A Phase 1b Study Evaluating the Safety, Tolerability, Pharmacokinetics, and Preliminary Anti-Tumor Activity of Subcutaneous Tarlatamab in Subjects With Extensive Stage Small Cell Lung Cancer (DeLLphi-308)

Inclusion Criteria: * Participants ≥ 18 years of age (or ≥ legal adult age within country if it is older than 18 years) at time of signing informed consent. * Participants with histologically or cytologically confirmed ES-SCLC that progressed or recurred following at least one line of platinum-based anti-cancer therapy for SCLC. Note: Participants with prior treatment for LS-SCLC should have also received another regimen for their recurrent, ES-SCLC disease. * Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) of 0 or 1. * Participants must have adequate organ function (cardi…