The drug is a powerful immuno-suppressant, and is a type of immuno-therapy that uses monoclonal anti-bodies-antibodies that are produced in the laboratory rather than in the body, as they normally are-and it's been licensed as a therapy for non-Hodgkin's lymphoma.
Despite the supposed limitations of its use, doctors have also been giving the agent to patients with the autoimmune disorder systemic lupus erythematosus (SLE), or lupus.
Around 10,000 SLE patients have been given Rituxan in the US alone-and it was two of these who died in 2006. Both of these patients develop-ed an opportunistic viral infection of the brain, known as PML (progress-ive multifocal
leucoencephalopathy), which is often associated with AIDS.
The future of the drug is uncertain but, while drug regulators deliberate, doctors are being told to watch out for early signs of PML in patients being given Rituxan chemotherapy (www.fda. gov/cder/drug/advisory/rituximab.htm).