Health officials report that a multiple sclerosis drug pulled from the market last year because of a rare but life-threatening side effect will return under a restricted distribution program.

The Food and Drug Administration says it will let Biogen Idec Inc. and Elan Corp. PLC continue selling Tysabri under a requirement that doctors, pharmacies and patients register with a program designed to ensure the safe use of the drug.

According to Associated Press, Tysabri received FDA approval in November 2004.

Biogen Idec, its Cambridge, Mass.-based manufacturer, voluntarily withdrew it in February 2005 after two patients in clinical trials died of a rare brain infection called progressive multifocal leukoencephalopathy, or PML.

Ireland-based Elan distributes the drug, which is also called natalizumab.