Hematological and nonhematological toxicities of imatinib mesylate in patients with chronic myeloid leukemia and gastrointestinal stromal tumor

Objectives: To determine the hematological and nonhematological toxicities of imatinib mesylate in patients with chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GIST) and to review the literature to compile a list of the etiologic agents responsible for these events. Materials and Methods: This was a prospective study conducted from May 2001 to February, 2007. Two hundred and thirty-two patients with CML and GIST treated with imatinib mesylate at the Aga Khan University Hospital were included in the study. Side effects were graded according to the common toxicity criteria of the National Cancer Institute version 3.0. Results: Ninety-seven patients experienced various side effects which, in decreasing order of frequency, were: generalized hypopigmentation, periorbital edema, nausea, and weight gain. Hematological toxicities included mainly grade I/II anemia and thrombocytopenia. Grade III/ IV hematological adverse events were rare in our group. The frequency of all events is equally distributed in all phases of CML and GIST. The side effects rarely lead to permanent discontinuation of therapy. Conclusion: Imatinib mesylate is a well-tolerated drug with some adverse events that are only rarely a permanent barrier to therapy.