Tarlatamab: First Approval.

Tarlatamab (tarlatamab-dlle: IMDELLTRA™) is a first-in-class, half-life extended bispecific delta-like ligand 3 (DLL3)-directed CD3 T-cell engager being developed by Amgen for the treatment of small cell lung cancer (SCLC) and neuroendocrine prostate cancer. Tarlatamab binds to DLL3 on the surface of tumour cells and CD3 on the surface of cytotoxic T lymphocytes (CTLs), resulting in T-cell activation, release of inflammatory cytokines and CTL-mediated cell death of DLL3-expressing tumour cells. In May 2024, tarlatamab received its first approval in the USA for the treatment of adults with extensive stage SCLC (ES-SCLC) with disease progression on or after platinum-based chemotherapy. Tarlatamab received accelerated approval for this indication based on overall response rate and duration of response in the pivotal phase 2 DeLLphi-301 study, and continued approval may be contingent on the demonstration of clinical benefit in a confirmatory trial(s). Tarlatamab is under regulatory review in Brazil, Canada, Israel and the UK, and clinical studies are underway in multiple countries. This article summarizes the milestones in the development of tarlatamab leading to this first approval for ES-SCLC with disease progression on or after platinum-based chemotherapy.