Clinical Trials

Numerous clinical trials evaluate clozapine's efficacy and safety across schizophrenia, treatment-resistant schizophrenia, schizoaffective disorder, bipolar disorder, and secondary outcomes like clozapine-associated infections and metabolic syndrome. Spanning Phase I through Phase IV with recruitment statuses including completed, recruiting, and enrolling by invitation, these investigations are led by academic and institutional sponsors such as the All India Institute of Medical Sciences Bhubaneswar and University Hospital Caen. Ultimately, these research efforts aim to refine the drug's therapeutic response and safety profile across diverse psychiatric and medical contexts.

NCT Number Recruitment Conditions Sponsor/Collaborators Start Date Phases
NCT06969755 RECRUITING
Schizophenia Disorder
Northwell Health
 2024-09-04 PHASE4
NCT05316883 RECRUITING
Schizophrenia; Psychosis
Jimmi Nielsen
 2021-02-28 PHASE4
NCT07326124 NOT_YET_RECRUITING
Treatment Resistant Psychosis; Psychosis
University of Oxford
 2026-06 PHASE3
NCT05208190 RECRUITING
Schizophrenia; Schizoaffective Disorder
New York State Psychiatric Institute
 2022-03-17 PHASE4
NCT05603104 RECRUITING
Schizophrenia and Related Disorders; Major Depressive Disorder; Bipolar Depression
Dr. Inge Winter
 2025-04-27 PHASE3
NCT05958875 RECRUITING
Schizophrenia and Related Disorders; Early Treatment-Resistance
Dr. Inge Winter
 2024-08-01 PHASE4
NCT07047651 ACTIVE_NOT_RECRUITING
Treatment Resistant Schizophrenia; Treatment Resistant Bipolar Disorder
Dr. Stavroula Rakitzi
 2025-06-04 PHASE4
NCT02639702 RECRUITING
Schizophrenia; Schizoaffective Disorder
Centre for Addiction and Mental Health
 2016-10-15 PHASE4
NCT06634641 RECRUITING
Clozapine; Parkinson's Disease (PD); Immunodeficiency; Psychosis
Centre Hospitalier Universitaire, Amiens
 2024-10-01 PHASE4
NCT06456983 RECRUITING
Schizophrenia; Treatment Resistant Schizophrenia
Central Institute of Mental Health, Mannheim
 2025-02-14
NCT04580134 RECRUITING
Schizophrenia; Schizoaffective Disorder; Bipolar 1 Disorder
University of Texas Southwestern Medical Center
 2022-03-01 PHASE4
NCT06596681 RECRUITING
Pain, Intractable
Beijing Tiantan Hospital
 2024-09-11 EARLY_PHASE1
NCT06174116 RECRUITING
Schizophrenia; Schizo Affective Disorder
University of Massachusetts, Worcester
 2024-04-02 PHASE4
NCT03094429 RECRUITING
Refractory Schizophrenia
SyneuRx International (Taiwan) Corp
 2017-03-29 PHASE2; PHASE3
NCT04892199 ACTIVE_NOT_RECRUITING
Metabolic Disturbance; Schizophrenia; Type 2 Diabetes; Clozapine; GLP-1; Olanzapine
Anders Fink-Jensen, MD, DMSci
 2021-09-01 PHASE4
NCT05741502 TERMINATED
Treatment-resistant Schizophrenia
Ohio State University
 2023-08-16 PHASE4
NCT06003036 COMPLETED
Schizophrenia; Schizoaffective Disorder
Deepak K. Sarpal, M.D.
 2023-12-01
NCT07085195 NOT_YET_RECRUITING
Parkinson Disease (PD); Gene Therapy; Safety and Efficacy; Clozapine
Ruijin Hospital
 2025-08-01 EARLY_PHASE1
NCT06501339 UNKNOWN
Clozapine Resistant Schizophrenia
All India Institute of Medical Sciences, Bhubaneswar
 2024-08-10 PHASE4
NCT06505668 UNKNOWN
Treatment Resistant Schizophrenia; Clozapine Adverse Reaction; Heart Rate Variability; Tachycardia
All India Institute of Medical Sciences, Bhubaneswar
 2023-08-01
NCT04529226 UNKNOWN
Psychosis; Intellectual Disability
