The objectives of this multi-center, randomized, controlled trial are to evaluate the safety and efficacy of PANVAC-VF in combination with Granulocyte-macrophage colony-stimulating factor (GM-CSF) versus best supportive care or palliative chemotherapy.

PANVAC-VF is an investigational cancer vaccine. The vaccine is based on the theory that the body can be taught to fight cancer by directing the immune system to attack specific targets found on cancer cells. These targets are called Tumor Associated Antigens, or TAA's. This trial will help determine if this vaccine can help fight cancer.

All patients will be required to sign an informed consent prior to the performance of any study-related procedures. Patients will be screened for eligibility within 14 days prior to their anticipated treatment start date (Day 0). Patients who meet all inclusion and exclusion criteria will be centrally randomized into the study and will receive a unique patient identification number and a treatment assignment. The ratio of active treatment to control is 1:1 (PANVAC-VF: best supportive care or palliative chemotherapy).

Inclusion Criteria:

• Patients > 18 years of age who have been vaccinated against smallpox;
• Histologically confirmed diagnosis of adenocarcinoma of the pancreas;
• Patient has metastatic (Stage IV) disease;
• ECOG performance status 0-1;
• Failed a gemcitabine-containing chemotherapeutic regimen within 3 months of study entry.

Exclusion Criteria:

• Prior or concurrent immunotherapy for cancer;
• Radiation therapy within 28 days prior to registration;
• Systemic corticosteroid therapy (except inhaled or topical steroids) within 28 days of registration;
• Significant cardiovascular abnormalities or diseases;
• Known positive for HIV, hepatitis B and/or C;
• Evidence of immunodeficiency or immune suppression.