Demonstration of Physicochemical and Functional Similarity of Biosimilar Pegfilgrastim-cbqv to Pegfilgrastim.

backgroundPegfilgrastim-cbqv/CHS-1701 (UDENYCA

objectiveThe current study demonstrates the analytical similarity of pegfilgrastim-cbqv and the reference product, pegfilgrastim. In addition to the physicochemical and functional characterization of the protein, the study assessed attributes specific to PEGylation including PEG size and polydispersity, site of attachment, linker composition, and PEGylation process-related variants.

methodsThe structural, functional, and stability attributes of pegfilgrastim-cbqv and pegfilgrastim were compared using state-of-the-art analytical methods. For the protein, the primary structure, disulfide structure, and secondary and tertiary structures were assessed using traditional protein characterization techniques such as mass spectrometry (MS), circular dichroism (CD), intrinsic fluorescence, and differential scanning calorimetry (DSC), as well as more advanced techniques such as two-dimensional (2D) nuclear magnetic resonance (NMR) and hydrogen deuterium exchange (HDX). For the PEG moiety, the site of attachment, occupancy, linker composition, size and polydispersity were compared using mass spectrometry (both intact and after endoprotease digestion), multiangle light scattering detection (MALS), and Edman degradation. Purity assessments included the assessment of both protein variants and PEGylation variants using chromatographic and electrophoretic analytical separation techniques. The functional similarity between pegfilgrastim-cbqv and pegfilgrastim was compared using both a cell-based bioassay and surface plasmon resonance (SPR). The degradation rates and stability profiles were compared under accelerated and stressed conditions.

resultsBiosimilarity was demonstrated by a thorough assessment of physiochemical and functional attributes, as well as comparative stability, of pegfilgrastim-cbqv relative to pegfilgrastim. These studies demonstrated identical primary structure and disulfide structure, highly similar secondary and tertiary structure, as well as functional similarity. The impurity profile of pegfilgrastim-cbqv was comparable to that of pegfilgrastim with only minor differences in PEGylation variants and a slight offset in the PEG molar mass. These differences were not clinically relevant. The degradation profiles were qualitatively and quantitatively similar under accelerated and stress conditions.

conclusionThe structural, functional, and stability data demonstrate that pegfilgrastim-cbqv is highly similar to the reference product, pegfilgrastim.