Clinical Outcomes of Treatment with Filgrastim Versus a Filgrastim Biosimilar and Febrile Neutropenia-Associated Costs Among Patients with Nonmyeloid Cancer Undergoing Chemotherapy

Real-World Noninferiority Assessment of Two Filgrastim Biosimilars in Patients Receiving Myelosuppressive Chemotherapy

PURPOSE

Although multiple filgrastim biosimilars are now available in the United States, no studies comparing clinical outcomes between products have been reported. This analysis evaluated real-world outcomes of filgrastim-aafi and filgrastim-sndz in patients with select solid tumors receiving myelosuppressive chemotherapy to compare the two filgrastim biosimilars.

METHODS

This was an observational, noninferiority, cohort study of patients from three integrated health care systems who received myelosuppressive chemotherapy and were prophylactically initiated on filgrastim-sndz between January and November 2021 or filgrastim-aafi between June and November 2022. Patients were followed from filgrastim biosimilar initiation until the start of their next chemotherapy cycle. The primary outcome of severe neutropenia was analyzed using a binary noninferiority test with a 5% upper margin. Secondary outcomes included the incidence of emergency department or hospital encounters due to febrile neutropenia and systemic antibiotic/antifungal medication use. If noninferiority was met, adjusted logistic regression modeling was conducted.

RESULTS

A total of 2,730 patients who initiated filgrastim-aafi (n = 880) or filgrastim-sndz (n = 1,850) during the study period were included. The overall mean age was 55 years, 87.4% were female, 42.3% were White, and 76.6% had breast cancer. Severe neutropenia occurred in 1.8% and 1.7% of patients initiated on filgrastim-aafi and filgrastim-sndz, respectively (P < .01 for noninferiority). The adjusted odds ratio for severe neutropenia with filgrastim-aafi compared with filgrastim-sndz was 0.91 (95% CI, 0.49 to 1.68; P = .76). Noninferiority was met for all secondary outcomes (P < .01), and there were no adjusted statistically significant differences between the groups (all P > .05).

CONCLUSION

Among patients with select solid tumors receiving myelosuppressive chemotherapy, severe neutropenia outcomes were comparable between filgrastim-aafi and filgrastim-sndz biosimilars. Findings from this study may support utilization of different filgrastim biosimilars in clinical practice.

Efficacy and safety of biosimilar Peg-filgrastim after autologous stem cell transplant in myeloma and lymphoma patients: a comparative study with biosimilar Filgrastim, Lenograstim, and originator Peg-filgrastim

Data about biosimilar Peg-filgrastim (bioPEG) in autologous stem cell transplant (ASCT) are still scarce. The aim of this study has been to assess efficacy and safety of bioPEG among lymphoma and myeloma patients undergoing ASCT, comparing these data with historical controls receiving other G-CSFs. Furthermore, an economic evaluation has been included to estimate the savings by using bioPEG. This is a prospective cohort study comparing lymphoma and myeloma patients undergoing ASCT and receiving bioPEG (n = 73) with three historical consecutive cohorts collected retrospectively who received other G-CSFs (Lenograstim - Leno - n = 101, biosimilar Filgrastim - bioFIL n = 392, and originator Peg-filgrastim - oriPEG n = 60). We observed a significantly shorter time to neutrophils and platelet engraftment (p < 0.001) in patients treated with bioPEG and oriPEG. Moreover, patients who received bioPEG showed a shorter hospitalization time (p < 0.001) and a lower transfusion need (p < 0.001). We did not observe any significant difference in terms of transplant-related mortality, mucositis, and diarrhea among the four groups. No serious adverse events were associated with bioPEG. Similar data were obtained after running a stratified analysis for lymphomas and myeloma separately conducted by using a propensity score matching. The average total cost per patient of bioPEG was € 18218.9 compared to € 23707.8, € 20677.3 and € 19754.9 of Leno, oriPEG, and bioFIL, respectively. In conclusion, bioPEG seems to be as effective as the originator and more effective than short-acting G-CSFs in terms of post-transplant engraftment in myeloma and lymphoma patients undergoing ASCT. Moreover, bioPEG was cost-effective when compared with the other G-CSFs.

