Tbo-Filgrastim versus Filgrastim during Mobilization and Neutrophil Engraftment for Autologous Stem Cell Transplantation. Biol Blood Marrow Transplant. 2015;21:1921-1925. [PMID: 26033279 DOI: 10.1016/j.bbmt.2015.05.024]

Stem cell mobilization in multiple myeloma: challenges, strategies, and current developments

Among hematological malignancies, multiple myeloma (MM) represents the leading indication of autologous hematopoietic stem cell transplantation (auto-HCT). Auto-HCT is predominantly performed with peripheral blood stem cells (PBSCs), and the mobilization and collection of PBSCs are essential steps for auto-HCT. Despite the improved success of conventional methods with the incorporation of novel agents for PBSC mobilization in MM, mobilization failure is still a concern. The current review comprehensively summarizes various mobilization strategies for mobilizing PBSCs in MM patients and the evolution of these strategies over time. Moreover, existing evidence substantiates that the mobilization regimen used may be an important determinant of graft content. However, limited data are available on the effects of graft characteristics in patient outcomes other than hematopoietic engraftment. In this review, we discussed the effect of graft characteristics on clinical outcomes, mobilization failure, factors predictive of poor mobilization, and potential mobilization regimens for such patients.

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.

Use of Biosimilar Granulocyte Colony-Stimulating Factor for Mobilization in Autologous and Allogeneic Hematopoietic Stem Cell Transplantation

The biologic medication filgrastim is approved by the Food and Drug Administration (FDA) to mobilize hematopoietic progenitor cells (HPCs) for collection by leukapheresis for autologous hematopoietic stem cell transplant (HSCT). The FDA-approved biologic tbo-filgrastim is currently used off-label for this indication in both autologous and allogeneic HSCT at the Tennessee Valley Healthcare System. The purpose of this review is to compare the efficacy of filgrastim and tbo-filgrastim for this indication. The primary outcomes were the proportion of autologous patients and allogeneic donors with a CD34+ count ≥15 × 103 cells/uL on day 4 of filgrastim or tbo-filgrastim mobilization. The secondary outcome was the use of plerixafor in the autologous population. A total of 469 subjects were identified for inclusion; 367 underwent mobilization for autologous HSCT and 102 for allogeneic HSCT donation. The primary outcome was achieved in 47.5% of patients who received filgrastim compared to 50.2% who received tbo-filgrastim in the autologous population (p = 0.67). Among donors for allogeneic HSCT, there was no difference between those eligible for collection on day 4 of filgrastim or tbo-filgrastim administration (97.6% vs. 100%, p = 0.41). No significant difference was identified in the number of patients requiring plerixafor use in the autologous HSCT population. The use of the biosimilar tbo-filgrastim for mobilization in either autologous HSCT patients or allogeneic HSCT donors has comparable outcomes to that of the biotherapeutic reference product filgrastim at a reduced cost to the healthcare system.

Extrapolation in Practice: Lessons from 10 Years with Biosimilar Filgrastim

Biosimilar filgrastim (Sandoz) was approved in Europe in 2009 and, in 2015, was the first biosimilar approved in the USA. These authorizations were based on the "totality of evidence" concept, an approach that considers data from structural and functional characterization and comparability analysis and non-clinical and clinical studies. For biosimilar filgrastim, phase III confirmatory clinical studies were performed in the most sensitive population, patients with breast cancer undergoing myelosuppressive chemotherapy. In Europe and the USA, approval was granted for all indications of the reference biologic. Hence, stem cell mobilization and severe chronic neutropenia indications were approved on the basis of extrapolation, with no clinical data available at the time of market authorization in the EU. Although extrapolation is well-accepted in biologic development and regulatory contexts, it remains a misunderstood part of the biosimilarity concept in the medical community. Since approval, more than a decade of obtained clinical experience supports the totality of evidence and reassures clinicians regarding the efficacy and safety of biosimilar filgrastim. This includes real-world data from MONITOR-GCSF, a multicenter, prospective, observational study describing treatment patterns and clinical outcomes of patients with cancer (n = 1447) receiving biosimilar filgrastim for the prophylaxis of chemotherapy-induced neutropenia in solid tumors and hematological malignancies. Evidence is also available from unrelated healthy donors and those with severe chronic neutropenia. Together, the experience from a decade of use of biosimilar filgrastim includes over 24 million patient-days of exposure, which can help reassure oncologists that extrapolation is based on strong scientific evidence and works in practice.

