Update of the multinational phase 1 DeLLphi-300 trial of tarlatamab for previously treated small cell lung cancer

Tarlatamab is a bispecific T-cell engager targeting delta-like ligand 3. The multinational phase 1 DeLLphi-300 trial evaluated tarlatamab for previously treated small cell lung cancer. An update of the study (median follow-up 12.1 months; range 0.2-34.3) has now been published. Among 152 patients who received a median of 2 (range 1-7) previous lines of therapy, the the objective response rate was 25.0%, the median duration of response was 11.2 months, and the median overall survival was 15.5 months. Among 17 patients treated with the selected RP2D of tarlatamab 10 mg every two weeks the ORR was 35.3%, the mDOR was 14.9 months, and the mOS was 30.3 months. Among 16 patients with a CNS lesion ≥ 10 mm, tumor shrinkage of ≥ 30% was seen in 10 (62.5%). No new safety signals were observed. The authors conclude that tarlatamab for previously treated SCLC resulted in unprecedented survival, with evidence of intracranial activity.