The following criteria is provided for health care professionals.

Inclusion Criteria:

• Recipients of first ASCT for the treatment of hematologic malignancies (multiple myeloma, Hodgkin's and non Hodgkin's lymphoma)
• Patients must be between 100 to 180 days after ASCT
• Dasatinib use prior to ASCT is allowed
• Performance status >= 60%
• Presence of LGL clone prior to enrollment will not be an exclusion criterion if the LGL clone is < 25% of T cell population
• Total bilirubin < 2.0 times the institutional upper limit of normal (ULN)
• Hepatic enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT]) =< 2.5 times the institutional ULN
• Serum creatinine < 1.5 times the institutional ULN
• Hemoglobin >= 8 g/dL
• Absolute neutrophil counts >= 1,500 cells per uL
• Platelets >= 100,000 per uL
• Patient should be able to provide signed written informed consent; before any study procedures are performed, subjects will have the details of the study described to them, and they will be given a written informed consent document to read; then, if subjects consent to participate in the study, they will indicate that consent by signing and dating the informed consent document in the presence of study personnel; written consent will include a Health Insurance Portability and Accountability Act (HIPAA) form according to institutional guidelines
• Patient should be able to take oral medication (dasatinib must be swallowed whole)

Exclusion Criteria:

• Patients who have evidence of disease progression before day 100 after ASCT
• Sex and reproductive status:
  • Women of childbearing potential (WOCBP) who are unwilling or unable to use an acceptable method to avoid pregnancy for the entire study period and for at least 4 weeks after the last dose of study drug
  • Women who are pregnant or breastfeeding
  • Women with a positive pregnancy test
  • Sexually active fertile men not using effective birth control if their partners are WOCBP
• Medical history and concurrent diseases:
• No malignancy (other than the one treated in this study) which required radiotherapy or systemic treatment within the past 5 years
• Concurrent medical condition which may increase the risk of toxicity, including:
  • Pleural or pericardial effusion of any grade at the time of screening for study
  • Cardiac symptoms; any of the following should be considered for exclusion:
    • Uncontrolled angina, congestive heart failure or myocardial infarction (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 corrected QT (QTc) interval on pre-entry electrocardiogram (> 450 msec)
  • 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 (=< 3 months) significant gastrointestinal bleeding
• Any previous history of >= grade 3 toxicity to dasatinib
• Prohibited treatments and or therapies
• Category I 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
• Patient agrees to discontinue St. Johns Wort while receiving dasatinib therapy (discontinue St. Johns Wort at least 5 days before starting dasatinib)
• Patient agrees that intravenous (IV) bisphosphonates will be withheld for the first 8 weeks of dasatinib therapy due to risk of hypocalcemia
• Other exclusion criteria:
• Prisoners or subjects who are involuntarily incarcerated
• Subjects who are compulsorily detained for treatment of either a psychiatric or physical (eg, infectious disease) illness