CDX-1307 is an experimental vaccine that is designed to generate an immune response against a protein called human chorionic gonadotropin-beta (hCG-β). hCG-β is made by several types of cancers, including bladder cancer, and has been shown to be associated with shorter times to development of metastases and reduced survival in bladder cancer. In this study, it is hoped that administering the CDX-1307 vaccine will cause the body's immune system to attack bladder cancer cells in order to kill them or otherwise keep them from spreading or coming back.