Inclusion Criteria:

• Pathologically confirmed stage IIIB or IV recurrent or progressive NSCLC
• Patients must have progressed while receiving treatment with a tyrosine kinase inhibitor targeting the EGFR pathway
• Measurable disease, as defined by RECIST criteria
• Patients must have a suitable frozen or paraffin-embedded tissue sample available for EGFR mutational analysis. Prior EGFR mutational analyses are allowable
• Patients with asymptomatic brain metastasis are eligible; however, they must have completed radiotherapy/radiosurgery at least 3 weeks prior to enrollment and be clinically stable
• ECOG Performance Status 0-2
• 18 years of age or older
• Negative pregnancy test within 7 days of treatment or be categorized as not of child-bearing potential
• Bone marrow function, renal function, hepatic function as outlined in protocol

Exclusion Criteria:

• Women who are pregnant of breastfeeding
• Active concurrent malignancy
• Major thoracic or abdominal surgery within 30 days prior to the first infusion of cetuximab
• Significant history of uncontrolled cardiac disease
• Uncontrolled seizure disorder, or active neurological disease
• Prior severe infusion reactions to a monoclonal antibody
• Prior chemotherapy regimen within 21 days prior to study entry
• Any EGFR tyrosine kinase inhibitor within 14 days of study entry
• Radiation therapy within 14 days prior to the first infusion of cetuximab
• Acute hepatitis or known HIV
• Active or uncontrolled infection
• Any concurrent chemotherapy or any other investigational agent(s)