OUR PURPOSE PIONEERING SCIENCE 131 SASB CONTENT INDEX BIOGEN 2021 YEAR IN REVIEW PATIENTS OUR PEOPLE ENVIRONMENT COMMUNITY REPORTING Code Accounting Metric Biogen 2021 Response Employee Recruitment, Development & Retention HC-BP-330a.1. Discussion of talent recruitment and retention efforts for scientists and research and development personnel Biogen has a range of active initiatives to help build a diverse talent pipeline. For example, the Biogen Community Lab is the longest-running hands-on corporate science education program in the U.S., and now reaches students in more than 19 countries. Collaborations with Massachusetts General Hospital and Duke University are giving the next generation in-depth exposure to the field of neurology. Through a collaboration with Morehouse School of Medicine, we welcomed intern cohorts from historically Black colleges and universities (HBCUs) through our Summer Health Equity Fellowship Program. The fellowship program, which engages M.D. and Ph.D. students, aims to advance health equity and improve patient experiences. In 2021, we increased overall participation from 5 to 18 interns, falling just shy of our goal to increase participation by 300% from our 2020 number. In 2016, Biogen helped create The Partnership Inc.’s BioDiversity Fellows Program, which nurtures the potential leadership of mid-career professionals who are underrepresented in the life sciences industry. In Latin America, the Biogen Intercontinental Region (BIR) developed FemSTEM, a campaign to empower girls and women to pursue a path in STEM. The campaign includes a podcast series and opportunities for participants to engage via Women in Bio, U.N. Women and NS Innovation in South America. Biogen employees volunteer in Women in Bio. We remain actively involved in a wide variety of industry programs that allow us to increase the visibility of Biogen as a purpose-driven company with a wide variety of career opportunities and a culture focused on helping employees thrive. We have a particular focus on increasing visibility and engagement with communities historically underrepresented and underserved in neuroscience, including through our engagement with groups such as Women of Color in Pharma (WOCIP) and American Women in Science (AWIS), among many others. We also have continued to expand our focus on talent retention, growth and engagement through programs such as Thrive@Biogen. A broader discussion of those efforts can be found in the Our People section of the 2021 Year in Review. HC-BP-330a.2. (1) Voluntary and (2) involuntary turnover rate for: (a) executives/senior managers, (b) mid-level managers, (c) professionals, and (d) all others Total Turnover Rate: 14% Voluntary Turnover Rate: 11% Involuntary Turnover Rate: 3% Please see disclosures in Biogen’s 2021 ESG Data Table . Supply Chain Management HC-BP-430a.1. Percentage of (1) entity’s facilities and (2) Tier I suppliers’ facilities participating in the Rx-360 International Pharmaceutical Supply Chain Consortium audit program or equivalent third- party audit programs for integrity of supply chain and ingredients Biogen outsources anywhere from 10% to 15% of our external supplier audits. We perform the vast majority of our audits through our own audit program using outsourced support or the use of third-party auditors depending on the type of service provided, risk and availability. Business Ethics HC-BP-510a.1. Total amount of monetary losses as a result of legal proceedings associated with corruption and bribery Biogen did not sustain any monetary losses in 2021 as a result of legal proceedings associated with corruption, bribery or anti-competitive behaviors. Biogen discloses all material legal and regulatory proceedings in its Annual Report and Quarterly Reports on Form 10-Q . HC-BP-510a.2. Description of code of ethics governing interactions with healthcare professionals We comply with the Pharmaceutical Research and Manufacturers of America’s (PhRMA) Code on Interactions with Healthcare Professionals. See our Code of Business Conduct section on Interactions with Healthcare Professionals. Activity Metrics HC-BP-000.A Number of patients treated Biogen has treated more than 2 million patients worldwide from 1996 through the end of 2021. Additionally, we have approximately 30 clinical programs across a broad set of disease areas. HC-BP-000.B Number of drugs (1) in portfolio and (2) in research and development (Phases 1–3) As of report publication, Biogen has 10 marketed therapies, as outlined on the Product Portfolio page of Biogen.com and approximately 30 therapies in the pipeline.