Treatment patterns and outcomes in the prophylaxis of chemotherapy-induced (febrile) neutropenia with biosimilar filgrastim (the MONITOR-GCSF study)

Impact of Guidance on the Prescription Patterns of G-CSFs for the Prevention of Febrile Neutropenia Following Anticancer Chemotherapy: A Population-Based Utilization Study in the Lazio Region

Background

Current guidelines recommend prophylaxis with granulocyte colony-stimulating factors (G-CSFs) for patients with cancer who are at greater risk of febrile neutropenia (FN) while receiving chemotherapy. G-CSF biosimilars are available and represent a savings opportunity; however, their uptake has thus far been low.

Objective

Our objective was to evaluate prescribing patterns for G-CSFs in the prevention of chemotherapy-related FN and to evaluate the impact of regional guidance on G-CSF prescription.

Methods

We conducted an observational drug-utilization study in the Lazio region of Italy using the Electronic Therapeutic Plan Registry, which collects information on G-CSF prescriptions reimbursed by the regional health service. This registry includes information on demographics, tumour, indication for G-CSF use and previous G-CSF exposure. All therapeutic plans (TPs) registered from 1 July 2015 to 30 June 2016 were selected. A pharmaceutical policy intervention was implemented in November 2015. We evaluated temporal trends regarding G-CSF substances and compared the frequency of TPs for each G-CSF substance during the pre- and post-intervention periods.

Results

A total of 7082 TPs were eligible for the analysis, corresponding to 6592 patients. The frequency of TPs prescribed after the intervention indicated a significant increase in the use of a filgrastim biosimilar (% difference: 14.4; p < 0.001) and significant decreases in the use of lenograstim (% difference: –6.0; p < 0.001) and pegfilgrastim (% difference: –7.8; p < 0.001). The temporal trends analysis showed an increase in TPs using a filgrastim biosimilar (from 34.4% in July 2015 to 49.8% in June 2016; p < 0.0001) and a decrease in TPs using lenograstim and pegfilgrastim.

Conclusions

This study shows it is possible to change attitudes towards the prescription of less expensive G-CSFs in the FN setting when the prescriber’s decision-making processes are supported by evidence that includes both regulatory and clinical information and the analysis of clinical practice data.

Electronic supplementary material

The online version of this article (doi:10.1007/s40259-017-0214-9) contains supplementary material, which is available to authorized users.

ZOHé: A Prospective Study of the Use of Biosimilar Filgrastim Zarzio in Clinical Practice in Patients Treated With Chemotherapy for Lymphoid Malignancies

BACKGROUND

The ZOHé study was a prospective, observational, multicenter study in France to assess use of biosimilar filgrastim Zarzio in routine clinical practice in patients undergoing neutropenia-inducing chemotherapy.

PATIENTS AND METHODS

Patients ≥ 18 years undergoing chemotherapy for a malignant disease and with a first prescription for Zarzio were enrolled in 2 cohorts: solid tumor (1174 patients) or hematological malignancy (633 patients); the latter is reported here. Analyses primarily described the prescription and use of Zarzio in current practice, and included identification of factors linked to prescription for primary prophylaxis, comparison of use in relation to European Organisation for the Research and Treatment of Cancer (EORTC) guidelines, and estimation of chemotherapy dose intensity maintenance in patients given Zarzio.

RESULTS

Use of Zarzio in clinical practice was relatively standardized and followed label indication in 96.7% of the analysis population (633 patients). Most patients had ≥ 2 EORTC patient-related risk factors for febrile neutropenia (FN). Chemotherapy dose intensity was maintained in 85.2% of evaluable patients and 89.6% of patients with non-Hodgkin lymphoma receiving R-CHOP (rituximab-cyclophosphamide/doxorubicin/vincristine/prednisone). The safety profile of Zarzio was confirmed.

CONCLUSIONS

In routine clinical practice in France, Zarzio is mostly used as primary prophylaxis for chemotherapy-induced neutropenia in patients with hematological malignancies. Patient-related risk factors appear to have more weight in clinicians' decisions to give Zarzio than the FN risk category of the chemotherapy regimen alone in real-world practice.

How did the Introduction of Biosimilar Filgrastim Influence the Prescribing Pattern of Granulocyte Colony-Stimulating Factors? Results from a Multicentre, Population-Based Study, from Five Italian Centres in the Years 2009-2014

BACKGROUND

Granulocyte colony-stimulating factors (G-CSFs) are biological products for which the main indication of use is chemotherapy-induced neutropenia. Biosimilars of G-CSFs have been available in Europe since 2007.

OBJECTIVE

The objective of this study was to investigate the prescribing pattern of G-CSFs in five Italian centres using different healthcare policy interventions to promote the use of biosimilars in routine care.

METHODS

This retrospective, population-based drug utilization study was conducted during the years 2009-2014 using the administrative databases of the Caserta, Treviso and Palermo Local Health Units (LHUs) and the Tuscany and Umbria regions. G-CSF users were characterized and the prevalence of use, proportion of biosimilar users and switching pattern of different G-CSFs were evaluated over time and across centres.

RESULTS

Overall, 30,247 patients were treated with G-CSFs in the years 2009-2014, of which 29,083 (96.2 %) were naïve users. The overall prevalence of G-CSF use increased from 0.8 per 1000 inhabitants in 2009 to 1.1 per 1000 in 2014. An increase in the proportion of the use of the biosimilar filgrastim by the total G-CSF users was observed in all centres: from 0.2 % (2009) to 66.2 % (2014). However, heterogeneity across different centres was reported, with the largest increase in Treviso LHU (from 0 to 89.1 % from 2009 to 2014). During the first year of treatment, switching between different G-CSFs was frequent (20.3 %).

