 ZD6474 has shown promising activity against a number of cancers in laboratory tests in animals with cancer and in some early clinical trials in patients with non-small cell lung cancer NSCLC. ZD6474 has also demonstrated significant reduction in pleural effusion in association with VEGF inhibition of tumor cells in mice with lung tumors and pleural effusion. It is hoped that ZD6474 will decrease the amount of pleural effusion that occurs in NSCLC patients. In addition, ZD6474 is thought to block the formation of new blood vessels, which may limit new blood vessel growth in the tumor and starve the tumor. 