The labeling for Rituxan is being revised following a report that a patient administered the drug to treat rheumatoid arthritis had died of the brain infection progressive multifocal leukoencephalopathy (PML). Cases of PML have previously been reported in patients taking Rituxan for unapproved uses, such as blood cancer and lupus. But according to the Food & Drug Administration (FDA), this is the first report of the infection in an individual undergoing treat for arthritis. In addition to rheumatoid arthritis, Rituxan is approved to treat non-Hodgkins Lymphoma.
PML is characterized by the progressive inflammation of the brain and central nervous system. Patients with PML exhibit neurological symptoms like confusion, dizziness or loss of balance, difficulty talking or walking, and vision problems. PML gets worse over time, and is usually fatal. There is no treatment or cure for the disease.
PML is caused by a polyomavirus, called the JC virus. The JC virus is often acquired during childhood. Most adults have been infected with the JC virus but do not develop PML. The virus appears to remain inactive until something (such as a weakened immune system) allows it to be reactivated and start to multiply.
Rituxan is a powerful medication that suppresses the immune system. In February 2006, the labeling of Rituxan was updated to include information about the risks of patients contracting several viral infections, including PML. The FDA also cautioned physicians who were considering treating a patient with Rituxan for any condition to inform the patient of the risk of developing PML.
Last year, the FDA warned that two patients taking Rituxan off-label for systemic lupus erythematosus had died from PML.
This latest PML-Rituxan fatality involved a woman taking the drug for rheumatoid arthritis. According to the FDA, the patient was undergoing chemotherapy and radiation treatment for cancer in the months before she developed the infection. The agency said the patient received Rituxan in a long-term safety extension clinical study. According to the FDA, the patient developed a JC virus infection with resultant PML and death 18 months after taking the last dose of Rituxan.
In a letter sent to healthcare providers, Genentech and Biogen Idec, the makers of Rituxan, advised doctors to consider PML in any patient presenting with new onset neurologic manifestations. Consultation with a neurologist, brain MRI and lumbar puncture should be considered as clinically indicated. Rituxan should be discontinued immediately in patients who develop PML, the letter said.
Ritixan is not the only Biogen Idec drug to be associated with PML. Earlier this summer, the FDA warned that the same brain disease had been associated with Tysabri, a drug for multiple sclerosis (MS) that Biogen Idec markets in a joint effort with Elan Inc. The FDA warning was prompted by reports of two European MS patients undergoing Tysabri monotherapy had developed PML.
In the U.S. Tysabri was taken off the market in 2005 after three patients in clinical trials developed PML. But the drug was reapproved in 2006, although it was subject to restrictions. The new European cases of Tysabri-related PML raised alarms because both patients had been taking Tysabri as monotherapy – with no other drugs. It had been theorized that patients contracting PML had done so because of exposure to multiple medications and that monotherapy with Tysabri was less risky.
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