European regulators have suspended sales of Genentech's psoriasis drug Raptiva after reports that three patients taking the drug have died of a rare brain infection.

Rapitiva is known to risk four cases of a deadly brain infection along with the skin-clearing treatment, according to officials of the US Food and Drug Administration (FDA).

Both the US FDA and the European Medicines Agency said they have received reports of three confirmed deaths and one possible case of progressive multifocal leukoencephalopathy, or PML (a fatal case of swelling of the brain), in patients taking Raptiva.

All the cases were reported in the last six months while the FDA announcement came after European Union regulators recommended a ban on marketing the drug.

"The benefits of Raptiva no longer outweigh its risks, because of safety concerns," the European Medicines Agency said.

Rapiva is marketed in Europe by Swiss drugmaker Merck Serono.

Genentech had earlier notified physicians and investors of the cases. "We take the risk of PML very seriously and are working diligently with the FDA to put the right plans in place that will help protect patient safety," said company spokeswoman Tara Cooper.

PML is seen mostly in patients with weakened immune systems, and has previously been linked to Rituxan, an arthritis and cancer drug marketed by Genentech and Biogen Idec.

First approved in 2003, Raptiva is a once-a-week injection used to treat red, scaly skin caused by psoriasis.

Genentech is now majority controlled by Swiss drug maker Roche, which has its US headquarters in Nutley, owns a majority stake in Genentech.

The FDA said it had earlier warned against the use of Raptiva in October after a 70-year-old patient died of PML after taking the drug for four years. The agency had also asked doctors to to monitor patients taking the drug for these signs.