A Phase 1, Open-label, Pilot Study to Assess the Safety, Feasibility and Initial Efficacy of IV infused Psilocin (TRP-8803) Administration in Concert with Psychotherapy Among Adult Patients with Binge Eating Disorder (BED)

This Phase I open-label trial (n=12) will investigate the safety, feasibility, and initial efficacy of intravenous psilocin (TRP-8803), administered in two doses (ranging from 6.7 mg to 15 mg) in combination with psychedelic-assisted psychotherapy for adults with binge eating disorder (BED).

Conducted as part of the BED-IV study, this pilot trial is a follow-up to earlier research and will explore the therapeutic effects of psilocin when paired with structured psychotherapy. Participants will undergo three preparatory psychotherapy sessions before their first intravenous dose of psilocin, followed by two integration sessions. A second dosing session will be held two weeks later, with three further integration sessions. Dosing regimens vary between cohorts, with infusion protocols such as 5 mg loading plus 6.7 mg maintenance over 60 minutes, or higher-dose options reaching 15 mg over extended durations.

The trial aims to assess safety through clinical monitoring, physical exams, lab tests, and tracking adverse events. Secondary outcomes include changes in binge eating frequency, body mass index, mood, body image, quality of life, and neurobiological markers such as EEG, MRI, and metabolic hormones (e.g., leptin, ghrelin, insulin). The study also measures participants’ subjective psychedelic experiences to better understand therapeutic mechanisms. The psychotherapy model is delivered by qualified dyads trained in psychedelic-assisted therapy, and focuses on preparation, non-directive support during dosing, and integration.

Trial Details

INTERVENTIONAL: This is a phase 1 open label uncontrolled trial of TRP-8803 (Psilocin) administered intravenously in conjunction with psychedelic-assisted psychotherapy. PSYCHEDELIC-ASSISTED PSYCHOTHERAPY: The study is a combined pharmacological and psychological treatment, and as such, each individual participant will receive psychotherapy before, during, and after each dosing session. All participants will be seen by the same two therapists from baseline through to the completion of the study. The trial therapists are qualified and experienced mental health professionals (i.e., psychiatrists, psychologists) with specialty training in empirically based therapeutic modalities and psychedelic-assisted psychotherapy. The therapist dyad will typically consist of one male and one female therapist. In every dyad, at least one therapist will be a medically qualified healthcare practitioner. This ensures appropriately qualified staff are able to administer trial medication, both the study drug and any medical interventions if required (i.e., anti-anxiety medication due to persistent psychological distress), and manage any medical events that emerge. The psychotherapy focuses on three distinct phases of this approach: (1) Preparation: emphasising therapeutic alliance, non-avoidance training, psychological and practical preparation for dosing sessions, nature of and relationship to distress, anxiety management strategies, the importance of set and setting, and intention formation; (2) Dosing session: establishing suitable set and setting, and providing non-directive support when necessary; (3) Integration: focus on sustaining the change, emotion and body-focused therapy, meaning-centred integration into wider context, mindfulness training, ongoing peer- and professional support, and facilitating contextual changes to support outcomes. Therapy guides will ensure trial fidelity. The intervention scheduled for all participants will commence with three preparatory psychotherapy sessions over a three-week period (weeks 0, 1, 2), within 48 hours of the third preparatory psychotherapy session the investigational medical product (IMP) will be administered in the first dosing session (week 2), followed by two sessions of integration psychotherapy; the first within 48 hours after the dosing session (week 2) and the second a week later (week 3). Participants will attend a second dosing session (week 4) to receive the IMP, followed by three sessions of integration psychotherapy, the first being with 48 hours of the dosing session the once a week thereafter (weeks 4, 5, 6). All psychotherapy sessions will be scheduled for 90 minutes, however, sessions can be extended if required. Treatment will be delivered to individual participants separately. Adherence to trial protocol (i.e., session attendance) will be documented. TRP-8803 ADMINISTRATION: For Cohort 1, the initial 5 mg loading dose infused over the first 20 minutes will provide a therapeutic dose of psilocin that will be maintained by infusing the maintenance dose of 5 mg over the following 120 minutes. Treatment of Cohort 1 is staggered with at least a 48-hour interval scheduled between the start of psilocin administration for the first and remaining participants, with no more than one participant being dosed on a single day. The nature and severity of any adverse events related to the dosing of the first participant of Cohort 1 will be reviewed by the investigators and the Data Safety Monitoring Board (DSMB) to determine whether to proceed with the remaining dosing for Cohort 1, modify the study, pause the study, or stop the study in accordance with pre-defined discontinuation rules.. After all participants in Cohort 1 have completed the second dose, the investigators and DSMB will review the safety data and prepare a report and recommendation for the Sponsor. Upon reviewing the report and recommendation, the Sponsor will advise as to which administration option Cohort 2 will receive. Cohort 2 will follow the same procedure outlined above for Cohort 1. Any safety data that appears between the last participant of Cohort 1 and first participant of Cohort 2 (i.e., identified during follow-up) will be reviewed by the investigators and DSMB, if required, adjustment to Cohort 2 will be made. All decision making by the investigators, DSMB, and Sponsor will be documented. Option A: LD 5 mg / 20 minutes + MD 6.7 mg / 40 minutes. Total: 6.7 mg / 60 minutes Option B: LD 5 mg / 20 minutes + MD 10 mg / 240 minutes. Total: 15 mg / 260 minutes Option C: LD 8 mg / 30 minutes + MD 7 mg / 120 minutes. Total: 15 mg / 150 minutes

Trial Number ACTRN12625000330448p

Data attribution

A large set of the trials in our database are sourced from ClinicalTrials.gov (CTG). We have modified these post to display the information in a more clear format or to correct spelling mistakes. Our database in actively updated and may show a different status (e.g. completed) if we have knowledge of this update (e.g. a published paper on the study) which isn't reflected yet on CTG. If a trial is not sourced from CTG, this is indicated on this page and you can follow the link to the alternative source of information.