Cancer Drug May Ease Rheumatoid Arthritis
New Approach in Rheumatoid Arthritis Treatment Targets Specific Immune Cells
June 18, 2004 -- Short-term rheumatoid arthritis treatment with a drug that targets a certain type of immune cell may provide lasting relief.
A new study shows adding two doses of the cancer drug Rituxan to traditional rheumatoid arthritis treatments significantly reduced symptoms of the painful joint disease for up to 48 weeks.
Rituxan is a biologic drug that targets and destroys particular cells within the immune system known as B-cells (or B-lymphocytes), which are thought to play a role in joint inflammation caused by rheumatoid arthritis. Rituxan is currently used to treat a form of non-Hodgkin's lymphoma caused by cancerous B-cells, and is manufactured by Genetech, Inc., a WebMD sponsor.
"The study provides support for the concept that B-lymphocytes play a central role in rheumatoid arthritis and suggests that B-lymphocyte-targeted therapy has potential," says researcher Jonathan Edwards, MD, of the University College of London, in a news release.
Rituxan May Offer New Type of Rheumatoid Arthritis Treatment
In the study, researchers looked at the effects of two doses of Rituxan, given by intravenous infusions two weeks apart, in 161 people with moderate to severe rheumatoid arthritis. All of the participants had previously been treated with methotrexate, a drug commonly used to treat rheumatoid arthritis, but still had active rheumatoid arthritis.
The participants were randomly assigned to receive methotrexate plus a placebo, Rituxan plus a placebo, or Rituxan in combination with methotrexate or cyclophosphamide, another cancer drug also used as a rheumatoid arthritis treatment. Each participant also was given a short course of anti-inflammatory corticosteroids.
After six months, more than 40% of those on Rituxan in combination with methotrexate or cyclophosphamide experienced a 50% improvement in rheumatoid arthritis symptoms compared with only 13% of those that received methotrexate alone. Rituxan alone was also more effective than methotrexate at improving symptoms.
Those beneficial effects lasted for another six months without additional treatments -- the length of the study.
In an editorial that accompanies the study, George C. Tsokos, MD, of the Walter Reed Medical Army Institute of Research, says the findings support the notion that B-cells play an important role in rheumatoid arthritis.
Tsokos says successful rheumatoid arthritis treatment with drugs that target specific immune cells, such as Rituxan, will likely involve continuing these drugs and possibly use of additional drugs to suppress the immune system. Therefore, people using these rheumatoid arthritis treatments should be closely monitored for loss of immune function, which could raise the risk of infection.
In Edwards' study, serious infections were about equal (3%) in all groups -- those taking methotrexate plus a placebo and those taking Rituxan.