Addex Therapeutics says spin-out company to complete NTX-253 study in Q2

Addex Therapeutics (ADXN) announced that its spin-out company, Neurosterix, is on track to complete its Phase 1 clinical study evaluating NTX-253 in Q2. NTX-253 is an investigational potent, selective, orally available positive allosteric modulator of the muscarinic M4 receptor being developed for the treatment of schizophrenia. The study is designed to generate an early-stage clinical data package assessing safety, tolerability, and pharmacokinetics across both healthy adult participants and those with stable schizophrenia. The clinical study includes 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 and multiple ascending dose components, incorporating key translational elements such as food-effect and cerebrospinal fluid assessments. Healthy adult participants will receive a single oral dose of NTX-253 or placebo across sequentially escalating dose cohorts. This phase includes a dedicated food-effect cohort to assess the impact of food on NTX-253 pharmacokinetics. A separate SAD cohort in healthy volunteers will evaluate NTX-253 concentrations in cerebrospinal fluid, providing early insight into central nervous system exposure and brain penetration. In the MAD phase, participants will receive once-daily oral dosing of NTX-253 or placebo for 10 consecutive days, with sequential dose escalation. This phase is designed to evaluate safety, tolerability, and steady-state pharmacokinetics following repeated dosing. The MAD phase includes two dedicated cohorts of adults with stable schizophrenia, representing early clinical evaluation in the target patient population. Participants in these cohorts will have their antipsychotic medications withdrawn for up to eight days prior to dosing with NTX-253, enabling assessment of safety and PK in patients while maintaining clinical stability. Neurosterix was spun-out of Addex in April 2024, raising $65M in a Series A financing led by funds affiliated with Perceptive Advisors. Addex retains a 20% equity interest in Neurosterix.