Identification of Low-Level Product-Related Variants in Filgrastim Products Presently Available in Highly Regulated Markets

Autor: William C. Lamanna, Andreas Seidl, Johann Holzmann, Hansjoerg Toll, Martin Hartinger, Anna Hausberger
Rok vydání: 2016
Předmět:
Zdroj: BioDrugs. 30:233-242
ISSN: 1179-190X
1173-8804
Popis: Filgrastim is a recombinant, non-glycosylated form of human granulocyte colony-stimulating factor, used to stimulate leukocyte proliferation in patients suffering from neutropenia. Since the expiration of patents associated with Amgen’s filgrastim biopharmaceutical, Neupogen®, in 2006, a number of filgrastim products have been marketed; however, a detailed characterization and comparison of variants associated with these products have not been publically reported. The objective of this study was to identify and quantify product-related variants in filgrastim reference products and biosimilars thereof that are presently available in highly regulated markets. In this study, we used intact and top–down mass spectrometry to identify and quantify product-related variants in filgrastim products. Mass spectrometry has become the method of choice for physicochemical characterization of biopharmaceuticals, allowing accurate and sensitive characterization of product-related variants. In addition to modifications ubiquitously present in biopharmaceuticals, such as methionine oxidation and asparagine/glutamine deamidation, we identified six different low-level, product-related variants present in some, but not all, of the tested products. Two variants, an acetylated filgrastim variant and a filgrastim variant containing an additional C-terminal tryptophan extension, are newly identified variants. This study demonstrates that filgrastim products already in widespread clinical use in highly regulated markets differ in low-level, product-related variants present at levels mostly below 1 % relative abundance. This study provides a comprehensive catalog of minor differences between filgrastim products and suggests that the filgrastim product-related variants described here are not clinically relevant when present at low abundance.
Databáze: OpenAIRE
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