Neuren Pharmaceuticals (ASX:NEU) has announced a US Notice of Allowance covering weight-banded dosing of trofinetide, marketed as DAYBUE for Rett syndrome. Once issued and including paediatric exclusivity, the Patent is expected to extend protection to 28 March 2041.

What did Neuren announce?

Neuren said the USPTO has issued a Notice of Allowance for US patent application No. 17/590,496, titled "Methods and Compositions for Treatment of Rett Syndrome". The patent covers weight-banded dosing of trofinetide.

Once issued, and including six months of pediatric exclusivity, the patent is expected to provide protection until 28 March 2041. That is nearly five years beyond the existing method-of-use patent, which expires in July 2036.

Trofinetide is sold in the United States as DAYBUE and DAYBUE STIX. The US Food and Drug Administration (FDA) has approved it for Rett syndrome in adults and paediatric patients aged two years and older.

The announcement relates to news first released by Neuren's partner, Acadia Pharmaceuticals (Nasdaq: ACAD), which holds the exclusive worldwide licence to trofinetide. Acadia's release is dated 28 September 2026 (US time). Acadia chief executive Catherine Owen Adams described the Notice of Allowance as "an important addition to the intellectual property protections for trofinetide".

Acadia's release said issuance of the patent is still pending completion of standard administrative steps. In other words, the extended term is expected rather than final.

Why could this announcement matter?

Intellectual property is central to the Economics of a specialty medicine. A later patent expiry date can extend the period in which a product is protected in its largest market, though it does not by itself change sales, pricing or clinical outcomes.

For Neuren, trofinetide is a key commercial asset developed in-house and licensed to Acadia. The company describes its focus as neurological disorders, with orally administered analogues of naturally occurring peptides related to insulin-like growth Factor 1 (IGF-1) in the brain.

The new allowance relates specifically to weight-banded dosing, which is how the therapy is administered. That detail may be relevant to how the protection is described, because it covers a specific dosing regimen rather than the underlying compound.

The announcement is an analysis point rather than a financial forecast.

What should investors watch next?

Investors may be watching for several developments:

  • Formal issuance of the patent by the USPTO and confirmation of the final expiry date.
  • Any further disclosure from Neuren or Acadia on how the patent fits within the wider trofinetide patent estate.
  • Acadia's ongoing reporting on DAYBUE and DAYBUE STIX, which the market may track for Demand signals.
  • Neuren's other pipeline programs and any updates on the regulatory pathway for trofinetide outside the United States.

As always, patent allowances can be challenged or narrowed in some circumstances, and issued terms depend on the completion of administrative steps.