Tarlatamab (AMG-757) is a first-in-class, high-affinity bispecific T-cell engager (BiTE) antibody targeting delta-like ligand 3 (DLL3), a protein primarily expressed in small-cell lung cancer (SCLC) with minimal expression in normal tissues. It has dissociation constants (KDs) of 0.64 nM and 0.50 nM for DLL3 in human and nonhuman primates (NHP), respectively, and 14.9 nM and 12 nM for CD3 in human and NHP, accordingly. As a pioneering HLE BiTE immuno-oncology therapy for DLL3-expression SCLC, tarlatamab shows promising potential for research in this area [1].