A Phase 2 Study of Tarlatamab in Patients With Small Cell Lung Cancer (SCLC)

Overview

• Tarlatamab is a bispecific T-cell engager binding delta-like ligand 3 on small-cell lung cancer and CD3 on T cells. In this phase 2 trial, 220 patients who had had a median of two previous lines received tarlatamab 10 mg or 100 mg intravenously every two weeks. Objective response by blinded independent central review was 40 percent (97.5 percent confidence interval 29 to 52) at 10 mg and 32 percent (21 to 44) at 100 mg; response lasted at least six months in 59 percent (40 of 68) and was ongoing at cutoff in 55 and 57 percent of responders. Median progression-free survival was 4.9 months (95 percent confidence interval 2.9 to 6.7) at 10 mg and 3.9 months at 100 mg. Cytokine release syndrome occurred in 51 percent at 10 mg and 61 percent at 100 mg, with immune effector cell-associated neurotoxicity syndrome in a minority; 3 percent discontinued for a related event (New England Journal of Medicine 2023). The FDA granted accelerated approval on 16 May 2024 and traditional approval on 19 November 2025. NICE TA1091 (20 August 2025) does not recommend tarlatamab in England.