Despite strong sales of its multiple sclerosis drugs, Biogen (NASDAQ:BIIB) reported a narrowed third-quarter profit on higher expenses.

The Weston, Mass-based company posted net income of $245.1 million, or $1.05 a share, compared with $277.6 million, or 95 cents a share, in the same quarter last year.

Results for the period ended Sept. 30 were sharply below average analyst estimates polled by Thomson Reuters of $1.23.

Earnings were led by sales of Avonex and Tysabri, two Biogen treatments for multiple sclerosis, up 11% and 7%, respectively, offset by a sales decline of Rituxan, the company’s treatment for certain types of non-Hodgkin’s lymphoma.

George A. Scangos, Biogen’s chief executive, called the quarter “solid,” attributing growth to the drug sales and the company’s continued MS leadership.

Revenue for the drug maker was $1.17 billion, up 5% from $1.12 billion a year ago, matching the Street’s view, while expenses grew to $981.6 million from $736.34 million a year ago.