01—Abstract
Summary
Summary of the 8-K filed December 3, 2025. Cited figures are marked; the original filing is the authoritative source.
Alnylam Pharmaceuticals (ALNY) disclosed in an 8-K filed December 3, 2025 that two directors, Michael W.
Bonney and Carolyn Bertozzi, Ph.D., resigned from the Board effective December 2, 2025. Neither resignation involved a disagreement with the company. The Board reduced its size from eleven to ten seats and elected Stuart A.
Arbuckle as a non-employee Class I director, effective January 5, 2026. Mr. Arbuckle is a former Vertex Executive Vice President and Chief Operating Officer, bringing commercial and operational experience from the company's perspective of scaling its business. For investors, the filing is primarily a governance update rather than a financial event, and no financial results or guidance are disclosed.
Dr. Bertozzi's departure is attributed in the press release to her recent election to the board of Eli Lilly (effective December 8, 2025), and she will remain a scientific advisor to Alnylam. Mr. Bonney, a long-tenured director and former Board Chair and Executive Chair, was in a Class I seat due to expire at the 2026 annual meeting, so his exit removes a historically influential voice from the Board.
Mr. Arbuckle's compensation package is standard for a non-employee director: a $75,000a annual cash retainer, a one-time stock option grant with a $600,000 Black-Scholes grant-date fair value vesting over three years, and eligibility for the regular annual equity award (currently $200,000 in RSUs and $200,000 in options). The company frames the changes as supporting its "Alnylam P5x25" strategy and its evolution toward a multi-product biotechnology company, but the filing itself offers no quantitative financial impact.
02—Key points
Key Highlights
- Michael W. Bonney (former Board Chair and Executive Chair) and Carolyn Bertozzi, Ph.D. resigned from the Board effective December 2, 2025, with no disagreement cited.
- Board size reduced from eleven to ten directors following the two resignations.
- Stuart A. Arbuckle, former Vertex EVP and COO, elected as a non-employee Class I director, effective January 5, 2026, serving until the 2026 annual meeting.
- Arbuckle's compensation: $75,000 annual cash retainer, a one-time option grant with $600,000 grant-date fair value vesting over three years, plus eligibility for standard annual director equity awards.
- Dr. Bertozzi's resignation follows her election to the Eli Lilly board (effective December 8, 2025); she will remain a scientific advisor to Alnylam.
- The Mr. Bonney's Class I seat was due to expire at the 2026 annual meeting, so his departure also affects that upcoming board cycle.
- The filing reports no financial results, guidance, or quantified financial impact; the Exhibit 99.1 press release is furnished, not filed.
03—Questions
Frequently Asked Questions
Why did Michael Bonney and Carolyn Bertozzi leave the Alnylam Board?
The filing states that neither resignation was caused by any disagreement with the company on operations, policies, or practices. The press release notes Dr. Bertozzi's decision followed her recent election to the Eli Lilly board, effective December 8, 2025. The company did not give a specific reason for Mr. Bonney's departure.
Who is Stuart Arbuckle and when does he join the Board?
Stuart A. Arbuckle is a former Executive Vice President and Chief Operating Officer at Vertex, where he spent about 13 years overseeing global commercial operations, HR, communications, and portfolio management. He also has experience at GSK and Amgen and currently sits on the board of Rhythm Pharmaceuticals. He joins Alnylam's Board effective January 5, 2026, as a Class I director.
How is Mr. Arbuckle compensated as a director?
He receives a $75,000 annual cash retainer, plus a stock option grant on his first day of service with a $600,000 grant-date fair value vesting in thirds over three years. He is also eligible for the standard annual equity award, currently $200,000 in restricted stock units and $200,000 in options vesting after one year, with the amount for his first annual award to be set by the Board. The company will also reimburse his travel and related expenses.
Does this board change have a material financial impact on Alnylam?
The filing does not disclose any financial results, guidance, or quantified financial effects. The changes are governance-related, and the company characterizes them as supporting its ongoing strategic evolution and pipeline expansion.
Will Dr. Bertozzi retain any relationship with Alnylam?
Yes. According to the press release, Dr. Bertozzi will continue to serve as a scientific advisor to Alnylam after leaving the Board.
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