Biosimilar Filgrastim (Tevagrastim, XMO2) for Allogeneic Hematopoietic Stem Cell Mobilization and Transplantation in Patients with Acute Myelogenous Leukemia/Myelodysplastic Syndromes

Is split-dose better than single-dose? Results of Turkish Stem Cell Coordination Center (TURKOK) donors in the era of rising biosimilar G-CSF

BACKGROUND

Turkish Stem Cell Coordination Center (TURKOK) carries out the procurement process of unrelated allogeneic hematopoietic stem cells in Turkey. This study aims to compare the efficacy of both once-daily and divided-dose G-CSF administration and the original and biosimilar G-CSF use and the frequency and severity of adverse events in TURKOK donors.

METHOD

The study was conducted retrospectively with 142 healthy TURKOK donors. For PBSC mobilization, two different subcutaneous G-CSF programs were used as 10 μ/kg/day single-dose and 5 μ/kg/12 h. Neupogen (Amgen, Puerto Rico) and Tevagrastim (Teva, Kfar Saba, Israel) were used as G-CSF. All donors started apheresis on the fifth day, and all side effects were recorded during the procedure.

RESULTS

Stem cell yield was similar between single-dose and divided-doses based on donor weight, favoring the split-dose based on recipient weight (P = .506 and P = .023, respectively). Both G-CSF posologies were comparable if the target CD34+ cell yield was ≥4 × 10⁶ /kg. CD34+ cell yield was equivalent when evaluated against recipient weight, significantly favoring Tevagrastim vs Neupogen by donor weight (P = .740 and P = .021, respectively). Side effects, duration of pain, and need for analgesia favor Tevagratim over Neupogen.

CONCLUSION

Split-dose may be recommended for cases where the need for large numbers of CD34+ cells to be harvested is anticipated due to significant cell yield relative to recipient weight. However, sufficient hematopoietic stem cells can be collected with both posology. Tevagrastim is non-inferiority effective to Neupogen. Side effects during administration are both low-grade and temporary.

Can biosimilar products be interchangeable? Pharmaceutical perspective in the implementation of biosimilars in oncology

OBJECTIVE

To evaluate the safety in the interchangeability of biosimilar products approved for cancer treatment from a pharmaceutical perspective.

METHODS

A literature review was carried out using the descriptors "Biosimilar", "Oncology Therapy", "Interchangeable drugs" and "Biological Products", in the Sciencedirect, MEDLINE, and CAPLUS databases.

RESULTS

Fifty-one articles were selected, which addressed the importance of establishing standards that prove the efficacy and safety of biosimilars with reference products, as well as the growing interest of the pharmaceutical industry in the development of biosimilars and the impact on costs and changes in the perspective of the treatment of cancer patients.

CONCLUSIONS

As they are large and complex molecules, it is impossible to obtain identical copies of their reference products, which generates conflicts and concerns on the part of the pharmaceutical class regarding the safety in the interchangeability of these products, highlighting the importance of pharmacovigilance in this process.

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.

Trends in peripheral stem/progenitor cell manipulation and clinical application

Transplants using peripheral blood hemopoietic stem/progenitor (PBHS) cells are widely performed for the treatment of patients with hematologic disorders in routine practice and clinical trials. Although the process from mobilization to infusion of PBHS cells has been mostly established, optimal conditions for each process remain undetermined. Adverse reactions caused by PBHS cell infusions have not been systematically recorded. In transplants using PBHS cells, a number of problems still exist. In this section, the current status of and future perspectives regarding PBHS cells are described.

What is the role of biosimilar G-CSF agents in hematopoietic stem cell mobilization at present?

Mobilization of hematopoietic stem cells, which has largely replaced bone marrow harvesting as a source of hematopoietic stem cells, using recombinant agents such as filgrastim or lenograstim has become a standard procedure in both patients and healthy donors prior to peripheral blood stem cell collection for autologous and allogeneic stem cell transplantation. Published literature data suggest that mobilization with recombinant granulocyte-colony stimulating factor (G-CSF) is safe and mobilization outcomes are satisfactory. In recent years, besides G-CSF originators, biosimilar G-CSF agents have been approved by the regulatory agencies for the same indications. Current data showed that by using the biosimilar G-CSF, similar results regarding safety and efficacy of hematopoietic stem cell mobilization may be achieved compared to the originator G-CSF. Although the issues such as the similarity to a licenced biological medicine, differences in manufacturing processes, the potential to cause immunogenicity, extrapolation and interchangeability of these biosimilar products are still being discussed by the scientific area, however, more experience with these agents now exists in approved endications and there seems to be no reason to expect significant differences between biosimilar G-CSF and originator G-CSF regarding their efficacy and safety in both patients and healthy donors. Also, the significant cost savings of biosimilars in real life setting may enhance the use of these agents in the future. Nonetheless, the collection of long-term follow-up data is mandatory for both patients and healthy donors, and multicentre randomized clinical trials that directly compare biosimilar G-CSF with the originator G-CSF are needed in order to allow the transplant community to make informed decisions regarding the choice of G-CSF.

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.

Comparison of transplant outcomes and economic costs between biosimilar and originator filgrastim in allogeneic hematopoietic stem cell transplantation

From January 2012 to September 2015, 49 patients received biosimilar filgrastim (BF) after allogeneic bone marrow transplantation (BMT, n = 31) or peripheral stem cell transplantation (PBSCT, n = 18) in our institution. To evaluate the clinical impact of BF on transplant outcomes of these patients, we compared hematological recovery, overall survival (OS), disease-free survival (DFS), transplantation-related mortality (TRM), cumulative incidence of relapse (CIR), and acute and chronic graft-versus-host disease (GVHD) with those of control patients who received originator filgrastim (OF) after BMT (n = 31) or PBSCT (n = 18). All cases were randomly selected from a clinical database in our institution. In both the BMT and PBSCT settings, neutrophil recovery (17 vs. 19 days in BMT; 13 vs. 15 days in PBSCT) and platelet recovery (27 vs. 31 days in BMT; 17 vs. 28 days in PBSCT) were essentially the same between BF and OF. They were also comparable in terms of OS, DFS, TRM, CIR, and the incidence of acute GVHD and chronic GVHD. On multivariate analysis, the use of BF in both BMT and PBSCT was not a significant factor for adverse transplant outcomes. Although BF significantly reduced filgrastim costs in both BMT and PBSCT, total hospitalization costs were not significantly different between BF and OF.

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.