Phase II Iressa Versus Vinorelbine (INVITE)

Inclusion Criteria: * Histologically confirmed NSCLC and willing to provide paraffin embedded tumour tissue * NSCLC - locally advanced (Stage IIIB) or metastatic (stage IV) disease, not amenable to curative surgery or radiotherapy chemonaïve, life expectancy of 12 weeks * WHO Performance status \<= 2 Exclusion Criteria: * Newly diagnosed CNS metastases * Less than 4 weeks since completion of radiotherapy or persistence of any radiotherapy related toxicity. * Hypersensitivity to ZD1839 or intravenous vinorelbine * Prior treatment with EGFR inhibitors * Other co-existing malignancies * ALT/AST \>2.5 x ULRR * ANC \< 2.0 x 10\^9/L or platelets \< 100 x 10\^9/L