Rapid expression of therapeutic antibodies in mammalian cells via mRNA transfection.

Messenger RNA (mRNA) has emerged as a powerful tool for protein expression in clinical settings, yet its potential as a platform for biologics manufacturing remains underexplored. Here, we evaluate transient mRNA transfection in Chinese hamster ovary (CHO) cells as a rapid and versatile system for protein production. Using reporter mRNAs, we optimize transfection efficiency and benchmark performance against industry-standard plasmid transfection and stable cell line methods. We demonstrate that co-transfection of heavy and light chain mRNAs enables the efficient synthesis, assembly and secretion of the monoclonal antibody bevacizumab with high fidelity. Compared to conventional approaches, mRNA transfection drives rapid and predictable protein expression, reducing cell incubation times and enabling sequential or conditional expression. These features highlight mRNA as a flexible and efficient platform for transient expression, providing a foundation for accelerating the development and manufacturing of biologics.