Clinical safety of biosimilar recombinant human granulocyte colony-stimulating factors

Balancing Benefits and Risks: A Literature Review on Hypersensitivity Reactions to Human G-CSF (Granulocyte Colony-Stimulating Factor)

Human granulocyte colony-stimulating factor (G-CSF) is a granulopoietic growth factor used in the treatment of neutropenia following chemotherapy, myeloablative treatment, or healthy donors preparing for allogeneic transplantation. Few hypersensitivity reactions (HRs) have been reported, and its true prevalence is unknown. We aimed to systematically characterize G-CSF-induced HRs while including a comprehensive list of adverse reactions. We reviewed articles published before January 2024 by searching in the PubMed, Embase, Cochrane Library, and Web of Science databases using a combination of the keywords listed, selected the ones needed, and extracted relevant data. The search resulted in 68 entries, 17 relevant to our study and 7 others found from manually searching bibliographic sources. A total of 40 cases of G-CSF-induced HR were described and classified as immediate (29) or delayed (11). Immediate ones were mostly caused by filgrastim (13 minimum), with at least 9 being grade 5 on the WAO anaphylaxis scale. Delayed reactions were mostly maculopapular exanthemas and allowed for the continuation of G-CSF. Reactions after first exposure frequently appeared and were present in at least 11 of the 40 cases. Only five desensitization protocols have been found concerning the topic at hand in the analyzed data. We believe this study brings to light the research interest in this topic that could benefit from further exploration, and propose regular updating to include the most recently published evidence.

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.

Diagnosis and management of neutropenia in children: The approach of the Study Group on Neutropenia and Marrow Failure Syndromes of the Pediatric Italian Hemato-Oncology Association (Associazione Italiana Emato-Oncologia Pediatrica - AIEOP)

Neutropenia refers to a group of diseases characterized by a reduction in neutrophil levels below the recommended age threshold. The present study aimed to review the diagnosis and management of neutropenia, including a diagnostic toolkit and candidate underlying genes. This study also aimed to review the progress toward the definition of autoimmune and idiopathic neutropenia rising in infancy or in late childhood but without remission, and provide suggestions for efficient diagnostics, including indications for the bone marrow and genetic testing. The management and treatment protocols for common and unique presentations are also reviewed, providing evidence tailored to a single patient.

Efficacy and Safety of Nivestim Versus Neupogen for Mobilization of Peripheral Blood Stem Cells for Autologous Stem Cell Transplantation

A retrospective cohort study was conducted in Singapore General Hospital to study the safety and efficacy of biosimilar granulocyte-colony stimulating factor (G-CSF) Nivestim for chemo-mobilization of stem cells for autologous stem cell transplant (autoSCT). All patients who underwent an autoSCT between January 2011 and December 2016 were screened for eligibility. A total of 194 patients were screened, and 131 were included. Nivestim was used in 65 patients and the originator G-CSF (Neupogen) in 66. Patient characteristics were similar between both arms except for chemo-mobilization regimen used (p < 0.0001). Mobilization success rates were found to be comparable, at 96.9% (Nivestim) and 97% (Neupogen). Adverse events rates were also similar. Median duration of G-CSF use and hospitalization were both found to be shorter in the Nivestim arm. Median drug acquisition cost per mobilization cycle was significantly lower in the Nivestim arm at $533.40 (range $213.40–$1280.20) as compared to $1261.90 (range $574–$2755.20) in the Neupogen arm (p < 0.0001). No difference was observed for neutrophil and platelet engraftment after autoSCT. Nivestim was found to be safe and non-inferior to Neupogen for chemo-mobilization of stem cells for autoSCT, and associated with lower cost and shorter length of hospitalization.

Real-world safety experience of tevagrastim/ratiograstim/biograstim and tbo-filgrastim, short-acting recombinant human granulocyte colony-stimulating factors

PURPOSE

Recombinant granulocyte colony-stimulating factors (rG-CSFs), such as filgrastim, are administered to prevent complications in patients receiving chemotherapy. In Europe, a biosimilar to filgrastim, tevagrastim/ratiograstim/biograstim, was approved in 2008. In the USA, the same product was approved as tbo-filgrastim under a 351(a) biologic license application in 2012 with the brand name Granix®. Postmarket surveillance remains a priority for monitoring the safety of biologics and biosimilars to identify rare and immunogenicity-related events. We report the global and US pharmacovigilance data for tevagrastim/ratiograstim/biograstim and tbo-filgrastim, respectively.

