Key Highlights

  • The European Commission has granted Marketing authorisation for DAYBU (trofinetide) for the treatment of neurobehavioral symptoms of Rett syndrome in adults and pediatric patients aged five years and older.
  • DAYBU is the first and only treatment approved for Rett syndrome in the European Union, and is now authorised for marketing across all 27 EU member states plus Iceland, Liechtenstein and Norway.
  • Under its licence agreement with Acadia Pharmaceuticals, Neuren is entitled to receive US$35 million following first commercial sale in Europe, plus potential sales milestone payments of up to US$170 million and tiered royalties from mid-teens to low-20s percent of net sales.
  • Commercial launch of DAYBU in Germany is anticipated in early Q4 2026, with trofinetide not currently approved for sale in Australia.

Neuren Pharmaceuticals Limited (ASX:NEU) has announced that its exclusive global licensee for trofinetide, Acadia Pharmaceuticals (Nasdaq: ACAD), has received marketing authorisation from the European Commission for DAYBU (trofinetide) for the treatment of neurobehavioral symptoms of Rett syndrome in adults and pediatric patients aged five years and older. The approval makes DAYBU the first and only treatment authorised for Rett syndrome within the European Union, with marketing now permitted across all 27 EU member states as well as Iceland, Liechtenstein and Norway. Shares in Neuren traded at $22.39 on the ASX at the time of the announcement, up 0.27 percent on the day.

Commercial Launch Timing

Acadia has previously indicated that the commercial launch of DAYBU in Germany is anticipated in early Q4 2026, marking the first market entry for the product following the European approval. The company noted that trofinetide is not approved for sale in Australia.

Financial Terms Under the Licence Agreement

Under the terms of its licence agreement covering Europe, Neuren is entitled to receive US$35 million following the first commercial sale of DAYBU in the region. The agreement also provides for potential sales milestone payments of up to US$170 million upon the achievement of escalating annual net sales thresholds, along with tiered royalties ranging from the mid-teens to low-20s percent of net sales.

Management Commentary

Neuren CEO Jon Pilcher said the approval was particularly rewarding for the company given its long-standing commitment to developing therapies for serious neurological disorders with profound unmet need, noting that the Rett syndrome community in Europe has, until now, had no approved treatment for the condition. He said Neuren looks forward to seeing its partner Acadia make DAYBU available to Rett syndrome patients and families across Europe.

Existing Regulatory Approvals and Broader Pipeline

DAYBUE (trofinetide) oral solution is already approved by the US Food and Drug Administration, Health Canada and the Ministry of Health in Israel, while DAYBUE STIX (trofinetide) powder is approved by the FDA, both for the treatment of Rett syndrome. Neuren has granted an exclusive worldwide licence to Acadia Pharmaceuticals for the development and commercialisation of trofinetide.

Beyond trofinetide, Neuren's investigative drug candidate NNZ-2591 (ercanetide) is in clinical development as an oral solution treatment for multiple neurodevelopmental disorders, including Phelan-McDermid syndrome, Pitt Hopkins syndrome and Angelman syndrome. Each of these programs has been granted Orphan Drug designation in the United States and the European Union, as well as Fast Track and Rare Pediatric Disease designations from the FDA. The company is also developing NNZ-2591 for the treatment of hypoxic ischemic encephalopathy, a serious condition caused by brain injury before or shortly after birth. Neuren is currently conducting a Phase 3 randomized, double-blind, placebo-controlled clinical trial known as Koala, evaluating the safety and efficacy of NNZ-2591 in children aged 3 to 12 years with Phelan-McDermid syndrome, alongside a 52-week open-label extension study.

Conclusion

Neuren Pharmaceuticals has secured a significant regulatory milestone with the European Commission's approval of DAYBU, extending the availability of trofinetide-based treatment for Rett syndrome beyond the United States, Canada and Israel into all EU member states plus Iceland, Liechtenstein and Norway. The approval activates a further Tranche of milestone payments and Royalty entitlements under the company's licence agreement with Acadia Pharmaceuticals, with commercial Revenue expected to begin following the anticipated German launch in early Q4 2026. Neuren's broader pipeline, centred on NNZ-2591 for a range of neurodevelopmental disorders, continues to progress through clinical development alongside the company's established trofinetide licensing arrangement.