New data on tarlatamab dosing in small cell lung cancer are focusing on whether patients can be treated with longer gaps between doses. The randomized Phase 2 DeLLphi-309 results, presented at the International Association for the Study of Lung Cancer (IASLC) 2026 World Conference on Lung Cancer, address schedule optimization for an immunotherapy that has already reshaped treatment discussions in the disease. For prescribers and payers, dosing flexibility can affect administration burden, patient convenience, and overall treatment cost—provided safety and clinical benefit are maintained. The key commercial and clinical question now is how longer intervals impact durability of response and whether schedule changes alter the risk profile in real-world dosing.