New leukemia treatment found

by Joel Sawyer

Researchers at the University’s Cancer Center may have found a new treatment for people suffering from a common form of leukemia.
The researchers developed a therapeutic agent that destroys myeloid leukemia cells in mice and might prove effective in humans, according to a report published Thursday in the medical journal “Blood”. But before testing can begin on humans researchers must gain approval from the Federal Drug Administration.
Myeloid leukemia accounts for more than one-third of all leukemia cases, and while the Cancer Center research could be a breakthrough, the battle against the disease is far from over. “This is not a cure at all,” said Dr. Daniel Vallera, a professor of therapeutic radiology in the Cancer Center. But, the research does have the earmarks of being a significant advance toward treating myeloid leukemia, added Vallera, who was involved in the research.
According to the National Cancer Institute, 11,000 new cases of myeloid leukemia are diagnosed each year. About two-thirds of those patients die within five years.
Leukemia is the growth of cancerous white blood cells in the blood stream. The cancerous cells replicate, taking up space and using up resources healthy cells need. They can eventually destroy the body’s immune system, damage the body’s organs and lead to death, Vallera said.
Myeloid leukemia is a form of leukemia that attacks the white blood cells that aid the body in fighting off infection.
The type of leukemia treatment Vallera and his colleagues have developed differs from other therapies because it focuses on attacking the cancer on a protein level rather than a DNA level, which is done with chemotherapy, Vallera said.
Vallera said he hoped the new therapy could be combined with DNA-directed therapies to produce more effective results.
The therapeutic agent he and others developed contains diphtheria toxin, a potent poison, that fuses with an immune system protein. The agent travels through the bloodstream in search of cells such as myeloid leukemia cells that attract the immune system protein.
Once the agent finds the cells, it attaches to them and kills them. Unfortunately, it also kills healthy cells that also are attracted to the immune system protein. But, Vallera said, the treatment is still viable because the body’s vitally important stem cells can survive it. Stem cells can produce new cells, replacing those lost to the agent.
Vallera conducted the study with Dr. Bruce Blazar, an associate professor of pediatrics, and doctoral student Chung-Huang Chan. The study was funded by the National Institutes of Health and the American Cancer Society.
Clinical trials using humans as test subjects should begin in about two years, Vallera said. Before that happens though, researchers will have to develop a therapeutic agent for humans and gain the approval of the University and the FDA.