Small cell lung cancer: antibody combination markedly extends survival

There is new trial data for people with advanced small cell lung cancer. Results of the Phase III DeLLphi-305 trial were presented on Oct. 24, 2026, at the ESMO 2026 cancer congress in Madrid and published simultaneously in the New England Journal of Medicine, the specialist outlet OncLive and AstraZeneca reported. A total of 563 adults with extensive-stage small cell lung cancer whose disease had not progressed after four cycles of platinum and etoposide chemotherapy plus durvalumab received maintenance treatment with either the antibody durvalumab (Imfinzi) alone or combined with tarlatamab (Imdelltra). According to AstraZeneca, tarlatamab is a bispecific antibody: it binds to the protein DLL3 on tumor cells and to CD3 on T cells, bringing immune cells to the cancer. According to AstraZeneca, the trial is sponsored by Amgen, with AstraZeneca providing partial funding and supplying Imfinzi.

In a planned interim analysis, median survival was 21.1 months with the combination and 12.7 months with durvalumab alone, a 58% reduction in the risk of death (hazard ratio 0.42). After one year, an estimated 79% versus 53% of patients were alive, according to AstraZeneca. Median time until the disease progressed lengthened from 1.9 to 7.4 months, and the benefit was also seen in patients with brain or liver metastases. Jacob Sands of the Dana-Farber Cancer Institute in Boston, who presented the data, said the results support the combination as a new standard for first-line maintenance therapy, OncLive reported.

The most common notable side effect was cytokine release syndrome, an excessive immune reaction: it occurred in 49.6% of patients on the combination, mostly mild, with one severe (grade 3) case, according to OncLive. Severe treatment-related side effects affected 20.9% versus 10.8%, and 3.2% stopped tarlatamab because of them. Patients are monitored after the first doses, for 6 to 8 hours in Europe, AstraZeneca said. According to the company, small cell lung cancer accounts for about 15% of all lung cancers, and the five-year survival rate in the extensive stage is 3.6%. The release cites no approval for the combination; patients decide on treatment together with their oncology team.