METHODS

Cumulative exposure and adverse event data from initial approval in Europe to December 31, 2016, were collected globally from spontaneous reports submitted by healthcare professionals and consumers, scientific literature, competent authorities, and solicited case reports from non-interventional studies. A separate search was conducted on the global data set to identify reports originating from the USA and Puerto Rico to describe the US experience.

RESULTS

Overall, the global safety profile of tevagrastim/ratiograstim/biograstim in the postmarket, real-world setting was comparable to clinical trial experience. Postmarket safety experience of tbo-filgrastim in the USA was consistent with global data. The most common SAEs were febrile neutropenia and decreased white blood cell count. The most common non-serious event was bone pain. There was no evidence of immunogenicity.

CONCLUSIONS

This pharmacovigilance analysis indicates that postmarket experience of tevagrastim/ratiograstim/biograstim and tbo-filgrastim is consistent with clinical trials. Adverse reactions associated with the originator rG-CSF (capillary leak syndrome and glomerulonephritis) have not been observed with tevagrastim/ratiograstim/biograstim or tbo-filgrastim during the postmarket period.

Quality Comparison of Biosimilar and Copy Filgrastim Products with the Innovator Product

Purpose

Filgrastim, a recombinant human granulocyte-colony stimulating factor, is widely used to treat congenital and acquired neutropenia. Following patent expiration of the innovator filgrastim product, biosimilar filgrastim products have been approved in the EU and shown to be comparable with the innovator with respect to quality, safety and efficacy. In less regulated markets, copy filgrastim products are available but data about their quality are scarce. In the present study, we provide a head-to-head comparative study on the quality of biosimilar and copy filgrastim products.

Methods

Innovator filgrastim product, Neupogen®, two EU-licensed biosimilars, Zarzio® and Tevagrastim®, and two copy filgrastim products, Biocilin® and PDgrastim®, were subjected to peptide mapping, circular dichroism spectroscopy, fluorescence spectroscopy, sodium dodecyl sulfate polyacrylamide gel electrophoresis, high performance size-exclusion chromatography, reversed-phase ultra-performance liquid chromatography, endotoxin test, flow imaging microscopy and in vitro potency assay.

Results

Zarzio® and Tevagrastim® have comparable quality to Neupogen®, while Biocilin® showed a significantly lower and PDgrastim® a higher specific activity. Moreover, PDgrastim® showed a higher level of impurities and a lower thermo stability than the other products.

Conclusions

Except for the deviating specific activities of the two copy filgrastim products, we found no substantial differences in product quality between the filgrastim products studied.

Comparison of biosimilar filgrastim with a reference product: pharmacokinetics, pharmacodynamics, and safety profiles in healthy volunteers

Purpose

Filgrastim, a granulocyte-colony stimulating factor, is used to treat patients with neutropenia, including neutropenic fever. Leucostim^® is a recombinant filgrastim product tested for biosimilarity with its reference product, Neupogen^®. We conducted a comparative clinical trial of the 2 products.

Patients and methods

A randomized, open-label, 2-way crossover, single-dose Phase I study was conducted for 56 healthy subjects. After a 5 and 10 μg/kg single subcutaneous administration of test and reference product, pharmacokinetic and pharmacodynamic parameters (absolute neutrophil count and CD34⁺ cell count) were compared. During the study, safety tests and adverse event monitoring were performed.

Results

The test and the reference products had a comparable pharmacokinetic, pharmacodynamic, and safety profile. In both 5 and 10 μg/kg dosing, the 90% CIs of the test to reference ratio for primary parameters (peak plasma concentration and area under the plasma concentration vs time curve from time 0 extrapolated to the infinite time for plasma filgrastim concentration; maximal effect and area under the time-effect curve from time 0 to time of the last quantifiable effect for absolute neutrophil count) were within the 0.8–1.25 range. In addition, safety profiles between the 2 products were similar without any serious adverse events.

