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Two MS patients treated with Tysabri recovering from PML
Last Updated: 2008-08-26 16:04:45 -0400 (Reuters Health)

LONDON (Reuters) - Two European patients who developed progressive multifocal leukoencephalopathy (PML) after being given Biogen Idec and Elan Corp's multiple sclerosis drug Tysabri are now recovering, a researcher involved in their care said on Tuesday.

One patient in Scandinavia is out of risk while a second man in Germany is in the early recovery phase, Ralf Gold of the Ruhr University Bochum, Germany, told Reuters.

Gold, who presented an update on the cases at the annual meeting of the European Federation of Neurological Societies in Madrid, said he was optimistic both men would survive.

"For the Swedish patient now, there's no question he is out of risk. For the other, I have moderate optimism," he said in a telephone interview.

Tysabri was withdrawn in 2005 when three cases of PML were reported, but returned to the market in 2006 with warnings and tougher prescription guidelines.

Gold said the new cases underlined the need for vigilance, but Tysabri remained a "very effective therapy" and the two cases need not change current prescribing practice.

However, if further cases of PML were seen in the coming months, the risk/benefit balance might have to be reassessed.

The latest cases involved patients who were using Tysabri as monotherapy for more than a year. Previously, PML had been seen in patients taking Tysabri with other medicines.

"These cases came earlier than expected under monotherapy. I always expected to see some in 2009; I never expected to see them in 2008," Gold said.