The Key to Antibody Immune Function and Structure

Xencor’s proprietary XmAb antibody engineering platform creates subtle, precise alterations to the antibody’s Fc domain — the stem of the structure that is responsible for antibodies’ natural immune functions and highly stable structure. These subtle changes elicit dramatically enhanced performance. XmAb Fc domains are plug-and-play and can be substituted into nearly any antibody.

We design a small number of amino acid changes at locations (typically two) that are critical for Fc domain interactions with immune cell receptors.  As a result, XmAb drug candidates are usually more than 99.5 percent identical in structure and sequence to natural antibodies. The resulting engineered antibodies retain the beneficial stability, pharmacokinetics and ease of development of natural antibodies, and are produced with standard methods for antibody manufacturing.