Peripheral blood stem cell mobilization and engraftment after autologous stem cell transplantation with biosimilar rhG-CSF

Filgrastim biosimilar (EP2006): A review of 15 years' post-approval evidence

Filgrastim is approved for several indications, including reduction of the incidence and duration of chemotherapy-induced neutropenia and for stem cell mobilization. The filgrastim biosimilar, EP2006, has been available in Europe since 2009, and in the United States since 2015. In this time, preclinical and clinical data used to support the approval of EP2006 have been published. These data established the biosimilarity of EP2006 to reference filgrastim in terms of structure, pharmacokinetics, pharmacodynamics, efficacy, safety, and immunogenicity. Additional real-world evidence studies have also demonstrated equivalent efficacy and safety of EP2006 compared with reference filgrastim, both in the reduction of neutropenia and in stem cell mobilization in clinical practice. This review summarizes these preclinical, clinical, and real-world data, as well as the available cost-effectiveness data, for EP2006 since its approval 15 years ago.

Stem Cells Collection and Mobilization in Adult Autologous/Allogeneic Transplantation: Critical Points and Future Challenges

Achieving successful hematopoietic stem cell transplantation (HSCT) relies on two fundamental pillars: effective mobilization and efficient collection through apheresis to attain the optimal graft dose. These cornerstones pave the way for enhanced patient outcomes. The primary challenges encountered by the clinical unit and collection facility within a transplant program encompass augmenting mobilization efficiency to optimize the harvest of target cell populations, implementing robust monitoring and predictive strategies for mobilization, streamlining the apheresis procedure to minimize collection duration while ensuring adequate yield, prioritizing patient comfort by reducing the overall collection time, guaranteeing the quality and purity of stem cell products to optimize graft function and transplant success, and facilitating seamless coordination between diverse entities involved in the HSCT process. In this review, we aim to address key questions and provide insights into the critical aspects of mobilizing and collecting hematopoietic stem cells for transplantation purposes.

Real World Clinical Experience of Biosimilar G-CSF (Grastofil) for Autologous Peripheral Blood Stem Cell Mobilization: Single Center Experience in Canada Following Early Adoption

Introduction: Granulocyte colony-stimulating factor (G-CSF) is the first line treatment for mobilization, most commonly using a regimen of daily filgrastim. The use of biosimilars can provide substantial cost savings to the health care system while delivering comparable efficacy outcomes. In 2016, the Saskatchewan Cancer Agency was a leader in Canada, instituting formulary changed from a G-CSF originator product to a cost savings alternative biosimilar for stem cell mobilization prior to autologous stem cell transplant (ASCT) and for engraftment. The purpose of this study was to investigate the clinical comparability of biosimilar G-CSF to its reference product in a real-world clinical setting and to validate use of the biosimilar in mobilization and engraftment-an indication which had been granted by extrapolation.

METHODS

A retrospective chart review was completed including all patients diagnosed with a hematological malignancy between 2012 and 2018 who underwent ASCT. To assess real-world outcomes across a diverse population, successful CD34+ stem cell collection was compared between patients mobilized with originator filgrastim, Neupogen, and biosimilar filgrastim, Grastofil. Additional comparisons included the number of apheresis required, time to absolute neutrophil count (ANC) engraftment, platelet engraftment, length of hospital stay, and Plerixafor use.

RESULTS

217 patients were mobilized and transplanted during the study period. There was no statistically significant difference in success rate between patients mobilized with biosimilar filgrastim and those who had received originator G-CSF (100% vs. 92.4%, p = 0.075). Neither disease type, nor concurrent chemomobilization regimen resulted in a detectable difference between the two G-CSF products in successful stem cell harvest. Engraftment was highly similar between groups, as demonstrated by ANC recovery (11.6 days Neupogen vs. 11.6 days Grastofil), platelet recovery (14.0 days Neupogen vs. 14.2 days Grastofil), and total length of hospital stay (22.4 days Neupogen vs. 22.3 days Grastofil). No statistically significant difference in adjunctive use of Plerixafor^® was observed between Neupogen and Grastofil patients (25.9% vs. 23.4%, p = 0.72).

