Definition

A half-life extended T-cell engaging bispecific antibody comprised of a single chain variable fragment (scFv) targeting the tumor-associated antigen (TAA) CD19, a scFv targeting the T-cell surface antigen CD3, and a single-domain heavy chain variable domain (VHH)-based antibody specific for human serum albumin (HSA), with potential immunostimulating and antineoplastic activities. Upon administration, anti-CD19/CD3 T-cell engaging bispecific antibody CLN-978 targets and binds to both CD19 antigen expressed on tumor cells and CD3 antigen expressed on T cells. This results in the cross-linking of T cells and tumor cells, and induces a cytotoxic T-lymphocyte (CTL) response against CD19-expressing tumor cells. CD19 antigen is a B-cell specific cell surface antigen overexpressed in B-cell lineage malignancies. The HSA binding domain prolongs the half-life of CLN-978.