A Study Evaluating Gemcitabine Plus Bosutinib for Patients With Resected Pancreatic Cancer

Inclusion Criteria: * Histologically proven adenocarcinoma of the pancreas. * Complete resection by standard pancreaticoduodenectomy (for tumors of the pancreatic head) or distal pancreatectomy (for tumors of the pancreatic tail). Positive microscopic margins are allowable. * No measurable disease. * ECOG performance status 0 - 1. * ≥ 18 years of age. * Ability to start adjuvant therapy within 8 weeks after pancreatic cancer surgery (but no sooner than 3 weeks). * CA 19-9 ≤ 2.5 times the upper limit of normal. * ANC (absolute neutrophil count) ≥ 1500/μL * Hemoglobin ≥ 9 gm/dL (may be transfused or may receive epoetin alfa to maintain this level) * Platelet count ≥ 100,000/μL * INR ≤ 1.5 (except those subjects who are receiving full-dose warfarin) * Total bilirubin ≤ 2.0 mg/dL * AST and ALT ≤ 2.5 times the upper limit of normal * Serum creatinine ≤ 2.0 * Negative pregnancy test for women of childbearing potential (serum or urine beta-HCG). * All patients must be informed of the investigational nature of this study and sign and give written informed consent in accordance with institutional and federal guidelines. * Women or men of reproductive potential must agree to use an effective contraceptive method during treatment and for 6 months afterwards. * At least one paraffin block from patient's pancreatic cancer surgery must be available for analysis (does not necessarily need to be received by the start of study treatment). Exclusion Criteria: * Any prior systemic or investigational therapy for pancreatic cancer. * Grossly positive surgical margins. * Any of the following post-operative complications: wound dehiscence or infection, intraabdominal abscess, pancreatic or biliary leak or fistula. * History of major psychiatric disorder or other chronic medical illness that, in the opinion of the treating physician, contraindicates the use of the investigational drugs in this protocol or that might render the subject at high risk of treatment related complications. * Serious active ongoing infection, including any requiring parenteral antibiotics. * Patients with a "currently active" second malignancy other than non-melanoma skin cancer. Patients are not considered to have a "currently active" malignancy if they have completed therapy and considered by their physician to be at less than 30% risk of relapse. * Pregnancy (positive pregnancy test) or lactation. * Known central nervous system disease. * Inability to swallow pills/tolerate oral intake. * Inability to comply with study and/or follow-up procedures.