Comparative effectiveness of pegfilgrastim biosimilars vs originator for prevention of febrile neutropenia: A retrospective cohort study

BACKGROUND: Real-world evidence on the comparative effectiveness of pegfilgrastim biosimilars compared with the originator product is limited. OBJECTIVE: To compare the risk of febrile neutropenia (FN) among users of pegfilgrastim biosimilars (pegfilgrastim-jmdb and pegfilgrastim-cbqv) and the originator product. METHODS: A retrospective cohort study was conducted using 2019 IBM MarketScan databases to assess comparative effectiveness of pegfilgrastim originator and biosimilars for prevention of FN among patients receiving myelosuppressive chemotherapy. Patients with cancer, including breast, lung, colorectal, esophageal and gastric, pancreatic, prostate, ovarian, and non-Hodgkin lymphomas, initiating myelosuppressive chemotherapy courses were selected. We further selected patients who used pegfilgrastim originator and biosimilars within 3 days of chemotherapy completion. FN-associated hospitalizations were measured by International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis codes. After 1:1 propensity score matching, we used equivalence (with a margin of 6%) hypothesis tests to compare FN-related hospitalization risk in the first cycle and across all cycles between biosimilars and originator users. RESULTS: A total of 2,045 patients were included, of which 445 (21.8%) used pegfilgrastim-jmdb, 636 (31.1%) used pegfilgrastim-cbqv, and 964 (47.1%) used pegfilgrastim originator. After matching, 13 out of 445 originator users and 17 out of 445 pegfilgrastim-jmdb users developed FN after the first chemotherapy cycle (risk difference was 0.9%; P < 0.001 for equivalence test indicating statistical equivalence). After matching, 14 out of 633 originator users and 16 out of 633 pegfilgrastim-cbqv users developed FN (risk difference was 0.32%; P < 0.001 for equivalence test indicating statistical equivalence). Results across all cycles (including the first cycle) were consistent with that in the first cycle. CONCLUSIONS: In this real-world study of patients with cancer receiving myelosuppressive chemotherapy, there was no difference in FN risk between patients receiving pegfilgrastim originator and biosimilars in the first cycle and across all cycles. These results add further to the current evidence on pegfilgrastim biosimilars and support wider adoption of pegfilgrastim biosimilars among payers, providers, and patients. Future studies assessing the tolerability, side effects, and other safety issues of pegfilgrastim biosimilars are needed.

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.

Patterns of primary prophylactic granulocyte colony-stimulating factor use in older Medicare patients with cancer receiving myelosuppressive chemotherapy

PURPOSE

Guidelines recommend primary prophylactic (PP) granulocyte colony stimulating factor (G-CSF) for prevention of febrile neutropenia (FN) in patients receiving myelosuppressive chemotherapy with high risk (HR: > 20%), or intermediate risk (IR:10-20%) of FN and ≥ 1 patient risk factor (e.g., age ≥ 65y). The current retrospective cohort study describes patterns of PP-G-CSF in older Medicare patients undergoing myelosuppressive chemotherapy with HR/IR of FN.

METHODS

Patients aged ≥ 66y initiating chemotherapy regimens with HR/IR of FN to treat breast, colorectal, lung, or ovarian cancer, or Non-Hodgkin's Lymphoma were selected using Medicare 20% sample (2013-2015) and 100% cancer patient (2014-2017) data. PP-G-CSF use was identified in the first cycle. Timing of pegfilgrastim pre-filled syringe (PFS) administration, proportion of patients completing all cycles (adherence) with pegfilgrastim PFS or on-body injector (OBI), and duration of short-acting G-CSF (sG-CSF) was described across all cycles.

RESULTS

Of 64,893 patients receiving HR/IR for FN, 71% received HR and 29% IR regimens. Overall, PP-G-CSF use in the first cycle was 53% (HR: 74%; IR: 44%) and varied across cancers. Adherence with pegfilgrastim was slightly higher among OBI initiators (78%) than PFS (74%). Number of PP-sG-CSF administrations (mean [SD]) per cycle was 5.1 (SD: 2.7) overall, 5.4 (2.6) for HR, and 4.9 (2.7) for IR.

