ROCKVILLE, Md., Dec. 19 -- Two patients treated with the immune modulator Rituxan (rituximab) for systemic lupus erythmatosus (SLE) have died of progressive multifocal leukoencephalopathy (PML), the FDA warned physicians.
The FDA said that PML, a viral infection of the central nervous system, has been reported in patients as late as 12 months after their last dose of Rituxan. PML is caused by reactivated JC virus which is present in about 80% of adults.
SLE is not an approved indication for Rituxan. It is indicated for patients with CD20-positive, B-cell, non-Hodgkin's lymphoma and for rheumatoid arthritis that has become refractory to standard therapies. Yet the FDA noted that Rituxan is prescribed off-label for SLE and other serious conditions.
Symptoms of PML include major changes in vision, balance, or coordination, or confusion, said Steven Galson, M.D., director of the FDA's Center for Drug Evaluation and Research. He said patients who are using Rituxan, or who have used it, should consult a physician if they have any of those symptoms.
The FDA updated the Rituxan label last February to include post-marketing reports of serious viral illnesses, including PML, in patients with lymphoma who were treated with Rituxan.
There have been 23 confirmed cases of PML in patients with lymphoid malignancies either during or after treatment with Rituxan. But the FDA said most of those patients had also been treated with other drugs known to affect the immune system.