The psoriasis treatment Raptiva (efalizumab) has been discontinued in the U.S. as of June 2009 because of it’s potentially fatal side effects.  It was originally approved by the FDA in 2003.

Genentech published this press release to explain the situation.  This is a bit of a let-down since Raptiva seemed to be so effective, especially in the case of CariDee English, who recently skyrocketed to fame as the winner of the 2008 season of America’s Next Top Model.  Hear more about CariDee English’s experiences with psoriasis here.

Specifically, Raptiva has been proven to increase people’s chances of getting progressive multifocal leukoencephalopathy (PML), which is a central nervous disease.  PML can be either debilitating or fatal as it causes brain damage that worsens over time.

The most common cause for PML is a weak immune system, which seems to be the most viable explanation for why Raptiva would increase a person’s chances of catching it.  This is an example of the unexpected risks that can arise out of using immunosuppressants (medicines that limit your body’s ability to fight off disease).