• Biogen average gross margin for 2023 was 76.17%, a 1.73% decline from 2022.
• Biogen average gross margin for 2022 was 77.51%, a 6.83% decline from 2021.
• Biogen average gross margin for 2021 was 83.19%, a 4.84% decline from 2020.

Gross margin can be defined as a company's total sales revenue minus its cost of goods sold, divided by the total sales revenue, expressed as a percentage.