Biogen’s revenue and profits shrank at the tail-end of 2023, according to its latest financials released Tuesday morning.

During the most recent quarter, Biogen’s total revenue slipped 6% to $2.3 billion, while its GAAP diluted earnings per share (EPS) fell 55% to $1.71.

For the full year, the company’s total revenue slid 3% to $9.8 billion while its GAAP diluted EPS tumbled 62% to $7.97.

A major drag on the company was the decline in multiple sclerosis (MS) product revenue. In Q4 2023, MS product revenue dropped 8% to $1.1 billion. For the full year, that segment’s revenue fell 14% to $4.6 billion.

Meanwhile, one of the company’s most promising assets — the Food and Drug Administration-approved Alzheimer’s treatment Leqembi — delivered $7 million in Q4 for in-market product revenue and $10 million for the year.

Eisai, which co-developed the drug with Biogen, said in its latest earnings report that it is likely to miss its patient goal for Leqembi by the end of March 2024.

Biogen’s earnings came two weeks after the company relinquished the controversial Alzheimer’s drug Aduhelm, terminating its development and commercialization efforts in order to support Leqembi.

The announcement marked the end of a tumultuous saga surrounding the drug since it received accelerated approval by the FDA in June 2021. 

A hefty price-tag, concerns around Aduhelm’s safety and efficacy led many health systems to refuse to prescribe as well as a declaration from the Centers for Medicare and Medicaid Services that it would limit coverage of the drug to patients who were participating in clinical trials ultimately spelled its doom.

Outside of its efforts in the Alzheimer’s and dementia treatment space, Biogen’s postpartum depression drug Zurzuvae generated $2 million during the quarter.

Looking ahead to 2024, Biogen expects its total revenue to decline by a low- to mid-single digit percentage while its operating income is projected to grow at a low-double digit percentage. Core pharmaceutical revenue is expected to be relatively flat year-over-year.

Biogen also said it projects a non-GAAP diluted EPS guidance range of $15 to $16, reflecting around 5% growth at the mid-point. 

“2023 was a year of transformation for Biogen as we saw approval for four first-in-class medicines while we realigned our cost structure, remained prudent in allocating shareholder capital, and reprioritized our pipeline,” Biogen CEO Christopher A. Viehbacher said in a statement. “We believe with these key elements in place we are now well positioned to return Biogen to sustainable growth. As we look to 2024, our focus is on operational execution, including building upon the progress of our recent new product launches. We believe this will allow us to continue to advance our goal of a new Biogen that creates enhanced value for patients and our shareholders.”