Reversible Cardiomyopathy Associated with Sunitinib and Sorafenib

To the Editor: Tyrosine kinase inhibitors with potent properties against vascular endothelial growth factor (VEGF) signaling pathway (VSP inhibitors) are effective antitumor agents in metastatic renal-cell carcinoma and are now increasingly used in the treatment of other tumors.1 Although VSP inhibitors have been associated with cardiomyopathy, the nature of this side effect is unclear. We report two cases of severe symptomatic, yet reversible, cardiomyopathy after VSP inhibitor therapy. A 46-year-old woman with metastatic gastrointestinal stromal tumor was started on sunitinib therapy after unsuccessful treatment with imatinib. She tolerated sunitinib well for 2 years at a dose of 25 mg once . . .