Comparative Assessment of the Structural Features of Originator Recombinant Human Follitropin Alfa Versus Recombinant Human Follitropin Alfa Biosimilar Preparations Approved in Non-European Regions

Abstract

Although the full primary structures of the alfa and beta subunits of reference r-hFSH-alfa and its biosimilars are identical, cell context-dependent differences in the expressing cell lines and manufacturing process can lead to variations in glycosylation profiles. In the present study, we compared the structural features of reference r-hFSH-alfa with those of five biosimilar preparations approved in different global regions outside Europe (Primapur®, Jin Sai Heng®, Follitrope®, Folisurge®, and Corneumon®) with respect to glycosylation, macro- and microheterogeneity, and other post-translational modifications and higher order structure. The mean proportion of N-glycosylation-site occupancy was highest in reference r-hFSH-alfa, decreasing sequentially in Primapur, Jin Sai Heng, Corneumon, Follisurge and Follitrope, respectively. The level of antennarity showed slightly higher complexity in Corneumon, Primapur and Follitrope versus reference r-hFSH-alfa, whereas Jin Sai Heng and Folisurge were aligned with reference r-hFSH-alfa across all N-glycosylation sites. Sialylation level was higher in Corneumon and Follitrope, but small differences were detected in other biosimilar preparations compared with reference r-hFSH-alfa. Jin Sai Heng showed higher levels of N-glyconeuramic acid than the other preparations. Minor differences in oxidation levels were seen among the different products. Therefore, in summary, we identified var ious differences in N-glycosylation occupancy, antennarity, sialylation and oxidation between reference r-hFSH-alfa and the biosimilar preparations analyzed.

Biological Assay to Determine Gonadotropin Potency: From In Vivo to In Vitro Sustainable Method

“…The presence or absence of post-translational modifications, and/or changes in their relative abundance, may impact clinical efficacy and safety; therefore, analysis of posttranslational modifications is common practice in characterization studies of biopharmaceuticals [10]. Overall, our data show that both the in vitro and in vivo bioassays demonstrated effectiveness in identifying differences in critical quality attribute levels (sialylation, oxidation, free-subunits) between r-hFSH variants.…”

“…Post-translational modifications, such as glycosylation (e.g., sialylation) and oxidation, play a crucial role in the stability and bioactivity of FSH preparations [10]. Glycosylation of the α subunit at both sites (Asn52 and Asn78) [11] is critical for normal biochemical functions [12].…”

“…Furthermore, while oxidation of methionine residues does not directly impact regions critical for FSHR binding, oxidation of these residues may lead to conformational changes that indirectly impact bioactivity, efficacy and safety. As such, analysis of post-translational modifications is common practice in characterization studies of biopharmaceuticals [10].…”

Follicle-Stimulating Hormone Biological Products: Does Potency Predict Clinical Efficacy?

“…Indeed, FSH is a complex glycoprotein that is expressed and secreted in different glycoforms, characterized by structural differences in the glycosylation resulting from post-translational modifications. It is known that glycan structure determines the biological activity, receptor binding, and PK properties (half-life and clearance) of the FSH molecule [21][22][23]. A full explanation of the terms used throughout this manuscript can be found in Appendix A.…”

Comparative assessment of the DNA damage caused in cumulus cells by Corneumon®, Gonal-F®, Pergoveris® and Puregon® in women undergoing assisted reproduction techniques, and its impact on reproductive outcomes

“…FSH preparations derived from a urinary source have been successfully used in women undergoing COH for ART, but recently several human recombinant follicle stimulating hormones (rhFSH) have become available [11,12]. Despite the identical amino acid sequences of the different rhFSH, various differences in N-glycosylation occupancy, sialylation, antennarity and oxidation have been reported between them, which in uence the isoform pro les of the rhFSH [13] The aim of the present study was to carry out a comparative assessment of the DNA damage caused in CCs by four rhFSH widely used in COH for IVF protocols, Corneumon®, Gonal-F®, Pergoveris® and Puregon® in women undergoing ART, and to analyze the impact of the CCs DNA damage on several reproductive outcomes.…”