RATIONALE: Monoclonal antibodies such as cetuximab can locate tumor cells and either kill them or deliver tumor-killing substances to them without harming normal cells. Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining monoclonal antibody therapy and chemotherapy may kill more tumor cells.

PURPOSE: Phase I/II trial to study the effectiveness of combining monoclonal antibody therapy with chemotherapy in treating patients who have stage IV non-small cell lung cancer.

OBJECTIVES: I. Determine the safety and toxicity of cetuximab when administered in combination with gemcitabine and carboplatin in patients with chemotherapy-naive stage IV non-small cell lung cancer. II. Determine the response rate and time to progression in patients treated with this regimen.

OUTLINE: This is a multicenter study. Patients receive cetuximab IV over 60-120 minutes on days 1, 8, and 15, and gemcitabine IV over 30 minutes on days 1 and 8 followed by carboplatin IV over 30 minutes on day 1. Courses repeat every 3 weeks in the absence of disease progression or unacceptable toxicity. Patients who experience unacceptable toxicity to gemcitabine or carboplatin may continue to receive cetuximab alone. Patients are followed at 4 weeks and then every 3 months thereafter.

PROJECTED ACCRUAL: A total of 30 patients will be accrued for this study within 5-7 months.

• Biological: cetuximab
• Drug: carboplatin
• Drug: gemcitabine hydrochloride

DISEASE CHARACTERISTICS: Histologically confirmed non-small cell lung cancer that is not amenable to potentially curative surgery Stage IV Epidermal growth factor receptor expression (1+ or more) by immunohistochemistry Measurable disease Chemotherapy-naive Histologically confirmed recurrent disease allowed after radiotherapy Meningeal or CNS involvement allowed

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 80-100% Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm3 WBC at least 3,000/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 9 g/dL Hepatic: Bilirubin no greater than 1.5 times upper limit of normal (ULN) AST and ALT no greater than 2.5 times ULN Alkaline phosphatase no greater than 2.5 times ULN Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine clearance at least 60 mL/min Cardiovascular: No uncontrolled angina No arrhythmias No congestive heart failure Neurologic: No uncontrolled seizure disorder No active neurological disease No neuropathy of grade 2 or greater Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No other malignancy within the past 3 years except basal cell skin cancer or carcinoma in situ of the cervix

PRIOR CONCURRENT THERAPY: Biologic therapy: No prior cetuximab Chemotherapy: See Disease Characteristics No other concurrent chemotherapy Endocrine therapy: Not specified Radiotherapy: See Disease Characteristics At least 4 weeks since prior wide-field radiotherapy (local radiotherapy for management of tumor-related symptoms allowed) No concurrent radiotherapy Surgery: See Disease Characteristics At least 30 days since prior major thoracic or abdominal surgery and recovered Other: At least 30 days since prior investigational agents At least 4 weeks since any prior therapy and recovered