Amgen's DLL3/CD3 Bispecific Tarlatamab Meets Primary OS Endpoint in Phase III Small Cell Lung Cancer Trial, Reducing Death Risk by 40%

▎Armstrong

On June 2, 2025, Amgen announced that the phase III clinical trial DeLLphl-304 of Tarlatamab for the treatment of small cell lung cancer met the primary endpoint of OS.

The phase III clinical data were presented as a Late-breaking oral report at ASCO and simultaneously published in the New England Journal of Medicine.

The mOS for the Tarlatamab treatment group and chemotherapy control group were 13.6 months and 8.3 months, respectively, with a 40% reduction in the risk of death, p＜0.001.

mPFS were 5.3 months and 4.3 months, respectively, with a 29% reduction in the risk of disease progression or death, p=0.002.

ORR was 35% and 20%, respectively, and mDOR was 6.9 months and 5.5 months, respectively.

Tarlatamab is built on Amgen's HLE-BiTE technology platform and is also the first CD3 bispecific antibody to achieve a breakthrough in common solid tumors.

Summary

For a long time, the successful application of CAR-T cell therapy and CD3 bispecific antibodies has been limited to hematological tumors, but this situation is rapidly changing. CAR-T is still in progress, TIL has been approved for the treatment of melanoma, and DLL3/CD3 bispecific antibody has been approved for the treatment of small cell lung cancer and succeeded in confirmatory phase III clinical trials.