Brain metastasis strikes at least one in five cancer patients—between 100,000 and 170,000 people each year. In many cases, cancer spreading to the brain will be the cause of death.

That’s why physicians and scientists at the University of Miami Sylvester Comprehensive Cancer Center are anxious to begin testing a novel radiation sensitizer in patients with metastatic brain cancer. “Cytochlor recognizes a tumor cell, enters it, releases an amino group, and forms Urochlor, which is then incorporated into tumor cell DNA,” explains Sheldon Greer, Ph.D., professor of microbiology and immunology and the creator of Cytochlor. “Upon irradiation, a chlorine molecule breaks off, which results in irreparable DNA damage, killing the tumor cell.”

Currently, patients with metastatic brain tumors are treated with some combination of surgery and radiation therapy. Surgery isn’t an option in multiple or large tumors. Radiation is the mainstay of treatment of brain metastases; however, damage of the surrounding normal tissue is a concern. Because chemotherapy can’t breach the blood- brain barrier, it doesn’t have a well-defined role in this disease.

But Cytochlor is a small molecule that can enter the brain and make the tumor cells more sensitive to the radiation than the normal cells. The effect is that it focuses radiation onto the tumor.

“In cases where Cytochlor shows efficacy, it can work with any form of radiation therapy, including traditional whole-brain radiation, CyberKnife, and GammaKnife,” says May Abdel-Wahab, M.D., associate professor of clinical radiation oncology. “Because it increases radiosensitivity or susceptibility of the cancer cells to radiation, it may be an ideal companion treatment for whole-brain radiotherapy, where cancer cells are intermingled with normal brain tissue.”