Amgen's Imdelltra Combo Extends Lung Cancer Survival by 8.4 Months

Amgen said on Oct 24 that adding its drug Imdelltra to AstraZeneca's Imfinzi cut the risk of death by 58% in a phase 3 trial in extensive-stage small cell lung cancer. The trial, DeLLphi-305, tested the pair as first-line maintenance treatment. The results were presented at the ESMO Congress 2026 in Madrid and published in The New England Journal of Medicine.

What happened

The global trial enrolled 563 patients whose cancer had not progressed after first-line treatment with Imfinzi, platinum chemotherapy and etoposide. Patients were randomly assigned to Imdelltra plus Imfinzi or to Imfinzi alone. Overall survival was the main goal.

• Survival: median overall survival was 21.1 months with the combination and 12.7 months with Imfinzi alone, at a median follow-up of about 16 months, Amgen said.
• Progression: the combination cut the risk of progression or death by 66%. Median progression-free survival was 7.4 months versus 1.9 months.
• Response: 26.4% of patients on the combination responded to treatment, compared with 4.1% on Imfinzi alone.
• Safety: treatment-related side effects of grade 3 or higher occurred in 20.9% of combination patients and 10.8% of Imfinzi patients. About half of patients on the combination had cytokine release syndrome. One case reached grade 3 and none were higher, the company said.

Fierce Pharma reported that the survival data come from an interim analysis.

Why it matters

Imdelltra is a bispecific T cell engager that targets DLL3 and CD3. The FDA first approved it in May 2024. Its US label covers only patients whose cancer progressed on or after platinum chemotherapy. Use as first-line maintenance is still investigational.

Amgen's head of research and development, Jay Bradner, said the company is moving with urgency to share the results with regulators worldwide. Amgen chief medical officer Paul Burton called the data a "watershed moment" for the disease, Fierce Pharma reported.

A wider label would reach more people. According to Fierce Pharma, the current second-line US label covers about 13,000 patients. Amgen estimates that successful studies could raise that to 35,000 to 40,000.

For context, Fierce Pharma noted that Jazz's Zepzelca plus Roche's Tecentriq cut the risk of death by 27% in the IMforte trial in the same maintenance setting. Trials differ in design, so direct comparisons are limited.

What it means for people in the industry

The sources do not mention new hiring or sites tied to this result. The things to watch are regulatory filings and Amgen's next trials. DeLLphi-312 tests Imdelltra with Imfinzi and chemotherapy from the start of first-line treatment. DeLLphi-306 tests it after chemoradiotherapy in limited-stage disease.

Competition for the DLL3 target is also growing. Fierce Pharma named AbbVie, Merck & Co., Novartis and Roche among the companies pursuing it.

This article is news, not medical advice.

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Sources

• IMDELLTRA in Combination With IMFINZI Reduced Risk of Death by an Unprecedented 58% in First-Line Extensive-Stage Small Cell Lung Cancer, Amgen
• ESMO: Amgen's Imdelltra drives massive survival benefit in 'watershed moment' for small cell lung cancer, Fierce Pharma
• ESMO 2026: Amgen's Imdelltra slashes death risk by nearly 60% in small cell lung cancer, BioSpace