CONCLUSION

Despite cancer treatment guidelines recommending PP-G-CSF use to reduce risk of FN associated with HR and IR (with ≥ 1 patient risk-factor) regimens, PP-G-CSF remains underutilized in older patients, across cancer types and regimens. Opportunities exist for improvement in use of PP-G-CSF.

The Real-World Experience of the Biosimilar (Grastofil®) to the Reference Biologic (Neupogen®) in Breast Cancer and Lymphoma: A Canadian Single-Centre Retrospective Study

Febrile neutropenia (FN) is a common side effect of cytotoxic chemotherapy that may result in poor treatment outcomes. The short acting granulocyte colony stimulating factors (G-CSF) act to stimulate granulocytes to increase production of white blood cells. The filgrastim biosimilar is useful, as it may provide a cheaper and equally effective treatment to FN. This study explored the usage of the filgrastim biosimilar (Grastofil^®) and the reference biologic (Neupogen^®) in breast cancer and lymphoma patients. A retrospective chart review of patients receiving Grastofil^® from January 2017 to June 2019 or Neupogen^® for primary prophylaxis of FN from January 2013 to December 2017 was conducted. The endpoints included the incidence of FN and the occurrence of dose reduction (DR) and dose delay (DD). One hundred and fifty-three Grastofil^® patients were matched to 153 Neupogen^® patients. This cohort was further split into breast cancer (n = 275) and non-Hodgkin’s lymphoma (n = 31) cohorts. After adjusting for chemotherapy cycles, the biosimilar filgrastim was non-inferior to the reference biologic based on FN incidence in addition to related outcomes including DR and DD.

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.

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.

Economic Analysis on Adoption of Biosimilar Granulocyte Colony-Stimulating Factors in Patients With Nonmyeloid Cancer at Risk of Febrile Neutropenia Within the Oncology Care Model Framework

Value-based programs, such as the Oncology Care Model (OCM), seek to improve care for patients undergoing chemotherapy, while reducing total costs. The purpose of this study is to quantify the impact of adopting biosimilar granulocyte colony-stimulating factors (G-CSFs) for febrile neutropenia (FN) primary prophylaxis (PP) from a US practice perspective.

Biosimilar Pegfilgrastim: Improving Access and Optimising Practice to Supportive Care that Enables Cure

Febrile neutropenia (FN) is a serious complication of chemotherapy, which can cause significant morbidity and mortality, result in dose delays and reductions and, ultimately, reduce cancer survival. Over the past decade, the availability of biosimilar filgrastim (short-acting granulocyte colony-stimulating factor [G-CSF]) has transformed patient access, with clear evidence of clinical benefit at preventing FN at reduced costs. In 2019, seven biosimilar pegfilgrastims (long-acting G-CSFs) were licensed, creating optimal market conditions and choice for prescribers. FN affects up to 117 per 1000 cancer patients, with mortality rates in the range of 2–21%. By reducing FN incidence and improving chemotherapy relative dose intensity (RDI), G-CSF has been associated with a 3.2% absolute survival benefit. Guidelines recommend primary prophylaxis and that filgrastim be administered for 10–14 days, while pegfilgrastim is administered once per cycle. When taken according to the guidelines, pegfilgrastim and filgrastim are equally effective. However, in routine clinical practice, filgrastim is often under-dosed (< 7 days) and has been shown to be inferior to pegfilgrastim at reducing FN incidence, hospitalisations and maintaining RDI. Once-per-cycle administration with pegfilgrastim might also aid patient adherence. The introduction of biosimilar pegfilgrastim should instigate a rethink of neutropenia management. Biosimilar pegfilgrastim offers countries using biosimilar filgrastim opportunities to improve adherence and thus cancer survival, whilst offering economic benefits for countries using reference pegfilgrastim. These benefits can be realised in full if biosimilar pegfilgrastim becomes part of routine clinical practice supported by drug and therapeutic committees implementing guidelines with multidisciplinary support in the hospital.