Fundación Pública Andaluza para la gestión de la Investigación en Sevilla
 2020-11-26 PHASE2
NCT06573320 UNKNOWN
Schizophrenia; Clozapine; Exercise
Dr. Lutfi Kirdar Kartal Training and Research Hospital
 2024-03-14
NCT05632094 UNKNOWN
Clozapine Poisoning
Alexandria University
 2023-06 PHASE2
NCT06906224 COMPLETED
Schizophrenia
Chuanfu Song
 2022-05-01 EARLY_PHASE1
NCT03510325 COMPLETED
Schizophrenia
Shanghai Mental Health Center
 2019-02-12 PHASE3
NCT05944510 Recruiting
Treatment Resistant Schizophrenia
All India Institute of Medical Sciences Bhubaneswar
 2023-08-31 Phase 4
NCT04325386 COMPLETED
Schizophrenia Schizoaffective
University of Maryland, Baltimore
 2020-02-01
NCT05919550 Completed
Infections
University Hospital Caen
 2023-04-11 --
NCT06413589 COMPLETED
Acute Poisoning
Alexandria University
 2022-01-01 PHASE2
NCT06011460 Enrolling by invitation
Bipolar Disorder
Medical University of Gdansk
 2023-02-23 --
NCT02533232 UNKNOWN
Schizophrenia; Schizoaffective Disorder; Schizophreniform Disorder
Pakistan Institute of Living and Learning
 2022-08-30 PHASE1
NCT04528095 UNKNOWN
Treatment-resistant Schizophrenia
Shanghai Mental Health Center
 2020-12 PHASE3
NCT04849026 COMPLETED
Schizophrenia
Whanin Pharmaceutical Company
 2021-01-15 PHASE1
NCT07262736 COMPLETED
Healthy Volunteers - Male and Female
Universiti Sains Malaysia
 2021-02-06 PHASE1
NCT02404155 COMPLETED
Schizophrenia
University of Maryland, Baltimore
 2015-07
NCT03652974 COMPLETED
Schizophrenia
Shanghai Mental Health Center
 2018-09-06 PHASE4
NCT03857581 UNKNOWN
Psychosis; Substance Use Disorders
Augusta University
 2020-07 PHASE4
NCT03772951 COMPLETED
Schizophrenia
Shanghai Mental Health Center
 2019-01-10 PHASE4
NCT05083377 Completed
Schizophrenia and Related Disorders
Fundación Pública Andaluza para la gestión de la Investigación en Sevilla
 2020-09-08 --
NCT03807882 COMPLETED
Treatment Resistant Schizophrenia
All India Institute of Medical Sciences, Bhubaneswar
 2019-02-01 PHASE4
NCT04240496 COMPLETED
CYP1A2 Polymorphism; CYP2C19 Polymorphism; Clozapine; Schizophrenia
University of Monastir
 2019-10-17
NCT02926976 UNKNOWN
Schizophrenia
Shanghai Mental Health Center
 2016-11
NCT02562287 UNKNOWN
Bipolar Disorder
Hospital de Clinicas de Porto Alegre
 2015-10 PHASE4
NCT03263533 WITHDRAWN
Schizophrenia
Virginia Commonwealth University
 2017-04 EARLY_PHASE1
NCT02613494 COMPLETED
Sialorrhea
Mersey Care NHS Trust
 2016-01-25 PHASE1; PHASE2
NCT02159001 UNKNOWN
Schizophrenia; Schizoaffective Disorder
Niuvanniemi Hospital
 2014-06
NCT02286206 WITHDRAWN
Psychotic Disorders; Schizophrenia
University of British Columbia
 2015-01 PHASE4
NCT02374567 TERMINATED
Dementia; Depression; Schizophrenia; Psychosomatic Disorders; Anxiety Disorders
Hannover Medical School
 2015-01 PHASE3
NCT01639872 COMPLETED
Schizophrenia; Cannabis Abuse; Cannabis Dependence; Dual Diagnosis
Dartmouth-Hitchcock Medical Center
 2013-05-01 PHASE4
NCT00882856 COMPLETED
Clozapine-induced Sinustachycardia
University of Aarhus
 2009-04
NCT01663077 COMPLETED
Schizophrenia
Tirat Carmel Mental Health Center
 2012-10 PHASE4
NCT02124811 COMPLETED
Schizophrenia; Schizoaffective Disorder
Emory University
 2015-02 PHASE4
NCT01759485 COMPLETED
Clozapine Resistant Schizophrenia
Geha Mental Health Center
 2014-05
NCT01248195 COMPLETED
