(Reuters) - Sales of Biogen Inc's (O:BIIB) roster of multiple sclerosis drugs failed to meet analysts' expectation, prompting the company to slash its full-year profit and sales forecast.
The company's shares fell 8.6 percent to $352 in trading before the bell on Friday.
Sales of Biogen's flagship oral multiple sclerosis (MS) drug, Tecfidera, came in below expectations for the second quarter in a row, hurt by higher discounting, saturation in the U.S. market and reports of serious brain infections linked to the drug.
Tecfidera's sales were $833 million in the second quarter ended June 30, well below Wall Street's estimate of about $933 million, according to Evercore ISI.
Sales of Biogen's injectable MS drug Tysabri came in at $463 million, also falling short of estimates of about $505 million.
Biogen's interferon-based MS drugs Avonex and its new longer-lasting Plegridy raked in sales of $690 million, far below expectations of about $767 million.
Overall, the U.S. biotechnology company's sales rose less than expected. Revenue of $2.59 billion missed analysts' average estimate of $2.71 billion, according to Thomson Reuters I/B/E/S.
Net profit attributable to Biogen rose 30 percent to $927.3 million, or $3.93 per share. Excluding items, it earned $4.22 per share.
The Cambridge, Massachusetts-based company slashed its full-year sales growth forecast to 6-8 percent from 14-16 percent. It also chopped its adjusted profit forecast to $15.50-$15.95 per share from $16.60-$17 per share.