A retrospective review of the real-world experience of the Pegfilgrastim biosimilar (Lapelga®) to the reference biologic (Neulasta®)

Introduction

Cancer patients receiving myelosuppressive chemotherapy are vulnerable to febrile neutropenia (FN) which contributes to poor treatment outcomes. The use of granulocyte colony-stimulating factors is administered to prevent chemotherapy-induced neutropenia. The introduction of biosimilars has allowed for greater cost-savings while maintaining safety and efficacy. This retrospective study assessed the incidence of FN and related treatment outcomes and the cost minimization of a pegfilgrastim biosimilar and its reference.

Methods

A retrospective chart review of breast cancer patients receiving (neo) adjuvant chemotherapy from February 2017 to May 2020 was conducted. The endpoints included the incidence of FN, the occurrence of dose reduction (DR), dose delay (DD) and pain. A cost minimization analysis was performed from a third-party payer perspective.

Results

One hundred Neulasta® and 74 Lapelga® patients were included in the first-cycle analysis. The rate of FN in cycle 1 for Neulasta® and Lapelga® was 2/100 and 4/74, respectively; risk difference (RD)  =  3.4%; 95% CI: –2.4 to 9.2%. Eighty-three Neulasta® and 59 Lapelga® patients were included in the all-cycle analyses, where DR was reported in 76 (15%) Neulasta® cycles vs 33 (10%) Lapelga® cycles (RD = –3.6, 95% CI: –10.2 to 2.9). DD was reported in 20 (4%) Neulasta® cycles vs. 11 (3.5%) Lapelga® cycles (RD = –0.3; 95% CI: –2.7 to 2.0). Adverse events were similar between groups. Cost minimization using a cohort of 20,000 patients translated into an incremental savings of $21,606,800 CAD for each cycle.

Conclusion

The biosimilar pegfilgrastim was non-inferior to the reference biologic based on FN incidence in addition to related outcomes including DR and DD.

Patterns of granulocyte colony-stimulating factor prophylaxis in patients with cancer receiving myelosuppressive chemotherapy

Purpose

To evaluate patterns of primary prophylactic (PP) granulocyte colony–stimulating factor (G-CSF) use following chemotherapy by cancer type and febrile neutropenia (FN) risk.

Methods

Using a commercial administrative database, we identified adult patients diagnosed with breast, colorectal, lung, ovarian cancer, or non-Hodgkin lymphoma (NHL) who initiated chemotherapy with high risk (HR) or intermediate risk (IR) for FN between January 1, 2013, and August 31, 2017. We describe use of PP-G-CSF, proportion completing all their cycles with pegfilgrastim, timing of pegfilgrastim, and duration of short-acting G-CSF.

Results

Among 22,868 patients (breast 11,513; colorectal 3765; lung 4273; ovarian 1287; and NHL 2030), 36.8% received HR and 63.2% received IR (64.4% of whom had ≥ 1 risk factor [RF] for FN). Proportions of patients receiving PP-G-CSF in the first cycle were 76.1%, 28.2%, and 26.4% among patients receiving HR, IR, and IR plus ≥ 1 RF, respectively. Among breast cancer patients receiving HR regimens and initiating PP-pegfilgrastim, 60.4% (95% confidence interval [CI] 57.2–63.6%) initiating via on-body injector (OBI) and 51.9% (95% CI 48.0–55.8%) initiating via prefilled syringe (PFS) completed all their cycles with OBI and PFS, respectively. Among all cycles with PP-PFS, 8.5% received PFS on the same day as chemotherapy completion. Mean administrations/cycle were 3.2 (standard deviation [SD] 2.3) for filgrastim, 3.0 (SD 1.6) for filgrastim-sndz, and 4.3 (SD 2.5) for tbo-filgrastim.

Conclusions

There is under- and mistimed use of PP-G-CSF among patients at HR for FN. Novel pegfilgrastim delivery devices could help breast cancer patients at HR for FN complete all their cycles with timely prophylaxis.

Electronic supplementary material

The online version of this article (10.1007/s00520-020-05295-2) contains supplementary material, which is available to authorized users.

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.

Incidence of febrile neutropenia during chemotherapy among patients with nonmyeloid cancer receiving filgrastim vs a filgrastim biosimilar

Background

Filgrastim and other granulocyte colony-stimulating factors are recommended to decrease febrile neutropenia (FN) incidence among patients with nonmyeloid cancers undergoing chemotherapy. Data comparing biosimilar filgrastim-sndz with reference filgrastim (filgrastim-ref) are limited outside of clinical trials in the US.

