AZD9291 Early Access Program (EAP) was available in Taiwan during October 2015 to September 2016, a time period before the approval of AZD9291, to supply the unlicensed AZD9291 for the NSCLC patients who received at least one prior EGFR TKI therapy. At the end of September 2016, more than 450 patients have been under AZD9291 treatment through the EAP. This observational study aims to evaluate the clinical benefit of AZD9291 treatment for these patients who were in the EAP

AZD9291 Early Access Program (EAP) was available in Taiwan during October 2015 to September 2016, a time period before the approval of AZD9291, to supply the unlicensed AZD9291 for the NSCLC patients who received at least one prior EGFR TKI therapy. At the end of September 2016, more than 450 patients have been under AZD9291 treatment through the EAP. This observational study aims to evaluate the clinical benefit of AZD9291 treatment for these patients who were in the EAP

Inclusion Criteria:

• At least 20 years of age
• Patients who were in the AZD9291 Early Access Program
• Received at least one dose of AZD9291 treatment as mono-therapy, supported by available source documents
• Patient who discontinued the single use of AZD9291, had disease progression, or died under AZD9291 treatment, whichever comes last, during the period from October 01, 2015 to December 31, 2018
• Patients agree to provide the written informed consent or the informed consent is waived by IRB.

Exclusion Criteria:

• Patients who did not receive at least one dose of EGFR TKI for the treatment of EGFR mutation (+) NSCLC

All the available patients who have participated in the AZD9291 EAP will be screened for the eligible criteria for data collection in this observational study