X Ainyiam Corporate Responsibility Report 2024 2Alnyian CHALLENGE ACCEPTED RNAi believe in being a forcefor good in theworld.

Corporate Responsibility Report 2024 Introduction Patients Science Employees Communities Planet Governance Data lifecanvas gles Table of Contents HDaCIen <thead> <th>03 |</th> <th>CEO Message</th> </thead> <tbody> <td>05 |</td> <td>About Alnylam</td> <td>07 |</td> <td>2024 Highlights</td> <td>08 |</td> <td>Corporate Responsibility at Alnylam</td> <td>14 |</td> <td>Patients</td> <td>25 |</td> <td>Science</td> <td>38 |</td> <td>Employees</td> <td>53 |</td> <td>Communities</td> <td>63 |</td> <td>Planet</td> <td>73 |</td> <td>Governance</td> <td>85 |</td> <td>Data Summary</td> </tbody> stol. S7 Catalina, patient (Spain) Catalina, patient (Spain) On the cover, left: Tsuyoshi, patient and his wife Rika (Japan)

Corporate Responsibility Report 2024 Introduction Patients Science Employees Communities Planet Governance Data CEO Letter A Pivotal Year at Alnylam Transforming Lives Through Innovation In our quest to realize the tremendous potential of RNAi therapeutics, This year was highlighted by the overwhelmingly positive data from 2024 was a pivotal year. We emerged as a top-tier biotechnology the landmark HELIOS-B study of vutrisiran for patients with ATTR company, with a flagship franchise, a spring-loaded pipeline, a strong amyloidosis with cardiomyopathy. The study demonstrated financial foundation, and a culture alive with purpose and innovation. a substantial impact in reducing mortality and improving quality Before us lies a profound opportunity: to reshape the future of of life, and we are thrilled with what these results mean for patients, medicine and impact the lives of millions of patients. physicians, families, and caregivers. We made equally strong progress At this transformational moment, we remain steadfast in our belief that making history means advancing groundbreaking science while shaping a healthier, more equitable, and sustainable future for all. In our 2024 Corporate Responsibility Report, Alnylam’s ‘Challenge Accepted’ ethos is showcased in the unwavering efforts of teams across the business to increase the value we deliver to society.

ncing groundbreaking science while shaping a healthier, more equitable, and sustainable future for all. In our 2024 Corporate Responsibility Report, Alnylam’s ‘Challenge Accepted’ ethos is showcased in the unwavering efforts of teams across the business to increase the value we deliver to society. in advancing potentially transformative medicines to treat a broad range of both rare and prevalent diseases. At Alnylam, we believe we are responsible for ensuring the patients who can benefit from our medicines have access to them. No patient should have to wait for hope. Our Patient Access Philosophy continues to guide us, holding us accountable for ensuring that access and outcomes align with the value our therapies bring to patients.

Corporate Responsibility Report 2024 Introduction Patients Science Employees Communities Planet Governance Data Investing in Our People and Culture Mitigating Our Environmental Impact Our people are the driving force behind Alnylam’s RNAi leadership. We continuously seek to minimize our impact on the environment Grounded by our Core Values, we continue to be a beacon for talent and work to address the growing threat of climate change. Our Together, we have been on through a focus on great science, a diverse and inclusive culture, increasing ability to gather robust data and track energy and and upholding the highest professional and ethical standards. natural resource usage enables us to activate new strategies to a 23-year quest to realize the While we are honored to receive many ‘Best Places to Work’ awards, we are most proud of the high marks from our own people. In our annual culture survey, 80% of employees recommend Alnylam as a great place to work, and 88% feel that they are accepted and treated fairly by the company and their peers. In this report, you will see stories of our growing Employee Resource Networks (ERNs), expansion of benefit programs, and efforts to recruit and develop top performers that underpin these results.

place to work, and 88% feel that they are accepted and treated fairly by the company and their peers. In this report, you will see stories of our growing Employee Resource Networks (ERNs), expansion of benefit programs, and efforts to recruit and develop top performers that underpin these results. protect the planet and respond to regulatory requirements. This year we achieved a significant milestone in efforts to manage our extraordinary promise of RNAi. carbon footprint with third-party verification of our Scope 1, 2, This year was one of great and 3 greenhouse gas (GHG) emissions. In addition, our Alewife and Norton manufacturing facilities are now 100% powered by achievements in that journey.” renewable energy. The moment in front of us is more promising than any before and the opportunities more extraordinary. We are just getting started and believe that the best is yet to come. Addressing Health Inequalities The passion to improve human health is the driver of our community impact work. Our signature program, Alnylam Sincerely, Challengers, seeks to improve health outcomes by rallying behind bold leaders and organizations increasing access to personalized Yvonne Greenstreet, MD, MBA care and support services for under-resourced communities.