NCT05401227

Glutamatergic Mechanisms: Aim2

Glutamatergic Mechanisms of Psychosis and Target Engagement: Aim2

• Status: Suspended
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 120 (estimated)
• Sponsor: New York State Psychiatric Institute · Academic / Other
• Sex: All
• Age: 18 Years – 55 Years
• Healthy volunteers: Accepted

Summary

In the present study, 120 healthy volunteers (HV) will be randomized to one of three ketamine-induced pharmacoBOLD (phBOLD) arms: low, medium, and high. Within each ketamine arm, participants will be randomized to 4 days of "study drug" \[TS-134 (1st 20 participants) or XT (remaining 100 participants)\] or placebo in a 5:3 ratio (25 study drug:15 placebo per arm). During the study, each participant will undergo a Screening Period (up to 31 days), a 4-day Treatment Period, and a total of two phBOLD sessions: a first session at Baseline and a second session on Day 4 of the Treatment Period, conducted at least 7 days apart, and a follow up visit.

Detailed description

Schizophrenia (Sz) is associated with psychotic symptoms, such as hearing voices and paranoid beliefs that remain partially or fully refractory to standard antipsychotic medications for \~2/3 of patients. Alternative, glutamatergic approaches for treatment development have been proposed but have not yet led to FDA-approved medications. Moreover, several glutamate-targeted medications, such as pomaglumetad (POMA), have failed in pivotal clinical trials despite robust effectiveness in preclinical models. A major barrier to effective glutamatergic treatment development is the absence of validated measures for target engagement that can identify effective compounds and guide dose selection. Target" refers to a factor that an intervention is intended to modify, leading to improvement in symptoms, and target engagement biomarkers are a measure of the ability of the intervention to "engage" the target. As part of the recently completed NIMH multicenter FAST-PS initiative and a parallel industry sponsored project, we evaluated ketamine-induced pharmacoBOLD (phBOLD) in healthy volunteers (HV) as a potential target engagement biomarker for development of metabotropic glutamate (mGluR2/3) agonists, as a prelude to planned studies in Sz. BOLD imaging indirectly measures brain energy, as a proxy for glutamate target engagement. The structure of the R01 grant funding this protocol was split into three studies, specific aim (SA) 1, 2 and 3. In FAST-PS, a high dose of ketamine (0.23 mg/kg) was used in order to produce robust pharmacological effects. Under SA1, which was conducted under IRB 8063, this dose was titrated downward in across two phBOLD sessions in HV in order to determine the lowest dose of ketamine that still produces a phBOLD response of Cohen's d≥1.5, hypothesizing that this dose would provide the best signal to noise for use in SA2. The study was conducted in groups of 10 subject per dose cohort, and the analysis supports using a low dose of 0.086 mg/kg for SA2. In the present study, 120 healthy volunteers (HV) will be randomized to one of three ketamine-induced pharmacoBOLD (phBOLD) arms: low, medium, and high. Within each ketamine arm, participants will be randomized to 4 days of "study drug" \[TS-134 (1st 20 participants) or XT (remaining 100 participants)\] or placebo in a 5:3 ratio (25 study drug:15 placebo per arm). During the study, each participant will undergo a Screening Period (up to 31 days), a 4-day Treatment Period, and a total of two phBOLD sessions: a first session at Baseline and a second session on Day 4 of the Treatment Period, conducted at least 7 days apart, and a follow up visit.

Conditions

• Healthy

Interventions

Type	Name	Description
DRUG	Ketamine	Ketamine during an MRI
DRUG	Ts-134	4 days of TS-134 20 mg
DRUG	Placebo	4 days of placebo TS-134

Timeline

• Start date: 2022-10-15
• Primary completion: 2028-08-01
• Completion: 2029-08-01
• First posted: 2022-06-02
• Last updated: 2026-04-13

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study