A review.Mammalian cells have become the dominant system for producing recombinant protein products in clin. applications because of their capacity to properly fold and assemble proteins and add human-like posttranslational modifications.However, when using mammalian host cell systems, cell line and process development are often very time-consuming.The need to speed up development may lead some companies to compromise the robustness and scalability of their manufacturing processes, often resulting in suboptimal product yields and/or quality.As a consequence, significant redevelopment may be necessary for pivotal clin. studies and can include extensive comparability studies.To avoid such addnl. costs, Rentschler Biotechnologie pursues a fast-track development strategy for mammalian cell lines that considers all aspects of drug approval right from the start of the process.Beginning with the generation of recombinant cell lines, each stage of development is assessed in view of regulatory and manufacturing considerations with the intention of preventing costly redevelopment efforts.The company has established a procedure using CHO dhfr- cells (Chinese hamster ovary cells that are dehydrofolate reductase neg.) allowing serum-free execution of all steps essential for development of a recombinant cell line including transfection, selection, amplification, and single-cell cloning.This established procedure significantly speeds up cell line development compared with a traditional serum-containing process while complying with regulatory requirements.
