Fab Engineered-BsAb Generation Service

Creative Biolabs has successfully developed several different forms of bispecific antibodies (BsAbs). To create heterodimeric IgG-like BsAbs, Fc engineering technologies have been widely studied to overcome heavy mispairing, and heavy-light chain mispairing can be obviated by Fab region engineering, such as Fab fragment crossover (CrossMab by Roche). With experienced scientists hammering at Creative Biolabs, we are confident in providing heterodimeric BsAbs with correct heavy chain-, light chain-pairing.

The field of BsAbs is developing rapidly, and they showed potent use in immunotherapy and oncology, as well as infectious disease. Compared to the first generation of therapeutic antibodies, engineered BsAbs combined the binding specificity of two antibodies in only one molecule. However, the main problem in the development of BsAbs is enforcement of the correct light and heavy chain association. The correct association of generic light chains can be achieved by using immunoglobulin domain crossover, also named as CrossMAb technology by Roche. This technology enables to be combined with methods enabling correct heavy chain association, for example, electrostatic steering or knobs-into-holes (KiH) technology. With Fab fragment crossover, it has proven to be very powerful, allowing the production of a variety of BsAbs formats.

Fig. 1. Some CrossMabs in clinical trial (Klein, C., 2016)

Fab engineering technology

Fab engineering technologies can be classed in two types, one is to change the combination of IgG region, such as fragments crossover, and the other is to create two different paratopes within one pair of variable domains, such as DutaMab by Roche.

In BsAbs with IgG region crossover, the sequences of variable domains are the same as that of parental antibodies. Different types of fragment crossover may result in vary by-side products. As reported, the format of CrossMab^CH1-CL has fewer side products than CrossMab^Fab and CrossMab^VH-VL.

DutaMab, with engineered variable regions, can recognize two unrelated antigens through two different binding sites on the antibody (paratopes), which utilize the diversity of only three CDRs for each antigen

Fig. 2. Schematic diagram of DutaMab (Christoph Spiess, 2015)

With our well-established antibody and BsAb development platforms, the experienced scientists here at Creative Biolabs are dedicated to helping you develop various formats of BsAbs to meet every client’s requirements. We also provide other various services regarding BsAbs development. Please feel free to contact us for more information and a detailed quote.

References

1. Klein, C.; et al. The use of CrossMAb technology for the generation of bi- and multispecific antibodies. MAbs. 2016, 8(6), 1010-20.
2. Regula, J. T.; et al. Targeting key angiogenic pathways with a bispecific CrossMAb optimized for neovascular eye diseases. EMBO Molecular Medicine. 2016, 8(11), 1265-1288.