A Positron Emission Tomography (PET) Study to Evaluate Dopamine D2 and D3 Receptor Occupancy by SIPI6398

NCT07626034 | Not Yet Recruiting Phase 1 FDA Drug

• 1 other identifier: ZZ6398-S02-RO01-202409
• Study Type: interventional
• Target: 9
• Locations: 0 countries
• Sites: N/A

Brief Summary

This is an open label study in 2 cohorts of healthy volunteers and 1 cohort of patients with Schizophrenia, designed to evaluate the Dopamine D2 and D3 Receptor Occupancy by SIPI6398 at various doses and timepoints.

Conditions

Schizophrenia Disorder

Outcome Measures

Primary Outcomes (1)

• Brain dopamine D2 and D3 receptor occupancy following oral doses as measured by PET.

  Baseline and post-dose, up to 9 days for healthy volunteers and up to 8 days for schizophrenia patients

Secondary Outcomes (1)

• Safety and Tolerability as Measured by Reported Adverse Events

  Up to 16 days

Study Arms (3)

SIPI6398 1-3 mg, Cohort 1 (healthy volunteers)

EXPERIMENTAL

Healthy volunteers will receive SIPI6398 Tablets 1 mg or 3 mg QD for 7 Days .

Drug: SIPI6398 Tablets

SIPI6398 3-6 mg, Cohort 2 (healthy volunteers)

EXPERIMENTAL

Healthy volunteers will receive SIPI6398 Tablets 3 mg or 6 mg QD for 7 Days .

Drug: SIPI6398 Tablets

SIPI6398 6-18mg, Cohort 3 (patients with schizophrenia)

EXPERIMENTAL

Patients with schizophrenia will receive SIPI6398 Tablets 6 mg, 12 mg or 18 mg QD for 8 Days.

Drug: SIPI6398 Tablets

Interventions

SIPI6398 Tablets DRUG

SIPI6398 Tablets will be administered orally once daily for 7 consecutive days to healthy volunteers or for 8 consecutive days to patients with schizophrenia.

SIPI6398 1-3 mg, Cohort 1 (healthy volunteers); SIPI6398 3-6 mg, Cohort 2 (healthy volunteers); SIPI6398 6-18mg, Cohort 3 (patients with schizophrenia)

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy Volunteers
• Participant is aged 18-55 years, inclusive.
• BMI between 19.0 and 32.0 kg/m2, inclusive.
• Participant is medically healthy as determined by clinical evaluations including laboratory safety tests, medical history, physical examination, ECG, and vital sign measurements performed at the Screening visit and before administration of the initial dose of study drug.
• Participant is willing and able to be confined to an inpatient setting for the study duration, follow instructions, and comply with the protocol requirements.
• Participant is capable of providing informed consent.
• A signed informed consent form must be provided before any study assessments are performed.
• Participant must be fluent (oral and written) in English to consent.
• Patients with schizophrenia
• Participant is aged 18-55 years, inclusive.
• BMI between 19.0 and 35.0 kg/m2, inclusive.
• Currently meet a diagnosis of schizophrenia as defined by Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Diagnosis and differential will be confirmed by using the Mini International Neuropsychiatric Interview (M.I.N.I) for Schizophrenia and Psychotic Disorders Studies version 7.0.2 at Screening Visit.
• The participant is currently stable: the total Positive and Negative Syndrome Scale (PANSS) score ≤ 60, including P7 (hostile) and G8 (not cooperative) scored ≤ 4.
• Participant is willing and able to be confined to an inpatient setting for the study duration, follow instructions, and comply with the protocol requirements.
• Participant is capable of providing informed consent.

You may not qualify if:

• Healthy Volunteers
• Women of childbearing potential (WOCBP), or fertile men whose sexual partners are WOCBP, who are unwilling or unable to use at least 1 highly effective method of contraception during the study and for 90 days following the last dose of trial medication. A female participant is considered to be a WOCBP after menarche and until she is in a postmenopausal state for 12 months or otherwise permanently sterile (for which acceptable methods include hysterectomy, bilateral salpingectomy, and bilateral oophorectomy).
• Females who are pregnant, lactating, or less than 90 days postpartum prior to the Screening Visit.
• History or presence of any clinically significant illness, such as cardiovascular, neurologic, pulmonary, hepatic, renal, metabolic, gastrointestinal, urologic, immunologic, endocrine, or psychiatric disease, considered by the investigator.
• Risk for suicidal behavior during the study as determined by the investigator's clinical assessment and C-SSRS as confirmed by the following: Answers "Yes" to any of the 5 items (C-SSRS - ideation) within the 3 months before Screening or between the Screening and Baseline Visits, or answers "Yes" to any of the 5 items (C-SSRS behavior) within the 12 months before Screening or between the Screening and Baseline Visits, or has a history of nonsuicidal, self-injurious behavior in the past 12 months.
• History of current hepatitis or acquired immunodeficiency syndrome or carriers of hepatitis B surface antigen (HBsAg) and/or anti- hepatitis C virus (HCV) or human immunodeficiency virus (HIV) antibodies or treponema pallidum antibody.
• Participants who had any major surgery, any blood transfusion, donation of blood or plasma within 30 days prior to Screening Visit.
• Participants with a history of allergy to more than one class of medications or known to be allergic to any components of the study drug or the radioligand.
• Physical and Laboratory Results
• Clinically significant abnormal findings on the physical examination, vital signs, 12-lead ECG, or clinical laboratory results.
• Neutrophils, absolute \<= 1000/mm3
• Aspartate Aminotransferase (AST) \> 1.5 times upper limit of normal (ULN)
• Alanine Aminotransferase (ALT) \> 1.5 times upper limit of normal
• Total Bilirubin (TBil) \> 1.5 times upper limit of normal
• Creatinine \>1.2 times upper limit of normal

Sponsors & Collaborators

• Shanghai Zhongze Therapeutics Co., Ltd.: lead
• Yale University: collaborator

MeSH Terms

Conditions

Schizophrenia

Condition Hierarchy (Ancestors)

Schizophrenia Spectrum and Other Psychotic Disorders; Mental Disorders

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 21, 2026
• First Posted: June 4, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): October 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: June 4, 2026

Record last verified: 2026-03