The comparison of effectiveness and safety between different biosimilars of G-CSF in the mobilization of peripheral blood stem cells (PBSCs) for autologous transplantation (autologous peripheral blood stem cell transplantation, auto-PBSCT)

BACKGROUND

Autologous peripheral blood marrow stem cell transplantation (auto-PBSCT) preceded by high-dose chemotherapy is a well-known method of treatment for patients with hematological cancers. Performing the procedure entails obtaining from the patient their own stem cells from peripheral blood using G-CSF. Currently, various filgrastim biosimilars are widely used.

AIM OF THE STUDY

The purpose of this study is to compare the efficacy and safety of three different biosimilars of filgrastim in PBSC mobilization in patients with hematological malignancies.

MATERIALS AND METHODS

This is a retrospective analysis of 282 patients (118 women and 164 men) who underwent stem cells mobilization for auto-PBSCT in the Department of Hematology in Wroclaw in 2012-2014. Three filgrastim biosimilars were used: Tevagrastim (95), Nivestim (92), and Zarzio (95). Ninety patients (32%) were diagnosed with multiple myeloma, 55 (19%) with Hodgkin's lymphoma, 90 (32%) with NHLs, 20 (7%) with acute myeloid leukemia, and 27 (10%) with another hematological cancer.

RESULTS

The mean number of CD34+ cells collected during the first leukapheresis was 5.95 × 10⁶ /kg for Tevagrastim, 7.08 × 10⁶ /kg for Nivestim, and 6.8 × 10⁶ /kg for Zarzio (P > .05). The necessary number of leukapheresis for patients receiving Zarzio, Nivestim, and Tevagrastim was 1.32, 1.37, and 1.66, respectively (P > .05). The percentage of effective mobilizations was 88.2% for Zarzio, 86.2% for Nivestim, and 84.9% for Tevagrastim. The side effects included bone pain and headache.

CONCLUSION

All tested biosimilars demonstrated similar effectiveness and safety profiles in patients with hematological tumors undergoing PBSC mobilization; therefore, they can be used interchangeably.

Tbo-filgrastim versus filgrastim for stem cell mobilization and engraftment in autologous hematopoietic stem cell transplant patients: A retrospective review

INTRODUCTION

Filgrastim, a granulocyte colony-stimulating factor, is commonly used in autologous hematopoietic stem cell transplants (HSCTs) to assist with peripheral blood progenitor cell (PBPC) collection and to support stem cell engraftment. In the United States, tbo-filgrastim is approved under its own Biologic License Application and is limited to a single indication excluding the HSCT population.

METHODS

Approximately one year after a system-wide formulary change to tbo-filgrastim for all on- and off-label indications, our institution conducted an IRB-approved retrospective comparison of tbo-filgrastim to filgrastim in the autologous HSCT setting. The study included 71 patients who received an autologous HSCT from 1 January 2013 to 31 December 2016 with a documented administration of tbo-filgrastim or filgrastim.

RESULTS

There were no statistically significant differences noted on CD34 + counts during stem cell mobilization, neutrophil engraftment, infection rates during the engraftment phase, nor duration of hospitalization during the engraftment phase. More patients in the tbo-filgrastim group received plerixafor per protocol resulting in more patients meeting their PBPC collection goal in one day with fewer collection days overall, a result potentially confounded by institutional protocol changes. Utilizing tbo-filgrastim offered an average cost savings per patient of $2664.26 ($1907.33 for PBPC mobilization and $756.93 for stem cell engraftment) when comparing dollars spent on granulocyte colony-stimulating factor products only.

