Form 4 Filing for Dennis A. Ausiello

This Form 4 filing details transactions made by Dennis A. Ausiello, a director at ALNYLAM PHARMACEUTICALS, INC. On May 20, 2026, Ausiello acquired 1441 stock options with a right to buy. Additionally, 671 shares of Common Stock were acquired, represented by restricted stock units (RSUs) granted under the company's 2018 Stock Incentive Plan. These RSUs vest in full on the first anniversary of the grant date or upon earlier retirement/resignation under specific conditions. The filing also notes that 3500 shares of Common Stock are held indirectly by a trust, where Ausiello's spouse acts as the trustee. Following these transactions, Ausiello has 1582 shares directly and 3500 shares indirectly held by a trust.