![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Chemically_linked_Fab%2527.svg/640px-Chemically_linked_Fab%2527.svg.png&w=640&q=50)
Chemically linked Fab
From Wikipedia, the free encyclopedia
Two chemically linked fragments antigen-binding form an artificial antibody that binds to two different antigens, making it a type of bispecific antibody. They are fragments antigen-binding (Fab or Fab') of two different monoclonal antibodies and are linked by chemical means like a thioether.[1][2] Typically, one of the Fabs binds to a tumour antigen (such as CD30) and the other to a protein on the surface of an immune cell, for example an Fc receptor on a macrophage. In this way, tumour cells are attached to immune cells, which destroy them.[3]
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Chemically_linked_Fab%27.svg/320px-Chemically_linked_Fab%27.svg.png)
In the late 1990s and early 2000s, clinical trials with chemically linked Fabs were conducted for the treatment of various types of cancer. Early results were promising,[3][4] but the concept was dropped because of high production costs.[5]
Bi-specific T-cell engagers employ a similar mechanism of action while being cheaper.