initiation within 24-72h. In the elderly, female gender, liver/renal/cardiovascular disease, secondary prophylaxis, and under-prophylaxis were associated with poorer outcomes. In the non-elderly, CIN4 at baseline or in a prior cycle was associated with poorer CIN/FN outcomes, and higher biosimilar filgrastim dose and, perhaps counter-intuitively, under-prophylaxis with better outcomes.

CONCLUSION

Adequate GCSF support is essential for all patients, but especially for elderly patients with serious chronic disease, certainly, if concomitant antibiotic prophylaxis is indicated and if a CIN4 episode occurred in a prior cycle. The potential impact of impaired performance status, especially ECOG≥2 at chemotherapy start or a worsening to such during chemotherapy; under-prophylaxis, including inadequate secondary prophylaxis, should be considered in elderly patients. Timely GCSF initiation and over-prophylaxis is associated with lower rates of adverse CIN/FN events in elderly and non-elderly patients, and should be further evaluated in prospective randomized trials.