TF4

TF4 is a humanized, trivalent, bispecific monoclonal antibody (bsMAb) developed by Immunomedics (now part of Gilead Sciences) using the proprietary Dock-and-Lock (DNL) platform. It is specifically designed for pretargeted radioimmunotherapy (PT-RAIT) of CD20-expressing B-cell malignancies, such as non-Hodgkin's lymphoma. The molecule is a tri-Fab construct consisting of two Fab fragments derived from the anti-CD20 antibody veltuzumab (hA20) and one Fab fragment derived from the anti-histamine-succinyl-glycine (HSG) antibody m679. In a pretargeting clinical or preclinical setting, TF4 is administered first to saturate CD20 receptors on tumor cells. After a clearance period, a radiolabeled hapten-peptide (e.g., 90Y-IMP-288) is administered, which binds with high affinity to the HSG-binding site on the tumor-localized TF4, thereby delivering a concentrated dose of radiation to the tumor while sparing healthy tissues.

Other names

anti-CD20 x anti-HSG bispecific antibodyanti-CD-20 x anti-HSG bispecific antibodyanti-CD 20 x anti-HSG bispecific antibodytrivalent anti-CD20 bispecific antibodyveltuzumab-based bispecific antibody