Serono Wins FDA Approval for MS Drug

Serono won Food and Drug Administration approval for the multiple sclerosis drug Rebif, threatening sales of Biogen Inc.’s Avonex. Biogen shares fell as much as 13%, and Serono’s rose 13%.

Europe’s biggest biotechnology company plans to introduce Rebif in the U.S. within days, Chief Financial Officer Jacques Theurillat said. The medication, approved in more than 70 countries, had sales of $110.5 million in the fourth quarter, about a third of Serono’s revenue.

Geneva-based Serono gained entry to the $1.1-billion MS market with a study that showed Rebif can prevent relapses better than Avonex. A U.S. program that encourages research on rare diseases had protected Avonex sales until May 2003 by barring approval of any rival drug not proved safer or more effective.

Shares of Cambridge, Mass.-based Biogen fell $4.75 to $51.65 on Nasdaq. Accredo Health Inc., which distributes Avonex, fell $4.57 to $48.93 a share, also on Nasdaq.

Rebif also will take on Betaferon from Schering and Chiron Corp. and Teva Pharmaceutical Industries Ltd.’s Copaxone.