Acadia Pharmaceuticals Inc. announced that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) informed the company it has formally adopted a negative opinion regarding the Marketing Authorization Application for trofinetide for the treatment of Rett syndrome in patients two years of age and older. Acadia has reviewed the CHMP grounds for refusal in detail and intends to request a re-examination of the opinion.

While the pivotal LAVENDER^TM trial successfully met its co-primary and key secondary endpoints, the CHMP issued a refusal based on perceived deficits including: the treatment effect observed with trofinetide after 12 weeks, while measurable, was viewed as limited in magnitude; the study did not capture all core symptoms of Rett syndrome; and that assessment of longer‑term outcomes was influenced by patient discontinuations over time. Acadia believes this feedback provides important information as it considers the intended re-examination.

“While we are disappointed by the CHMP’s recommendation to refuse approval, we continue to be encouraged by the meaningful benefits trofinetide has demonstrated for people living with Rett syndrome,” said Catherine Owen Adams, Acadia’s Chief Executive Officer. “The strong engagement and positive feedback we have seen from patients, caregivers, and clinicians in the Rett community reinforce our belief in the treatment’s clinical value. We remain committed to working constructively with EU regulators to explore next steps and to bring this therapy to patients.”

“Our family and others who play an important role in the delivery of care know first-hand the challenges that individuals living with Rett syndrome face every day,” said Markus Schulze, caregiver and member of the Rett Syndrome Society Nordrhein-Westfalen from Germany. “It is our hope that this important therapy will be approved to help the EU Rett community better navigate life with Rett syndrome.”

Trofinetide is approved in the United States, Canada and Israel, where it represents the first and only treatment approved for Rett syndrome.