Biogen said profit from operations rose 42%...

Biogen said profit from operations rose 42% in the first quarter to $65 million, or 41 cents a share--2 cents less than analysts’ consensus forecast. Sales rose 26% to $217 million.

Sales of Avonex, the world’s top-selling treatment for multiple sclerosis, rose 33% to $174.6 million, a performance that also disappointed analysts, helping to send Biogen’s shares down as much as 15% in after-hours trading.

“They’re about $5 million light in Avonex sales,” said Erik Anderson, fund manager at Sit Investment Associates in New York.

The company announced results after markets closed. Before the results were released, Biogen closed off $2.06 at $65 on Nasdaq. The shares fell as low as $57 in after-hours trading.