"A Study of a Deuterated Psilocin Analog (CYB003) in Humans With Major Depressive Disorder"

Last updated: July 16, 2025
Sponsor: Cybin IRL Limited
Overall Status: Active - Recruiting

Phase

3

Condition

Depression

Mood Disorders

Affective Disorders

Treatment

Placebo

CYB003

Psychological Support

Clinical Study ID

NCT06564818
CYB003-002
  • Ages 18-85
  • All Genders

Study Summary

The purpose of this study is to examine the efficacy, safety, and tolerability of CYB003 compared to matching placebo as adjunctive treatment in participants with MDD.

Eligibility Criteria

Inclusion

Inclusion Criteria:

Participants must meet all the following criteria to be included in the trial:

  • Aged 18 to 85 years inclusive, at Screening

  • Participant has a diagnosis of MDD (single or recurrent episode as defined by DSM-5TR [if single episode, duration of ≥4 weeks and ≤24 months] and established as perevaluation by the Investigator. The first MDD episode must have occurred prior toage 60.

  • Depression is of moderate to severe degree at Screening, independently confirmed byadditional clinical assessments

  • Participant has been on a stable dose of a single antidepressant medication at anadequate dose (label specified) for an adequate duration in the last 4 weeks priorto Screening and has had an inadequate response (less than 50% improvement), asjudged by the Investigator and clinical interviews.

  • Participant has a body mass index (BMI) of 40 kg/m2 or less (BMI ≤ 40 kg/m2),inclusive, at Screening.

  • Participant is able to refrain from nicotine use during the dosing session (up to 8hours)

  • Registered with a healthcare professional who can confirm the diagnosis and previoustreatments received by the participant.

  • Participants capable of producing sperm must use a condom during the trial and for 12 weeks after their final dose of trial medication, if their partner is a person ofchildbearing potential. In addition, their partner of childbearing potential mustuse a highly effective method of contraception (i.e., failure rate less than 1% whenused consistently and correctly) from first dosing until 12 weeks following finaldosing.

  • Participants of childbearing potential who have a partner capable of producing spermmust agree to use a highly effective method of contraception (i.e., failure rateless than 1% when used consistently and correctly) in combination with the use of acondom plus spermicide during the trial and for 12 weeks after their final dose oftrial medication. Such participants must have a negative pregnancy test at Screeningand Day -1 prior to dosing.

  • Female participants who were capable of producing eggs (ova) must be postmenopausalor permanently sterile following hysterectomy, bilateral salpingectomy, andbilateral oophorectomy. Postmenopausal is defined as spontaneous amenorrhea for atleast 12 months, and a serum follicle-stimulating hormone level in the menopausalrange, unless the participant is taking hormone replacement therapy or is usinghormonal contraception.

  • Participant has provided written informed consent, which includes compliance withthe requirements and restrictions listed in the informed consent form.

Exclusion

Exclusion Criteria:

Participants with any of the following characteristics/conditions will be excluded from trial participation:

  • Current or previously diagnosed schizophrenia spectrum or other psychotic disorders,including schizophrenia, schizoaffective disorder, schizotypal disorder,schizophreniform disorder, brief psychotic disorder, attention deficit hyperactivitydisorder, current or previous history of bipolar disorder, or current borderlinepersonality disorder.

  • Family history of schizophrenia, schizoaffective disorder, or bipolar disorder type 1 (first degree relatives).

  • Significant suicide risk within the past 6 months, during the Screening Period, orat Baseline; or (b) suicidal behaviors within 12 months of Screening; or (c)clinical assessment of significant suicidal risk during clinical interview; or (d)non-suicidal self-injury within 12 months of Screening.

  • Current or previous diagnosis of treatment-resistant MDD, defined as failure torespond to 2 or more antidepressant treatments of 2 different classes given at anadequate dose for an adequate duration as judged by the Investigator and clinicalinterview.

  • Has had electroconvulsive treatment, transcranial magnetic stimulation, deep brainstimulation, or vagal nerve stimulation for any episode of MDD in the last 6 months.

  • Currently receiving a monoamine oxidase inhibitor, tricyclic antidepressant,mirtazapine, trazodone, moclobemide, buspirone, ketamine or S-ketamine, or anantipsychotic or mood stabilizer for MDD.

  • Participant report of (or if available in medical record) exposure to psilocin, or 5-HT2a receptor agonists, or any other psychedelics, such as ayahuasca, mescaline,lysergic acid diethylamide, peyote, or 3,4-methylenedioxymethamphetamine, more than 

  • Participant is able to refrain from nicotine use during the dosing session (up to 8
hours)
 

  • Registered with a healthcare professional who can confirm the diagnosis and previous
treatments received by the participant.
 

  • Participants capable of producing sperm must use a condom during the trial and for
 12 weeks after their final dose of trial medication, if their partner is a person of
childbearing potential. In addition, their partner of childbearing potential must
use a highly effective method of contraception (i.e., failure rate less than 1% when
used consistently and correctly) from first dosing until 12 weeks following final
dosing.
 

