Vandetanib is an anticancer drug approved for the treatment of medullary thyroid cancer. It works by inhibiting the growth of the blood vessels that tumors need to grow and spread. In this study, researchers are assessing vandetanib in patients with another type of thyroid cancer called papillary thyroid cancer which cannot be successfully treated with radioiodine therapy (the standard treatment for this disease).
Patients in this study will be randomly assigned to receive vandetanib or a placebo. Patients in the placebo group whose tumors continue to grow may be offered therapy with vandetanib if their doctors feel they may benefit. Vandetanib is a tablet that is taken orally (by mouth).