Beamion 44: A Study to Test How Well Zongertinib is Tolerated by People With Advanced Non-small Cell Lung Cancer With HER2 Mutations When Given in Combination With Chemotherapy With or Without Pembrolizumab

Inclusion criteria: 1. Patients ≥18 years of age or over the legal age of consent in countries where that is greater than 18 years at the time of signature of the informed consent form (ICF) 2. Histologically or cytologically confirmed diagnosis of an advanced and/or metastatic non-squamous non-small cell lung cancer (NSCLC) 3. Documented activating human epidermal growth factor receptor 2 (HER2) mutation as per existing local lab result 4. An archival tumor tissue sample must be submitted to the central laboratory after randomization to retrospectively confirm the HER2 status 5. Patients who have not received any systemic treatment for unresectable, locally advanced or metastatic disease 6. Presence of at least one measurable non-Central Nervous System (CNS) lesion according to response evaluation criteria in solid tumors (RECIST) 1.1 7. Eligible to receive treatment with the selected platinum based doublet chemotherapy and pembrolizumab in accordance with the summary of product characteristics (SmPC)/Product Information 8. Eastern Cooperative Oncology Group (ECOG) score of 0 or 1 Further inclusion criteria apply. Exclusion criteria: 1. Tumors with targetable alterations with approved available therapy 2. Presence or history of leptomeningeal disease 3. Radiotherapy within 4 weeks prior to treatment start with exception of palliative radiotherapy to regions other than the chest if completed at least 2 weeks prior to treatment start 4. Major surgery (major according to the investigator's assessment) performed within 4 weeks prior to randomization or planned within 6 months after screening 5. Any history of or concomitant condition that, in the opinion of the investigator, would compromise the patient's ability to comply with the trial or interfere with the evaluation of the safety and efficacy of the test drug 6. Previous therapy with a HER2-directed agent 7. History or presence of cardiovascular abnormalities which are considered as clinically relevant by the investigator. Myocardial infarction, stroke, or pulmonary embolism within 6 months prior to randomization Further exclusion criteria apply.