Rituximab Alert

Posted by Elaine Moore Dec 19, 2006

The U.S. Food and Drug Administration has issued a new warning for Rituxan after the death of two patients with systemic lupus erythematosus (SLE) who were being treated with Rituxan. The cause of death was a brain infection known as progressive multifocal leukoencephalopathy or PML, which had previously been associated with Rituxan in people who were immunosuppressed. Immunosuppression, a condition of decreased immune function, is seen in people with acquired immune deficiency syndrome (AIDS) and in people being treated with immunosuppressant drugs such as methotrexate.

Rituxan is the brand name for rituximab, a monoclonal antibody, produced by Biogen Idec and Genetech. Rituximab was first introduced as a treatment for non-Hodgkin's leukemia and B-cell leukemia. It is also used for rheumatoid arthritis and off label for several autoimmune conditions including systemic lupus. Rituxan is usually used in combination with another immunosuppressant medication.

Rituximab decreases the production of specific white blood cells associated with antibody production. Besides interfering with the production of autoantibodies, Rituximab interferes with the immune system's ability to fight against infection. In patients who are immunosuppressed Rituximab opens the doors to opportunistic infections. Opportunistic infections are infections caused by organisms such as yeast that are not usually the cause of serious disease.

Most cases of PML have traditionally occurred in patients with AIDS. Opportunistic infections are one of the leading causes of death in patients with AIDS as their immune systems become too weak to fight.

In a Marketwatch alert, it was reported that on December 19, 2006 Biogen Idec and Genetech company officials advised physicians to watch for signs of PML in their patients on Rituximab. Early symptoms of PML include problems with vision, coordination or balance.

Other warnings issued for rituximab previously include warnings for symptoms of oral ulceration and an increased risk of developing viral infections including hepatitis. In addition, Rituxan has been reported to cause bowel and gastrointestinal disease.

In an FDA alert on Rituxan issued on December 18, 2006 officials advised doctors to discuss the chances of PML with their patients on Rituxan, cautioning that there is no known treatment available for PML. The FDA also clarified that Rituximab is not an approved medication for patients with systemic lupus. The risk of developing PML can occur as long as one year after the last injection of Rituxan, making follow-up with patients previously treated critically important.

Although rituximab is currently being studied in clinical trials for patients with SLE, the two lupus patients who died were not enrolled in clinical trials.

Resources:

Clinical Trials at www.clinicaltrials.gov

Marketwatch

Reuters Health News