Bispecific and Trispecific Antibodies

Binding multiple epitopes with a single antibody offers several benefits. For example, one specificity may target individual molecules while another could recruit effector cells or deliver a drug to the target. Other options include dual-target bispecifics which might detect a desired cell type with much higher selectivity than a monospecific antibody.

One of Absolute Antibody’s engineering services is the design and manufacture of multispecific antibody formats. Starting with a hybridoma cell line or antibody sequence, we can deliver from milligrams to grams of your custom bispecific, 100% royalty-free. Contact us with any enquiries.

Knob-into-holes (KIH) – and other approaches

The most widely-recognized method for making bispecific antibodies is known as the knob-into-holes (KIH) approach. Two antibody chains are co-expressed recombinantly with mutations to create a “knob” on one and “hole” on the other such that heterodimer is the predominant product. When people refer to bispecific antibodies, they are typically referring to these heterodimeric antibodies, i.e., a traditional IgG molecule but with one arm targeting one antigen and the other targeting a second.

However, by making use of Fab fragments and the single chain Fv (scFv) as building blocks, many other options become available. Some of these are summarized below.

You can learn more about multispecific antibodies on our Antibody Resource. In addition, download our research poster to learn about our platform for creating fully murine KIH bispecific antibodies as surrogate molecules for drug development models, or view our presentation to learn more about our approach to bispecific antibody engineering.

Formats we have made

Below are just some of the antibody formats that we have engineered and produced. For more information, visit our pages on our antibody engineering services and the formats we have made.

A selection of the formats we have made at Absolute Antibody.

Comparing bispecific formats

Not all bispecific antibodies are created equal. How easily they are expressed and how they perform can vary significantly between various formats. Absolute Antibody scientists systematically built and evaluated 17 bispecific designs comprising of trastuzumab and a humanized OKT3, including a number of well-utilized formats. We found that Fc-containing formats and the placement of scFv can influence the expression dramatically. Download the poster here.