Highlights

  • ACAD receives negative trend vote from EMA’s CHMP on trofinetide for Rett syndrome.
  • Company plans to request re-examination of CHMP opinion under EU regulatory rules.
  • Trofinetide already approved in the US, Canada, and Israel, with over 1,000 patients treated.

Acadia Pharmaceuticals Inc. (NASDAQ:ACAD) reported that the European Medicines Agency’s (EMA) Committee for Medicinal Products for Human Use (CHMP) indicated a negative trend vote on its Marketing Authorization Application (MAA) for trofinetide, intended for the treatment of Rett syndrome. The feedback follows the recent CHMP oral explanation.

The outcome of the CHMP vote is expected in February. Subject to the formal adoption of the opinion, Acadia intends to submit a request for re-examination. EU legislation allows applicants 15 calendar days to request a re-examination and 60 calendar days to provide supporting grounds, after which the CHMP has up to 60 days to review the submission.

Trofinetide Treatment Background
Trofinetide is a synthetic analog of the N-terminal tripeptide of insulin-like growth factor. Its therapeutic mechanism in Rett syndrome patients is not fully understood. Preclinical studies indicate that trofinetide may enhance dendritic branching and synaptic plasticity signals.

Trofinetide is approved for Rett syndrome treatment in the US, Canada, and Israel. Globally, more than 1,000 patients are actively receiving the therapy, spanning from newly diagnosed children to adults. Real-world data continues to reflect outcomes observed in clinical trials across various age groups.

Understanding Rett Syndrome
Rett syndrome is a rare neurodevelopmental disorder, affecting approximately one in 10,000–15,000 female births globally. Children generally show normal development until 6–18 months, followed by a regression phase where acquired skills, such as communication and purposeful hand use, are lost. Patients may enter a plateau stage with mild cognitive recovery, but motor skills often remain impaired.

Symptoms include hand stereotypies, gait abnormalities, and long-term motor deterioration. Most affected individuals live into adulthood and require ongoing intensive care.

Stock Performance
ACAD shares closed at USD 26.13, up 3.98% as of February 2, 2026.