DESTINY-Lung04 will investigate the efficacy and safety of Trastuzumab Deruxtecan (T-DXd) versus Standard of Care (SoC) as first-line treatment of Non-Small Cell Lung Cancer (NSCLC) with HER2 Exon 19 or 20 mutations

Eligible participants will be those diagnosed with unresectable, locally advanced or metastatic histologically documented non-squamous NSCLC with HER2 exons 19 or 20 mutations and who are treatment-naïve for palliative intent systemic therapy for locally advanced or metastatic disease.

The study aims to evaluate the efficacy, safety and tolerability of trastuzumab deruxtecan as first-line treatment of Non-Small Cell Lung Cancer (NSCLC) as compared with Standard of Care treatment (Investigator's choice of cisplatin or carboplatin + pembrolizumab + pemetrexed). This study aims to see if trastuzumab deruxtecan allows patients to live longer without the cancer getting worse or simply to live longer, compared to patients receiving standard of care treatment. This study is also looking to see how the treatment and the cancer affects patients' quality of life.

Inclusion Criteria:

• Participants at least 18 years of age
• Locally advanced and unresectable NSCLC, 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

Exclusion Criteria:

• 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 untreated brain metastases, including asymptomatic or clinically inactive brain metastases
• 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

Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal. All request will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

When a request has been approved AstraZeneca will provide access to the de-identified individual patient-level data in an approved sponsored tool . Signed Data Sharing Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information. Additionally, all users will need to accept the terms and conditions of the SAS MSE to gain access. For additional details, please review the Disclosure Statements at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.