There weren't many patients on the drug but a skittish FDA pulled Raptiva from the market today over concerns of PML the rare brain infection. Three patients died of the brain infection this year alone and given the alternatives in the market and the (usually) non life-threatening course of psoriasis the decision seems justified. The drug recognizes CD11a and is a monoclonal antibody. The next time I hear someone say at tumor board that Rituxan is safe because it's "only" a monoclonal antibody I will remind them that some of these antibodies can kill people and they deserve a healthy measure of respect. What we need is a way to turn off the "bad" part of the immune system without destroying the "good" immune function. We are at a pretty rudimentary level right now when it comes to the immune system and we will be stuck with low level progress occasional breakthroughs and dead ends like Raptiva until we have a clearer understanding of what's going on.