Conclusion

This study has provided firm clinical evidence that the test filgrastim product is similar to its reference filgrastim product.

Biosimilar filgrastim vs filgrastim: a multicenter nationwide observational bioequivalence study in patients with chemotherapy-induced neutropenia

Background

We studied the comparative effectiveness of biosimilar filgrastim vs original filgrastim in patients with chemotherapy-induced neutropenia.

Patients and methods

This multicenter, observational study was conducted at 14 centers. The study included 337 patients experiencing neutropenia under chemotherapy. Patients were given either filgrastim 30 MIU or 48 MIU (Neupogen^®) or biosimilar filgrastim 30 MIU (Leucostim^®). Data regarding age, chemotherapeutic agents used, number of chemotherapy courses, previous diagnosis of neutropenia, neutrophil count of patients after treatment, medications used for the treatment of neutropenia, and duration of neutropenia were collected. Time to absolute neutrophil count (ANC) recovery was the primary efficacy measure.

Results

Ambulatory and hospitalized patients comprised 11.3% and 45.1% of the enrolled patients, respectively, and a previous diagnosis of neutropenia was reported in 49.3% of the patients, as well. Neutropenia occurred in 13.7% (n=41), 45.5% (n=136), 27.4% (n=82), 11.4% (n=34), and 2.0% (n=6) of the patients during the first, second, third, fourth, and fifth cycles of chemotherapy, respectively. While the mean neutrophil count was 0.53±0.48 before treatment, a significant increase to 2.44±0.66 was observed after treatment (p=0.0001). While 90.3% of patients had a neutrophil count <1.49 before treatment, all patients had a neutrophil count ≥1.50 after treatment. Neutropenia resolved within ≤4 days of filgrastim therapy in 60.1%, 56.7%, and 52.6% of the patients receiving biosimilar filgrastim 30 MIU, original filgrastim 30 MIU, and original filgrastim 48 MIU, respectively. However, there was no significant difference between the three arms (p=0.468). Similarly, time to ANC recovery was comparable between the treatment arms (p=0.332).

Conclusion

The results indicate that original filgrastim and biosimilar filgrastim have comparable efficacy in treating neutropenia. Biosimilar filgrastim provides a valuable alternative; however, there is need for further studies comparing the two products in different patient subpopulations.

The Impact of Biosimilars in Supportive Care in Cancer

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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.

Compatibility of Biosimilar Filgrastim with Cytotoxic Chemotherapy during the Treatment of Malignant Diseases (VENICE): A Prospective, Multicenter, Non-Interventional, Longitudinal Study

Introduction

Febrile neutropenia (FN) is a serious and frequent complication of cytotoxic chemotherapy. Biosimilar filgrastim (Nivestim™, Hospira Inc, A Pfizer Company, Lake Forest, IL, USA) is a granulocyte-colony stimulating factor licensed for the treatment of neutropenia and FN induced by myelosuppressive chemotherapy. The primary goal of this VENICE study (ClinicalTrials.gov identifier, NCT01627990) was to observe the tolerability, safety and efficacy of biosimilar filgrastim in patients receiving cancer chemotherapy.

Methods

This was a prospective, multicenter, non-interventional, longitudinal study. Consenting adult patients with solid tumors or hematologic malignancies for whom cytotoxic chemotherapy and treatment with biosimilar filgrastim was planned were enrolled.

Results

Among the enrolled patients (N = 386), 81% were female, with a median age (range) of 61 (22–92) years, with 39% >65 years old. Most patients (n = 338; 88%) had solid tumors and the remainder (n = 49; 13%) had hematological malignancies. The majority of the patients (64%) received biosimilar filgrastim as primary prophylaxis and 36% as secondary prophylaxis. At the follow-up visits, for the majority of patients (95.6%) there had been no change in chemotherapy dose due to FN. For two patients (0.5%) the chemotherapy was discontinued due to FN and for four patients (1.0%) the chemotherapy dose was reduced due to FN. For the majority of patients (96.9%) the chemotherapy cycle following the first biosimilar filgrastim treatment was not delayed due to FN. For 3 patients (0.8%), the chemotherapy was delayed following the first biosimilar filgrastim treatment. Less than one-third (29.8%) of the patients experienced ≥1 adverse event that was at least potentially related to biosimilar filgrastim treatment.

