Dasatinib in Treating Patients With Chronic Lymphocytic Leukemia

PRIMARY OBJECTIVES: I. To estimate the biologic target activity of dasatinib in CLL patients found to have pre-treatment in vitro dasatinib cytotoxicity (as defined by a \>= 50% decrease in absolute lymphocyte count and/or bone marrow CLL count and/or lymph node or spleen size). SECONDARY OBJECTIVES: I. To evaluate overall objective response rates per CLL National Cancer Institute (NCI) working group. II. To determine drug safety and tolerability of dasatinib in patients with CLL. III. To determine overall (OS) and progression-free survival (PFS). TERTIARY OBJECTIVES: I. To determine if v-src avian sarcoma (Schmidt-Ruppin A-2) viral oncogene homolog (SRC), Bruton agammaglobulinemia tyrosine kinase (BTK), or tec protein tyrosine kinase (TEC) family kinase inhibition correlates with clinical response. II. To determine which prognostic subgroups (presence of \>= 1 of the following: 11q or 17p deletion; cluster of differentiation \[CD\]38 or zeta-chain-associated protein kinase 70 \[Zap 70\] expression; unmutated immunoglobulin heavy chain \[IgVH\]) respond to dasatinib therapy. III. To evaluate differences in baseline CLL gene expression between CLL samples that are sensitive or in-sensitive to dasatinib. IV. To analyze changes in CLL gene expression after dasatinib treatment. V. To evaluate dasatinib pharmacokinetics. VI. To evaluate changes in type I receptor tyrosine kinase-like orphan receptor (ROR-1) expression with dasatinib treatment. VII. To correlate response to pre-clinical IC50 in the presence/absence of HS-5 conditioned media. VIII. To explore role of possible kinase mutations related to dasatinib response. IX. To measure chemokines before and during treatment. OUTLINE: Patients receive dasatinib orally (PO) once daily (QD) during course 1 and if tolerated, twice daily (BID) in subsequent courses. Courses repeat every 4 weeks in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up for 2 years.