Actively Recruiting
An Efficacy and Safety Study Comparing Two Doses of CYB003 and Placebo in Adults with Major Depressive Disorder
Led by Cybin IRL Limited · Updated on 2026-06-03
330
Participants Needed
67
Research Sites
7 weeks
Total Duration
On this page
Sponsors
C
Cybin IRL Limited
Lead Sponsor
W
Worldwide Clinical Trials
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are studying Major Depressive Disorder MDD to evaluate the effectiveness, safety, and tolerability of a drug called CYB003 compared to a placebo. This Phase III trial involves adults with moderate to severe depression who have not responded well to current antidepressant treatments. The study is sponsored by Cybin IRL Limited and aims to understand how well CYB003 works as an additional treatment alongside existing antidepressants. Participants will be divided into three groups. One group will receive 8 mg of CYB003 in two dosing sessions about three weeks apart, another group will receive 16 mg of CYB003 on the same schedule, and a third group will receive a placebo during the two sessions. All participants will continue their current antidepressant medication and receive psychological support throughout the study. Non-responders to placebo may be eligible for an extension trial to receive CYB003. During the trial, participants will be evaluated using several scales that measure depression severity, anxiety, global impression of illness, and quality of life at various points before, during, and after treatment. These assessments include the Montgomery-Asberg Depression Scale MADRS, Beck Depression Inventory, and others. The study will monitor participants for safety and treatment effects over about 12 weeks, including follow-up visits at the end of the trial.
CONDITIONS
Brief Title
A Study of a Deuterated Psilocin Analog (CYB003) in Humans With Major Depressive Disorder
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Age 18 to 85 years
- Diagnosis of Major Depressive Disorder (single or recurrent episode) as defined by DSM-5 TR
- Moderate to severe depression confirmed at Screening and Baseline
- Stable dose of antidepressant medication for at least 4 weeks prior to Screening with inadequate response
- Body mass index (BMI) of 40 kg/m2 or less at Screening
- Ability to refrain from nicotine use during dosing sessions
- Use of effective contraception methods as required for participants and partners
- Postmenopausal or permanently sterile if non-childbearing potential
- Provided written informed consent including compliance with study requirements
You will not qualify if you...
- Current or past diagnosis of schizophrenia spectrum or other psychotic disorders
- History of bipolar disorder or borderline personality disorder
- Taking medication for ADHD
- Family history of schizophrenia, schizoaffective disorder, or bipolar disorder type 1 in first-degree relatives
- Significant suicide risk or recent suicidal behavior
- Treatment-resistant MDD defined by failure to respond to 2 or more antidepressants
- Recent electroconvulsive or brain stimulation therapies
- Current use of certain antidepressants, antipsychotics, or mood stabilizers
- Extensive lifetime or recent use of psychedelics
- Recent use of ketamine or S-ketamine
- Clinically relevant abnormal physical health or uncontrolled thyroid disorders
- Uncontrolled hypertension, arrhythmia, or abnormal heart rate
- Presence or history of organic brain disorders
- Recent use of certain supplements or blood/plasma donation
- Pregnancy, breastfeeding, planning to conceive, or unwillingness to abstain from egg/sperm donation as required
- History of serotonin syndrome
- Unwillingness to consent to audio and video recording of sessions
Research Team
C
Clinical Development
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