Arsenic linked to a drug that binds to the blood vessels of cancerous tumors provides a powerful imaging agent that could one day allow physicians to detect hard-to-find tumors and more closely monitor cancer's response to therapy, researchers at UT Southwestern Medical Center have found.
The findings, based on animal studies and appearing in today's issue of Clinical Cancer Research , mark the first time arsenic has been used to label antibodies for the detection of tumors.
Dr. Philip Thorpe, professor of pharmacology at UT Southwestern and senior author of the study, helped create the cancer drug called bavituximab, an antibody that homes in on a specific molecular target on the blood vessels that feed tumors. Bavituximab is being tested in clinical trials to treat solid-tumor cancers in combination with chemotherapy.
“While arsenic has been used as a poison for centuries, the dose of arsenic needed for imaging tumors is about one-millionth of that needed to cause toxicity,” Dr. Thorpe said. “Arsenic-labeled bavituximab appears to be safe.”