Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed adenocarcinoma of the pancreas (ductal or
undifferentiated)

- Metastatic disease

- No islet cell, acinar cell, or cystadenocarcinomas

- No locally advanced disease

- No history or known presence of CNS metastases

PATIENT CHARACTERISTICS:

- ECOG performance status 0-1

- Life expectancy ≥ 3 months

- ANC ≥ 1,500/mm^3

- Platelet count ≥ 100,000/mm^3

- Total bilirubin ≤ 2 times upper limit of normal (ULN) (patients may be stented)

- AST ≤ 2.5 times ULN

- Creatinine ≤ 2.0 times ULN

- Magnesium ≥ lower limit of normal

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- Willing to provide a stool specimen

- No malignancy diagnosed within the past 3 years except basal cell or squamous cell
skin cancer, prostate cancer (Gleason < 7), or carcinoma in situ of the cervix

- No uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection, or psychiatric illness/social situations that would limit compliance with
study requirements

- No clinically significant cardiovascular disease (i.e., myocardial infarction,
unstable angina, symptomatic congestive heart failure, or serious uncontrolled
cardiac arrhythmia) within the past year

- No known positive test(s) for HIV infection, hepatitis C virus, or acute or chronic
active hepatitis B infection

- No liver dysfunction from cirrhosis or viral hepatitis

- No enteral hyperalimentation

- No grapefruit or grapefruit juice during the study

PRIOR CONCURRENT THERAPY:

- Recovered from prior therapy

- More than 4 months since prior radiotherapy, immunotherapy, or biologic therapy

- More than 4 weeks since prior and no elective or planned major surgery

- More than 2 weeks since prior minor and no elective or planned surgery

- No prior cytotoxic chemotherapy for metastatic disease

- Adjuvant chemotherapy for completely resected disease or chemoradiotherapy for
locally advanced disease is allowed, provided it was administered > 6 months
prior to study entry

- Adjuvant chemotherapy must not have contained an EGFR inhibitor

- Gemcitabine hydrochloride used as either a radiosensitizer or as maintenance
therapy is allowed, provided more than 6 months have elapsed since the last day
of treatment

- No prior anti-EGFR antibody therapy (e.g., cetuximab) or treatment with small
molecule EGFR inhibitors (e.g., gefitinib hydrochloride, erlotinib hydrochloride, or
lapatinib)

- No concurrent immunotherapy or radiotherapy

- No other concurrent chemotherapy

- No concurrent colony-stimulating factors during the first course of study therapy