Study Finds 57 Rituxan Patients Developed PMLMay 20, 2009 | Parker Waichman LLP
Patients Taking Rituxan may be at Risk
Patients taking Rituxan may be at risk of developing a serious, and often fatal brain infection called progressive multifocal leukoencephalitis (PML), according to the findings of a new study. The study, published in the journal Blood, reports on 57 cases of PML that developed in patients taking Rituxan between 1997 and 2008.
The study, which is detailed in Science Daily, was conducted by researchers with the Northwestern University Feinberg School of Medicine RADAR project. RADAR ((Research on Adverse Drug Events and Reports) is an international consortium of physicians that collaborate to identify adverse reactions to medications and devices.
According to Science Daily, Rituxan is the most important and widely used cancer drug for lymphoma, and is also approved as a therapy for rheumatoid arthritis. In addition, Rituxan is also used off-label to treat multiple sclerosis, lupus erythematosus and autoimmune anemias.
Last September, the labeling for Rituxan was updated to reflect its association with PML. At the time, the Food & Drug Administration (FDA) said that at least two patients given Rituxan as a treatment for systemic lupus erythematosus had died from PML.
PML is a viral infection that affects the white matter of the brain. 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. It is often associated with drugs that suppress the immune system.
57 Rituxan PML Patients Identified in the RADAR Study were Using the Drug as a Treatment for Anemia
According to Science Daily, the 57 Rituxan PML patients identified in the RADAR study were using the drug as a treatment for anemia, rheumatoid arthritis or lymphoma. On average, they died just two months after being diagnosed. While it is known that a small number of lymphoma patients will develop PML regardless the treatment they undergo, it is not typically seen in anemia or arthritis patients, Science Daily said.
In many cases, the researchers found that PML patients taking Rituxan were misdiagnosed with disease like dementia and Alzheimer's, Science Daily said.
The head of the RADAR project told Science Daily that considering the study's findings, there is a need for caution in prescribing Rituxan. "The drug has tremendous usefulness in lymphoma, but as its use expands to diseases that are not cancer, we might have to reconsider the risk benefit," Charles Bennett, M.D said. "Some cancer patients take this drug chronically for non-fatal chronic leukemia where the risk-benefit calculations differ from lymphoma."
Bennett told Science Daily that the next step in RADAR's research will be to determine what risk factors might be linked to Rituxan-associated PML.