16-02-2017 | Image
BiTE® are constructed of single polypeptide chain that consists of two VL and VH pairs that recognize CD3 and CD19, respectively. DARTs are constructed of two separate, but paired, polypeptide chains, each comprising VL and VH regions that recognize different cell-surface molecules; the two polypeptide chains dimerize and are linked by interchain disulphide bridge, forming two functional VL–VH pairs that each comprise a VL from one polypeptide and a VH from the other. TandAb®are constructed of dimerized single polypeptide chains; each chain contains two different VL regions and two different VH regions, which upon dimerization, form four antigen-recognition sites for two different antigen (two VL–VH pairs; targeting CD19 and CD3 in this case). DARTs and TandAb® have longer half-life compared to BiTE® due to their structure. Abbreviations: BiTE®, bispecific T-cell engagers; DART, dual affinity retargeting antibody; TandAb®, tetravalent tandem diabody; VH, antibody heavy-chain variable region; VL, antibody light-chain variable region.