Schizophrenia; Schizophreniform Disorder; Schizoaffective Disorder
Rene Kahn
 2011-05 PHASE4
NCT02625103 COMPLETED
Schizophrenia
Anders Fink-Jensen, MD, DMSci
 2015-09 PHASE4
NCT01398189 UNKNOWN
Schizophrenia; Schizoaffective Disorder
Seoul National University Bundang Hospital
 2011-07
NCT01654640 TERMINATED
Schizophrenia
Seoul National University Hospital
 2012-09 PHASE4
NCT01246232 COMPLETED
Schizophrenia
Imperial College London
 2011-09 PHASE4
NCT02751307 COMPLETED
Metabolic Syndrome
Taipei Medical University WanFang Hospital
 2013-05 PHASE4
NCT02222220 COMPLETED
Clozapine-induced Hypersalivation
Beersheva Mental Health Center
 2012-01 PHASE3
NCT01433055 COMPLETED
Schizophrenia
University of Maryland, Baltimore
 2011-07
NCT02049021 UNKNOWN
Refractory Schizophrenia; Super Refractory Schizophrenia
University of Sao Paulo
 2010-02 PHASE4
NCT01448499 WITHDRAWN
Schizophrenia; Treatment Resistant Disorders
Geha Mental Health Center
 2011-10
NCT02140788 TERMINATED
Schizophrenia; Schizo-affective Disorder
Duke University
 2011-05 PHASE4
NCT00981526 COMPLETED
Schizophrenia; Schizoaffective Disorder
University of Massachusetts, Worcester
 2009-03 PHASE4
NCT00753051 COMPLETED
Schizophrenia
Khon Kaen University
 2008-06
NCT00690235 COMPLETED
Schizophrenia; Schizoaffective Disorder; Diabetes; Weight Gain
University of Texas Southwestern Medical Center
 2007-11 PHASE4
NCT00374244 COMPLETED
Schizophrenia
Yale University
 2004-01 PHASE2
NCT00337350 COMPLETED
Schizophrenia
Massachusetts General Hospital
 2003-09 PHASE4
NCT01401491 COMPLETED
Schizophrenia
Taipei Medical University Hospital
 2008-01 PHASE4
NCT00573287 COMPLETED
Cannabis-Related Disorder; Substance-Related Disorders; Schizophrenia; Psychotic Disorders
Dartmouth-Hitchcock Medical Center
 2006-06
NCT00345982 COMPLETED
Schizophrenia
University of Aarhus
 2006-09
NCT00918021 COMPLETED
Schizophrenia; Schizoaffective Disorder
Niuvanniemi Hospital
 2009-06 PHASE4
NCT00617058 TERMINATED
Weight Gain
University of North Carolina, Chapel Hill
 2007-03 PHASE2
NCT00794963 TERMINATED
Metabolic Syndrome
Northwell Health
 2008-11
NCT01045720 UNKNOWN
Schizophrenia; Clozapine; Hypersalivation; Traditional Chinese Medicine
Taichung Veterans General Hospital
 2010-01 PHASE2
NCT00154258 COMPLETED
Schizophrenia
Novartis
 2001-04 PHASE2
NCT01015001 COMPLETED
Schizophrenia; Auditory Hallucinations
Hospital de Clinicas de Porto Alegre
 2008-05 PHASE3
NCT00250575 COMPLETED
Schizophrenia
Novartis
 2005-11 PHASE3
NCT00345033 COMPLETED
Schizophrenia; Insulin Resistance
Massachusetts General Hospital
 2005-03 PHASE4
NCT01279213 COMPLETED
Schizophrenia; Schizophrenic Disorders; Psychotic Disorder
Universidad Nacional de Rosario
 2009-01 PHASE4
NCT01300637 UNKNOWN
Obesity; Metabolic Syndrome; Schizophrenia
Taipei Medical University WanFang Hospital
 2008-11
NCT00501618 COMPLETED
Schizophrenia; Schizoaffective Disorder
Manhattan Psychiatric Center
 2006-11 PHASE4
NCT00395915 UNKNOWN
Schizophrenia
Universita di Verona
 2006-09 PHASE4
NCT00498550 COMPLETED
Schizophrenia; Dual Diagnosis; Schizoaffective Disorder; Psychotic Disorder; Cannabis Abuse
Dartmouth-Hitchcock Medical Center
 2000-10 PHASE4
NCT00158223 COMPLETED
Schizophrenia; Psychotic Disorders
Icahn School of Medicine at Mount Sinai
 2004-10 PHASE4
NCT00534573 COMPLETED
Clozapine-induced Hypersalivation
Beersheva Mental Health Center
