Drugs aimed at suppressing inflammation-provoking cytokines - specifically those linked to T-cells - have improved the treatment of rheumatoid arthritis (RA), a chronic, inflammatory autoimmune disease. Still, the frequency of remission achieved by these biologic agents remains below 50 percent.
To increase the success rate of biologic therapy for RA patients, researchers have honed in on a new target: the B cell.
Rituximab, a biologic agent that selectively depletes B cells, has been successfully used to treat non-Hodgkin's lymphoma. It has also been shown to improve disease symptoms for RA patients, when injected at aggressive levels for a two-week period. To investigate this biologic's potential long-term therapeutic value, an international team of scientists set out to compare the effectiveness and safety of different rituximab doses over a 24-week period, with and without steroids. Their study focused on 465 RA patients with moderate to severe symptoms resistant to disease-modifying antirheumatic drugs (DMARDs), including other biologics. The results, featured in the May 2006 issue of Arthritis & Rheumatism, indicate the promise of low-dose rituximab to achieve remission for RA patients, without serious side effects and without the need for prescribing harsh steroids.
Drawn from outpatient populations in California, Texas, Arizona, Switzerland, Sweden, Poland, and England, the subjects were randomly divided into nine treatment groups. Three groups received a 1,000 mg. dose of rituximab--two infusions two weeks apart--with either intravenous steroid, oral steroid, or placebo. Three groups received a 500 mg. dose of rituximab--two infusions two weeks apart--with either intravenous steroid, oral steroid, or placebo. Three groups received a placebo with either intravenous steroid, oral steroid, or another placebo. All subjects received the DMARD methotrexate (MXT). All subjects were evaluated every four weeks for changes in the Disease Active Score (DAS), a 28-joint assessment for swelling and tenderness, as well as for overall disease improvement, with the goal of meeting the American College of Rheumatology (ACR) 20 percent improvement criteria.