Study summary

Tarlatamab added to durvalumab maintenance extended survival by more than 8 months

DeLLphi-305 trial · 563 people, phase 3 · Presented at ESMO October 2026; published in NEJM

What was tested

Tarlatamab, a bispecific antibody that links T cells to DLL3 on cancer cells, plus durvalumab, against durvalumab alone as maintenance after first chemo-immunotherapy for extensive-stage small cell lung cancer.

What they found

• Median survival was 21.1 vs 12.7 months; risk of death fell 58%.
• 38% vs 10% were free of growth at 12 months.
• Cytokine release syndrome occurred in about half, mostly mild.

What it means

Likely to become the new first-line maintenance standard. Approval for this use has not yet been reported.