CONCLUSION

Extrapolation of indications for biosimilars is justified. This real-world evidence builds upon registrational studies to confirm that no clinically meaningful differences were detected between originator Neupogen and biosimilar Grastofil in the setting of PBSC mobilization and engraftment post ASCT. Biosimilars are as safe and effective as originator products. Implementation across all approved indications without hesitation maximizes cost savings to the provincial system, allowing for more optimal allocation of health care resources.

Lenograstim versus filgrastim in mobilization before autologous hematopoietic stem cell transplantation in patients with multiple myeloma and lymphoma - Single center experience

OBJECTIVE

Peripheral blood stem cell transplantation is frequently used in the treatment of various hematological malignancies after intensive chemotherapy. The primary aim of our study is to compare the amount of collected CD34+ cells and engraftment times in patients mobilized with filgrastim or lenograstim.

MATERIAL AND METHODS

Demographic and clinical data of multiple myeloma (MM) and lymphoma patients who underwent autologous transplantation and mobilized with G-CSF (filgrastim or lenograstim) without chemotherapy were collected retrospectively.

RESULTS

One hundred eleven MM and 58 lymphoma patients were included in the study. When mobilization with filgrastim and lenograstim was compared in MM patients, there was no significant difference in neutrophil and thrombocyte engraftment times of lenograstim and filgrastim groups (p = 0.931 p = 0.135, respectively). Similarly, the median number of CD34+ cells collected in patients receiving filgrastim and lenograstim was very similar (4.2 × 10⁶/kg vs 4.3 × 10⁶/kg, p = 0.977). When compared with patients who received lenalidomide before transplantation and patients who did not receive lenalidomide, the CD34+ counts of the two groups were similar. However, neutrophil and platelet engraftment times in the group not receiving lenalidomide tended to be shorter (p = 0.095 and p = 0.12, respectively). When lymphoma patients mobilized with filgrastim and lenograstim were compared, neutrophil engraftment time (p = 0.498), thrombocyte engraftment time (p = 0.184), collected CD34+ cell counts (p = 0.179) and mobilization success (p = 0.161) of the groups mobilized with filgrastim and lenograstim were similar.

CONCLUSION

The superiority of the two agents to each other could not be demonstrated. Multi-center prospective studies with larger numbers of patients are needed.

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.

Mobilization and Collection of Peripheral Blood Stem Cells in Adults: Focus on Timing and Benchmarking

Peripheral blood stem cells (PBSCs) are preferentially used as a hematopoietic stem cell source for autologous blood stem cell transplantation (ABSCT) upon high-dose chemotherapy (HDT) in a variety of hemato-oncologic diseases. As a prerequisite, hematopoietic stem cells have to be mobilized into the peripheral blood (PB) and collected by leukapheresis (LP). Despite continuous improvements, e.g., the introduction of plerixafor, current challenges are the further optimization regarding the leukapheresis procedure, preventing collection failures, as well as benchmarking and harmonization of mobilization approaches between institutions.This chapter summarizes the current PBSC mobilization and collection approaches and is focusing on timely orchestration of mobilization therapy, granulocyte colony-stimulating factor (G-CSF) application, and peripheral blood (PB) CD34⁺ cell assessment. Moreover, strategies for prediction and performance assessment of the PBSC collection yield are discussed.

Comparison of biosimilar filgrastim, originator filgrastim, and lenograstim for autologous stem cell mobilization in patients with multiple myeloma

BACKGROUND

Granulocyte-colony-stimulating factor (G-CSF) originators such as filgrastim (Neupogen) and lenograstim (Granocyte) are widely used for peripheral blood stem cell (PBSC) mobilization. In recent years, biosimilar agents have been approved for the same indications. The aim of this retrospective study was to compare the mobilization efficiency of the three G-CSF variants originator filgrastim, lenograstim, and the biosimilar Filgrastim Hexal in a homogeneous group of multiple myeloma (MM) patients in first-line therapy.

STUDY DESIGN AND METHODS

Overall mobilization data of 250 patients with MM were included. Of these patients, 74 (30%), 131 (52%), and 45 (18%) were mobilized with originator filgrastim, biosimilar Filgrastim Hexal, or lenograstim, respectively, at a dose of 5 to 10 µg/kg body weight subcutaneously starting from Day 5 after chemomobilization with CAD (cyclophosphamide, doxorubicin, dexamethasone) until completion of PBSC collection.

