Cancer Drug Shows Promise in Lupus
Rituxan Stops Immune System Attack on Healthy Tissue
Oct. 4, 2002 -- Early research suggests that a commonly used cancer drug could also be effective in the treatment of lupus. The drug, Rituxan, targets specific white blood cells that prompt the immune system to attack healthy tissue.
As many as 1.4 million Americans are believed to have some form of lupus; 90% of patients are women. Symptoms vary and can include fatigue, arthritis, and damage to the kidneys, heart, lung, brain, blood, and skin.
Although the cause of lupus is not well understood, it is known that immune system cells called B cells play a major role in the chronic rheumatic disorder. Depleting the body of B cells has proved effective in the treatment of certain leukemias and lymphomas, and research from the University College London recently showed the treatment to be effective in rheumatoid arthritis patients.
In their latest study, the researchers used this form of treatment -- called B lymphocyte depletion therapy -- to treat six women with advanced lupus who had no other treatment options. The findings were published in the October issue of the journal Arthritis and Rheumatism.
Patients received two infusions of Rituxan over a two-week period, along with infusions of the cancer drug Cytoxan, which is also used in the treatment of lupus. They also received high-dose oral steroids -- a common treatment for lupus.
While one woman did not complete the study, the remaining five had significant improvement in symptoms such as fatigue and joint inflammation six months after the treatment. Kidney and lung function also improved, and the treatment was well tolerated.
According to lead researcher Maria J. Leandro, MD, two of the women are still doing well, with few lupus symptoms, more than two years after treatment. She tells WebMD that it is unclear whether patients will benefit from repeated infusions and whether the treatment protocol used in this study is optimal.
"There are many unanswered questions and we need larger, formal trials to answer them," she says. More than 250,000 cancer patients have been treated with this therapy, and many have had repeat infusions. Theoretically, there is no reason why we could not retreat lupus patients."
Lupus expert Joan Merrill, MD, tells WebMD that it remains to be seen whether B lymphocyte depletion therapy offers a true advance for the treatment of lupus. She says much of the current research is aimed at targeting the specific B cells that cause the immune system to turn against healthy tissue, but several once-promising therapies have been abandoned because they performed poorly in clinical trials. Merrill heads the clinical pharmacology research program at the Oklahoma Medical Research Foundation.
"We don't yet have the kind of drugs for lupus that are anywhere near as sophisticated as what we have for other rheumatic diseases like rheumatoid arthritis," she says. "We need drugs that target the specific problem without having a lot of global side effects." -->