CONCLUSION

Tbo-filgrastim demonstrates comparable efficacy with a cost savings benefit compared to filgrastim for autologous PBPC mobilization and stem cell engraftment.

Granulocyte colony-stimulating factor utilization postautologous hematopoietic stem cell transplant in multiple myeloma patients: Does one size fit all?

PURPOSE

To evaluate a single institution's experience with granulocyte colony-stimulating factor after autologous hematopoietic stem cell transplant in myeloma patients to identify populations that benefit most from granulocyte colony-stimulating factor administration.

METHODS

Retrospective chart reviews were conducted on patients 18+ years with multiple myeloma that underwent autologous hematopoietic stem cell transplant at UW Health from January 2012 to May 2016. Data collection included demographics, length of stay, time to engraftment, Eastern Cooperative Oncology Group performance status score, and hematopoietic cell transplantation-comorbidity index. The primary outcome was days from transplant to engraftment, defined as absolute neutrophil count  > 500/mm³ for two consecutive days or absolute neutrophil count > 1000/mm³ once. A subset analysis was performed on patients whose date of engraftment was known.

RESULTS

In total, 216 individual patients were included in the full cohort and 122 patients included in the subset analysis. Median time to engraftment between patients administered granulocyte colony-stimulating factor and the nongranulocyte colony-stimulating factor group was 12 versus 19 days (P < 0.001) in the full cohort and 12 versus 14 days (P < 0.001) in the subset analysis. The average length of stay posthematopoietic stem cell transplant in the granulocyte colony-stimulating factor group was 15 days versus 17 days in the nongranulocyte colony-stimulating factor group (P = 0.026) in the subset analysis. Additionally, no difference in time to engraftment was seen when stratified by age, Eastern Cooperative Oncology Group performance status score, or hematopoietic cell transplantation-comorbidity index.

CONCLUSION

Our study supports use of granulocyte colony-stimulating factor posthematopoietic stem cell transplant in myeloma patients to decrease time to engraftment and length of stay. Consideration should be given to utilization in all patients in this population posthematopoietic stem cell transplant. Further research is needed to identify the populations that benefit most from granulocyte colony-stimulating factor administration.

Conversion from Filgrastim to Tbo-filgrastim: Experience of a Large Health Care System

BACKGROUND

In 2008, tbo-filgrastim was approved as a biosimilar in Europe and then approved in the United States by the FDA in 2012 as a biologic product with 1 similar indication to filgrastim. Because tbo-filgrastim was less expensive than filgrastim, and clinical information and expert opinion supported similarity, the Pharmacy & Therapeutics Committee of a large health care system approved tbo-filgrastim as the preferred granulocyte-colony stimulating factor (G-CSF) product in March 2014.

OBJECTIVES

To (a) assess the use of filgrastim and tbo-filgrastim products by comparing baseline characteristics, setting of care, indication for use, and payer type and (b) understand potential barriers of conversion to tbo-filgrastim.

METHODS

A retrospective evaluation of filgrastim and tbo-filgrastim use was conducted on all patients (N = 204) who received the drugs between July 2015 and December 2015 at the 2 largest hospitals in the health system. Baseline characteristics, indication requiring use of filgrastim or tbo-filgrastim, setting of care, and payer information were collected from electronic medical records, and descriptive analyses were conducted.

RESULTS

Overall, G-CSFs were administered to 204 patients for 261 episodes of care (filgrastim and tbo-filgrastim were used in 65 and 196 episodes of care, respectively). Baseline characteristics were similar between the 59 patients who received filgrastim and the 174 patients who received tbo-filgrastim. G-CSF was primarily used in the inpatient setting (163 episodes of care, 63%) with 90% of patients using tbo-filgrastim. In the outpatient setting (98 episodes of care, 38%), filgrastim and tbo-filgrastim were each used by 50% of patients. Tbo-filgrastim was the preferred G-CSF by clinical providers for all indications, except for stem cell mobilization, where filgrastim use was higher (55% vs. 45% of 71 episodes of care). In the outpatient setting, analysis by payers showed that the majority of patients on commercial plans were using filgrastim (58%), while half of Medicare patients were using filgrastim (50%, n = 12). Twelve patients were self-paid, and all were using tbo-filgrastim. Subgroup analysis by hospital showed differences in utilization patterns.

