The DeLLphi-304 phase 3 trial evaluated tarlatamab—a bispecific T-cell engager targeting DLL3—versus standard second-line chemotherapy (topotecan, lurbinectedin, or amrubicin) in patients with extensive-stage small-cell lung cancer (ES-SCLC) who had progressed following platinum-based chemotherapy and immunotherapy [21]. Here, DLL3 is linked to small cell lung carcinoma.