The benefits of rituximab for the treatment of rheumatoid arthritis

This article examined the benefits and risks of using rituximab (Rituxan, MabThera) for the treatment of rheumatoid arthritis.

Rheumatoid arthritis is a chronic (long-term) disease that leads to inflammation of the joints. The severity of patients’ symptoms can be graded using the ACR 50 (the American College of Rheumatology 50 grade). The ACR 50 grades the severity of rheumatoid arthritis based on the number of swollen joints, pain and patient disability. This scoring system can be used by researchers to determine how well a patients’ medication is working.

Methotrexate (Rheumatrex, Trexall) is one of the most commonly used drugs for treating rheumatoid arthritis. It can either be prescribed as a monotherapy (no other drug is given at the same time) or prescribed along with other drugs. Rituximab is given intravenously (directly into the vein) and is currently given to patients who do not improve after methotrexate and other biologics (drugs that decrease immune system activity). There is evidence to suggest that rituximab is effective and well tolerated when used in combination with methotrexate for rheumatoid arthritis.

This article evaluated 8 studies including 2720 patients with rheumatoid arthritis, 1791 of whom were given rituximab plus methotrexate. The authors focused on rituximab (two 1000 mg doses) in combination with methotrexate as this is the approved rituximab dose and most commonly used combination.

Benefits of rituximab

Based on the ACR50 score, rituximab significantly improved patients’ symptoms: swollen joints, pain and disability. 29% of patients taking rituximab plus methotrexate experienced improvements compared to 9% of patients taking methotrexate alone. This was associated with 85% of patients who took both drugs having a meaningful improvement in their physical function compared to only 61% of patients who took methotrexate only.

Rituximab plus methotrexate treatment also appeared to slow the occurrence of joint damage. X-ray analysis showed that 57% of patients who took both drugs had no joint damage after 2 years compared to 39% of patients who took methotrexate only.

Rituximab plus methotrexate treatment also improved patient quality of life; general health, pain, ability to perform physical activities and mental health. More patients taking rituximab plus methotrexate rated their physical quality of life better (70% of patients compared to 36% of patients taking the methotrexate only). Slightly more patients taking rituximab plus methotrexate also rated their mental quality of life to be better (48% of patients compared 35% of patients taking methotrexate only).

Harms of rituximab

Similar percentages of patients taking rituximab plus methotrexate stopped taking their medication as patients receiving methotrexate only: 3% taking both drugs compared to 5% taking methotrexate only. Patients taking rituximab plus methotrexate also had similar rates of serious adverse events compared to patients receiving methotrexate only (13% taking both drugs compared to 17% taking methotrexate only).

The authors concluded that rituximab probably improves pain, function and other symptoms, reduces disease activity, and reduces joint damage as seen on x-rays. Evidence suggests that rituximab in combination with methotrexate is better than methotrexate alone for improving the symptoms and preventing disease progression.

Rituximab in combination with methotrexate is currently FDA-approved for adult patients who have an inadequate response to other biologics (such as infliximab [Remicade], etanercept [Enbrel], adalimumab [Humira], golimumab [Simponi)], and certolizumab pegol [Cimzia]).