Phase 1 Clinical Studies Completed: NTX-253 for the Treatment of Schizophrenia

Neurosterix has completed its phase 1 clinical studies evaluating NTX-253, a positive allosteric modulator (PAM) of the muscarinic M4 receptor being developed for the treatment of schizophrenia, and plans to advance NTX-253 into phase 2 clinical development.¹

Neurosterix is a spin-out company of Addex Therapeutics, a clinical-stage biopharmaceutical company focused on developing a portfolio of novel small molecule allosteric modulators for neurological disorders.

“Completing phase 1 and the decision by Neurosterix to progress NTX-253 into phase 2 studies in schizophrenia patients is a significant achievement,” said Tim Dyer, the CEO of Addex. “The well-designed study combining healthy volunteers and schizophrenia patients within a single study has provided important safety and pharmacokinetic data.”

More About the Study

The clinical study has a multi-part, ascending-dose design intended to efficiently characterize NTX-253’s clinical profile and support subsequent patient-focused development. The study includes both single ascending dose (SAD) and multiple ascending dose (MAD) components, incorporating key translational elements such as food-effect and cerebrospinal fluid (CSF) assessments. The studies included both healthy volunteers and stable schizophrenia patients, and has provided important safety and pharmacokinetic data.

More About NTX-253

The M4 muscarinic receptor is a validated target for treating schizophrenia and related disorders through indirect modulation of dopamine signaling. NTX-253 is a potent, selective, oral PAM of M4 that fine-tunes muscarinic signaling with the potential to reduce psychosis symptoms while avoiding the movement disorders and metabolic complications associated with traditional dopamine antagonists. Preclinical studies demonstrate robust antipsychotic-like activity and a favorable safety profile.²

More About Neurosterix

Neurosterix was spun-out of Addex in April 2024, raising $65 million in a Series A financing led by funds affiliated with Perceptive Advisors. Addex retains a 20% equity interest in Neurosterix.

References

1. Addex spin-out Neurosterix completes phase 1 clinical studies of NTX-253 for schizophrenia. News release. October 8, 2026. Accessed October 8, 2026. https://www.addextherapeutics.com/en/investors/press-releases/addex-spin-out-neurosterix-completes-phase-1-clinical-studies-ntx-253-schizophrenia/

2. Walters J. Neurosterix announces phase 1 study of NTX-253 for schizophrenia. Psychiatric Times. January 7, 2026. https://www.psychiatrictimes.com/view/neurosterix-announces-phase-1-study-of-ntx-253-for-schizophrenia