Afatinib vs Erlotinib as 2nd TKI After Failure to 1st TKI and Chemotherapy for Metastatic NSCLC

Inclusion Criteria:

* Patients with stage IV epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer who were previously responsive to one line of EGFR tyrosine kinase inhibitor and at least one line of systemic chemotherapy
* Adequate hematological function (ANC \>=1.5 x 10\^9/l, Hb \>=9.0 x 10\^9/l, plt \>=100 x 10\^9/l)
* Adequate renal function (with estimated creatinine clearance \>=50ml/min as determined by Cockcroft-Gault formula)
* Adequate liver function (ALT/AST \<2.5 x upper normal limit or ALT/AST \<5 x upper normal limit in the presence of liver metastasis)
* Eastern Cooperative Oncology Group (ECOG) performance status 0, 1 or 2
* Evaluable target lesions according to RECIST 1.1 for tumour response assessment
* Patients able to give written consent

Exclusion Criteria:

* Symptomatic brain metastases requiring steroids/surgery/radiation therapy within 4 weeks of commencement of study medication
* Significant cardiovascular abnormalities
* Significant psychiatric disorders
* Patients who have documented history of interstitial lung disease