TYSABRI: Panel to Weigh Reinstating Drug for MS on Tuesday & Wednesday - New York Times...[read more]:

"An advisory panel of the Food and Drug Administration will begin discussing Tuesday whether to permit a promising multiple sclerosis drug to return to the market, according to documents released Monday.

The risks of a rare brain disease and other infections from the drug, Tysabri, remain a concern for regulators, according to the documents.

If Tysabri returns to the market, F.D.A. officials said, its use should be restricted and patients monitored during treatment and for at least five years afterward to curtail the risk they run of developing progressive multifocal leukoencephalopathy, or P.M.L., and other opportunistic infections.

The panel is to spend Tuesday and Wednesday discussing whether to recommend that the F.D.A. allow Tysabri back on the market. The F.D.A. typically follows the advice of its advisory committees. One concern of F.D.A. officials is the 'absence of tools with documented effectiveness to manage' the risks associated with use of the drug. Tools like regular neurological examinations, magnetic resonance imaging scans and the testing of spinal fluid and blood serum, might not be useful in monitoring for the presence of the JC virus, which is believed to cause P.M.L., the FDA staff wrote......"