RESULTS

All but one patient reached the collection goal of a minimum of at least 2 × 10⁶ CD34+ cells/kg body weight during a median of one (range, one to three) leukapheresis session. No significant differences in CD34+ mobilization and collection yields between the filgrastim-mobilized (median, 10.5; range, 2.7-40.4), Filgrastim Hexal-mobilized (median, 9.9; range, 0.2-26.0), and lenograstim-mobilized (median, 10.7; range, 3.1-27.9 CD34+ cells × 10⁶ /kg body weight) patients were observed.

CONCLUSION

Concerning the clinically relevant efficiencies of PBSC mobilization and in terms of reaching the individual collection target, this retrospective study did not detect any significant differences between the three G-CSF variants in the analyzed patient cohort.

Update on biosimilars of granulocyte colony-stimulating factor - when no news is good news

PURPOSE OF REVIEW

With the approval of the first biosimilar granulocyte colony-stimulating factor (G-CSF), biosimilars - copies of therapeutic biologicals whose patent protection has expired - have finally reached the US healthcare market. Its advent is an occasion for a closer look at recent insights into biosimilar G-CSF and an attempt at prognosticating the future (future role) of biosimilars in general.

RECENT FINDINGS

Recent literature regarding biosimilar G-CSF orbits significantly around patient access and effects on healthcare expenditure. The advent of biosimilar G-CSF has induced unexpectedly large price reductions for short-acting G-CSF. On the clinical side, little excitement is tangible, probably appropriately so, since clinical data indicate nothing short of biological similarity. Although formal clinical trials are few, the plethora of case series and historic comparisons which have come forth offer reassurance about the appropriateness of the regulators' assessment of biosimilar G-CSF as indeed in all respects biologically similar to the originator.

SUMMARY

All evidence points to an overwhelming similarity of originator and biosimilar G-CSF in all indications. Overall clinical acceptance, albeit possibly significantly dictated by economic pressures, is good. Price reductions exceed predictions and may jeopardize the economic viability of biosimilar programs. A concurrent shift towards long-acting G-CSF ('biobetters') is observed in Europe.

Mobilization of autologous and allogeneic peripheral blood stem cells for transplantation in haematological malignancies using biosimilar G-CSF

BACKGROUND AND OBJECTIVES

Biosimilars of the granulocyte colony stimulating factor (G-CSF) filgrastim were approved by the European Medicines Agency (EMA) for registered indications of the originator G-CSF, including prevention and treatment of neutropenia, as well as mobilization of peripheral blood stem cells in 2008. Nevertheless, there is still an ongoing debate regarding the quality, efficacy and safety of biosimilar G-CSF.

MATERIALS AND METHODS

This article is a meta-analysis of clinical studies on the use of biosimilar G-CSF for mobilization and transplantation of haematopoietic stem cells as available in public databases. All data sets were weighted for the number of patients and parameters and then subjected to statistical meta-analysis employing the Mann-Whitney U-test followed by the Hodges-Lehmann estimator to assess differences between biosimilar and originator G-SCF.

RESULTS

A total of 1892 individuals, mostly with haematological malignancies but also including 351 healthy donors have been successfully mobilized for autologous or allogeneic stem cell transplantation using biosimilar G-CSF (Zarzio(TM) : 1239 individuals; Ratiograstim(TM) /Tevagrastim(TM) : 653 individuals). A total of 740 patients with multiple myeloma, 491 with non-Hodgkin's lymphoma (NHL), 150 with Hodgkin's lymphoma (HL) and other diseases are included in this meta-analysis, as well as 161 siblings and 190 volunteer unrelated donors. For biosimilar and originator G-CSF, bioequivalence was observed for the yield of CD34+ stem cells as well as for the engraftment of the transplants.

CONCLUSION

Biosimilar G-CSF has equivalent effects and safety as originator G-CSF.

Cell Therapy in Patients with Critical Limb Ischemia

Critical limb ischemia (CLI) represents the most advanced stage of peripheral arterial obstructive disease (PAOD) with a severe obstruction of the arteries which markedly reduces blood flow to the extremities and has progressed to the point of severe rest pain and/or even tissue loss. Recent therapeutic strategies have focused on restoring this balance in favor of tissue survival using exogenous molecular and cellular agents to promote regeneration of the vasculature. These are based on stimulation of angiogenesis by extracellular and cellular components. This review article carries out a systematic analysis of the most recent scientific literature on the application of stem cells in patients with CLI. The results obtained from the detailed analysis of the recent literature data have confirmed the beneficial role of cell therapy in reducing the rate of major amputations in patients with CLI and improving their quality of life.

