Rituxan OK'd for Rheumatoid Arthritis

March 1, 2006 - The FDA has approved a first-of-its-kind treatment for rheumatoid arthritis (RA).

Rituxan is recommended to treat moderate-to-severe rheumatoid arthritis in combination with methotrexate. It's specifically intended for people who have not improved with treatments called tumor necrosis factor (TNF) antagonists, such medications include Enbrel and Remicade.

New drugs to treat RA target the immune system to help calm the inflammation that damages joints. Rituxan hones in on the immune system in a brand new way.

It's the first rheumatoid arthritis treatment that selectively targets immune cells known as CD20-positive B cells. B cells are believed to play a role in the inflammation associated with RA.

Like other RA treatments, including methotrexate, Rituxan was first used to treat cancer. It's been used since 1997 to treat non-Hodgkin's lymphoma, a cancer of the lymph nodes.

"The FDA approval of Rituxan for RA provides an important new treatment approach for patients who do not respond adequately to TNF antagonist therapy," says Stephen Paget, MD, in a news release. Paget is chairman, professor of medicine, and physician-in-chief at the department of medicine, division of rheumatology, at the Hospital for Special Surgery in New York.

Rheumatoid arthritis is a type of chronic arthritis that occurs in joints on both sides of the body (such as hands, wrists, or knees). This symmetry helps distinguish rheumatoid arthritis from other types of arthritis. In addition to affecting the joints, rheumatoid arthritis may affect the skin, eyes, lungs, heart, blood, nerves, or kidneys.

Side Effects

In a 24-week study that compared Rituxan plus methotrexate with using methotrexate alone, more patients on the combination treatment achieved a significant response, including less pain and disability.

In patients with rheumatoid arthritis, Rituxan is given as two infusions -- separated by two weeks -- in the vein in combination with methotrexate.

The most common side effects seen in clinical trials were infections and reactions soon after the medicine is given (called infusion reactions). Symptoms of infusion reactions include flu-like illness, fever, chills, nausea, and headache.

Severe infusion reactions, including death, have been seen in lymphoma patients treated with Rituxan.

While infusion reactions are common, especially the first time Rituxan is given, fewer than 1% of people in a clinical trial for RA had a serious reaction, which can include trouble breathing, low blood pressure, and low oxygen levels.

In addition to rheumatoid arthritis, researchers are studying Rituxan for other autoimmune diseases, including lupus and multiple sclerosis.