CONCLUSIONS

Although tbo-filgrastim was the preferred G-CSF in our formulary, 29% of patients continued to receive filgrastim. Conversion to tbo-filgrastim has been largely successful, but extra steps may be needed to achieve full conversion to biosimilars.

DISCLOSURES

No outside funding supported this study. Agboola was employed by Partners Healthcare at the time of the study. The authors have nothing to disclose. Study concept and design were contributed equally by Agboola and Reddy. Agboola collected the data, and data interpretation was performed by both authors. The manuscript was written primarily by Agboola, with assistance from Reddy. Both authors revised the manuscript.

Autologous hematopoietic progenitor cell mobilization and collection in adult patients presenting with multiple myeloma and lymphoma: A position-statement from the Turkish Society of Apheresis (TSA)

Autologous hematopoietic cell transplantation (AHCT) is a routinely used procedure in the treatment of adult patients presenting with multiple myeloma (MM), Hodgkin lymphoma (HL) and various subtypes of non-Hodgkin lymphoma (NHL) in upfront and relapsed/refractory settings. Successful hematopoietic progenitor cell mobilization (HPCM) and collection are the rate limiting first steps for application of AHCT. In 2015, almost 1700 AHCT procedures have been performed for MM, HL and NHL in Turkey. Although there are recently published consensus guidelines addressing critical issues regarding autologous HPCM, there is a tremendous heterogeneity in terms of mobilization strategies of transplant centers across the world. In order to pave the way to a more standardized HPCM approach in Turkey, Turkish Society of Apheresis (TSA) assembled a working group consisting of experts in the field. Here we report the position statement of TSA regarding autologous HPCM mobilization strategies in adult patients presenting with MM and lymphoma.

Current practice of autologous hematopoietic progenitor cell mobilization in adult patients with multiple myeloma and lymphoma: The results of a survey from Turkish hematology research and education group (ThREG)

Autologous hematopoietic cell transplantation (AHCT) is an established treatment option for adult patients presenting with multiple myeloma (MM), Hodgkin lymphoma (HL) and various subtypes of non-Hodgkin lymphoma (NHL) in upfront and/or relapsed/refractory disease settings. Although there are recently published consensus guidelines addressing critical issues regarding autologous hematopoietic progenitor cell mobilization (HPCM), mobilization strategies of transplant centers show high variability in terms of routine practice. In order to understand the current institutional policies regarding HPCM in Turkey and to obtain the required basic data for preparation of a national positional statement on this issue, Turkish Hematology Research and Education Group (ThREG) conducted a web-based HPCM survey. The survey was designed to include multiple-choice questions regarding institutional practice of HPCM in adults presenting MM, HL, and NHL. The representatives of 27 adult HCT centers participated to the study. Here we report the results of this survey shedding light on the real-world experience in Turkey in terms of autologous HPCM mobilization strategies in patients presenting with MM and lymphoma.

Peripheral blood stem cell mobilization in multiple myeloma: Growth factors or chemotherapy?

High-dose therapy followed by autologous hematopoietic stem cell (HSC) transplant is considered standard of care for eligible patients with multiple myeloma. The optimal collection strategy should be effective in procuring sufficient HSC while maintaining a low toxicity profile. Currently available mobilization strategies include growth factors alone, growth factors in combination with chemotherapy, or growth factors in combination with chemokine receptor antagonists; however, the optimal strategy has yet to be elucidated. Herein, we review the risks and benefits of each approach.

