By Matt Grossman

Biogen Inc. recorded a slimmer third-quarter profit as revenue from the company's multiple-sclerosis treatments declined by a single-digit percentage amid new generic competitors.

The Cambridge, Mass.-based pharmaceutical company logged a profit of $701.5 million, or $4.46 a share, down from a profit of $1.55 billion, or $8.39 a share, in the same three-month period a year earlier.

On an adjusted basis, Biogen's profit was $8.84 a share. Analysts polled by FactSet had forecast a profit of $8.03 a share.

Revenue was $3.38 billion, compared with $3.6 billion in last year's third quarter. Analysts were expecting revenue of $3.33 billion.

Revenue from the company's multiple-sclerosis segment declined 4% year over year to $2.26 billion. Revenue from Spinraza, a treatment for spinal muscular atrophy, fell 10% to $495 million. Revenue from the company's biosimilars grew 13% to $208 million.

Chief Executive Michel Vounatsos noted that Biogen began to face competition from the launch of generic versions of its Tecfidera multiple-sclerosis drug in the quarter. Biogen's aducanumab, a potential treatment for Alzheimer's disease, faces a key hurdle on Nov. 6 in the form of a Food and Drug Administration advisory-committee meeting.

Write to Matt Grossman at matt.grossman@wsj.com

(END) Dow Jones Newswires

10-21-20 0805ET