The purpose of this study is to observe an improvement in overall response rate in NSCLC subjects who have been treated with gefitinib or erlotinib and are genotypically EGFR mutation positive or who have had a prior a response.

Inclusion Criteria:

• Recurrent, metastatic or progressive NSCLC without any indication of radiotherapy. Subjects must have:
• Pathologically confirmed NSCLC
• Previously received treatment with single agent Gefitinib or Erlotinib and completed treatment at least 2 weeks prior to study entry
• Any one of the following:
• A tumor that harbors an EGFR mutation
• Objective clinical benefit from treatment with Gefitinib or Erlotinib as defined by either documented and confirmed partial or complete response (RECIST or WHO), or significant and durable (≥ 6 months) clinical benefit (stable disease as defined by RECIST or WHO) Progression of NSCLC while on continuous treatment with gefitinib or erlotinib as noted by CT/MRI increase in disease after having a confirmed partial or complete response or evidence of ≥ 6 months of SD within 3 months of study enrollment

Exclusion Criteria:

• Symptomatic brain metastasis
• History of TIA, CVA, or thrombotic/thromboembolic event (within last 6 months)
• History of hemoptysis greater than 10 mL/day within last 30 days
• Uncontrolled or significant cardiovascular disease
• History of uncontrolled diarrhea, Crohn's disease or ulcerative colitis
• Inability to swallow tablets, untreated malabsorption or GI surgery that results in inability to absorb protocol therapy
• Women unwilling to avoid pregnancy or use adequate contraception
• History of allergy or adverse drug reaction to gefitinib or erlotinib