OUR PURPOSE PIONEERING SCIENCE PATIENTS OUR PEOPLE ENVIRONMENT COMMUNITY REPORTING 11 BIOGEN 2021 YEAR IN REVIEW Our purpose and business performance Biogen’s purpose is to serve humanity through science so that people can live healthier, fuller lives. Our cutting-edge approach aims to fundamentally change how we attack neurological disease since we believe that true leadership in neuroscience requires a pioneering spirit and a fearless commitment. Since our founding in 1978, Biogen has embraced this mindset to deliver breakthrough innovations in some of the world’s most intractable neurological diseases, including multiple sclerosis, spinal muscular atrophy, Alzheimer’s disease and more. Today, our growing global footprint serves millions of people around the world, and we are innovating to transform patient care. As we look to the future, we see an opportunity to go beyond treating a disease to preventing it. We believe that to do this successfully we must wield our deep knowledge of disease mechanisms and therapeutic strategies, while growing our multi-target, multi-modality approach and leveraging big data and technology. We are progressing a diverse neuroscience pipeline, leveraging the interconnectivity between diseases in our existing portfolio like with new areas such as Parkinson’s disease, ALS and depression. 40 direct Affiliates and growing +40 additional countries addressed through distribution partners 17 geographies added in the last three years WE CONTINUE TO EXPAND OUR GLOBAL FOOTPRINT 1 Multiple sclerosis myelinated axons. 1. As of December 31, 2021. Our people are the backbone of our organization. Together, we’re collaborating at the frontiers of science, healthcare and digital medicine to forge a future that redefines what’s possible for Biogen and the millions of patients we serve. At Biogen, we go where others won’t. True to our purpose and mission, we are continuing to advance breakthrough science that addresses significant unmet needs. As we advance our multi- franchise portfolio, we are excited by the possibility of bringing new treatment options to people in need.