 2008-11 PHASE3
NCT00493233 COMPLETED
Schizophrenia
Centre for Addiction and Mental Health
 2006-11
NCT00042224 COMPLETED
Schizophrenia
Northwell Health
 2000-12 PHASE1; PHASE2
NCT00381589 COMPLETED
Hypersalivation
Centre for Addiction and Mental Health
 2006-10
NCT00001656 COMPLETED
Childhood Schizophrenia; Psychotic Disorder; Schizophrenia
National Institute of Mental Health (NIMH)
 1997-06 PHASE4
NCT01105481 COMPLETED
Treatment-resistant Schizophrenia
National Health Research Institutes, Taiwan
 2006-05 PHASE4
NCT00176436 COMPLETED
Schizophrenia
University of Maryland, Baltimore
 2004-02 PHASE4
NCT00757978 COMPLETED
Schizophrenia
Hospital de Clinicas de Porto Alegre
 2006-01 PHASE4
NCT00654576 COMPLETED
Schizophrenia
Central South University
 2005-02 PHASE4
NCT00056498 COMPLETED
Schizophrenia
University of Maryland, Baltimore
 2001-12 PHASE4
NCT00573417 COMPLETED
Schizophrenia
North Suffolk Mental Health Association
 2003-09 PHASE4
NCT00289861 COMPLETED
Schizophrenia
Massachusetts General Hospital
 2003-02 PHASE4
NCT00328367 COMPLETED
Schizophrenia
Seoul National University Hospital
 2005-12 PHASE4
NCT00628420 COMPLETED
Schizophrenia
University of Texas Southwestern Medical Center
 2005-01 PHASE1
NCT00216281 TERMINATED
Schizophrenia
Indiana University
 2005-09 PHASE3
NCT00048828 COMPLETED
Schizophrenia
Northwell Health
 2001-10 PHASE4
NCT00000372 WITHDRAWN
Schizophrenia
Massachusetts General Hospital
 1998-03 PHASE3
NCT00235352 COMPLETED
Schizophrenia
North Suffolk Mental Health Association
 2002-02 PHASE2; PHASE3
NCT02640300 COMPLETED
Schizophrenia; Schizoaffective Disorder
Centre for Addiction and Mental Health
 1999-05 PHASE4
NCT01123408 COMPLETED
Schizophrenia
Nathan Kline Institute for Psychiatric Research
 1999-06
NCT00169091 TERMINATED
Schizophrenia
Harvard Medical School (HMS and HSDM)
 1996-03 PHASE4
NCT00169065 COMPLETED
Schizophrenia
Harvard Medical School (HMS and HSDM)
 1998-08 PHASE4
NCT00179231 COMPLETED
Schizophrenia; Schizoaffective Disorder
Vanderbilt University
 2000-05
NCT00169039 TERMINATED
Schizophrenia
Harvard Medical School (HMS and HSDM)
 1994-12 PHASE4
NCT00065273 COMPLETED
Mental Retardation; Developmental Delay Disorder
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
 1998-07 PHASE3
NCT00031317 COMPLETED
Panic Disorder
National Institute of Mental Health (NIMH)
 2002-02 PHASE4
NCT00189995 WITHDRAWN
Schizophrenia
Beersheva Mental Health Center
 PHASE3
NCT00029458 COMPLETED
Bipolar Disorder
National Institute of Mental Health (NIMH)
 2002-01 PHASE2
NCT00649844 COMPLETED
Schizophrenia
Pfizer's Upjohn has merged with Mylan to form Viatris Inc.
 2003-01 PHASE3
NCT00224315 COMPLETED
Schizophrenia, Schizoaffective Disorder
Central Institute of Mental Health, Mannheim
 2003-11 PHASE4
NCT00351000 COMPLETED
Schizophrenia
North Suffolk Mental Health Association
 2005-01 PHASE4
NCT00169026 TERMINATED
Schizophrenia; Dual Diagnosis; Schizoaffective Disorder; Psychotic Disorder; Substance Abuse; Alcohol Abuse
Dartmouth-Hitchcock Medical Center
 1999-05 PHASE4
NCT00014001 COMPLETED
Schizophrenia
National Institute of Mental Health (NIMH)
 2000-12 PHASE4
NCT00036582 COMPLETED
Bipolar Disorder
National Institute of Mental Health (NIMH)
 2002-05 PHASE3
NCT00004826 COMPLETED
Parkinson Disease
Memorial Hospital of Rhode Island
 1993-10

