Neuren Pharmaceuticals’ partner Acadia Pharmaceuticals is seeking a re-examination of the European Medicines Agency’s refusal to approve trofinetide for Rett syndrome, aiming to overturn the setback and bring the treatment to European patients.
- Acadia to request CHMP re-examination of trofinetide’s EU marketing refusal
- CHMP cited limited treatment effect and study design concerns in refusal
- Trofinetide already approved in US, Canada, and Israel for Rett syndrome
- Neuren supports re-examination amid significant unmet need in Europe
- Neuren advancing NNZ-2591 for multiple neurodevelopmental disorders
Background on Trofinetide and Regulatory Setback
Neuren Pharmaceuticals, an ASX-listed biotech focused on neurological disorders, has received a mixed regulatory update from its partner Acadia Pharmaceuticals. Acadia confirmed plans to request a re-examination by the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) following the CHMP’s refusal to approve trofinetide for treating Rett syndrome in patients aged two and older. This decision, while disappointing, was anticipated after a prior trend vote indicated a negative outcome.
Clinical Trial Results and CHMP Concerns
Trofinetide’s pivotal LAVENDER trial met its primary and key secondary endpoints, demonstrating measurable benefits. However, the CHMP’s refusal was based on concerns that the treatment effect was limited in magnitude, the trial did not capture all core Rett syndrome symptoms, and longer-term outcomes were complicated by patient dropouts. These points highlight the challenges of demonstrating clinical benefit in rare and complex neurodevelopmental disorders.
Market Approvals and Patient Perspectives
Despite the European setback, trofinetide is already approved in the United States, Canada, and Israel, where it remains the only treatment authorised for Rett syndrome. Acadia’s CEO Catherine Owen Adams emphasised the meaningful benefits observed and the strong support from patients, caregivers, and clinicians. Caregivers like Markus Schulze from Germany expressed hope that the therapy will eventually gain approval in Europe, reflecting the urgent unmet medical need.
Neuren’s Position and Future Outlook
Neuren’s CEO Jon Pilcher voiced full support for the re-examination process, underscoring the company’s commitment to addressing the substantial and urgent needs of the European Rett community. Beyond trofinetide, Neuren is advancing NNZ-2591, a second drug candidate targeting multiple neurodevelopmental disorders, with promising Phase 2 results and ongoing Phase 3 trials. This pipeline diversification may help mitigate regulatory risks tied to any single product.
Implications for Investors and Patients
The CHMP’s refusal and the planned re-examination introduce uncertainty around European market access for trofinetide, a key growth region. However, the company’s proactive stance and the drug’s existing approvals elsewhere provide a foundation for optimism. Investors will be watching closely for the outcome of the re-examination and any regulatory dialogue that could shape the therapy’s European future.
Bottom Line?
The CHMP re-examination will be a critical test for trofinetide’s European prospects and Neuren’s broader growth strategy.
Questions in the middle?
- What additional data or analyses will Acadia present in the CHMP re-examination?
- How might the CHMP’s concerns influence future trial designs for trofinetide or NNZ-2591?
- What is the anticipated timeline for the CHMP re-examination decision and potential EU approval?