Objective

To compare the incidence of FN across chemotherapy cycles 1-6 between patients treated with filgrastim-sndz vs filgrastim-ref.

Materials and methods

This was a retrospective claims analysis of patients with nonmyeloid cancer enrolled in commercial or Medicare Advantage plans from March 2015 to June 2016 and receiving filgrastim-sndz or filgrastim-ref during ≥1 completed chemotherapy cycle. Patients undergoing hematopoietic stem cell transplantation, pregnant patients, and those with missing data were excluded. FN was identified using the diagnosis codes for neutropenia + fever, neutropenia + bacterial/fungal infection, and neutropenia + infection + fever. Equivalence testing for FN incidence at the cycle level across chemotherapy cycles 1-6 was conducted for filgrastim-sndz vs filgrastim-ref after adjusting for baseline characteristics using inverse probability of treatment weighting. Results were considered equivalent if the 90% CIs for between-cohort differences were within ±6.0%.

Results

The analysis included 3,459 patients (162 filgrastim-sndz and 3,297 filgrastim-ref). Before weighting, the filgrastim-sndz cohort was younger than filgrastim-ref and had a higher proportion of men, a higher proportion with commercial insurance, and lower proportions with granulocyte colony-stimulating factor prophylaxis or metastatic cancer. After weighting, baseline characteristics were similar between cohorts. Adjusted FN incidence was equivalent for filgrastim-sndz vs filgrastim-ref, respectively: neutropenia + fever, 0.81% vs 0.61% (difference [90% CI]=0.20 [-0.57 to 1.56]); neutropenia + infection, 1.21% vs 1.33% (difference [90% CI]=-0.12 [-1.17 to 2.28]); neutropenia + infection + fever, 0.0% vs 0.14% (difference=-0.14; CI not calculated because filgrastim-sndz had 0 events).

Conclusion

Filgrastim-sndz and filgrastim-ref are statistically equivalent for preventing FN across chemotherapy cycles 1-6 among patients with nonmyeloid cancer.

Home administration of filgrastim (Nivestim™) in primary prophylaxis of chemotherapy-induced febrile neutropenia

BACKGROUND

The granulocyte-colony stimulating factor (G-CSF) biosimilar filgrastim (Nivestim™) reduces the duration and severity of neutropenia and the frequency of occurrence of febrile neutropenia (FN). Administration of this biosimilar filgrastim and the patient population receiving it at home have not been sufficiently documented in day-to-day medical practice. Insight into home administration may help optimize the management of FN in this setting, potentially at a reduced cost and patient burden vs hospital administration.

MATERIALS AND METHODS

This was a prospective, non-interventional, non-comparative, multisite study involving 171 patients across 29 sites treated with at least one dose of filgrastim. Mean age was 59.3 years, and most patients were female and G-CSF-naïve. The data collected originated from paper-based patient questionnaires and routine documentation by the treating physicians. The primary endpoint was the characterization of patients treated with filgrastim. Secondary endpoints were satisfaction with filgrastim, effectiveness, safety and tolerability, and compliance with prescription.

RESULTS

Most patients had solid tumors (95.9%), mainly located in the breast, while 4.7% had malignant hematological disease. Solid tumors were recorded as grade 1 (7.9%), grade 2 (28.0%), grade 3 (45.7%), and grade 4 (3.0%), and the majority of patients classified at TNM Stages I and II. Many patients (71.0%) could self-inject filgrastim and 72.2% found the handling instructions "extremely straightforward and easy to understand" at least once. Nearly all (99.4%) patients found the syringes "easy to use" at least once and 91.7% were willing to continue home administration. The mean patient satisfaction score for home administration was 1.9±0.9, ranging from 1 (very satisfied) to 6 (absolutely dissatisfied). No cases of neutropenia were observed and only one event of FN occurred.

CONCLUSION

Home-based prophylaxis for FN with filgrastim was found to be effective, well tolerated, and well received by patients (ClinicalTrials.gov Identifier: NCT02956967).