Results of a Prospective Randomized, Open-Label, Noninferiority Study of Tbo-Filgrastim (Granix) versus Filgrastim (Neupogen) in Combination with Plerixafor for Autologous Stem Cell Mobilization in Patients with Multiple Myeloma and Non-Hodgkin Lymphoma

Autologous hematopoietic stem cell transplantation (auto-HSCT) improves survival in patients with multiple myeloma (MM) and non-Hodgkin lymphoma (NHL). Traditionally, filgrastim (Neupogen; recombinant G-CSF) has been used in as a single agent or in combination with plerixafor for stem cell mobilization for auto-HSCT. In Europe, a biosimilar recombinant G-CSF (Tevagrastim) has been approved for various indications similar to those of reference filgrastim, including stem cell mobilization for auto-HSCT; however, in the United States, tbo-filgrastim (Granix) is registered under the original biological application and is not approved for stem cell mobilization. In retrospective studies, stem cell mobilization with tbo-filgrastim has shown similar efficacy and toxicity as filgrastim, but no prospective studies have been published to date. We have conducted the first prospective randomized trial comparing the safety and efficacy of tbo-filgrastim in combination with plerixafor with that of filgrastim in combination with plerixafor for stem cell mobilization in patients with MM and NHL. This is a phase 2 prospective randomized (1:1) open-label single-institution noninferiority study of tbo-filgrastim and filgrastim with plerixafor in patients with MM or NHL undergoing auto-HSCT. Here 10 µg/kg/day of tbo-filgrastim/filgrastim was administered s.c. for 5 days (days 1 to 5). On day 4 at approximately 1800 hours, 0.24 mg/kg of plerixafor was administered s.c. Apheresis was performed on day 5 with a target cumulative collection goal of at least 5.0 × 10⁶ CD34⁺ cells/kg. The primary objective was to compare day 5 CD34⁺ cells/kg collected. Secondary objectives included other mobilization endpoints, safety, engraftment outcomes, and hospital readmission rate. A total of 97 evaluable patients were enrolled (tbo-filgrastim, n = 46; filgrastim, n = 51). Tbo-filgrastim was not inferior to filgrastim in terms of day 5 CD34⁺ cell collection (mean, 11.6 ± 6.7 CD34⁺ cells/kg versus 10.0  ± 6.8 CD34⁺ cells/kg. Multivariate analysis revealed a trend toward increased mobilization in the tbo-filgrastim arm, but this was not statistically significant. The tbo-filgrastim and filgrastim arms were similar in all secondary endpoints. Tbo-filgrastim is not inferior in efficacy and has similar safety compared to reference filgrastim when used for stem cell mobilization in patients with MM and NHL. Granix can be safely used instead of Neupogen for stem cell collection in patients undergoing auto-HSCT for MM or NHL. The study is registered at https://clinicaltrials.gov/ct2/show/NCT02098109.

Tbo-Filgrastim: A Review in Neutropenic Conditions

Tbo-filgrastim (filgrastim XM02; Biograstim(®), Ratiograstim(®), Tevagrastim(®)) is approved in the EU as a biosimilar of filgrastim (Neupogen(®)) for use in all indications for which reference filgrastim is approved, including chemotherapy-induced neutropenia, neutropenia in patients undergoing myeloablative therapy followed by bone marrow transplantation, mobilization of peripheral blood stem cells (PBSCs), severe chronic neutropenia, and neutropenia in HIV infection. Tbo-filgrastim (Granix(®)) is also approved as a biologic in the USA for neutropenia associated with chemotherapy. Tbo-filgrastim has demonstrated bioequivalence to reference filgrastim in terms of its pharmacokinetic and pharmacodynamic profiles. In phase III trials, tbo-filgrastim was equivalent to reference filgrastim in ameliorating severe neutropenia in patients receiving chemotherapy for breast cancer, lung cancer, or non-Hodgkin lymphoma. In addition, the efficacy of tbo-filgrastim for PBSC mobilization in the allogeneic and autologous settings has been demonstrated in several small studies. Tbo-filgrastim was generally well tolerated, with a similar safety profile to that of reference filgrastim. Most adverse events were of mild or moderate severity. Biosimilars such as tbo-filgrastim have the potential to reduce healthcare costs compared with those of reference filgrastim; this may provide patients with more cost-effective treatment options. Current evidence indicates that tbo-filgrastim is a useful alternative to reference filgrastim in patients requiring filgrastim therapy for various neutropenic conditions.