a study of a deuterated psilocin analog (cyb003) in humans with major depressive disorder

Conditions: Major Depressive Disorder (MDD)

Summary: the purpose of this study is to determine the efficacy, safety and tolerability of cyb003 compared to matching placebo as adjunctive treatment in patients with mdd.


Eligibility criteria:
inclusion criteria: * participants must meet all the following criteria to be included in the trial: * age18 to 85 years. * participant has a diagnosis of mdd. * moderate to severe depression at screening. * participants have been on a stable dose of antidepressant medication at an adequate dose in the last 4 weeks prior to screening. * participant has a body mass index (bmi) of 40 kg/m2 or less (bmi ≤40 kg/m2), inclusive, at screening. * participants with well controlled hypertension. * participant is able to refrain from smoking during the dosing session. * participants must use a condom plus spermicide during the trial and for 12 weeks afterwards. participants of childbearing potential must agree to use a highly effective method of and a negative pregnancy test at screening and day -1 prior to dosing. * participants of non-childbearing potential who are or were capable of producing eggs (ova) must have been postmenopausal or permanently sterile following hysterectomy, bilateral salpingectomy, or bilateral oophorectomy. * participants have 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. * family history of schizophrenia, schizoaffective disorder, or bipolar disorder type 1 (first-degree relatives). * significant suicide risk within 12 months of screening. * current or previous diagnosis of treatment-resistant mdd. * 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 antidepressants, mirtazapine, trazodone, moclobemide, buspirone, or an antipsychotic or mood stabilizer. * clinically relevant history of abnormal physical health interfering with the trial (including but not limited to, neurological, cardiovascular, respiratory, gastrointestinal \[including dyspepsia or gastroesophageal reflux disease\], hepatic, or renal disorder). * has hypothyroidism or hyperthyroidism, unless controlled on appropriate medication. * current diagnosis of uncontrolled hypertension or an arrhythmia, or clinically relevant abnormal results for heart rate. * participants have a presence or relevant history of organic brain disorders. * participant is taking or has taken otc doses of 5 hydroxytryptophan or st john's wort within prior to trial medication administration. * strenuous exercise prior to each clinic visit. * donation of blood or plasma within 4 weeks prior to first dosing and until 4 weeks after final dosing. * participants capable of producing sperm who will not abstain from sperm donation between first dosing and 12 weeks after final dosing. * participants of childbearing potential who are pregnant, breastfeeding, planning to conceive or unwilling to abstain from egg (ova) donation between first dosing and 12 weeks after final dosing. * history of serotonin syndrome. * unwilling to consent to audio and video recording of psychological support and dosing sessions.

Keywords: mdd psilocybin psychedelic depression major depressive disorder cyb003 cyb003-001 cyb003-002 psilocin-7438