Vandetanib for aggressive and symptomatic medullary thyroid cancer

Medullary thyroid cancer accounts for less than 10% of all thyroid cancers. Aggressive metastatic forms of this disease however, are incurable and can cause significant symptoms including diarrhea and pain. Hereditary and some sporadic forms of the disease are characterized by a mutation of the proto-oncogene RET. This results in an abnormal growth factor receptor that, in turn, allows the malignant cells to survive and metastasize. New tyrosine kinase inhibitors have been shown to effectively target RET in vitro. One of the first of these agents, vandetanib, has been evaluated in international Phase II and III clinical trials. In 2011, vandetanib became the first agent approved by the US FDA for use in metastatic medullary thyroid cancer. This article examines the clinical use of this agent.