Rituxan PML Side Effects

On December 18, 2006, the FDA issued a Public Health Advisory, warning about the risk of progressive multifocal leukoencephalopathy (PML) in patients using Rituxan. At the time, the FDA noted that it had received reports of two patients who were treated with Rituxan and died after developing PML.

A study reported in the journal Blood, in May 2009 that evaluated PML case descriptions among patients treated with rituximab from the FDA, the manufacturer Genentech, physicians, and a literature review from 1997 to 2008, revealed "Overall, 52 patients with lymphoproliferative disorders, 2 patients with systemic lupus erythematosus, 1 patient with rheumatoid arthritis, 1 patient with an idiopathic autoimmune pancytopenia, and 1 patient with immune thrombocytopenia developed PML after treatment with rituximab and other agents." The median time to death following a diagnosis of PML was 2.0 months, with a fatality rate of 90 percent.

PML is a serious viral infection of the brain. It is usually fatal and there is no known effective treatment.

In 2006 the labeling for Rituxan was updated to include a black box warning for PML, the symptoms of which include dizziness, confusion, loss of balance, vision problems, and possibly difficulty walking and talking.