(data from https://clinicaltrials.gov, updated on 2026-07-31)

Check the Clozapine product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.

Compliance for Clinical Use

Mechanism and Biochemical Profile

Clozapine acts as a potent serotonin 5-HT1C receptor antagonist with an IC50 of 110 nM, inhibiting 5-HT-stimulated phosphoinositide hydrolysis and modulating downstream dopaminergic pathways. This selective receptor blockade restores neurochemical balance and suppresses aberrant central signaling, providing clinical therapeutic efficacy in treatment-resistant schizophrenia, schizoaffective disorder, and bipolar disorder.

Appendix RUO and cGMP Quality Standards

Quality Dimension RUO (Research Use Only) cGMP (Current Good Manufacturing Practice)
Clinical Applicability Prohibited in human clinical trials or medical diagnostics. Mandatory for human clinical trials (Phase I–III) and therapies.
Regulatory Status Non-regulated grade; exempt from drug manufacturing laws. Legally enforced by health authorities (e.g., FDA, EMA, NMPA).
Facility Environment Unclassified analytical or research laboratories. Validated Cleanrooms (ISO Class 5–8) with continuous monitoring.
Quality Control Basic purity and activity testing. Rigorous safety release testing (Sterility, Endotoxin, Mycoplasma).
Process Validation Basic equipment calibration; no process validation required. Full qualification (IQ/OQ/PQ) and complete batch records.
Quality Assurance Vendor self-declared without required formal QMS. Mandatory QA/QC unit, Change Control, CAPA, and vendor audits.
Regulatory Impact High risk of IND rejection if used as a critical raw material. Required for IND/NDA filings, supported by Drug Master Files (DMF).

Footnotes

Regulatory Note: Governed by FDA (21 CFR Parts 210/211/312), EMA (EudraLex Vol 4), ICH Guidelines (E6/Q7/Q9/Q10), and compendial standards (USP <71>/<85>/<1043>).

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Note: Technical data last updated: Sep 1, 2026.