Study 109609 is a single-arm, non-randomized, single-stage Phase II study of pazopanib in subjects with Stage IIIB or IV non-small cell lung cancer who have progressed after one or two prior regimens of systemic therapy. The study will be conducted at a limited number of institutions in the US. A total of 40 evaluable subjects will be enrolled and treated. Pazopanib will be given at a dose of 800mg (as determined by previous Phase I studies) orally once per day. Subjects may continue to receive study drug for up to two years unless they experience disease progression or withdraw from treatment for other reasons, or unless the Sponsor terminates the study. A rollover study may be available to those subjects who are exhibiting clinical benefit (stable disease or better). Evaluable subjects will be assessed for response as the primary endpoint.