Conclusions

Biosimilar filgrastim was effective and well-tolerated in both the primary and secondary prophylactic setting in patients undergoing chemotherapy for solid tumors and hematological malignancies.

Trial Registration

ClinicalTrials.gov identifier, NCT01627990.

Funding

Hospira Inc, A Pfizer Company, Lake Forest, IL, USA.

Highly sensitive ligand-binding assays in pre-clinical and clinical applications: immuno-PCR and other emerging techniques

Recombinant DNA technology and corresponding innovations in molecular biology, chemistry and medicine have led to novel therapeutic biomacromolecules as lead candidates in the pharmaceutical drug development pipelines. While monoclonal antibodies and other proteins provide therapeutic potential beyond the possibilities of small molecule drugs, the concomitant demand for supportive bioanalytical sample testing creates multiple novel challenges. For example, intact macromolecules can usually not be quantified by mass-spectrometry without enzymatic digestion and isotopically labeled internal standards are costly and/or difficult to prepare. Classical ELISA-type immunoassays, on the other hand, often lack the sensitivity required to obtain pharmacokinetics of low dosed drugs or pharmacodynamics of suitable biomarkers. Here we summarize emerging state-of-the-art ligand-binding assay technologies for pharmaceutical sample testing, which reveal enhanced analytical sensitivity over classical ELISA formats. We focus on immuno-PCR, which combines antibody specificity with the extremely sensitive detection of a tethered DNA marker by quantitative PCR, and alternative nucleic acid-based technologies as well as methods based on electrochemiluminescence or single-molecule counting. Using case studies, we discuss advantages and drawbacks of these methods for preclinical and clinical sample testing.

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.

Clinical safety of tbo-filgrastim, a short-acting human granulocyte colony-stimulating factor

The recombinant human granulocyte colony-stimulating factor (G-CSF) known as filgrastim (Tevagrastim(®), Ratiograstim(®), Biograstim(®)) in Europe (approved in 2008) and tbo-filgrastim (Granix(®)) in the USA (approved in 2012; Teva Pharmaceutical Industries Ltd., Petach Tikva, Israel) is indicated to reduce the duration of severe neutropenia in patients with non-myeloid malignancies receiving myelosuppressive anti-cancer drugs associated with a clinically significant incidence of febrile neutropenia. This article presents pooled clinical data for tbo-filgrastim compared with Neupogen(®) (Amgen, Thousand Oaks, CA, USA) as well as tbo-filgrastim post-marketing safety data. The safety and efficacy of tbo-filgrastim were evaluated in three phase III studies in 677 patients receiving myelosuppressive chemotherapy and study drug (348 patients with breast cancer, 237 with lung cancer, 92 with non-Hodgkin lymphoma). In each study, the efficacy of tbo-filgrastim was similar to that of Neupogen. Overall, 633 (93.5 %) patients receiving the study drug experienced 6093 treatment-emergent adverse events (AEs), most of which were related to chemotherapy. Adverse events related to the study drug (tbo-filgrastim or Neupogen) were experienced by 185 (27.3 %) patients; 19 (2.8 %) had severe drug-related AEs, 5 (0.7 %) had drug-related serious AEs, and 6 (0.9 %) discontinued the study due to drug-related AEs. Overall, the most common drug-related AEs were bone pain (7.1 %), myalgia (4.0 %), and asthenia (4.4 %). The post-marketing safety profile of tbo-filgrastim was consistent with that observed during the clinical studies. The availability of tbo-filgrastim, a G-CSF with safety and efficacy comparable to those of Neupogen, provides physicians with an alternative treatment option for supportive care of patients with non-myeloid malignancies receiving myelosuppressive chemotherapy.

