Additional Study Information: This research study is being done to see how an investigational drug called DKN-01 combined with standard cancer drugs (gemcitabine and cisplatin) works in people with biliary or gallbladder cancer. DKN-01 is an antibody that blocks the function of another protein in the body called dickkopf-1 (Dkk-1). Too much (over expression) of the Dkk-1 protein has been implicated in tumor growth and disease progression and elevated levels may play a role in the growth and spread of biliary, gallbladder, and other cancers. DKN-01 is being studied in multiple investigational research studies including this one to see whether it can slow tumor growth and help patients with different types of cancer.