A Study to Investigate the Efficacy and Safety of Trastuzumab Deruxtecan as the First Treatment Option for Unresectable, Locally Advanced/Metastatic Non-Small Cell Lung Cancer With HER2 Mutations

Open to people ages 18-123

• Participants at least 18 years of age
• Locally advanced not amenable to curative therapy, or metastatic disease
• Histologically documented non-squamous NSCLC with HER2 mutation in exons 19 or 20 by tissue NGS or ctDNA
• Treatment-naïve for palliative intent systemic therapy for locally advanced or metastatic disease
• Left ventricular ejection fraction (LVEF) ≥ 50%
• Measurable disease assessed by Investigator based on RECIST 1.1
• Protocol-defined adequate organ function including cardiac, renal, hepatic function
• ECOG 0-1
• Having tumour tissue available for central testing

• Tumors with targetable alterations to EGFR (or other targetable mutations including but not limited to ALK, if routinely tested as a targetable alteration with approved available therapy)
• Any clinically active brain metastases; previously treated brain metastases allowed
• Active autoimmune or inflammatory disorders
• Medical history of myocardial infarction within 6 months prior to randomization
• History of non-infectious pneumonitis/ILD, current or suspected ILD
• Lung-specific intercurrent clinical significant severe illness
• Contraindication to platinum-based doublet chemotherapy or pembrolizumab