  • Participants of childbearing potential who have a partner capable of producing sperm
must agree to use a highly effective method of contraception (i.e., failure rate
less than 1% when used consistently and correctly) in combination with the use of a
condom plus spermicide during the trial and for 12 weeks after their final dose of
trial medication. Such participants must have a negative pregnancy test at Screening
and Day -1 prior to dosing.
 

  • Female participants who were capable of producing eggs (ova) must be postmenopausal
or permanently sterile following hysterectomy, bilateral salpingectomy, and
bilateral oophorectomy. Postmenopausal is defined as spontaneous amenorrhea for at
least 12 months, and a serum follicle-stimulating hormone level in the menopausal
range, unless the participant is taking hormone replacement therapy or is using
hormonal contraception.
 

  • Participant has provided written informed consent, which includes compliance with
the requirements and restrictions listed in the informed consent form.
 
 Exclusion Criteria:
 
 Participants with any of the following characteristics/conditions will be excluded from
 trial participation:
 

  • Current or previously diagnosed schizophrenia spectrum or other psychotic disorders,
including schizophrenia, schizoaffective disorder, schizotypal disorder,
schizophreniform disorder, brief psychotic disorder, attention deficit hyperactivity
disorder, current or previous history of bipolar disorder, or current borderline
personality disorder.
 

  • Family history of schizophrenia, schizoaffective disorder, or bipolar disorder type
 1 (first degree relatives).
 

  • Significant suicide risk within the past 6 months, during the Screening Period, or
at Baseline; or (b) suicidal behaviors within 12 months of Screening; or (c)
clinical assessment of significant suicidal risk during clinical interview; or (d)
non-suicidal self-injury within 12 months of Screening.
 

  • Current or previous diagnosis of treatment-resistant MDD, defined as failure to
respond to 2 or more antidepressant treatments of 2 different classes given at an
adequate dose for an adequate duration as judged by the Investigator and clinical
interview.
 

  • Has had electroconvulsive treatment, transcranial magnetic stimulation, deep brain
stimulation, or vagal nerve stimulation for any episode of MDD in the last 6 months.
 

  • Currently receiving a monoamine oxidase inhibitor, tricyclic antidepressant,
mirtazapine, trazodone, moclobemide, buspirone, ketamine or S-ketamine, or an
antipsychotic or mood stabilizer for MDD.
 

  • Participant report of (or if available in medical record) exposure to psilocin, or
 5-HT2a receptor agonists, or any other psychedelics, such as ayahuasca, mescaline,
lysergic acid diethylamide, peyote, or 3,4-methylenedioxymethamphetamine, more than
 4 times over the participant's lifetime or any psychedelic use within 12 monthsprior to Screening.

  • Clinically relevant history of abnormal physical health interfering with the trialas determined by medical history and physical examinations obtained during Screeningas judged by the Investigator (including but not limited to, neurological,cardiovascular, respiratory, gastrointestinal [including dyspepsia orgastroesophageal reflux disease], hepatic, or renal disorder).

  • Participants with renal insufficiency.

  • Has hypothyroidism or hyperthyroidism, unless controlled on appropriate medicationwith no change in dosage for at least 12 weeks prior to Screening.

  • Current diagnosis of uncontrolled hypertension or an arrhythmia, or clinicallyrelevant abnormal results for heart rate or blood pressure

  • History or clinical evidence of any disease and/or existence of any surgical ormedical condition which might interfere with the absorption, distribution,metabolism, or excretion of the trial medication.

  • Participant has a presence or relevant history of organic brain disorders (e.g.,epilepsy, seizure, intracranial hypertension, intracranial bleed and aneurysmaldisease, brain tumor or other medical conditions associated with seizures orconvulsions).

  • Known sensitivity to psilocin and/or any excipients present in the formulation.

  • Participant is taking or has taken OTC doses of 5 hydroxytryptophan or St John'sWort within 45 days prior to trial medication administration.

  • Strenuous exercise within 48 hours prior to each clinic visit.

  • The participant has participated in a clinical trial and has received a medicationor a new chemical entity within 12 weeks prior to dosing of current trialmedication.

  • Participants capable of producing sperm who will not abstain from sperm donationbetween first dosing and 12 weeks after final dosing.

  • Participants of childbearing potential who are pregnant, breastfeeding, planning toconceive or unwilling to abstain from egg (ova) donation between first dosing and 12weeks after final dosing.

  • History of serotonin syndrome.

  • Unwilling to consent to audio and video recording of psychological support anddosing sessions.