Comparison of EP2006, a filgrastim biosimilar, to the reference: a phase III, randomized, double-blind clinical study in the prevention of severe neutropenia in patients with breast cancer receiving myelosuppressive chemotherapy

This randomized, double-blind comparison demonstrates that biosimilar filgrastim (EP2006) and the US-licensed reference filgrastim are similar with no clinically meaningful differences regarding efficacy and safety in prevention of severe neutropenia. Biosimilar filgrastim could represent an important alternative to the reference product, potentially increasing access to filgrastim treatment.

Background

Biosimilars of filgrastim are in widespread clinical use in Europe. This phase III study compares biosimilar filgrastim (EP2006), with the US-licensed reference product, Neupogen^®, in breast cancer patients receiving (neo)adjuvant myelosuppressive chemotherapy (TAC).

Patients and methods

A total of 218 patients receiving 5 µg/kg/day filgrastim over six chemotherapy cycles were randomized 1:1:1:1 into four arms. Two arms received only one product (nonalternating), biosimilar or reference, and two arms (alternating) received alternating treatments during each cycle (biosimilar then reference or vice versa). The primary end point was duration of severe neutropenia (DSN) during cycle 1.

Results

The baseline characteristics were balanced between the four treatment arms. Noninferiority of biosimilar versus the reference was demonstrated: DSN (days) in cycle 1 was 1.17 ± 1.11 (biosimilar, N = 101) and 1.20 ± 1.02 (reference, N = 103), 97.5% confidence interval lower boundary for the difference was −0.26 days (above the predefined limit of −1 day). No clinically meaningful differences were observed regarding any other efficacy parameter: incidence of febrile neutropenia (FN); hospitalization due to FN; incidence of infections; depth and time of absolute neutrophil count (ANC) nadir and time to ANC recovery during cycle 1 and across all cycles. The pattern and frequency of adverse events were similar across all treatments.

Conclusion

This study demonstrates that biosimilar and the reference filgrastim are similar with no clinically meaningful differences regarding efficacy and safety in prevention of severe neutropenia. Biosimilar filgrastim could represent an important alternative to the reference product, potentially benefiting public health by increasing access to filgrastim treatment.

Study number

NCT01519700.

Potential cost savings from chemotherapy-induced febrile neutropenia with biosimilar filgrastim and expanded access to targeted antineoplastic treatment across the European Union G5 countries: a simulation study

PURPOSE

The objectives of this study were to simulate for the European Union G5 countries the potential cost savings of converting patients from originator granulocyte colony-stimulating factor (G-CSF) filgrastim and pegfilgrastim to a biosimilar filgrastim, to evaluate how reallocating these savings could increase patient access to antineoplastic therapy, and to estimate the number of patients needed to convert to provide antineoplastic treatment to one patient.

METHODS

Three models were built: (1) to estimate the costs of using originator G-CSFs and the savings generated from switching to a biosimilar G-CSF, (2) to estimate the incremental number of patients who could be provided antineoplastic therapy-rituximab or trastuzumab-in a hypothetical panel of 10,000 patients with cancer, and (3) to calculate the number of patients needed to convert to provide access to anticancer therapy. Scenarios were developed in which the rate of conversion was varied to estimate the effect on total cost savings. This study took the perspective of the payer in the European Union.

FINDINGS

The savings associated with the biosimilar filgrastim over the originator filgrastim ranged from €785 (day 4) to €2747 (day 14) and increased with longer duration of therapy. By contrast, the savings associated with the biosimilar filgrastim over pegfilgrastim decreased over time, ranging from €6199 (day 4) to €471 (day 14). In a hypothetical panel of 10,000 patients with cancer, the savings associated with the biosimilar filgrastim over the originator filgrastim and the expanded access to antineoplastic therapy improved over time, irrespective of conversion rates. Conversely, in the same hypothetical panel, the savings associated with the biosimilar filgrastim over pegfilgrastim reduced over time, irrespective of conversion rates, along with the expanded access to antineoplastic treatment. Under conversion of the originator filgrastim to the biosimilar filgrastim, the number needed to convert to expand access to rituximab ranged from 4 to 14 patients, and the number needed to convert to expand access to trastuzumab ranged from 11 to 38 patients. Under conversion of pegfilgrastim to the biosimilar filgrastim, the number needed to convert to expand access to rituximab ranged from 2 to 24 patients, and the number needed to convert to expand access to trastuzumab ranged from 5 to 63 patients.

