pazopanib + iodine I 131

This combination therapy consists of the multi-targeted tyrosine kinase inhibitor (TKI) pazopanib and the radiopharmaceutical iodine I 131. It was investigated in a Phase I dose-escalation study led by the University of Washington for the treatment of patients with radioiodine-refractory well-differentiated thyroid carcinoma. Pazopanib targets vascular endothelial growth factor receptors (VEGFR-1, -2, and -3), platelet-derived growth factor receptors (PDGFR-alpha and -beta), and the stem cell factor receptor (c-KIT). The rationale for the combination was to determine if pazopanib could enhance the uptake or retention of radioactive iodine in resistant tumors. However, the trial was terminated due to significant toxicities, including dose-limiting cardiac arrhythmias and hematologic adverse events, without clear evidence that pazopanib improved iodine kinetics.

Brand names

Votrient

Other names

pazopanib hydrochloride + iodine I 131pazopanib + 131Ipazopanib + radioactive iodine