Prolonged Cellcept usage?

Q: Are there any long-term studies of the affects of prolonged CellCept usage?

A: I would say one thing to think about with Cellcept is that it was thought for a long time to be one of the safest immunosuppressants. But in the last couple of years there have been a couple of reports of this disease called PML or Progessive Multifocal Leukoencephalopathy, which is a fatal brain disease that is caused by the reactivation of a virus called the JC virus, and it’s a little bit scary because we hadn’t seen it with this particular immunosuppressant before although it has been seen with pretty much all the other powerful immunosuppressants. It’s one of those things that can live inside of people for a long time. Our body keeps it at bay, but if you lower your defenses too much, it can come up, and it’s impossible at this point to tell who has it and who could be at risk. It’s exceedingly rare but it’s yet another unfortunate risk that we now have to discuss before starting any of these kinds of powerful medications.

Excerpted from the Ask-the-Experts Session, 2010 NEA Conference