Biosimilars in the management of neutropenia: focus on filgrastim

A case of acute lung injury in a peripheral blood stem cell donor mobilized with pegylated recombinant human granulocyte colony-stimulating factor

Pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) has been introduced for the mobilization of peripheral blood stem cells (PBSCs). However, no cases of acute lung injury (ALI) in healthy donors have been reported, and the underlying mechanisms remain poorly understood. We first reported a case of ALI caused by PEG-rhG-CSF in a healthy Chinese donor, characterized by hemoptysis, hypoxemia, and patchy shadows. Ultimately, hormone administration, planned PBSC collection, leukocyte debridement, and planned PBSC collection resulted in active control of the donor's ALI. The donor's symptoms improved without any adverse effects, and the PBSC collection proceeded without incident. Over time, the lung lesion was gradually absorbed and eventually returned to normal. PEG-rhG-CSF may contribute to ALI in healthy donors via mechanisms involving neutrophil aggregation, adhesion, and the release of inflammatory mediators in the lung. This case report examines the clinical manifestations, treatment, and mechanism of lung injury induced by PEG-rhG-CSF-mobilized PBSCs.

Mitigating Effect of 1-Palmitoyl-2-Linoleoyl-3-Acetyl-Rac-Glycerol (PLAG) on a Murine Model of 5-Fluorouracil-Induced Hematological Toxicity

5-Fluorouracil (5-FU) is an antimetabolite chemotherapy widely used for the treatment of various cancers. However, many cancer patients experience hematological side effects following 5-FU treatment. Here, we investigated the protective effects of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) as a mitigator against 5-FU-induced hematologic toxicity, including neutropenia, monocytopenia, thrombocytopenia, and thrombocytosis, in Balb/c mice injected with 5-FU (100 mg/kg, i.p.). Administration of PLAG significantly and dose-dependently reduced the duration of neutropenia and improved the nadirs of absolute neutrophil counts (ANCs). Moreover, while the ANCs of all mice in the control fell to the severely neutropenic range, none of the mice in the PLAG 200 and 400 mg/kg-treated groups experienced severe neutropenia. Administration of PLAG significantly delayed the mean first day of monocytopenia and reduced the duration of monocytopenia. PLAG also effectively reduced extreme changes in platelet counts induced by 5-FU treatment, thus preventing 5-FU-induced thrombocytopenia and thrombocytosis. PLAG significantly decreased plasma levels of the chemokine (C–X–C motif) ligand 1 (CXCL1), CXCL2, interleukin (IL)-6, and C-reactive protein (CRP), which were elevated consistently with the occurrence time of neutropenia, monocytopenia, and thrombocytopenia. When compared with olive oil and palmitic linoleic hydroxyl glycerol (PLH), only PLAG effectively mitigated 5-FU-induced hematological toxicity, indicating that it has a distinctive mechanism of action. In conclusion, PLAG may have therapeutic potential as a mitigator for 5-FU-induced neutropenia and other hematological disorders.

The Comparison of The Efficacy and Safety of Original and Biosimilar Filgrastim in Prevention of Chemotherapy-Induced Neutropenia in Children with Cancer

Objective

In adults and children, the duration of chemotherapy-induced neutropenia and associated complications has decreased because of the prophylactic use of granulocyte colony-stimulating factors (G-CSFs). Biosimilar G-CSFs can play an important role in reducing treatment costs in daily practice. However, some concerns regarding the efficacy and safety of new biosimilar products exist among clinicians. This study compared the efficacy and safety of original and biosimilar filgrastims for the prophylaxis of chemotherapy-induced neutropenia in children.

Materials and Methods

Thirty children receiving myelosuppressive chemotherapy were enrolled in this study. Filgrastims (5 μg/kg/day) were subcutaneously administered in Group A (biosimilar, Leucostim®; Dem İlaç) and Group B (original drug, Neupogen®; Roche). Hemoglobin, white blood cell (WBC) count, platelet count, transfusion requirements, duration of hospitalization, and frequency and duration of adverse events including fever, neutropenia, and mucositis were evaluated following 25 treatment cycles in both groups.

Results

The hemoglobin value, WBC count, and platelet count on days 1, 5, and 10, and the red blood cell and platelet transfusion requirements, frequency, duration, and severity of mucositis, and durations of fever, febrile neutropenia, and hospitalization were similar in both groups. Although the mean WBC counts on days 1 and 5 were lower in Group A, the difference was statistically insignificant.

Conclusion

The biosimilar filgrastim, Leucostim, is as effective and safe as the original drug for prophylaxis of chemotherapy-induced neutropenia in children.

Construction, Purification, and Characterization of a Homodimeric Granulocyte Colony-Stimulating Factor

Granulocyte colony-stimulating factor (G-CSF) has found widespread clinical application, and modified forms with improved biopharmaceutical properties have been marketed as well. PEGylation, the covalent modification of G-CSF with polyethylene glycol (PEG), has a beneficial effect on drug properties, but there are concerns connected to the immunogenicity of PEGylated compounds and bioaccumulation of the synthetic polymer. To overcome challenges connected with chemical modifications, we developed fusion proteins composed of two G-CSF molecules connected via different peptide linkers. Three different homodimeric G-CSF proteins were purified, and their in vitro and in vivo activities were determined. A G-CSF dimer, GCSF-Lα, was constructed using an alpha-helix-forming peptide linker, and it demonstrated an extended half-life in serum with a stronger neutrophil response as compared to the monomeric G-CSF protein. The GCSF-Lα protein, therefore, might be selected for further studies as a potential drug candidate.