DAREONᵀᴹ-8: A Study to Test How Well Different Doses of BI 764532 in Addition to Standard of Care Are Tolerated by People With Advanced Small Cell Lung Cancer

Inclusion Criteria: * Male or female participants ≥18 years old and at least at the legal age of consent in countries where it is greater than 18 years at the time of signature of the informed consent form (ICF) * Signed and dated written informed consent in accordance with International Council for Harmonisation-Good Clinical Practice (ICH-GCP) and local legislation prior to admission to the trial * Histologically or cytologically confirmed extensive-stage small cell lung carcinoma (ES-SCLC) * Availability of archival tumour tissue * Patients must be eligible for platinum+etoposide+anti-Programmed Cell Death Ligand 1 (PD-L1) regimen as first line standard of care (SoC) treatment: * In Part A, patients must be eligible to receive carboplatin + etoposide + atezolizumab * In Part B, patients must be eligible to receive etoposide, carboplatin or cisplatin, and atezolizumab or durvalumab * No prior systemic treatment for ES-SCLC * Prior systematic anti-cancer treatment for limited-stage small cell lung cancer (SCLC) must have been complete at least 6 months prior to the diagnosis of ES-SCLC * Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 Further inclusion criteria apply. Exclusion Criteria: * Previous treatment in this trial * Treatment with a systemic anti-cancer therapy or investigational drug within 28 days or 5 half-lives (whichever is longer) of the first administration of trial medication * Presence of leptomeningeal carcinomatosis * Previous treatment with Delta-like ligand 3 (DLL3)-targeting T cell engagers and cell therapies * Patients who have been treated with extensive field radiotherapy including whole brain irradiation within 2 weeks prior to first administration of BI 764532 * Persistent toxicity from previous treatments that has not resolved to ≤ Common Terminology Criteria for Adverse Events (CTCAE) Grade 1 (except for alopecia, asthenia/fatigue, CTCAE Grade 2 neuropathy, or Grade 2 endocrinopathies controlled by replacement therapy) * Major surgery (major according to the investigator's assessment) within 28 days prior to first administration of BI 764532 or planned during treatment period, e.g. hip replacement * Any documented active or suspected malignancy or history of malignancy within 5 years prior to Screening (other than the target indication), except for appropriately treated basal cell carcinoma of the skin or in situ carcinoma of uterine cervix Further exclusion criteria apply.