Neuren edges closer to EU approval as CHMP backs DAYBU for Rett syndrome

About Neuren Pharmaceuticals Ltd

Neuren Pharmaceuticals Limited (ASX: NEU) is an Australian biotechnology company headquartered in Hawthorn East, Victoria, focused on developing drug therapies for serious neurological disorders caused by genetic abnormalities or brain injury where no or limited approved treatment options exist. Neuren’s therapies target the critical role of insulin-like growth factor 1 (IGF-1) in the brain, using orally administered analogs of naturally occurring peptides. The company has granted an exclusive worldwide licence to Acadia Pharmaceuticals Inc. (Nasdaq: ACAD) for the development and commercialisation of trofinetide. Under that arrangement, Neuren earns royalties on net sales on a tiered basis together with commercial and geographic milestone payments, without bearing the direct costs of marketing or distribution. DAYBUE (trofinetide) oral solution is approved by the US Food and Drug Administration, Health Canada and the Ministry of Health in Israel. DAYBUE STIX, a powder formulation, received FDA approval in December 2025 and launched broadly in the United States in early 2026.

The CHMP recommendation

The positive opinion from the CHMP, EMA’s scientific committee responsible for evaluating medicines for human use, recommends the granting of a marketing authorisation for DAYBU for the treatment of neurobehavioral symptoms of Rett syndrome in adults and paediatric patients aged five years and older. The opinion came through a re-examination procedure, meaning Acadia had previously requested a review of an earlier CHMP position, and the committee’s reconsidered view is now favourable. Following the CHMP recommendation, the European Commission will review the opinion and is expected to issue a final decision in the coming months. If approved, the marketing authorisation would cover all 27 EU member states, as well as Iceland, Liechtenstein and Norway.

About Rett syndrome

Rett syndrome is a rare and complex neurodevelopmental disorder occurring in approximately one in every 10,000 to 15,000 female births worldwide. Children with Rett syndrome typically develop apparently normally until six to 18 months of age, when skills begin to stagnate. A regression phase follows in which communication skills and purposeful hand use are lost, followed by a plateau period in which mild recovery in cognitive interest may occur, though body movements remain severely diminished. As individuals age, a stage of motor deterioration can persist for the rest of the patient’s life. The condition is typically caused by a genetic mutation on the MECP2 gene, which is thought to impair synaptic communication and brain plasticity. Symptoms include characteristic hand stereotypies such as hand wringing and clapping, as well as gait abnormalities. Most individuals living with Rett syndrome survive into adulthood and require intensive round-the-clock care.

Commercial backdrop and financial terms

Trofinetide has established meaningful commercial traction in the United States since its FDA approval in March 2023. DAYBUE net sales reached US$177.2 million in calendar year 2023, grew to US$348.4 million in 2024 and US$391 million in 2025. In the first quarter of 2026, DAYBUE net sales reached US$101 million, up 20% on the prior corresponding period, with Acadia guiding for full-year 2026 DAYBUE sales of US$460 million to US$490 million. Neuren’s royalty income from DAYBUE was approximately $65 million in 2025 and is expected to be between $70 million and $77 million in 2026, representing growth of 8% to 18%.

Under the licence agreement for Europe specifically, Neuren is entitled to receive US$35 million following first commercial sale in the EU, sales milestone payments of up to US$170 million on achievement of escalating annual net sales thresholds, and tiered royalties from mid-teens to low-20s per cent of net sales. The European market represents a substantial new addressable opportunity for trofinetide, given there is currently no approved treatment for the indication in the region.

Pipeline context

Beyond trofinetide, Neuren’s second drug candidate, NNZ-2591, is in clinical development as an oral solution for multiple neurodevelopmental disorders. Phase 2 clinical trials have produced positive results in Phelan-McDermid syndrome, Pitt Hopkins syndrome and Angelman syndrome, and each of these programs has received orphan drug designation in both the United States and the European Union, as well as Fast Track and Rare Paediatric Disease designations from the FDA. Neuren is currently conducting the Koala Phase 3 trial, a randomised double-blind, placebo-controlled study evaluating NNZ-2591 in children aged three to 12 years with Phelan-McDermid syndrome, alongside a 52-week open-label extension. The company is also developing NNZ-2591 for hypoxic ischaemic encephalopathy, a serious brain injury condition occurring before or shortly after birth. A strong cash position of approximately $310 million supports the pipeline without the need for equity dilution.

Conclusion

The CHMP recommendation represents the most significant milestone in Neuren’s European strategy since its global licence agreement with Acadia, and positions the company to receive its first EU commercial trigger payment upon approval and first sale. With a growing royalty stream from the United States, a new powder formulation gaining traction, potential Japanese approval in the near term and a Phase 3 pipeline anchored by NNZ-2591, the near-term trajectory will depend on the timing and scope of the European Commission’s final decision and the subsequent pace of commercialisation across EU markets.