Custom Antibody Services Case Study: Improving Manufacturability Through Expression Engineering
A pharmaceutical company was initiating QC testing in a phase 3 clinical drug trial. They had requested large quantities of a mouse monoclonal antibody. However, neither the hybridoma nor the recombinant antibody could be expressed at levels needed by the company.
The successful development and manufacturing of therapeutic antibodies is dependent on the ability to express these proteins at high levels as antibody yields obtained from the manufacturing process determines production cost. Antibody expression systems, such as recombinant murine myeloma or Chinese hamster ovary cells, have been optimized to attain large antibody titers. However, not all antibodies can be produced in large quantities. Many times, the sequence of an antibody limits its production. To help our partner’s achieve large antibody quantities, we have generated a novel proprietary sequence database where we have cataloged information, such as light-heavy chain pairing and expression at production, along with protein sequence. Using this information, we can engineer an antibody to improve its manufacturability by increasing its expression, in some instances, by more than 200-fold.
We used our sequence database to identify a compatible high producing clone. Critical sequences were sequentially graphed to the low producing clone to make a panel of four engineered antibody clones. These clones were expressed in our transient expression system at pilot scale. Engineered antibody clones 1 (Figure 1A; green bar) and 3 (Figure 1A; light blue bar) had more than 5-fold higher expression than the native or wild type antibody.
Figure 1. Expression levels of engineered antibody clones.
Engineered antibody clone 1 had fewer amino acid substitutions from the native antibody, thus it was further tested in a three-liter transient production line. At production, engineered antibody clone 1 yielded over one gram of recombinant antibody (Figure 1B; green bar). Specificity of engineered antibody clone 1 was tested in a direct ELISA and was indistinguishable from the wild type (Figure 2).
Figure 2. Specificity testing for engineered antibody clone 1.