Surprising OS and PFS Findings With Tarlatamab/Durvalumab in DeLLphi-305

Jacob Sands, MD, discusses what stood out in the first look at data from the phase 3 DeLLphi-305 trial (NCT06211036) of tarlatamab-dlle (Imdelltra) plus durvalumab (Imfinzi) in the maintenance setting for extensive-stage small cell lung cancer, presented at the European Society for Medical Oncology (ESMO) 2026 Congress.

Sands explains that the median overall survival (OS) of 21.1 months, with about 16 months of median follow-up, was in line with what was seen in the phase 1b DeLLphi-303 study. He notes that the DeLLphi-305 OS curve is still maturing, and that updated DeLLphi-303 data at ESMO showed median OS rising from 25.3 months to 37.9 months with longer follow-up. He also highlights the median progression-free survival (PFS) of 7.4 months, which was better than in DeLLphi-303, and the 38% of patients who remained progression free at 1 year. Finally, he discusses oligoprogression with immunotherapy-based regimens, noting that 44% of patients were still receiving tarlatamab plus durvalumab at the last data cut, which suggests that more patients may be benefiting durably than the PFS rate alone indicates.