The FDA has approved Imdelltra (tarlatamab-dlle) for adults with extensive-stage small cell lung cancer (ES-SCLC) who have progressed following platinum-based chemotherapy. This marks the first approval of a DLL3-targeted bispecific T-cell engager in SCLC, offering a long-awaited therapeutic option in a disease with historically limited advancements.
Clinical Data (DeLLphi-301)
Approval was supported by results from the DeLLphi-301 trial, which demonstrated:
Objective Response Rate: ~40 %
Median Duration of Response: ~9 months Rapid and meaningful tumor shrinkage in a heavily pre-treated population
Safety Profile: Primarily low-grade CRS and early-onset neurologic events, typically manageable with standard supportive measures
These outcomes highlight both the activity and durability of DLL3-directed T-cell engagement in relapsed SCLC.
Clinical Significance
Imdelltra introduces a first-in-class, biomarker-driven therapy for SCLC, targeting the overexpression of DLL3 on tumor cells. Its approval adds a new mechanism of action into a treatment landscape where relapse options have remained limited for decades
