ACADIA Pharmaceuticals Inc. - Amendment to Schedule 13D Filing

This filing is an amendment to a Schedule 13D filed by Baker Bros. Advisors LP and related entities. The amendment supplements information regarding beneficial ownership of ACADIA Pharmaceuticals Inc. common stock. As of February 26, 2026, Baker Bros. Advisors LP holds 43,151,054 shares, representing 25.3% of the class. The filing details holdings by various funds managed by the Adviser, including direct holdings of common stock and prefunded warrants. It also outlines compensation arrangements for directors Julian C. Baker and Dr. Stephen R. Biggar, involving stock options and RSUs. A new Registration Rights Agreement was entered into on February 24, 2026, granting the Funds resale registration rights for certain securities.