Dasatinib in Relapsed or Refractory Non-Hodgkin's Lymphoma

Inclusion Criteria: * Histologically confirmed diagnosis of non-hodgkin's lymphoma that is recurrent or refractory after at least one prior therapy and for which no other potentially curative therapy is available. * Subject, age \> or = 19 years * Performance status (ECOG) 0-2 * Patients must have relapsed or refractory disease after at least one prior systemic therapy, with at least a 3 week interval from the completion of the most recent chemotherapy or radiotherapy regimen. Recover to ≤ grade 1 from all toxicities related to the prior treatments is required. * Patients must be ineligible or relapsed after an autologous or allogeneic stem cell transplant if clinically appropriate. * Adequate Laboratory Parameters: * ANC ≥ 1000/μL * Platelet count ≥ 50,000/μL * Total bilirubin \< 2.0 times the institutional upper limit of normal (ULN) * Hepatic enzymes (AST, ALT ) ≤ 2.5 times the institutional ULN * Serum creatinine \< 2.0 times the institutional ULN * PTT within institutional normal limits * Ability to take oral medication (dasatinib must be swallowed whole) * Women of childbearing potential (WOCBP) must have a negative serum or urine pregnancy test (sensitivity \< or = 25IU HCG/L) within 72 hours prior to the start of study drug administration * Persons of reproductive potential must agree to use an adequate method of contraception throughout treatment and for at least 6 months after study drug is stopped * Signed written informed consent including HIPAA according to institutional guidelines Exclusion Criteria: * No malignancy \[other than the one treated in this study\] which required systemic treatment within the past 3 years. * Concurrent medical condition which may increase the risk of toxicity, including: * Clinically significant pleural or pericardial effusion * Clinically-significant coagulation or platelet function disorder (e.g. known von Willebrand's disease) * Cardiac Symptoms, consider the following: * Uncontrolled angina, congestive heart failure or MI within (6 months) * Diagnosed congenital long QT syndrome * Any history of clinically significant ventricular arrhythmias (such as ventricular tachycardia, ventricular fibrillation, or Torsades de pointes) * Prolonged QTc interval on pre-entry electrocardiogram (\> 450 msec) * Subjects with hypokalemia or hypomagnesemia if it cannot be corrected * History of significant bleeding disorder unrelated to cancer, including: * Diagnosed congenital bleeding disorders (e.g., von Willebrand's disease) * Diagnosed acquired bleeding disorder within one year (e.g., acquired anti-factor VIII antibodies) * Ongoing or recent (\< or = 3 months) significant gastrointestinal bleeding * Concomitant Medications, consider the following prohibitions: * Drugs that are generally accepted to have a risk of causing Torsades de Pointes including: (Patients must discontinue drug 7 days prior to starting dasatinib.) quinidine, procainamide, disopyramide, amiodarone, sotalol, ibutilide, dofetilide,erythromycin, clarithromycin, chlorpromazine, haloperidol, mesoridazine, thioridazine, pimozide, cisapride, bepridil, droperidol, methadone, arsenic, chloroquine, domperidone, halofantrine, levomethadyl, pentamidine, sparfloxacin, lidoflazine. * The concomitant use of H2 blockers or proton pump inhibitors with dasatinib is not recommended. The use of antacids should be considered in place of H2 blockers or proton pump inhibitors in patients receiving dasatinib therapy. * Patient agrees to discontinue St. Johns Wort while receiving dasatinib therapy * Patient agrees that IV bisphosphonates will be withheld for the first 8 weeks of dasatinib therapy due to risk of hypocalcemia. * Patient may not be receiving any prohibited CYP3A4 inhibitors * Women: * Are unwilling or unable to use an acceptable method to avoid pregnancy for the entire study period and for at least 4 weeks 6 months after cessation of study drug * Have a positive pregnancy test at baseline * Are pregnant or breastfeeding * Prisoners or subjects who are compulsorily detained (involuntarily incarcerated) for treatment of either a psychiatric or physical (e.g., infectious) illness