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%. To increase the success rate of biologic therapy for RA patients, researchers have honed in on a new target: the B cell.
Rituximab (marketed as Rituxan by Genentech and Biogen Idec), 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 the 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, which are featured in the journal 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.
Steroids, whether received intravenously or orally, showed no significant correlation with disease improvement scores among the rituximab groups tested. Intravenous steroid, however, showed a positive correlation to improved tolerability during the first rituximab infusion in both dosage groups.
Overall, adverse events associated with rituximab were mild and easily managed. Headache was the most common complaint.
Confirming the role of B cells in the inflammatory processes behind RA, this study demonstrates the effectiveness and safety of a unique biologic therapy, in moderate doses and independent of steroids. Yet, as its leading author, Dr Paul Emery, notes, further studies are needed before applying the results to the routine treatment of RA patients. “Both doses of rituximab explored in this study warrant further differential exploration and longer-term follow-up,” he stresses.