OUR PURPOSE PIONEERING SCIENCE PATIENTS OUR PEOPLE ENVIRONMENT COMMUNITY REPORTING 29 ENHANCING OUR STRATEGIC PORTFOLIO BIOGEN 2021 YEAR IN REVIEW FEATURE Biogen experts work to unlock the mysteries of the brain Of the body’s many organs, none holds more secrets than the brain. Weighing just 1.3 kilograms (three pounds), it is the command center for the entire body and a mystery that has captivated and confounded generations of scientists. “There’s been an exponential gain in our understanding of the brain itself, and we have also been learning about diseases like ALS, which has always been recognized as a huge clinical challenge, a dreadful disease and a tough one to take on in developing treatments,” said Chris Henderson, Ph.D., Head of Research at Biogen. Scientists have been working on ALS for decades, but it is only in recent years that we have been able to understand some of the triggers and complexities within the brain. We are committed to discovering effective treatments across neuroscience as scientists begin to overcome some of the obstacles that previously blocked progress in drug discovery. One such obstacle is literally a barrier: the blood-brain barrier, a physical boundary surrounding the brain’s blood vessels that only lets certain tiny molecules into the brain and keeps out most others. With the ability to administer therapies into the spinal fluid, allowing the drug to go directly to the brain, antisense oligonucleotides (ASOs) have made a tremendous impact in the field. Sequencing of the human genome has also helped researchers uncover specific mutations that trigger a disease. This is how Biogen developed the first approved treatment for SMA. Another big step forward has been the use of advanced imaging technologies to identify biomarkers, which allow researchers and clinicians to see whether a drug is reaching its target and to get early indications if the drug is modifying disease progression. Over time, seemingly insurmountable challenges in brain research may become attainable. Biogen remains focused, investing in research that seeks to prevent or treat brain diseases once considered too difficult, too unpredictable or too risky to tackle. Þ READ THE FULL ARTICLE, UNLOCKING THE MYSTERIES OF THE BRAIN Kate Dawson, M.D., Head of Biogen’s Therapeutics Development Unit, and Chris Henderson, Ph.D., Head of Research. When I was training in neurology, we did not have any therapies for ALS and we focused on improving quality of life. Now there are treatments to help maintain function and improve quality of life for people with ALS, yet significant unmet needs remain. Our goal at Biogen is to meaningfully affect the disease itself.” Kate Dawson M.D., Head of Biogen’s Therapeutics Development Unit