Full Breakdown
Amgen and AstraZeneca’s Immunotherapy Duo Cuts Death Risk in Aggressive Lung Cancer
By Drooid · · How we work
Trial Results Reveal Significant Survival Gain
A late-stage Phase III trial (DeLLphi-305) showed that adding Amgen’s bispecific T-cell engager tarlatamab (Imdelltra) to AstraZeneca’s checkpoint inhibitor Imfinzi (durvalumab) reduced the risk of death by 58 % in patients with extensive-stage small cell lung cancer (ES-SCLC) who had not progressed after induction therapy. Median overall survival increased to 21.1 months with the combination, compared with 12.7 months for Imfinzi alone—a gain of roughly eight months. About half of the patients receiving the duo were alive at the 21-month mark.
Background on Extensive-Stage Small Cell Lung Cancer
Small cell lung cancer accounts for about 15 % of all lung cancers and is the leading cause of cancer death globally, responsible for roughly one-in-five cancer fatalities. Approximately two-thirds of patients present with ES-SCLC, a fast-growing form that frequently spreads to the brain, liver and other organs. Current first-line therapy, which includes Imfinzi plus chemotherapy, yields a median overall survival of about one year, and five-year survival rates are under 4 % for ES-SCLC.
Trial Design and Key Numbers
- Population: 563 patients who completed Imfinzi-based induction (platinum chemotherapy + etoposide) were randomized 1:1 to receive Imfinzi + tarlatamab or Imfinzi alone until progression or unacceptable toxicity.
- Primary endpoint: Overall survival (OS).
- Secondary endpoint: Progression-free survival (PFS).
- Efficacy: 58 % reduction in death risk; median OS 21.1 months vs 12.7 months.
- Safety: Grade 3-4 treatment-related adverse events occurred in 20.9 % of the combination arm versus 10.8 % with Imfinzi alone. About 50 % experienced cytokine release syndrome, most mild; roughly 1 % developed a neurological adverse event. No treatment-related deaths were reported.
Official Statements & Responses
Amgen’s chief medical officer highlighted the pronounced survival benefit, while AstraZeneca’s executive vice president of oncology hematology R&D described the T-cell engager as a way to sensitize tumors less responsive to checkpoint inhibition. Both companies said the safety profile aligns with known risks of each agent.
What It Means for Patients and the Market
The survival extension positions the Imfinzi + tarlatamab regimen as a potential new maintenance standard for ES-SCLC, addressing a gap where only about half of patients receive any subsequent therapy after first-line treatment. Commercially, Imdelltra’s 2025 global sales reached $627 million, and the combination’s success could accelerate its trajectory toward blockbuster status. For AstraZeneca, Imfinzi is projected to become the company’s top-selling oncology product next year, and the trial’s safety data supports broader use of bispecific antibodies in combination regimens.
Timeline
- Induction phase: Patients received Imfinzi with platinum-based chemotherapy and etoposide.
- Randomization: 563 eligible patients entered the maintenance phase.
- Data presentation: Results were disclosed at the European Society for Medical Oncology meeting in Madrid.
- Publication: Findings appeared in the New England Journal of Medicine shortly thereafter.