The purpose of this phase II study is to determine the safety, tolerability, and activity of XL647 in previously untreated subjects with non-small cell lung cancer (NSCLC). XL647 is a small molecule that potently inhibits multiple receptor kinases, including EGFR, VEGFR2 (KDR), ErbB2, and EphB4. Sensitivity to EGFR inhibitors has been linked to specific EGFR mutations and associated with certain clinical characteristics in patients with NSCLC (eg, female, minimal and remote smoking history, and adenocarcinoma histology).