Inclusion Criteria:

- Male or female patients aged 18 years or older (For Japan only- male or female
patients aged 20 years or older)

- Cytological or histological confirmation of NSCLC other than predominantly squamous
cell histology with an activating EGFR TK mutation as determined locally

- Patients with documented 'acquired resistance' on first line gefitinib

- Patients suitable to start cisplatin based pemetrexed combination chemotherapy.

- Provision of informed consent prior to any study specific procedures.

Exclusion Criteria:

- Prior chemotherapy or other systemic anti-cancer treatment (excluding gefitinib).
Palliative radiotherapy must be completed at least 4 weeks before start of study
treatment with no persistent radiation toxicity).

- Past medical history of interstitial lung disease, drug-induced interstitial disease,
radiation pneumonitis which required steroid treatment or any evidence of clinically
active interstitial lung disease

- Other co-existing malignancies or malignancies diagnosed within the last 5 years,
with the exception of basal cell carcinoma or cervical cancer in situ or completely
resected intramucosal gastric cancer

- Any evidence of severe of uncontrolled systemic disease Treatment with an
investigational drug within 4 weeks before randomization