Adding tarlatamab (Imdelltra) to durvalumab (Imfinzi) as first-line maintenance helped people with advanced small-cell lung cancer live longer than durvalumab alone, OncLive and AJMC reported from the phase 3 DeLLphi-305 trial. NBC News called the advance a big shift for care for a disease that still kills quickly.

At a planned early look with about 16 months of follow-up, median overall survival was 21.1 months with the combination versus 12.7 months with durvalumab alone, a hazard ratio of 0.42, OncLive reported. That means a 58 percent lower risk of death. Six-month survival was 92 percent versus 75 percent. Median time without the cancer growing was 7.4 months versus 1.9 months (hazard ratio 0.34). Among patients with measurable disease, the response rate was 26.4 percent versus 4.1 percent.

The trial enrolled 563 adults whose disease had not progressed after four cycles of platinum, etoposide, and durvalumab. Patients got tarlatamab 10 mg every two weeks plus durvalumab 1500 mg every four weeks, or durvalumab alone. Jacob Sands of Dana-Farber said the data support a new standard of care, OncLive reported. Results were presented at the 2026 ESMO Congress in Madrid and published in the New England Journal of Medicine.

A fever-and-chills side effect occurred in 49.6 percent of patients on the combo, mostly low grade, with grade 3 in one patient (0.4 percent), OncLive said. Grade 3 or higher drug side effects were 20.9 percent versus 10.8 percent. Tarlatamab carries a boxed warning for CRS and nerve side effects, AJMC noted.

Small-cell lung cancer often responds to first chemo then returns fast. Maintenance that extends life by months is rare, which is why trial doctors and NBC News framed DeLLphi-305 as a major shift if regulators agree.

What we know: DeLLphi-305 met its survival goal with a large benefit. Side effects match the known drug risks.
What we don't: How regulators will label the combo and how community clinics will handle monitoring.