Gemcitabine, Bevacizumab and Erlotinib in Pancreatic Cancer

* Participants will receive study treatment as an outpatient. The study treatment will be given in time periods called cycles. Each treatment cycle will be 28 days. * Gemcitabine will be given intravenously on days 1, 8, and 15 (once per week for the first three weeks) of the treatment cycle. * Bevacizumab will be given intravenously on days 1 and 15 (once every 2 weeks) of the treatment cycle. * Erlotinib will be taken orally every day of the treatment cycle. * Participants will see the doctor or nurse practitioner every week for the first 28 days of treatment. During all of the following cycles, they will see the doctor or nurse practitioner on day 1 and day 15 of each cycle. * Each 4-week cycle can be repeated until the participant or the doctor decided that they should be removed from the study.