Rituxan may heal common kidney condition

WASHINGTON (Reuters) - The cancer drug rituximab can help heal the kidneys of patients with a common condition known as membranous nephropathy, Italian researchers reported on Wednesday.

The drug, sold under the brand name Rituxan by Genentech and Biogen Idec Inc and as MabThera by Roche AG in Europe, suppresses the rogue immune cells that cause the condition, the researchers found.

Writing in the Clinical Journal of the American Society of Nephrology, they said their findings suggest the condition, which causes kidney failure in 30 percent to 40 percent of cases, can be cured in some patients.

"Whether this may apply to other (similar kidney conditions) and may translate into long-term protection from renal function loss and the potentially life-threatening complications ... remains to be established," Dr. Piero Ruggenenti of the Negri Bergamo Laboratories in Bergamo, Italy, and colleagues wrote.

Membranous nephropathy, also known as membranous glomerulopathy, affects an estimated two out of 10,000 people, and doctors believe it is caused by autoimmune reactions against the kidney.

Researchers have attempted to treat the condition with several immune-suppressing drugs, but none has worked consistently. And these drugs, used in other autoimmune diseases such as rheumatoid arthritis, raise the risk of infections and cancer.

Ruggenenti and his colleagues treated 50 patients with membranous nephropathy with rituximab, which selectively reduces the effects of immune cells called B cells. Ten of the patients eventually achieved a complete remission of their disease, they reported.

Rituxan, originally developed as a treatment for non-Hodgkin's lymphoma, was also approved in 2006 for treating rheumatoid arthritis and a study has shown it can also reduce the risk that a transplanted kidney will be rejected.

(Reporting by Maggie Fox; Editing by Julie Steenhuysen)