Definition

A T-cell receptor (TCR)-like T-cell engaging bispecific antibody (T-BsAb) targeting both the RMFPNAPYL nonapeptide (RMF peptide), which is derived from the intracellular Wilms tumor 1 (WT1; WT-1) and presented on human leukocyte antigen A2 (HLA-A2), and the CD3 antigen found on T lymphocytes, with potential immunostimulating and antineoplastic activities. Upon administration, anti-HLA-A2-WT1/anti-CD3 T-cell engaging bispecific antibody RO7283420 simultaneously binds to both CD3 on cytotoxic T lymphocytes (CTLs) and the HLA-A2 WT1 complex found on WT1-expressing tumor cells. This activates and redirects CTLs to WT1-expressing tumor cells, which results in the CTL-mediated cell death of WT1-expressing tumor cells. WT1, an intracellular oncoprotein and transcription factor, is overexpressed in a variety of tumor cell types.