The US Food and Drug Administration (FDA) has approved AstraZeneca's Iressa (gefitinib) tablets, 250mg once daily, for the first-line treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumours have epidermal growth factor receptor (EGFR) exon 19 deletions or exon 21 (L858R) substitution mutations, as detected by an FDA-approved test.


