NNZ-2591
NNZ-2591 is an investigational oral analog of cyclic glycine-proline studied in genetic neurodevelopmental disorders. Favorable open-label changes require placebo-controlled confirmation.
Quick Facts
A cyclic glycine-proline analog
Neuren Pharmaceuticals developed NNZ-2591 from cyclic glycine-proline, a naturally occurring IGF-1 breakdown product. The oral candidate has been studied in Phelan–McDermid, Rett, Angelman and Pitt–Hopkins syndromes, which are distinct conditions rather than one interchangeable indication.
IGF-1-related signaling
The proposed action is modulation of the IGF-1 system, including normalization of available IGF-1 to support formation and function of neural connections. That provides a developmental-circuit rationale; an IGF-1 hypothesis is not a clinical benefit by itself.
Supporting references: IGF-1 signaling.
Sources: [1]
Open-label Phase 2 findings
An indexed single-group study in children and adolescents with Phelan–McDermid syndrome described general tolerability and improvement from baseline on most efficacy measures over 13 weeks. Without a placebo group, natural variation and expectation cannot be separated from a treatment effect. Rett, Angelman and Pitt–Hopkins findings have mainly appeared through company announcements, with the same need to distinguish reporting and study design.
Supporting references: DOI: 10.1212/NXG.0000000000200405.
Sources: [2]
Confirmatory development
NNZ-2591 remains unapproved. Phase 2 studies have completed in several indications and a placebo-controlled Phase 3 Phelan–McDermid trial is enrolling. That study is intended to establish whether the promising early signal reflects efficacy; enrollment is not a positive result or approval.
References and further reading
This reference draws on Superpower’s Peptide Library and the research linked below. Peptide Dossier’s editorial team adapted and integrated the material on .
- 10.1212/NXG.0000000000200338IGF-1-related signalingCited in: IGF-1-related signaling
- 10.1212/NXG.0000000000200405Open-label Phase 2 findingsCited in: Open-label Phase 2 findings
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Disclaimer: This article is for informational and educational purposes only. It is not intended as medical advice. The information presented is based on published research and should not be used as a substitute for professional medical guidance. Always consult a qualified healthcare provider before starting any peptide protocol. Some peptides discussed may not be approved for human use by the FDA or equivalent regulatory bodies.