Trofinetide (NNZ-2566)

Trofinetide (NNZ-2566) is a potential therapy for Rett syndrome being developed by Neuren Pharmaceuticals.

Trofinetide is derived from a protein called the human insulin-like growth factor 1 (IGF-1) that naturally occurs in the brain and is required for brain development.

Acadia Pharmaceuticals holds an exclusive license from Neuren to develop and market trofinetide in North America.

Both the U.S. Food and Drug Administration (FDA) and the European Medicines Agency designated trofinetide an orphan drug as a potential Rett syndrome treatment. The FDA also gave trofinetide fast track and rare pediatric designations; all are meant to support treatments for rare diseases and speed their development and review.

How trofinetide works

IGF-1 is an important growth factor that is required for proper brain development. In the brain, IGF-1 is broken down into a protein fragment called glypromate (GPE) consisting of the amino acids glycine-proline-glutamate, which also is referred to as a tri-peptide. (Amino acids are the building blocks of proteins.) The mechanisms by which GPE helps promote brain function are still being studied. However, it is known that GPE reduces inflammation in the brain, confers neuroprotection, and helps in responding to disease and stress.

Trofinetide is a modified form of GPE that is much more effective and lasts longer in the bloodstream. It also is easy to store and can be administered orally, unlike GPE or IGF-1, which can be administered only with an injection.

These properties of trofinetide make it a potentially viable therapy for Rett syndrome. It is thought that trofinetide can help in reducing inflammation in the brain and help in the development of nervous connections.

Trofinetide in clinical trials

Pre-clinical studies in rat models of stroke have confirmed the neuroprotective effects of trofinetide.

A Phase 2 multicenter clinical clinical trial (NCT02715115) to assess the safety, tolerability, and effectiveness of trofinetide in children with Rett syndrome was completed in 2017. The results of this study showed the treatment was safe and well-tolerated. It also led to clinically relevant improvements in symptoms compared to placebo.

Neuren aims to recruit about 180 Rett syndrome patients, ages 5 to 20, for a Phase 3 clinical trial that is planned for the second half of 2019 to further evaluate the safety and effectiveness of trofinetide. This will be followed by an extension study to evaluate the long-term safety and tolerability of the treatment.


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