IMPLICATIONS

Use of biosimilar G-CSFs for supportive cancer care could yield potential cost savings and improve patient access to antineoplastic therapy in a budget neutral way-a financial effect with an ethical perspective.

Biosimilar granulocyte-colony-stimulating factor for healthy donor stem cell mobilization: need we be afraid?

Biosimilars are approved biologics with comparable quality, safety, and efficacy to a reference product. Unlike generics, which are chemically manufactured copies of small-molecule drugs with relatively simple chemical structures, the biosimilar designation is applied to drugs that are produced by living organisms, implying much more difficult to control manufacturing and purification procedures. To account for these complexities, the European Medicines Agency (EMA), the US Food and Drug Administration, the Australian Therapeutic Goods Administration, and other regulatory authorities have devised and implemented specific, markedly more demanding pathways for the evaluation and approval of biosimilars. To date, several biosimilars have been approved, including versions of somatropin, erythropoietin, and granulocyte-colony-stimulating factor (G-CSF), and several biosimilar monoclonal antibodies are currently in development. The reference G-CSF product (Neupogen, Amgen) has been used for many years for prevention and treatment of neutropenia and also for mobilization of peripheral blood stem cells (PBSCs). However, concerns have been raised about the safety and efficacy of biosimilar G-CSF during PBSC mobilization procedures, especially in healthy donors. This article reviews the available evidence on the use of biosimilar G-CSF in this setting. Aggregate clinical evidence supports the assessment by the EMA of biosimilar and originator G-CSF as highly biologically similar, with respect to desired and undesired effects.

Regulatory and clinical considerations for biosimilar oncology drugs

Biological oncology products are integral to cancer treatment, but their high costs pose challenges to patients, families, providers, and insurers. The introduction of biosimilar agents-molecules that are similar in structure, function, activity, immunogenicity, and safety to the original biological drugs-provide opportunities both to improve health-care access and outcomes, and to reduce costs. Several international regulatory pathways have been developed to expedite entry of biosimilars into global marketplaces. The first wave of oncology biosimilar use was in Europe and India in 2007. Oncology biosimilars are now widely marketed in several countries in Europe, and in Australia, Japan, China, Russia, India, and South Korea. Their use is emerging worldwide, with the notable exception of the USA, where several regulatory and cost barriers to biosimilar approval exist. In this Review, we discuss oncology biosimilars and summarise their regulatory frameworks, clinical experiences, and safety concerns.

How we manage autologous stem cell transplantation for patients with multiple myeloma

An estimated 22 350 patients had multiple myeloma diagnosed in 2013, representing 1.3% of all new cancers; 10 710 deaths are projected, representing 1.8% of cancer deaths. Approximately 0.7% of US men and women will have a myeloma diagnosis in their lifetime, and with advances in therapy, 77 600 US patients are living with myeloma. The 5-year survival rate was 25.6% in 1989 and was 44.9% in 2005. The median age at diagnosis is 69 years, with 62.4% of patients aged 65 or older at diagnosis. Median age at death is 75 years. The rate of new myeloma cases has been rising 0.7% per year during the past decade. The most common indication for autologous stem cell transplantation in the United States is multiple myeloma, and this article is designed to provide the specifics of organizing a transplant program for multiple myeloma. We review the data justifying use of stem cell transplantation as initial management in myeloma patients. We provide selection criteria that minimize the risks of transplantation. Specific guidelines on mobilization and supportive care through the transplant course, as done at Mayo Clinic, are given. A review of the data on tandem vs sequential autologous transplants is provided.