CONCLUSIONS

Heterogeneity in the use of G-CSF and, in particular, biosimilar filgrastim across different Italian centres was observed, probably due to different regional healthcare policy interventions. During the first year of treatment, switching between different G-CSFs was frequent. Considering the impact of biological drugs on pharmaceutical expenses, it is necessary to harmonize healthcare policies promoting the use of biological drugs with the lowest cost.

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.

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

BACKGROUND

Risk models of chemotherapy-induced (CIN) and febrile neutropenia (FN) have to date focused on determinants measured at the start of chemotherapy. We extended this static approach with a dynamic approach of CIN/FN risk modeling at the start of each cycle.

DESIGN

We applied predictive modeling using multivariate logistic regression to identify determinants of CIN/FN episodes and related hospitalizations and chemotherapy disturbances (CIN/FN consequences) in analyses at the patient ('ever' during the whole period of chemotherapy) and cycle-level (during a given chemotherapy cycle). Statistical dependence of cycle data being 'nested' under patients was managed using generalized estimation equations. Predictive performance of each model was evaluated using bootstrapped c concordance statistics.

RESULTS

Static patient-level risk models of 'ever' experiencing CIN/FN adverse events and consequences during a planned chemotherapy regimen included predictors related to history, risk factors, and prophylaxis initiation and intensity. Dynamic cycle-level risk models of experiencing CIN/FN adverse events and consequences in an upcoming cycle included predictors related to history, risk factors, and prophylaxis initiation and intensity; as well as prophylaxis duration, CIN/FN in prior cycle, and treatment center characteristics.

CONCLUSIONS

These 'real-world evidence' models provide clinicians with the ability to anticipate CIN/FN adverse events and their consequences at the start of a chemotherapy line (static models); and, innovatively, to assess risk of CIN/FN adverse events and their consequences at the start of each cycle (dynamic models). This enables individualized patient treatment and is consistent with the EORTC recommendation to re-appraise CIN/FN risk at the start of each cycle. Prophylaxis intensity (under-, correctly-, or over-prophylacted relative to current EORTC guidelines) is a major determinant. Under-prophylaxis is clinically unsafe. Over-prophylaxis of patients administered chemotherapy with intermediate or low myelotoxicity levels may be beneficial, both in patients with and without risk factors, and must be validated in future studies.

Randomized, double-blind study comparing proposed biosimilar LA-EP2006 with reference pegfilgrastim in breast cancer

AIM

This randomized, double-blind trial compared proposed biosimilar LA-EP2006 with reference pegfilgrastim in women receiving chemotherapy for breast cancer (PROTECT-1).

PATIENTS & METHODS

Women (≥18 years) were randomized to receive LA-EP2006 (n = 159) or reference (n = 157) pegfilgrastim (Neulasta(®), Amgen) for ≤6 cycles of (neo)-adjuvant TAC chemotherapy. Primary end point was duration of severe neutropenia (DSN) during cycle 1 (number of consecutive days with absolute neutrophil count <0.5 × 10(9)/l) with equivalence confirmed if 90% and 95% CIs were within a ±1 day margin.

RESULTS

For DSN, LA-EP2006 was equivalent to reference (difference: 0.07 days; 90% CI: -0.09-0.23; 95% CI: -0.12-0.26).

CONCLUSION

LA-EP2006 and reference pegfilgrastim showed no clinically meaningful differences regarding efficacy and safety in breast cancer patients receiving chemotherapy.

Biosimilars in the management of neutropenia: focus on filgrastim

Advances in chemotherapy and surgery allows the majority of patients to survive cancer diseases. Yet, the price may be a proportion of patients dying of complications due to treatment-induced infectious complications, such as neutropenia. With the aim of decreasing morbidity and mortality related to infectious complications, recombinant human granulocyte colony-stimulating factor (G-CSF), filgrastim, and pegylated filgrastim have been used to reduce time and degree of neutropenia. A biosimilar is a copy of an approved original biologic medicine whose data protection has expired. The patent for filgrastim expired in Europe in 2006 and in the US in 2013. This review analyses the available evidence to be considered in order to design a strategy of use of G-CSF and its biosimilars. The clinical and safety outcomes of biosimilars are well within the range of historically reported data for originator filgrastim. This underscores the clinical effectiveness and safety of biosimilar filgrastim in daily clinical practice. Biosimilars can play an important role by offering the opportunity to reduce costs, thus contributing to the financial sustainability of treatment programs.

Biosimilars: Here and Now

Congress passed the Biologics Price Competition and Innovation Act (BPCI Act) as part of the Affordable Care Act on March 23, 2010. The BPCI Act authorized an approval pathway for biosimilar and interchangeable products. It defines biosimilarity to mean "that the biological product is highly similar to the reference product notwithstanding minor differences in clinically inactive components" and that "there are no clinically meaningful differences between the biological product and the reference product in terms of safety, purity, and potency of the product." The biosimilar pathway has the potential to facilitate access to biologic products through increased competition, in the same manner as biosimilars have done for almost 10 years in Europe. The goal of a biosimilar program is not to independently establish safety and effectiveness for each condition of use. Rather, the goal is to demonstrate biosimilarity through an extensive analytical characterization and a targeted clinical program designed to assess for clinically meaningful differences, if they exist. The regulatory approaches in both the United States and Europe involve a totality-of-the-evidence approach to demonstrate biosimilarity. Importantly, the biosimilar pathway allows for extrapolation of data across indications so that a sponsor, with adequate scientific justification, need not conduct clinical studies in each intended condition of use. Without extrapolation, development may not be feasible for many products, and patients and resources could be diverted from clinical studies of newer agents for cancer.