Custom Cell Line Development

Our custom cell line development platform for monoclonal antibody production is designed to optimize production yields while minimizing development costs. The first step in each project is a developability assessment where antibody leads are transiently expressed in our proprietary system – XtenCHO™. This highly productive cell line can express antibodies with glycosylation profiles and secondary structures comparable to stable cell lines such as CHO-S™. It also produces antibodies in quantities that allow extensive characterization of key antibody properties.

Based on this assessment, we develop a custom protocol for stable cell line generation and predict production yields. Stable expression and selection vectors are then designed, synthesized, and transfected into competent cells.

Selection and amplification of positive clones are then performed. Positive clones are isolated and evaluated for stability and productivity. If single clones with robust productivity are identified, the process is optimized and scaled up or transferred to the customer’s facilities or a selected CMO.

ProteoGenix’s stable cell line generation service offers a high diversity of cell lines * including CHO-DG44, CHO-S, and proprietary CHO-K1 and HEK cell lines adapted for culture in suspension. We are also able to carry out stable cell line development starting from customer-provided cell lines.

Alternatively, given our 28+ years of experience in protein production, we can produce antibodies in a variety of non-mammalian systems including bacterial (Escherichia coli, Bacillus subtilis), yeast (Saccharomyces cerevisiae, Pichia pastoris), and insect/baculovirus systems. These systems may be particularly interesting for the production of antibody fragments or antibodies intended for non-therapeutic use.

More than 100 projects were successfully completed using our platform of stable cell line generation for monoclonal antibody production with a productivity record of 8 g/L. These projects ranged from the production of full-length IgG, bispecific antibodies, Fc-fusion proteins, and antibody fragments including Fab, scFv, or VHH.

Our typical process of custom cell line development for monoclonal antibody production starts at 4 to 6 months. The most laborious and time-intensive part of the process involves the selection of stable single clones and subsequent stability studies (upon request).

Custom cell line development is a mandatory step in the successful clinical development of monoclonal antibodies. At ProteoGenix, we recommend the extensive early testing of antibody leads before committing to large-scale production.

Early developability assessment is a well-established and successful approach used to ensure an antibody meets the best stability, reactivity, and effectiveness before developing a custom and optimized production protocol. In this way, we can bypass many stable expression hurdles and ensure optimal production at reasonable costs. Antibody characteristics such as aggregation, affinity and avidity, specificity and selectivity, and glycosylation profile are known to have the greatest impact on developability and can be analyzed in silico and further measured on recombinant antibodies produced in our facilities.

Full-length monoclonal antibodies are often produced in mammalian expression systems such as Chinese hamster ovary (CHO) or mouse myeloma (NS0) cells. At ProteoGenix, we specialize in CHO cell lines offering a large diversity of hosts including our proprietary CHO-K1 cell line and also CHO-DG44 (a cell line lacking both alleles of DHFR, suitable for metabolic selection) or CHO-S, among others.
After over 28 years of experience in protein production in different expression systems (mammalian, bacterial, yeast, insect), CHO-based stable production is our system of choice when expressing antibodies. CHO cells are more tolerant to changes in pH, temperature, pressure, and oxygen concentrations. Plus, they are more amenable to gene amplification leading to production levels significantly higher than those achieved by other production systems. Plus, CHO cells produce proteins with glycosylation profiles similar to humans resulting in lower immunogenicity and optimal therapeutic efficacy.

In contrast, antibody fragments devoid of glycans may be produced faster at high titers in simpler systems such as bacterial cells (e.g. Escherichia coli or Bacillus subtills) known for their high turnover rates. The simpler genetic background of bacteria makes them more amenable to manipulation and scale-up. However, antibodies in E. coli are produced in the cytoplasm or periplasm requiring harsher extraction methods.

In addition, our service includes a comprehensive early testing phase. The comprehensive characterization of antibody leads allows us to predict potential production hurdles and guarantee production yields. In this way, we can protect our clients’ investments while transferring all risks directly to us.

Furthermore, you retain the intellectual property (IP) of the cell lines and protocols generated at ProteoGenix. This simplifies protocol and cell transfer to a CMO or your facilities for large-scale production. Our FTO (freedom-to-operate) stable cell line generation ensures a smooth transition from the bench to large-scale bioreactors and greatly simplifies the process of licensing your antibodies for therapeutic or in vitro diagnostic applications.

As experts in antibody production and engineering, we also offer a wide range of upstream services, including affinity maturation, antibody humanization, bispecific antibody development, antibody-drug conjugate development, and antibody reformatting. Our downstream capabilities include research cell bank development and stability studies. By partnering with us, you can save time and reduce costs while maximizing the therapeutic efficacy of your antibody leads and minimizing foreseeable production risks.