Shares of Biogen Inc. /zigman2/quotes/201531540/composite BIIB -2.89% were up 1.8% in premarket trading on Wednesday after the company beat expectations for the third quarter despite lower-than-expected utilization of Aduhelm, its controversial and closely watched new Alzheimer's disease treatment. Biogen had net income of $329.2 million, or $2.22 per share, in the third quarter of 2021, compared with net income of $701.5 million, or $4.47 per share, in the same quarter a year ago. Adjusted earnings per share were $4.47, against a FactSet consensus of $4.09. Biogen's revenue was $2.7 billion in the third quarter of the year, down 18% from $3.37 billion in the same three months of last year, against a FactSet consensus of $2.6 billion in revenue. The drop in revenue is due to several factors, including ongoing declining sales in its multiple-sclerosis portfolio and weak uptick of Aduhelm, which reported sales of $300,000. "The potential uptake of Aduhelm in the U.S. is delayed, but we continue to believe in its long-term potential," CEO Michel Vounatsos said in a news release. The company updated its guidance for the year, saying it now expects revenue of $10.8 billion to $10.9 billion in 2021, compared with previous guidance of $10.6 billion to $10.8 billion. It also expects adjusted EPS of $18.85 to $19.35, compared with previous guidance of $17.50 to $19.00. Biogen's stock is up 9.5% for the year, while the broader S&P 500 /zigman2/quotes/210599714/realtime SPX -2.27% is up 20.3%.