Patients who have not received any prior chemotherapy will be randomized to receive Gemcitabine plus Virulizin® versus Gemcitabine plus placebo in a double blind fashion. On disease progression patients may be switched to 5-Fluorouracil and continue to receive Virulizin® or placebo. Patients may continue Virulizin® alone, if clinically indicated when 5-Fluorouracil is discontinued.