Study Design

Total Participants: 220
Treatment Group(s): 3
Primary Treatment: Placebo
Phase: 3
Study Start date:
November 15, 2024
Estimated Completion Date:
May 31, 2026

Connect with a study center

  • Scottsdale Research Institute

    Phoenix, Arizona 85022
    United States

    Site Not Available

  • Del Sol Research Management

    Tucson, Arizona 85715
    United States

    Site Not Available

  • Noble Clinical Research

    Tucson, Arizona 85704
    United States

    Active - Recruiting

  • CenExel CIT (Clinical Innovations, Inc)

    Bellflower, California 90706
    United States

    Active - Recruiting

  • Kadima Neuropsychiatry Institute

    La Jolla, California 92037
    United States

    Active - Recruiting

  • Kadima Neuropsychiatry Institute

    LaJolla, California 92037
    United States

    Site Not Available

  • Catalina Research Institute

    Montclair, California 91763
    United States

    Site Not Available

  • Excell Research, Inc

    Oceanside, California 92056
    United States

    Site Not Available

  • Open Mind Collective/UCSF Medical Center Mount Zion

    San Francisco, California 94114
    United States

    Active - Recruiting

  • Inland Psychiatric Medical Group Inc

    San Juan Capistrano, California 92675
    United States

    Site Not Available

  • Pacific Neuroscience Institute

    Santa Monica, California 90404
    United States

    Site Not Available

  • Mountain View Clinical Research

    Denver, Colorado 80209
    United States

    Active - Recruiting

  • Starlight Clinical Research

    Evergreen, Colorado 80439
    United States

    Site Not Available

  • Research Centers of America

    Hollywood, Florida 33024
    United States

    Active - Recruiting

  • K2 Medical Research-Maitland

    Maitland, Florida 32751
    United States

    Site Not Available

  • Floridian Neuroscience Institute

    Miami, Florida 33135
    United States

    Active - Recruiting

  • Innovative Clinical Research, INC

    North Miami, Florida 33161
    United States

    Active - Recruiting

  • Charter Research

    Orlando, Florida 32803
    United States

    Site Not Available

  • Clinical Neuroscience Solutions, Inc

    Orlando, Florida 32801
    United States

    Active - Recruiting

  • Combined Research Orlando Phase I-IV

    Orlando, Florida 32807
    United States

    Site Not Available

  • K2 Medical Research-Tampa

    Tampa, Florida 32751
    United States

    Site Not Available

  • Atlanta Center for Medical Research, CenExel

    Atlanta, Georgia 30331
    United States

    Active - Recruiting

  • CenExel iResearch Atlanta

    Decatur, Georgia 30330
    United States

    Active - Recruiting

  • CenExel iResearch Savannah

    Savannah, Georgia 31405
    United States

    Site Not Available

  • Great Lakes Clinical Trials, DBA Flourish Research

    Chicago, Illinois 60640
    United States

    Site Not Available

  • Uptown Research Institute

    Chicago, Illinois 60640
    United States

    Active - Recruiting

  • Psychiatric Medicine Associates, LLC

    Skokie, Illinois 60076
    United States

    Site Not Available

  • DelRicht Research

    New Orleans, Louisiana 70115
    United States

    Site Not Available

  • Sunstone Medical, PC

    Rockville, Maryland 20850
    United States

    Active - Recruiting

  • Adams Clinical

    Boston, Massachusetts 02472
    United States

    Active - Recruiting

  • Adams Clinical Boston

    Boston, Massachusetts 02116
    United States

    Site Not Available

  • Elixia Health

    Springfield, Massachusetts 01103
    United States

    Site Not Available

  • Oasis Clinical Trials

    Las Vegas, Nevada 89121
    United States

    Active - Recruiting

  • Redbird Research, LLC

    Las Vegas, Nevada 89119
    United States

    Site Not Available

  • Global Medical Institues, Princeton Medical Institute

    Princeton, New Jersey 08540
    United States

    Site Not Available

  • Adams Clinical Bronx

    Bronx, New York 10461
    United States

    Site Not Available

  • Adams Clinical Harlem

    New York, New York 100029
    United States

    Site Not Available

  • Nautilus Psychiatric Services, PLLC

    New York, New York 10017
    United States

    Site Not Available

  • Monroe Biomedical Research

    Monroe, North Carolina 28112
    United States

    Site Not Available

  • Neurobehavioral Clinical Research

    North Canton, Ohio 44720
    United States

    Active - Recruiting

  • Clinical Neuroscience Solutions, CNS Healthcare

    Memphis, Tennessee 38119
    United States

    Site Not Available

  • HCA Healthcare/Medical City Green Oaks

    Dallas, Texas 75251
    United States

    Site Not Available

  • InSite Clinical Research, LLC

    DeSota, Texas 75115
    United States

    Site Not Available

  • InSite Clinical Research, LLC

    DeSoto, Texas 75115
    United States

    Active - Recruiting

  • Zillan Clinical Research

    Houston, Texas 77433
    United States

    Site Not Available

  • AIM Trials

    Plano, Texas 75093
    United States

    Site Not Available

  • Cedar Clinical Research

    Murray, Utah 84107
    United States

    Active - Recruiting

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