Process Development for Bispecific Antibodies

Bispecific antibodies (BsAbs) contain two different antigen-binding sites. They are a type of reconstructive molecule that can recognize two different epitopes. Generally, BsAb can be divided into two major classes, those bearing an Fc region and those lacking an Fc region, the latter normally being smaller than the IgG and IgG-like bispecific molecules comprising an Fc. BsAb aims to treat multifaceted, complex diseases by engaging two disease targets with one molecule. BsAb recognizes two different epitopes. This dual specificity opens up a wide range of applications, including redirecting T cells to tumor cells, blocking two different signaling pathways simultaneously, dual targeting different disease mediators, and delivering payloads to targeted sites.

Fig. 1 Bispecific antibodies can be engineered with two, three, or four different peptide chains. (Williams and Ambrose J., 2018)

With advanced technology and experienced staff, Creative Bioarray provides comprehensive cell support services in the process development for bispecific antibodies to help our customers worldwide. We delivered rapid and accurate results to assist customers to accelerate their research.

Our Processing Methods of Bispecific Antibodies

• Duobody system. This is the simplest method for creating bispecific antibodies. Two IgG1 antibodies with complementary CH3 mutations are expressed separately. After purification, these antibodies can bind in a process known as Fab arm exchange.
• IgG-scFvs. This is a format that uses four binding sites, two for each target, where one scFv is added to the C-terminus of each antibody heavy chain, usually linked with a flexible linker. The expression and purification of this form are variable and depend greatly on the specific scFv sequence used.
• Knob-in-Hole, Crossmab, Electrostatic Steering, and related formats. The bi-specificity of these two binding sites, one for each target, is generated by transfecting cells with 2 different heavy chains and one or two light chains during mammalian cell culture.

The Role of Cell Banks in Bispecific Antibodies Expression and Production

• Appropriate host platforms are determinant to the efficient expression and production of bispecific antibodies, and there exist several different viable platforms for bispecific antibody expression including bacteria, yeast, mammalian cells, insect cells, plant, and cell-free systems.
• Among them, mammalian cells represent the most widely used production platform for therapeutic proteins and a promising expression vehicle for bispecific antibodies due to their advanced protein folding pathways and post-translational modifications. Another organism of interest is the insect cell, which allows the utilization of the baculovirus-mediated gene expression system.
• We provide cGMP-compliant CHO and other cell banking services as strong support for monoclonal antibodies, which ensure that our clients have rapid access to high-quality, well-characterized, and consecutive cells.

As a professional services provider in the field of cell science, Creative Bioarray provides strong cell support in the process development for bispecific antibodies to our customers worldwide. We provide our clients with direct access to our experts and prompt responses to their questions. If you are interested in our services or have any questions, please feel free to contact us or make an online inquiry.