Tarlatamab (AMG-757) is a bispecific T-cell engager (BiTE) antibody targeting delta-like ligand 3 (DLL3). DLL3 is a target that is selectively expressed in small-cell lung cancer (SCLC) tumors, but with minimal normal tissue expression. Tarlatamab has the KDs of 0.64 nM and 0.50 nM for human and nonhuman primate (NHP) DLL3, respectively. Tarlatamab has the KDs of 14.9 nM and 12 nM for human and NHP CD3, respectively. Tarlatamab is a first-in-class HLE BiTE immuno-oncology therapy targeting DLL3 and has the potential for SCLC research.