On September 26, 2023, Marsha H. Fanucci informed the Board of Directors of Alnylam Pharmaceuticals, Inc. of her resignation from the Board effective as of September 29, 2023. Upon the effectiveness of Ms. Fanucci?s resignation, Peter N. Kellogg will become the Chair of the Audit Committee of the Board. The Board has determined that Mr. Kellogg qualifies as an ?audit committee financial expert?

as such term is defined in Item 407(d)(5) of Regulation S-K. In addition, on September 27, 2023, following the recommendation of its Nominating and Corporate Governance Committee, the Board approved a reduction in the size of the Board from thirteen to twelve members effective upon Ms. Fanucci?s resignation.