Amgen says Imdelltra plus Imfinzi cut risk of death 58% in Phase 3 small-cell lung cancer trial

As of 3:56 p.m. ET, Saturday, Oct. 24, 2026

Amgen said Saturday that its drug Imdelltra (tarlatamab-dlle), given with AstraZeneca's Imfinzi (durvalumab), reduced the risk of death by 58% compared with Imfinzi alone as a first-line maintenance treatment for extensive-stage small cell lung cancer, according to interim results from the Phase 3 DeLLphi-305 trial.

Median overall survival was 21.1 months with the combination versus 12.7 months with durvalumab alone, at a median follow-up of about 16 months, the company said. The hazard ratio was 0.42.

The trial enrolled patients whose disease had not progressed after initial treatment with durvalumab, platinum-based chemotherapy and etoposide, Amgen said. The results were presented in a Presidential Symposium at the European Society for Medical Oncology congress (abstract LBA3) and published simultaneously in The New England Journal of Medicine, according to the company.

Other results

At one year, nearly 80% of patients on the combination were alive compared with 53% on durvalumab alone, Amgen said. Median progression-free survival was 7.4 months versus 1.9 months, and 26.4% of patients on the combination had an objective response compared with 4.1% on durvalumab alone, according to the release.

Side effects

Grade 3 or higher treatment-related adverse events occurred in 20.9% of patients on the combination and 10.8% of those on durvalumab alone, the company said. Cytokine release syndrome was reported in 49.6% of patients who received Imdelltra; it was mostly Grade 1 (41.8%) or Grade 2 (7.4%), with one Grade 3 event and no Grade 4 or higher events, Amgen said. Immune effector cell-associated neurotoxicity syndrome occurred in 1.1% of patients on Imdelltra, with no Grade 3 or higher cases.

"These results represent an unprecedented advance for patients with extensive-stage small cell lung cancer, demonstrating a magnitude of survival benefit rarely seen in this aggressive disease," said Jay Bradner, Amgen's executive vice president of research and development, artificial intelligence and data. Amgen said it is moving to share the results with regulatory authorities worldwide.

The results are from an interim analysis.