Inclusion Criteria:

- Signed informed content obtained prior to treatment

- Cytological or histological confirmed carcinoma of the pancreas

- Metastatic cancer

- Measurable lesion according to RECIST criteria

- ECOG/ WHO performance 0-2

- Age > 18 years

- Adequate renal function (creatinine < 150 µmol/L and/ or a creatinine clearance > 60
ml/ L)

- Adequate liver function (bilirubin < 1.5 times upper limit of normal, ALAT or ASAT <
5.0 times upper limit of normal in case of liver metastases and < 2.5 the upper limit
of normal in absence of liver metastases).

- Adequate bone marrow function (WBC > 3.0 x 10 9/L, platelets > 100 x 10 9/L)

- Mentally, physically, and geographically able to undergo treatment and follow up

Exclusion Criteria:

- Clinical or radiological evidence of CNS metastases

- Pregnancy (positive serum pregnancy test) and lactation

- Serious concomitant systemic disorder that would compromise the safety of the
patient, at the discretion of the investigator

- Patients who have any severe and/or uncontrolled medical conditions:

- unstable angina pectoris, symptomatic congestive heart failure, myocardial
infarction ≤ 6 months prior to randomization, serious uncontrolled cardiac
arrhythmia

- uncontrolled diabetes as defined by fasting serum glucose >2X ULN.

- active or uncontrolled severe infection.

- cirrhosis, chronic active hepatitis or chronic persistent hepatitis

- severely impaired lung function

- Previous treatment with erlotinib

- Previous treatment with gemcitabine for metastatic disease

- Previous treatment with gemcitabine combined with radiotherapy for locally advanced
pancreatic cancer within 6 months prior to study entry

- Patients with a known hypersensitivity to metformin

- Use of metformin in the previous 6 months