This Phase 2a clinical trial is designed to evaluate the safety, tolerability, and preliminary efficacy of a 3 mg dose of psilocybin oral solution for the treatment of Generalized Anxiety Disorder (GAD).
The study consists of three sequential phases: Screening Phase (up to 4 weeks), Open-label Run-in Phase (4 weeks), Double-blind Treatment Phase (4 weeks)
Screening Phase During the Screening Visit, participants will provide informed consent and undergo a comprehensive medical evaluation, including an abbreviated psychiatric assessment, to determine eligibility. To qualify, patients must have a clinician-rated Hamilton Anxiety Rating Scale (HAM-A) score ≥14. Additionally, participants must not be on regular anxiolytic treatment or must have discontinued such treatment at least 4 weeks prior to the start of the Open-label Run-in Phase.
Open-label Run-in Phase Eligible patients will proceed to the 4-week Open-label Run-in Phase. During this phase, patients will attend four weekly clinic visits, supplemented by weekly remote contacts (via phone or email).
At different timepoints during the OL Run-in Phase, participants will complete safety assessments, undergo cognitive testing and EEG and other patient reported outcomes (PROs).
Double-blind Treatment Phase Participants who demonstrate a treatment response during the Open-label Phase-defined as a ≥50% reduction in GAD-7 score from baseline-will be randomized 1:1 to receive either psilocybin oral solution or placebo at the Double-blind Baseline Visit. Patients not meeting the response criteria will undergo End-of-Treatment (ET) procedures at this visit.
At different timepoints during the DB Treatment Phase, participants will complete safety assessments, undergo cognitive testing and EEG and other patient reported outcomes (PROs).
Completion of the End of Treatment (ET) phase will be 2 weeks to further assess safety and PROs.
Must provide written informed consent prior to the initiation of any protocol-specific procedures.
Male and female adults, between 18 and 60 years of age, inclusive.
Meets DSM-V criteria for a primary diagnosis of GAD at Screening (duration of diagnosis ≥1 year, based on self-report), confirmed using the MINI.
Clinician-rated GAD-7 score ≥14 at Screening (Visit 1).
Personal history of schizophrenia, bipolar affective disorder, delusional disorder, paranoid disorder, moderate or severe panic disorder, moderate or severe social anxiety disorder, schizoaffective disorder, moderate or severe obsessive-compulsive disorder, anorexia nervosa, bulimia nervosa, moderate or severe post-traumatic stress disorder (as assessed by the IES-R), moderate or severe personality disorder (Cluster B and Cluster C only), moderate or severe MDD (as assessed by the MINI and total scores on the MADRS > 19).
History or presence of any clinically significant cardiac, endocrine, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, renal, or other disease at Screening, which, in the opinion of the investigator, would jeopardize the safety of the patient or the validity of the study results.
Recently initiated non-pharmacological treatment (e.g., Cognitive Behavioral Therapy, psychotherapy) with a psychologist or health care professional (i.e., <4 weeks prior to Screening). Patients who began a stable non-pharmacological treatment regimen >4 weeks prior to Screening will be permitted. Patients currently stable on treatment will not be permitted to modify or introduce new elements to their existing treatment regimen while enrolled in the study.
Currently taking pharmacological treatment for GAD or depressive symptoms on a daily basis as outlined in Table 2. Patients who discontinue pharmacological treatment within a minimum of 4 weeks or more of baseline will be permitted to enroll in the study. Sporadic, prn use of anxiolytics will be permitted; however, patients will be required to document all medication use prior to study enrollment (See Section 9.7).
Queen's University
Lead sponsor
Diamond Therapeutics Inc.
Collaborator
Kingston Health Sciences Centre
Collaborator