Production of a Dulaglutide Analogue by Apoptosis-Resistant Chinese Hamster Ovary Cells in a 3-Week Fed-Batch Process.
This study describes the development of a high-yield Chinese hamster ovary (CHO) cell manufacturing platform for a biosimilar of dulaglutide, a GLP-1/IgG4-Fc fusion protein approved for type 2 diabetes. Researchers used apoptosis-resistant CHO 4BGD cells and sequentially transfected two expression plasmids encoding dulaglutide, employing a two-step transgene amplification strategy using methotrexate (MTX) followed by methionine sulfoximine (MSX) selection. The dual-selection approach resulted in approximately 30% higher titers in polyclonal populations compared to MTX amplification alone. Through a clonal cell line selection pipeline, the top clone (4BGD/Dul #73) achieved a product titer of 1.05 g/L in a 3-week fed-batch process, with a specific productivity of up to 22 pg·cell⁻¹·day⁻¹ and stable expression over 69 days without selective pressure. Purity assessed by size-exclusion HPLC showed ≥95% monomer content. Biological activity testing in a GLP-1 receptor/CRE-luciferase reporter assay yielded an EC₅₀ of 52 pM for the biosimilar candidate versus 76 pM for the reference drug. Limitations include the absence of in vivo or clinical data, with all findings limited to cell culture and in vitro bioassay systems.
Why this grade: The study is conducted entirely in CHO cell culture and a cell-based reporter assay with no animal or human data, providing no direct clinical evidence for dulaglutide's efficacy or safety in humans.
Background: Dulaglutide, a GLP-1-IgG4 Fc fusion, is a long-acting GLP-1 receptor agonist used for type 2 diabetes therapy and other emerging indications. It is produced commercially in Chinese hamster ovary (CHO) cells. The supply of the original drug is now limited in some regions, so creation of highly productive biosimilar manufacturing platforms is important. Methods: Two expression plasmids (p1.1-Tr2-Dul, p1.2-GS-Dul) encoding dulaglutide were sequentially transfected into apoptosis-resistant CHO 4BGD cells. Two-step transgene amplifications with methotrexate (MTX), followed by methionine sulfoximine (MSX) selection and subsequent cell cloning pipeline, were employed. Candidate clonal cell lines were selected using fed-batch culturing and long-term productivity testing. Results: Transfection with a second plasmid encoding glutamine synthetase (p1.2-GS-Dul) and selection with MSX resulted in a further ~30% increase titer in polyclonal population even after MTX-driven amplification. Top clone 4BGD/Dul #73 reached 1.05 g/L product titer in fed-batch culture (qP up to 22 pg·cell -1 ·day -1 ) and remained stable for 69 days in medium without MTX/MSX. Size exclusion-high-performance liquid chromatography showed ≥95% monomer; EC 50 of the purified GLP-1-Fc in a GLP-1R/CRE-Luc assay was 52 pM for the obtained product versus 76 pM for the original reference drug. Conclusions: The sequential transfection and dual-marker selection approach enables the efficient generation of a robust, high-yield, and glutamine-independent CHO producer, representing a productive strategy suitable for industrial biosimilar development.
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