[RITUXIMAB IN RHEUMATOID ARTHRITIS - THERAPEUTIC ASPECTS BASED ON 18 YEARS OF GLOBAL EXPERIENCE]

Rituximab, a monoclonal antibody against CD20 positive B cell, depletes these cells peripherally, and is a successful treatment in rheumatoid arthritis (RA). It is the second efficacious biologic to be established in the treatment of RA after TNFα blockers. Eighteen years of global experience from diverse clinical trials and from "real world" data, have demonstrated clinical efficacy in various disease scenarios and patient populations - short and long disease duration, methotrexate naïve patients and those with incomplete response to methotrexate, biologic naïve patients and those with incomplete response to previous biologics. Moreover, it has demonstrated the inhibition of radiographic progression. It seems to be most efficacious in seropositive patients. Despite vast experience, the need for concomitant traditional disease-modifying anti rheumatic drugs (DMARD), the optimal retreatment dose, and the favored retreatment interval remain somewhat uncertain. The recommended dosage is 1000 mg, administered twice, with a 2 weeks interval, although in some cases, a reduced dosage of 500 mg, administered twice may be considered. The safety profile of rituximab includes mainly infusion-related reactions, which are usually mild. A small risk of major infections has remained stable over time and repeated courses. Opportunistic infections are infrequent. Nevertheless, reactivation of hepatitis B is still a concern. Tuberculosis, malignancies, cardiovascular events and deterioration of interstitial lung disease do not appear to be increased. Since rituximab severely impairs the humoral response to vaccinations, they should be administered prior to treatment whenever possible. Rituximab has been a powerful addition to the large armamentarium for the treatment of RA. Rituximab is indicated in Israel as a second line biologic treatment for active RA.