Neuren Pharmaceuticals (ASX: NEU) is developing new therapies for highly debilitating neurodevelopmental disorders that emerge in early childhood and are characterised by impaired connections and signalling between brain cells.
Neuren's lead product trofinetide (also known as NNZ-2566) is licensed to Acadia Pharmaceuticals for North America, with Neuren retaining all rights outside North America and full access to all data generated by Acadia. In December 2021, Acadia announced positive top-line results from a Phase 3 trial in Rett syndrome and plans to submit a New Drug Application to the US Food and Drug Administration (FDA) in mid-2022. Neuren previously conducted double-blind placebo-controlled Phase 2 trials in Rett syndrome and Fragile X syndrome, which demonstrated clinical benefit from treatment with trofinetide.
Under the Licence Agreement with Acadia, Neuren is eligible to receive development and commercial milestone payments of up to US$455 million, plus escalating, tiered double-digit percentage royalties on net sales in North America, plus one third of the value of a Rare Pediatric Disease Priority Review Voucher if awarded to Acadia on marketing authorisation. If trofinetide is approved and launched in the US, in 2022 and 2023 Neuren expects to receive from Acadia A$111 million plus royalties on net sales.
Neuren's second product NNZ-2591 has shown positive effects in mouse models of Phelan-McDermid syndrome, Angelman syndrome, Pitt Hopkins syndrome and Prader-Willi syndrome. Neuren has completed a Phase 1 clinical trial and is preparing to initiate Phase 2 trials in all four of these disorders. The target number of patients across these four disorders is estimated as five times the number of Rett syndrome patients.
Currently there are no drugs approved for these conditions, apart from growth hormone to treat some aspects of Prader-Willi syndrome. Some drugs that are approved for other indications are also used to treat selected symptoms, but none are more than modestly effective and none are disease-modifying. Trofinetide and NNZ-2591 provide an opportunity potentially to be the first approved therapy for one or more of these important indications.
Because these are serious medical conditions with unmet need, drugs being developed to treat them may qualify for favourable regulatory pathways intended to expedite the development and approval of therapeutically important drugs. The FDA has granted Fast Track designation for trofinetide in Rett syndrome and Fragile X syndrome. Fast Track designation provides for early and frequent communication with the FDA, ensuring that questions and issues are resolved quickly to minimise any potential impact on the progress of development. The FDA and the European Medicines Agency (EMA) have both granted orphan drug designation for trofinetide in Rett and Fragile X syndromes and for NNZ-2591 in each of Phelan-McDermid, Angelman and Pitt Hopkins syndromes. The FDA has also granted orphan drug designation for Prader-Willi syndrome. Orphan drug designation is a special status that the regulatory authorities may grant to a drug to treat a rare disease or condition. Orphan drug designation qualifies the sponsor of the drug for seven years of marketing exclusivity in the United States and ten years in the Europe Union following approval, as well as other development incentives.
Trofinetide and NNZ-2591 are covered by issued patents, with additional patent applications pending. All patents are owned by Neuren and no royalties are payable to third parties.