The purpose of this study is to learn about dacomitinib for the possible treatment of lung cancer.

This study is seeking participants who:

• have lung cancer that could not be controlled.
• have a type of gene called epidermoid growth factor receptor. A gene is a part of your DNA that has instructions for making things your body needs to work.
• have received dacomitinib for their lung cancer.

All participants in this study had received dacomitinib. Dacomitinib is a tablet that is taken by mouth at home. They continued to take dacomitnib until their cancer was no longer responding. The study will look at the experiences of people receiving the study medicine. This will help to see if the study medicine is safe and effective.

Inclusion Criteria:

• Evidence of histologically or cytologically confirmed diagnosis of advanced NSCLC with EGFR-activating mutations detected by an appropriate test
• Patients who were treated with dacomitinib as first-line treatment for advanced NSCLC during 01 October 2020 to 31 December 2022.
• Age ≥18 years old
• Evidence of a personally signed and dated informed consent document indicating that the patient (or a legally acceptable representative) has been informed of all pertinent aspects of the study.

Exclusion Criteria:

• Patients who have been treated with any systemic anti-cancer therapies within 12 months prior to dacomitinib treatment.

Patients with non-small cell lung cancer and treated with dacomitnib in medical center or regional hospital will be enrolled.

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.