Biosimilar G-CSF based mobilization of peripheral blood hematopoietic stem cells for autologous and allogeneic stem cell transplantation

The use of granulocyte colony stimulating factor (G-CSF) biosimilars for peripheral blood hematopoietic stem cell (PBSC) mobilization has stimulated an ongoing debate regarding their efficacy and safety. However, the use of biosimilar G-CSF was approved by the European Medicines Agency (EMA) for all the registered indications of the originator G-CSF (Neupogen^®) including mobilization of stem cells. Here, we performed a comprehensive review of published reports on the use of biosimilar G-CSF covering patients with hematological malignancies as well as healthy donors that underwent stem cell mobilization at multiple centers using site-specific non-randomized regimens with a biosimilar G-CSF in the autologous and allogeneic setting.

A total of 904 patients mostly with hematological malignancies as well as healthy donors underwent successful autologous or allogeneic stem cell mobilization, respectively, using a biosimilar G-CSF (520 with Ratiograstim®/Tevagrastim, 384 with Zarzio®). The indication for stem cell mobilization in hematology patients included 326 patients with multiple myeloma, 273 with Non-Hodgkin's lymphoma (NHL), 79 with Hodgkin's lymphoma (HL), and other disease. 156 sibling or volunteer unrelated donors were mobilized using biosimilar G-CSF. Mobilization resulted in good mobilization of CD34+ stem cells with side effects similar to originator G-CSF. Post transplantation engraftment did not significantly differ from results previously documented with the originator G-CSF. The side effects experienced by the patients or donors mobilized by biosimilar G-CSF were minimal and were comparable to those of originator G-CSF.

In summary, the efficacy of biosimilar G-CSFs in terms of PBSC yield as well as their toxicity profile are equivalent to historical data with the reference G-CSF.

Biosimilars: Implications for health-system pharmacists

PURPOSE

An update on scientific and regulatory challenges in the rapidly evolving field of biosimilar product development is presented.

SUMMARY

The U.S. market for biosimilar products (i.e., highly similar "follow-on" versions of approved biological drugs) is expected to expand with establishment of an expedited-approval pathway for biosimilars similar to that implemented in European Union countries eight years ago. In 2012, the Food and Drug Administration (FDA) published draft guidance clarifying the requirements of the biosimilars approval pathway; although no biosimilar has yet been approved via that pathway, FDA is engaged in ongoing meetings with a number of potential applicants. Due to molecular differences between innovator products and biosimilar versions, biosimilars are highly sensitive to manufacturing changes that can potentially have important safety and efficacy implications. Establishing the interchangeability of biosimilar and innovator drugs may be difficult at first, and it is possible that some biosimilars might not carry all the same indications for which the reference drug is approved. Pharmaceutical cost savings attained through the use of biosimilars are expected to average 20-30%. With several top-selling biologicals likely to lose patent exclusivity by 2020, health systems should prepare for the availability of new biosimilars by addressing formulary management and therapeutic interchange issues, pharmacovigilance and patient safety concerns, and related financial and operational issues.

CONCLUSION

Over the coming years, biosimilars will present opportunities for health care organizations to manage the growth of pharmaceutical expenditures. Pharmacists can play a key role in preparing health systems for projected rapid expansion in the use of biosimilars and associated medication-use policy challenges.

Update on the safety and bioequivalence of biosimilars - focus on enoxaparin

Generic forms of chemically-derived drugs must exhibit chemical identity and be bioequivalent in healthy human subjects. The use of generic drugs results in a considerable savings of healthcare expenditures. Biologic drugs are produced in living systems or are derived from biologic material and extend beyond proteins to include antibodies, polysaccharides, polynucleotides, and live viral material. Such drugs pose a challenge to characterize as they tend to be larger in size than chemically-derived drugs, can exhibit a variety of post-translational modifications, and can have activities that are dependent on specific conformations. Biosimilars are not true generics, but rather, exhibit a high degree of similarity to the reference product and are considered to be biologically and clinically comparable to the innovator product. Therefore, the development process for biosimilars is more complex than for a true generic. Guidance is now available from the US Food and Drug Administration and from the European Medicines Agency for the development of biosimilar drugs. Biosimilar drugs are expected to have a major impact in the management of various diseases in coming years.