Inclusion Criteria

Inclusion criteria:

- Pathologically confirmed diagnosis of Stage IIIB (with cytologically proven pleural
effusion or pericardial effusion) or Stage IV adenocarcinoma of the lung. Patients
with mixed histology are eligible if adenocarcinoma is the predominant histology.

- Epidermal Growth Factor Receptor mutation detected by central laboratory analysis of
tumour biopsy material.

- Measurable disease according to RECIST 1.1.

- Eastern Cooperative Oncology Group score of 0 or 1.

- Age >/= 18 years.

- Life expectancy of at least three months.

- Written informed consent that is consistent with ICH-GCP guidelines.

Exclusion criteria:

- Prior chemotherapy for relapsed and/or metastatic NSCLC. Neoadjuvant/adjuvant
chemotherapy is permitted if at least 12 months has elapsed between the end of
chemotherapy and randomisation.

- Prior treatment with Epidermal Growth Factor Receptor targeting small molecules or
antibodies.

- Radiotherapy or surgery (other than biopsy) within 4 weeks prior to randomisation.

- Active brain metastases

- Any other current malignancy or malignancy diagnosed within the past five years

- Known pre-existing interstitial lung disease.

- Significant or recent acute gastrointestinal disorders with diarrhoea as a major
symptom.

- History or presence of clinically relevant cardiovascular abnormalities.

- Any other concomitant serious illness or organ system dysfunction.

- Adequate absolute neutrophil count and platelet count

- Adequate liver and kidney function

- Active hepatitis B infection, active hepatitis C infection or known HIV carrier.