Vandetanib: A novel targeted therapy for the treatment of metastatic or locally advanced medullary thyroid cancer

Abstract

The pharmacology, pharmacokinetics, efficacy, safety and tolerability, drug and food interactions, cost, and place in therapy of vandetanib are reviewed. Vandetanib is a small-molecule inhibitor of vascular endothelial growth factor receptor, epidermal growth factor receptor, and receptor tyrosine kinase signaling pathways, which are involved in the pathogenesis of medullary thyroid cancer (MTC). Vandetanib is currently approved as an alternative to local therapies for both unresectable and disseminated disease. Vandetanib was evaluated in a randomized, placebo-controlled, double-blind Phase III study comparing vandetanib with placebo in adult patients with unresectable locally advanced or metastatic hereditary or sporadic MTC. Vandetanib demonstrated a statistically significant longer progression-free survival (predicted median of 30.5 months) compared with placebo (median of 19.3 months) (hazard ratio, 0.46; 95% confidence interval, 0.31-0.69; p = 0.0001). The most commonly observed adverse effects of vandetanib include nausea, diarrhea, headache, rash, prolongation of the Q-T interval, and hypertension. Because it can prolong the Q-T interval, vandetanib is contraindicated for use in patients with serious cardiac complications, including congenital long QT syndrome, bradyarrhythmias, uncompensated heart failure, and a history of torsades de pointes. Vandetanib has been shown to be more effective than placebo in the treatment of advanced MTC; however, it has not been compared with radiation, resection, or embolization. Vandetanib also has significant and fairly common cardiac toxicities. The cost, benefits, and risks of vandetanib for patients with MTC should be weighed, as alternative treatments remain an option for most patients.