Fcabs are antibodies fragments engineered from the constant region of an antibody (Fc). In naturally occurring antibodies (such as IgGs), the antigen-binding sites are located at the variable regions (Fab).
Overview
Fcabs can be expressed as soluble proteins or they can be engineered back into a full IgG. This type of antibodies are therefore able to recognise two different antigens, one at their Fab region and a second one at the Fc region, hence the name of bispecific antibodies. This antibody fragment is part of the modular antibody technology of F-star Biotechnology Ltd.
References
Fcab Wikipedia(Text) CC BY-SA