PRIMARY OBJECTIVE:~I. To establish the maximum tolerated dose (MTD) of actinium Ac 225-DOTA-anti-CEA Monoclonal Antibody M5A (225Ac-DOTA-M5A) humanized anti-carcinoembryonic antigen (CEA) antibody when given intravenously and to describe the toxicities at each dose studied.~SECONDARY OBJECTIVES:~I. To begin to evaluate the clinical activity of the agent in metastatic colorectal cancer.~II. To evaluate the organ biodistribution, pharmacokinetics and organ dose estimates of 225Ac-DOTA-M5A.~OUTLINE: This is a dose-escalation study.~Patients receive Ac225-DOTA-M5A intravenously (IV) over 25 minutes on day 1.~After completion of study treatment, patients are followed weekly for 6-10 weeks, and then medical records are reviewed for 6 months.
This phase I study tests the safety, side effects, and best dose of Ac225-DOTA-M5A in treating patients with CEA positive colorectal cancer that has spread to other places in the body (advanced). Ac225-DOTA-M5A is a humanized monoclonal anti-CEA antibody, linked to a radioactive agent called actinium 225. M5A attaches to CEA positive cancer cells in a targeted way and delivers actinium 225 to kill them.