In 2024, the bispecific DLL3 × CD3 T cell engager tarlatamab was granted FDA accelerated approval for previously treated extensive stage small cell lung cancer (SCLC) on the basis of data from the single-arm phase II DeLLphi-301 trial. Now, results from the confirmatory phase III DeLLphi-304 trial demonstrate that tarlatamab improves outcomes compared with the current second-line standard of care.

In DeLLphi-304, 509 patients with SCLC that had progressed on or after first-line platinum-based chemotherapy, with or without an anti-PD-(L)1 antibody, were randomly assigned (1:1) to receive tarlatamab or standard chemotherapy (topotecan, lurbinectedin or amrubicin). The primary end point was overall survival (OS).