Biogen Idec Inc, the maker of multiple sclerosis drugs Avonex, Tysabri and Tecfidera, boosted its 2013 forecast after Tecfidera sales topped analysts’ third-quarter estimates.

Revenue this year will grow by 23 percent to 25 percent, with adjusted earnings of $8.65 to $8.85 a share, the Weston, Massachusetts-based drugmaker said today in a statement. The company previously had projected revenue gaining 22 percent to 23 percent and adjusted earnings of $8.25 to $8.50 a share.
Investors are focused on Biogen’s first pill for MS, Tecfidera, which was cleared for sale by the U.S. Food and Drug Administration in March. Tecfidera sales were $286.4 million, beating analysts’ average $217.2 million estimate. The medicine more than doubled the analysts’ estimate last quarter, and they expect it to draw $3.5 billion in annual revenue by 2016.

“Tecfidera crushed it,” Mark Schoenebaum, an analyst with ISI Group, wrote in a note to clients today. “This is really, truly, incredible.’”

Biogen gained less than 1 percent to $254.43 at the close in New York. The shares gained 74 percent this year.