Amgen presented Phase III DeLLphi-305 results showing that tarlatamab combined with AstraZeneca's durvalumab reduced the hazard of death by 58% compared with durvalumab alone in first-line maintenance treatment of extensive-stage small-cell lung cancer.
Among 563 randomized patients, median overall survival was 21.1 months versus 12.7 months, corresponding to a hazard ratio of 0.42 (95% CI: 0.32–0.54; p<0.001).
Grade 3 or higher treatment-related adverse events occurred in 20.9% of combination-treated patients versus 10.8% of controls, while cytokine release syndrome occurred in 49.6% of patients receiving tarlatamab, predominantly at Grade 1 or 2.
The results were presented at ESMO 2026 and simultaneously published in the New England Journal of Medicine. Amgen
Primary source: Amgen — DeLLphi-305 Phase III Results, October 24
Why it matters strategically
Tarlatamab is already approved in the United States for extensive-stage small-cell lung cancer following progression on platinum-based chemotherapy.
The new results support evaluating its use earlier in the treatment sequence.
The magnitude of the reported overall survival benefit is clinically important.
However, expanding treatment into first-line maintenance also changes the population exposed to the drug, the duration and timing of treatment, and the associated healthcare costs.
A treatment that provides substantial survival benefit may still require complex implementation because of monitoring requirements and adverse-event management.
