Blood Cancer Drug Shows Promise Against Lupus

By Steven Reinberg
HealthDay Reporter
Monday, June 9, 2008; 3:00 AM

Copyright © 2008 ScoutNews, LLC. All rights reserved.

SUNDAY, June 8 (HealthDay News) -- A drug used to treat multiple myeloma, a cancer of the white blood cells, may also be a treatment for the chronic autoimmune disease lupus, German researchers report.

The drug, Velcade (bortezomib), which is a proteasome inhibitor, worked against the disease and prolonged survival in mice with lupus. The finding could one day offer treatment options for other antibody-associated diseases, too, the researchers said.

"Autoantibody-mediated diseases such as autoimmune hemolytic anemia, immune thrombocytopenia, myasthenia gravis and systemic lupus erythematosus are often difficult to treat," said lead researcher Dr. Reinhard Voll, of the University of Erlangen-Nuremberg.

A big problem is that plasma cells, which are the predominant producers of the disease-causing autoantibodies, can't be efficiently attacked with current treatments, Voll said.

Lupus is a so-called autoimmune disease in which the immune system attacks healthy cells and tissues by mistake, leading to damage to joints, skin, blood vessels and organs. There are many kinds of lupus, with the most common type being systemic lupus erythematosus, which affects many parts of the body. There's no one test to diagnose lupus, and it may take months or years to make the diagnosis. There's also no cure, but medicines and lifestyle changes can help control the disease, according to the U.S. National Institutes of Health

For the new study, Voll's team found that bortezomib efficiently eliminated the plasma cells in the mice, leading to a drastic decrease in autoantibodies and prolonged survival. And, the drug had no effect on other cells, he said.

"Proteasome inhibitors may be beneficial in refractory human diseases caused predominantly by autoantibodies," Voll said. "Proteasome inhibitors can selectively deplete plasma cells, which are resistant to current treatments."

Outside experts were divided on the findings, published in the June 8 online edition of Nature Medicine.

"This is a very exciting study that explores a novel mechanism for treating lupus erythematosus," said Dr. Jennifer Grossman, an assistant professor of medicine at the University of California, Los Angeles.