Granulocyte colony-stimulating factors in the prevention of febrile neutropenia: review of cost-effectiveness models

Mitigating acute chemotherapy-associated adverse events in patients with cancer

Despite the enthusiasm surrounding novel targeted agents and immunotherapies, chemotherapy remains the mainstay treatment for most human malignancies, either alone or in combination. Yet, the burden of chemotherapy-associated adverse events (CAAEs) remains high and, importantly, is associated with considerable morbidity, mortality and costs that affect patients across multiple dimensions, including physical, emotional and social functioning. CAAEs can directly affect patient outcomes and indirectly increase the risk of cancer recurrence by compromising treatment intensity and continuity. Systematic efforts to identify and critically summarize the evidence on management approaches for CAAEs remain limited. Herein, we review the most common acute CAAEs having a major effect on survival, quality of life, function and/or continuation of optimal therapy. We focus on selected acute toxicities that occur during treatment, summarizing their underlying pathophysiology, multifactorial aetiologies, evidenced-based treatments, prevention strategies and management recommendations. We also summarize the available evidence on risk factors, validated risk assessment tools and other efforts to optimize symptom control in patients most likely to benefit in order to personalize the prevention and treatment of acute CAAEs. Finally, we discuss innovative symptom monitoring and supportive care interventions that are under development to further improve the outcomes of patients with cancer.

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.

Patient-Administered Biologic and Biosimilar Filgrastim May Offer More Affordable Options for Patients with Nonmyeloid Malignancies Receiving Chemotherapy in the United States: A Budget Impact Analysis from the Payer Perspective

BACKGROUND

Granulocyte colony-stimulating factors (G-CSFs) are often administered to reduce the incidence, severity, and duration of febrile neutropenia (FN) in chemotherapy patients. Tbo-filgrastim and filgrastim-sndz represent a follow-on biologic and a biosimilar version, respectively, of the short-acting G-CSF filgrastim with comparable efficacy and safety.

OBJECTIVE

To estimate the budget impact of increasing use of patient-(home-) administered tbo-filgrastim and filgrastim-sndz from a U.S. payer perspective.

METHODS

An interactive budget impact model was developed to estimate the changes in drug cost associated with projected increases in the market share of tbo-filgrastim from 5% to 10% and of filgrastim-sndz from 10% to 12% (with a corresponding decrease in filgrastim market share from 85% to 78%) for a 1 million-member health plan among patients with nonmyeloid malignancies receiving chemotherapy with a high risk of FN. Patient self-administration at home was assumed for 20% of patients receiving short-acting G-CSF treatment; all products were purchased through the patient's pharmacy benefit and were assumed to have tier 3 formulary status with a patient copay of $54 per prescription. Base-case data were derived from publicly available resources. The total plan budget impact was calculated using a 1-year time horizon, along with the differences in per member per month and per member per year (PMPY) costs between the current and future scenarios.

RESULTS

The effective annual per-patient drug cost to the plan totaled between $16,961 and $27,199, depending on dosage and packaging, for tbo-filgrastim; between $16,216 and $26,015 for filgrastim-sndz; and between $19,134 and $30,663 for filgrastim. The estimated total annual plan cost associated with patient-administered short-acting G-CSFs was $53,298,217 (PMPY = $53.30) in the current scenario and $52,828,832 (PMPY = $52.82) in the future scenario. Cost savings totaled $469,385 (PMPY = $0.48). The model was most sensitive to changes in the percentage of patients self-administering G-CSF at home and to the wholesale acquisition cost for filgrastim.

CONCLUSIONS

The effective annual plan per-patient drug costs for tbo-filgrastim and filgrastim-sndz were 11% and 15% lower than filgrastim, respectively. The present analysis estimated an annual U.S. health plan cost savings approaching $0.5 million following increases in market shares of approximately 5% for tbo-filgrastim and 2% for filgrastim-sndz.

DISCLOSURES

This study was sponsored by Teva Branded Pharmaceutical Products R & D, which participated in the study design, data interpretation and analysis, the writing of the report, and the decision to submit. Aventine Consulting received consulting fees from Teva Pharmaceuticals and developed the cost model and provided data analysis support. Trautman and James are employed by Aventine Consulting. Szabo and Tang are employed by Teva Pharmaceuticals.