Amgen's Imdelltra Plus AstraZeneca's Imfinzi Extends Survival in Small Cell Lung Cancer Trial

Amgen's Imdelltra combined with AstraZeneca's Imfinzi reduced the risk of death by 58% compared with Imfinzi alone in patients with extensive-stage small cell lung cancer, according to data presented at a medical meeting on October 24, 2026. Yahoo published the report. Patients given both drugs lived a median of 21.1 months, versus 12.7 months for those treated only with Imfinzi.

How the DeLLphi-305 Trial Worked

Full results of the 563-patient trial were presented at the European Society for Medical Oncology meeting in Madrid and published in the New England Journal of Medicine. TradingView reported that the DeLLphi-305 Phase III trial also showed progression-free survival of 7.4 months versus 1.9 months. Amgen had previously announced that the Phase 3 study was successful.

Imdelltra belongs to a dual-target class of drugs called bispecific antibodies designed to pull immune system T cells into contact with cancer cells to destroy them. Imfinzi is an older type of immunotherapy that blocks the mechanism tumors use to hide from immune-system assault. Imfinzi is currently the standard of care following chemotherapy for patients whose cancer does not worsen after initial chemotherapy.

"If you give Imdelltra earlier and earlier, you get bigger clinical benefit," said Paul Burton, chief medical officer at California-based Amgen. He called the results "unprecedented in advancing the treatment of extensive-stage small cell lung cancer."

Amgen said that nearly 80% of trial patients treated with the combination were alive after one year, compared with 53% of those on Imfinzi alone. Serious side effects, including low white blood cell counts, occurred in 20.9% of patients on the dual therapy and 10.8% with the single therapy. Cytokine release syndrome was reported in 49.6% of patients who received Imdelltra, but only one case was serious and there were no CRS-related deaths.

Amgen's Imdelltra Approval and Pricing

According to akta.pro company records, the FDA approved IMDELLTRA (tarlatamab) for extensive-stage small cell lung cancer in May 2024, the first T-cell engager therapy for SCLC. Imdelltra's US list price is about $30,000 per cycle, or over $390,000 a year. Wall Street analysts have estimated annual sales reaching more than $2.5 billion by 2030, according to LSEG data.

Earlier Amgen Cancer Data at ESMO

On October 23, 2026, FierceBiotech reported that Boehringer Ingelheim presented data on its DLL3xCD3 T-cell engager obrixtamig at ESMO, showing a 72% overall response rate in second-line small cell lung cancer patients. On October 20, 2026, PR Newswire reported that Amgen would host a webcast call for the investment community on Saturday, October 24, 2026, at 11:30 a.m. PT, in conjunction with the European Society of Medical Oncology Congress 2026.

What Comes Next for Amgen

Amgen said patient follow-up continues. The company will host a webcast call for the investment community on Saturday, October 24, 2026, at 11:30 a.m.