Efficacy of biosimilar granulocyte colony-stimulating factor versus originator granulocyte colony-stimulating factor in peripheral blood stem cell mobilization in de novo multiple myeloma patients

BACKGROUND AIMS

Filgrastim and lenograstim are the standard granulocyte colony-stimulating factor (G-CSF) agents for peripheral blood stem cell mobilization (PBSC) in patients who undergo autologous stem cell transplantation.

METHODS

To assess whether biosimilars are effective, we conducted a single-center, prospective study that included 40 consecutive de novo multiple myeloma patients who received cyclophosphamide 4 g/m(2) per day plus biosimilar filgrastim G-CSF to mobilize PBSC. These patients were compared with a group of 37 patients matched for age, diagnosis, previous chemotherapy and mobilization who had been treated with originator G-CSF. The mean number of CD34+ cells/μL in the peripheral blood was 199.6 ± 207.4 in the biosimilar and 192.8 ± 154.7 in the originator group (P = 0.87). The median number of CD34+ cells/kg recipient collected was 11.5 ± 5.8 and 12.3 ± 5.3 in the biosimilar and originator groups, respectively (P = 0.51). The mobilization failure rate was 2.5% and 2.7% in the biosimilar filgrastim and originator filgrastim cohorts (P = NS), respectively.

RESULTS

Twenty-nine patients in the biosimilar group and 28 patients in the originator group underwent autologous transplantation. There were no statistically significant differences between the biosimilar and originator G-CSF cohorts in terms of hematopoietic recovery parameters and transplant-related toxicities.

CONCLUSIONS

The efficacy of biosimilar G-CSF appears to be equivalent to the reference G-CSF.

Tbo-Filgrastim versus Filgrastim during Mobilization and Neutrophil Engraftment for Autologous Stem Cell Transplantation

There are limited data available supporting the use of the recombinant granulocyte colony-stimulating factor (G-CSF), tbo-filgrastim, rather than traditionally used filgrastim to mobilize peripheral blood stem cells (PBSC) or to accelerate engraftment after autologous stem cell transplantation (ASCT). We sought to compare the efficacy and cost of tbo-filgrastim to filgrastim in these settings. Patients diagnosed with lymphoma or plasma cell disorders undergoing G-CSF mobilization, with or without plerixafor, were included in this retrospective analysis. The primary outcome was total collected CD34(+) cells/kg. Secondary mobilization endpoints included peripheral CD34(+) cells/μL on days 4 and 5 of mobilization, adjunctive use of plerixafor, CD34(+) cells/kg collected on day 5, number of collection days and volumes processed, number of collections reaching 5 million CD34(+) cells/kg, and percent reaching target collection goal in 1 day. Secondary engraftment endpoints included time to neutrophil and platelet engraftment, number of blood product transfusions required before engraftment, events of febrile neutropenia, and length of stay. A total of 185 patients were included in the final analysis. Patients receiving filgrastim (n = 86) collected a median of 5.56 × 10(6) CD34(+) cells/kg, compared with a median of 5.85 × 10(6) CD34(+) cells/kg in the tbo-filgrastim group (n = 99; P = .58). There were no statistically significant differences in all secondary endpoints with the exception of apheresis volumes processed (tbo-filgrastim, 17.0 liters versus filgrastim, 19.7 liters; P < .01) and mean platelet transfusions (tbo-filgrastim, 1.7 units versus filgrastim, 1.4 units; P = .04). In conclusion, tbo-filgrastim demonstrated similar CD34(+) yield compared with filgrastim in mobilization and post-transplantation settings, with no clinically meaningful differences in secondary efficacy and safety endpoints. Furthermore, tbo-filgrastim utilization was associated with cost savings of approximately $1406 per patient utilizing average wholesale price.

Use of biosimilar filgrastim compared with lenograstim in autologous haematopoietic stem-cell transplant and in sibling allogeneic transplant

OBJECTIVES

Biosimilar filgrastim was compared with lenograstim for autologous haematopoietic stem-cell transplant (HSCT) in patients with haematological malignancies. Data from a separate group of sibling donors who underwent allogeneic HSCT are also reported.

