EGFR and non-small cell lung carcinoma: Two further randomized, phase III, double-blind, trials investigated the efficacy of vandetanib as a single agent in NSCLC patients: the ZEST trial, which compared vandetanib with erlotinib in patients with locally advanced or metastatic NSCLC after failure of at least one prior anti-cancer therapy, and the ZEPHYR trial, which tested vandetanib versus placebo in patients with refractory NSCLC who failed chemotherapy and an anti-EGFR therapy.