Altered Bone and Mineral Metabolism in Patients Receiving Imatinib Mesylate

Hypophosphatemia, with associated changes in bone and mineral metabolism, developed in some patients with chronic myelogenous leukemia or gastrointestinal stromal tumors who were receiving imatinib, which inhibits several tyrosine kinases associated with these two diseases. The drug may thus inhibit bone remodeling in some patients. Hypophosphatemia developed in some patients with chronic myelogenous leukemia or gastrointestinal stromal tumors who were receiving imatinib. The drug may inhibit bone remodeling in some patients. Imatinib mesylate (Gleevec, Novartis) inhibits several tyrosine kinases associated with disease. These enzymes include BCR-ABL in patients with chronic myelogenous leukemia (CML), C-KIT in patients with gastrointestinal stromal tumors, and platelet-derived growth factor (PDGF) receptors α and β in patients with certain myeloproliferative disorders and dermatofibrosarcoma protuberans, respectively. 1 Most patients appear to tolerate imatinib well, and no consistent metabolic abnormalities during routine electrolyte screening have been reported. 2 However, we noted that hypophosphatemia (a serum phosphate level of less than 2.5 mg per deciliter [0.8 mmol per liter]) developed in some patients with newly diagnosed CML who began imatinib therapy as . . .