Adding Amgen’s Imdelltra (tarlatamab) to AstraZeneca’s Imfinzi (durvalumab) as first-line maintenance reduced the risk of death by 58 percent (hazard ratio 0.42, p<0.001) in the 563-patient Phase 3 DeLLphi-305 trial in extensive-stage small cell lung cancer patients who had not progressed after initial Imfinzi, platinum chemotherapy and etoposide, Amgen announced at the ESMO Congress in Madrid, with the results published simultaneously in The New England Journal of Medicine. Median overall survival was 21.1 months on the combination against 12.7 months on Imfinzi alone, nearly 80 percent of combination patients were alive at one year against 53 percent, and median progression-free survival was 7.4 months against 1.9 months. Grade 3 or higher treatment-related adverse events occurred in 20.9 percent of combination patients against 10.8 percent on Imfinzi alone, and cytokine release syndrome was reported in 49.6 percent of Imdelltra patients, predominantly grade 1 or 2 with one grade 3 event and no grade 4 or higher events.
Amgen combination cuts small cell lung cancer death risk
Amgen's Imdelltra combined with AstraZeneca's Imfinzi cut the risk of death by 58 percent as first-line maintenance in extensive-stage small cell lung cancer in the Phase 3 DeLLphi-305 trial, with median survival of 21.1 months against 12.7 months on Imfinzi alone.
Why it matters: Extensive-stage small cell lung cancer has a median survival of about a year on current maintenance treatment, so an eight-month survival gain in a 563-patient Phase 3 trial, presented at ESMO and published in The New England Journal of Medicine, would move Imdelltra from later-line use into first-line maintenance if regulators accept the data.
Data as of Amgen press release of October 24, 2026, read in full, is the primary source for all trial figures; CNBC report of October 24, 2026, read in full, independently reports the same survival figures and investigator comment, and the Endpoints News summary matches on the 58 percent figure and the 21.1-month median. Results are interim Phase 3 data presented at the ESMO Congress 2026 in Madrid. Developing item.
Sources
- Imdelltra in combination with Imfinzi reduced risk of death by an unprecedented 58% in first-line extensive stage small cell lung cancer - Amgen, via PR Newswire - 2026-10-24
- Amgen says drug combo cuts risk of death by 58% in patients with aggressive lung cancer - CNBC - 2026-10-24
- Amgen's Imdelltra regimen more than halves risk of death in Phase 3 lung cancer trial - Endpoints News - 2026-10-24