Inclusion Criteria: - Adult patients, >/= 18 years of age - Eastern Cooperative Oncology Group (ECOG) performance status 0-1 - Histologically or cytologically confirmed incurable Stage IIIb/IV NSCLC tumor - Met diagnostic-positive status tested by IHC - Results of EGFR-activating mutation testing - Radiographic evidence of disease - Prior treatment with at least one platinum-based line of treatment (for stage IIIb/IV) and no more than one additional line of chemotherapy treatment; the last dose of chemotherapy must have been administered >/= 21 days prior to Day 1 - availability of tissue sample for diagnostic testing is required Exclusion Criteria: - More than 30 days of exposure to an investigational or marketed agent that can act by EGFR inhibition, or a known EGFR-related toxicity resulting in dose modifications (EGFR inhibitors including but not limited to gefitinib, erlotinib and cetuximab) - Brain metastases or spinal cord compression not definitively treated with surgery and/or radiation, or previously treated central nervous system (CNS) metastases or spinal cord compression without evidence of stable disease for >/= 14 days - History of another malignancy in the previous 3 years, unless cured by surgery alone and continuously disease free for at least 3 years; patients with prior history of non-invasive cancers are eligible - Inadequate hematological, biochemical or organ function - Significant history of cardiac disease - Serious active infection at time of randomization or other serious underlying medical conditions that would impair the ability of the patient to receive protocol treatment - Any inflammatory changes of the surface of the eye - Clinically significant gastro-intestinal disease, including uncontrolled inflammatory gastro-intestinal diseases - Pregnant or lactating women - Positive for HIV infection