XmAb® Fv Technology
To complement our XmAb® Fc technology, Xencor also developed a full suite of XmAb tools to optimize the variable region (Fv) of antibodies.
Restringing, a Novel Technology for Humanizing Antibodies
A key part of XmAb variable region optimization is a novel and proprietary method for humanizing antibodies called human restringing. Human restringing taps the entire naturally occurring repertoire of human antibody sequences to select the best human sequence components that match the structure of the antibody. This combined approach allows simultaneous optimization of affinity and physical properties while increasing human sequence content of murine antibodies to match that of traditional humanized or fully human antibodies. Further, XmAb human restringing allows the maintenance of human sequence content in fully human antibodies that are being optimized for other properties such as solubility or expression yield.
The XmAb technology is unique in using structure-based design tools on antibody variable domains to generate pre-filtered, high-quality sequence diversity, which is then screened for improved affinity, stability and production yield. An enormous breadth of sequence diversity can be tested computationally, allowing Xencor scientists to create previously inaccessible combinations of new properties with only modest use of expensive experimental screening resources.
Xencor’s entire XmAb pipeline has been created using these in-house tools.