04:29 PM EDT, 06/02/2025 (MT Newswires) -- Amgen ( AMGN ) said Monday its Imdelltra drug lowered the risk of death by 40% compared to standard chemotherapy in patients with small cell lung cancer whose disease had progressed after earlier treatment.

The phase 3 DeLLphi-304 trial showed patients lived a median of 13.6 months on Imdelltra versus 8.3 months with chemotherapy, meeting the study's primary endpoint, the company said.

The drug also improved progression-free survival and helped ease symptoms like breathing difficulty and coughing, based on patient-reported outcomes, it added.

Fewer serious side effects were reported with Imdelltra than with chemotherapy, and only 27% of patients experienced severe treatment-related issues compared to 62% in the control group. The most common serious side effects with Imdelltra were low white blood cell counts, while the chemotherapy group experienced more anemia and other complications, Amgen ( AMGN ) said.

Cytokine release syndrome, a known side effect, was generally mild and occurred early in treatment, Amgen ( AMGN ) added.

The company said the trial involved 509 patients worldwide and is intended to confirm Imdelltra's earlier accelerated approval for treating advanced small cell lung cancer after chemotherapy.