METHODS

Patients with lymphoma or multiple myeloma (MM) who underwent autologous HSCT with biosimilar filgrastim were compared with a historical control group of patients who received lenograstim. Peripheral blood (PB) cells counts were monitored after 7-8 consecutive days of granulocyte-colony stimulating factor (G-CSF) injection and apheresis was performed on day 8 if PB CD34+ cell count was ⩾10 cells/µl. The target PB CD34+ cell doses were ⩾2.0 × 10(6)/kg (lymphoma), ⩾4.0 × 10(6)/kg (MM ⩾60 years old) or ⩾8.0 × 10(6)/kg (MM <60 years old).

RESULTS

A total of 259 patients were included in the autologous HSCT comparison (biosimilar filgrastim, n = 104; lenograstim, n = 155). In patients with lymphoma and older MM patients (⩾60 years old), no significant differences were observed between groups with regard to stem-cell mobilization parameters. However, in MM patients <60 years old, all parameters were significantly superior in the biosimilar filgrastim group, including the need for 1 rather than 2 apheresis procedures. No significant differences were observed between groups in median number of days to absolute neutrophil count (ANC) or platelet recovery. In the allogeneic setting, 47 sibling donors received biosimilar filgrastim. Mean CD34+ count at the first apheresis was 6.1 × 10(6)/kg. A total of 13 donors needed a second apheresis and 4 required a third. Among recipients, median days to ANC recovery was 16 (10-28) and to platelet recovery was 13 (9-54).

CONCLUSIONS

Biosimilar filgrastim is as effective as lenograstim for autologous HSCT in patients with lymphoma or MM patients ⩾60 years old. However, mobilization with biosimilar filgrastim appeared to be superior to that with lenograstim in younger MM patients.

Safety and efficacy of granulocyte colony-stimulating factor biosimilars in engraftment after autologous stem cell transplantation for haematological malignancies: a 4-year, single institute experience with different conditioning regimens

BACKGROUND

Filgrastim biosimilars have recently been introduced into clinical practice. To date biosimilars have demonstrated comparable efficacy and safety as the originator in chemotherapy-induced neutropenia. Published experience in engraftment after autologous stem cell transplantation (ASCT) is limited and concerns relatively few patients.

MATERIALS AND METHODS

With the aim of assessing the efficacy and the safety of filgrastim biosimilars in post-ASCT bone marrow recovery, we conducted a single institution, retrospective study in 56 lymphoma and myeloma patients who received filgrastim biosimilars (Tevagrastim(®) and Zarzio(®)) at standard doses from day 5. We compared our results with recently published data on the originator. A cost analysis of each biosimilar was performed.

RESULTS

Neutrophil counts recovered in 55 patients. The median number of filgrastim biosimilar vials injected was seven per patient. The median time to neutrophil and platelet recovery was 10 and 12 days, respectively. Twenty-six patients had febrile neutropenia, in half of whom the agent involved was identified. In the cost analysis, the use of Tevagrastim(®) and Zarzio(®) was associated with cost reductions of 56% and of 86%, respectively.

DISCUSSION

Despite differences in CD34+ cell counts and time of starting filgrastim, our results in terms of time to engraftment and median number of vials injected are similar to published data. Comparing our results by single conditioning regimen to recent literature data, the time to engraftment and duration of hospitalisation were equivalent. Significant differences were observed in the incidence of febrile neutropenia, perhaps due to different preventive and prophylactic protocols for infections. Although prospective studies should be performed to confirm our results, filgrastim biosimilars were found to be effective and safe in engraftment after ASCT.

Biosimilars: the science of extrapolation

Despite the establishment of a specific approval pathway, the issuance of detailed scientific guidelines for the development of similar biological medicinal products (so-called "biosimilars") and the approval of several biosimilars in the European Union, acceptance of biosimilars in the medical community continues to be low. This is especially true in therapeutic indications for which no specific clinical trials with the biosimilar have been performed and that have been licensed based on extrapolation of efficacy and safety data from other indications. This article addresses the concerns frequently raised in the medical community about the use of biosimilars in such extrapolated indications and explains the underlying scientific and regulatory decision making including some real-life examples from recently licensed biosimilars.