Complete radiological and metabolic response of metastatic renal cell carcinoma to SU5416 (semaxanib) in a patient with probable von Hippel-Lindau syndrome.

We report a case of a patient with probable von Hippel-Lindau (VHL) syndrome and metastatic renal cell cancer (RCC) who had a complete radiological and metabolic response to SU5416 (semaxanib). The patient was enrolled on a clinical study examining the efficacy of SU5416 in patients with metastatic cancer. Treatment with SU5416 was given at a dose of 145 mg/m2 intravenously twice-weekly for 11 doses. The patient achieved an early metabolic response on an F-18 fluorodeoxyglucose (FDG) Positron Emission Tomographic (PET) scan within 2 weeks of therapy. Subsequent computerized tomography (CT) and PET scans (9 and 12 months after treatment, respectively) confirmed ongoing complete radiological and metabolic response. He remains tumor-free 18 months after treatment. This is the first documented report of metastatic RCC in the setting of presumed VHL syndrome responding to treatment with SU5416. While vascular endothelial growth factor (VEGF) inhibitors have been shown to produce a modest response in sporadic metastatic RCC, further studies utilizing VEGF inhibitors in patients with VHL syndrome and RCC warrants exploration.