ACADIA Pharmaceuticals(US:ACAD) ZACKS·2026-03-04 14:05Core Viewpoint - Acadia Pharmaceuticals faces a regulatory setback as the European Medicines Agency's CHMP has issued a negative opinion against the approval of trofinetide for treating Rett syndrome in the EU [1][6]. Regulatory Developments - The negative opinion from CHMP was anticipated following an early February notification of a negative trend vote on the marketing application for trofinetide [2]. - Acadia plans to request a re-examination of the CHMP's decision after reviewing the grounds for refusal [2][6]. Clinical Study Insights - The pivotal LAVENDER study met its co-primary and key secondary endpoints; however, CHMP cited limitations such as the modest treatment effect after 12 weeks and incomplete capture of core symptoms of Rett syndrome [3][6]. - Concerns were raised regarding the assessment of long-term outcomes due to patient discontinuations over time [3]. Market Context - Rett syndrome is a rare neurodevelopmental disorder affecting approximately one in 10,000-15,000 female births globally [4]. - The FDA approved trofinetide as the first and only treatment for Rett syndrome in the U.S. in 2023, marketed as Daybue [5]. Financial Outlook - Despite the regulatory hurdle, Acadia is positioned for long-term growth, expecting combined net sales of around $1.7 billion by 2028, with $1 billion from Nuplazid and $700 million from Daybue [7]. - Nuplazid, the first FDA-approved treatment for hallucinations and delusions associated with Parkinson's disease psychosis, recorded $680.1 million in sales in 2025, reflecting a 12% year-over-year increase [8]. - Daybue has also shown promising sales uptake, with $391.4 million in sales in 2025, marking a 12% year-over-year growth [9]. Product Developments - The FDA approved Daybue Stix, a new formulation of trofinetide, for oral solution in late 2025, expanding the Daybue franchise [10]. - Acadia plans a limited launch of Daybue Stix in Q1 2026, with broader availability expected in Q2 [11][13].