Generation of dual-variable-domain immunoglobulin molecules for dual-specific targeting

Bispecific antibodies may be used to improve clinical efficacy by targeting two disease mechanisms for the treatment of complex human diseases in a single agent. Bispecific antibodies also hold promise for certain therapeutic applications difficult to achieve by single-targeting monospecific antibodies, such as immune (T cell or NK) cell retargeting, site-specific targeting, enabling therapeutics to cross the blood-brain barrier, and unique receptor modulation. Although the history of bispecific antibody research is almost as long as hybridoma technology, it is not until recent that bispecific antibodies have made substantial breakthrough, thanks to promising clinical trial results of a few bispecific antibodies and the development of new formats which largely ease manufacturing and physicochemical property challenges encountered by early bispecific antibody formats. The dual-variable-domain immunoglobulin (DVD-Ig™) format was initially described in 2007. In this format, the target-binding variable domains of two monoclonal antibodies can be combined via naturally occurring linkers to create a tetravalent, dual-targeting single agent. Viable DVD-Ig molecules can be identified through optimization of antibody pair, antibody variable domain orientation, and linkers. An optimized DVD-Ig™ molecule has many desirable properties of a mAb, such as good expression in mammalian cells, easy purification to homogeneity using standard approaches, displaying good drug-like biophysical and pharmacokinetic properties, and amenability to large-scale manufacturing. Several DVD-Ig molecules have demonstrated favorable pharmacokinetic properties and efficacy in preclinical animal models. Here, we provide an example of construction and preliminary characterization of a DVD-Ig™ molecule and discuss the general approach used in optimization.