New Phase 2 data suggest patients on tarlatamab in small cell lung cancer may be able to stretch dosing intervals without losing early activity signals. In the randomized DeLLphi-309 analysis, investigators presented findings at the International Association for the Study of Lung Cancer 2026 World Conference on Lung Cancer, moving the field toward more operationally flexible immunotherapy schedules after prior DeLLphi-308 safety and activity readouts.