Imfinzi-Imdelltra combo shows major survival gain in small cell lung cancer

AstraZeneca ↘ 1.15% and Amgen ↗ 0.75% on Tuesday announced that a combination of Imfinzi (durvalumab) and Imdelltra (tarlatamab) delivered a statistically significant improvement in overall survival compared to Imfinzi alone as first-line maintenance therapy for extensive-stage small cell lung cancer, a disease in which median survival with current treatment is roughly one year.astrazeneca+1

The results come from a planned interim analysis of the Phase III DeLLphi-305 trial, which enrolled 563 patients who had completed Imfinzi-based induction treatment with platinum chemotherapy and etoposide without disease progression. Patients were randomized to receive either the combination or Imfinzi alone. The trial also met key secondary endpoints, with statistically significant improvements in progression-free survival and objective response rate.amgen+3

A First-of-Its-Kind Combination

The pairing marks the first time an immunotherapy combined with a bispecific T-cell engager has demonstrated a survival benefit in this setting. Tarlatamab works by simultaneously binding to DLL3, a protein expressed on the surface of small cell lung cancer cells in roughly 85 to 96 percent of patients, and CD3 on T cells, redirecting the immune system to attack the tumor.astrazeneca

"These are among the most compelling survival results I have seen" in extensive-stage small cell lung cancer, said Jacob Sands, associate chief of the Lowe Center for Thoracic Oncology at Dana-Farber Cancer Institute. "DeLLphi-305 represents an unprecedented milestone and suggests we may be entering a new era where meaningfully longer survival is possible for more patients."astrazeneca

Safety and Next Steps

The safety profile of the combination was consistent with the known profiles of each drug individually, with no new signals identified. The companies said the full data will be presented at a forthcoming medical meeting and shared with global regulatory authorities.stocktitan+3

Small cell lung cancer accounts for about 15 percent of lung cancers, and roughly two-thirds of patients are diagnosed at the extensive stage, when the disease has already spread beyond the lung. Only 3.6 percent of those patients survive five years. An estimated 195,000 people globally will be treated for ES-SCLC in 2026.astrazeneca

Imdelltra already holds full FDA approval for second-line treatment of ES-SCLC following platinum-based chemotherapy, based on the DeLLphi-304 trial that showed a 40 percent reduction in the risk of death compared to standard chemotherapy. The DeLLphi-305 results now open a potential path for the drug to move into frontline maintenance use.amgen