Abstract
We retrospectively analyzed the clinical outcome of dasatinib in 7 patients with chronic myelogenous leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) resistant or intolerant to imatinib. Three patients with chronic phase CML and two patients with Ph+ALL achieved major molecular response, however, two CML patients in accelerated phase (AP)/blast crisis (BC), did not. Grade≥3 pancytopenia was seen in four patients. Among these, two AP/BC-CML patients required interruption/or dose reduction of dasatinib. As for nonhematologic adverse events, pleural effusion was seen in one patient and cytomegalovirus (CMV) colitis was observed in two patients. No patients who had been intolerant to imatinib experienced the same nonhematologic toxicity following treatment with dasatinib. We identified three patients who developed peripheral lymphocytosis, identified as natural killer cells or cytotoxic T-cells based on their large granular lymphocyte (LGL) morphologies and immunophenotypic profiles, out of six patients receiving dasatinib therapy. All three cases that developed LGL lymphocytosis achieved optimal molecular response, two of the patients, however, had pleural effusion and CMV colitis, respectively. Dasatinib inhibits off-target kinases, which may result in unexpected drug responses.
