Clinical TrialHealthy VolunteersNot yet recruiting

A Phase 1, Open-label, Single Cohort Study to Evaluate the Safety and Pharmacokinetics (PK) of a Single Intravenous (IV) Infusion of TRP-8803 [Psilocin Besylate formulation] in Healthy Adult Participants

Phase I open-label single-cohort IV study (n=4) assessing safety and PK of a single TRP-8803 (psilocin besylate) infusion (5 mg loading over 20 min then 5 mg over 120 min) with psychedelic-assisted psychotherapy in healthy adults.

Target Enrollment
4 participants
Study Type
Phase I interventional
Design
Non-randomized

Detailed Description

This open-label Phase I study will administer a single intravenous infusion of TRP-8803 (psilocin besylate) in healthy adult participants while delivering preparatory, during-session, and integration psychotherapy by a consistent therapist dyad to evaluate safety and tolerability.

Pharmacokinetic sampling includes multiple timepoints from pre-dose through 24 hours to determine plasma concentrations and PK profile; safety monitoring includes AEs, vital signs, ECG and laboratory tests with DSMB review after first participant before dosing others.

Therapy comprises one 2-hour preparation session, the dosing session with non-directive support, and two 1-hour integration sessions (within 24 hours and at two weeks) to support meaning-making and implementation of therapeutic changes.

Study Protocol

Preparation

1 sessions
120 min each

Dosing

1 sessions
140 min each

Integration

2 sessions
60 min each

Therapeutic Protocol

supportmindfulness

Study Arms & Interventions

TRP-8803 IV

experimental

Single-cohort IV psilocin (TRP-8803) infusion with concomitant psychedelic-assisted psychotherapy.

Interventions

  • Compound10 mg
    via IV• single dose• 1 doses total

    TRP-8803 (Psilocin Besylate) administered as 5 mg loading over 20 minutes then 5 mg maintenance over 120 minutes (IV infusion); psychotherapy provided before, during and after dosing by a therapist dyad.

Participants

Ages
18 – 65
Sexes
Male & Female

Inclusion Criteria

  • Voluntary informed consent and willingness to attend follow-up visits.
  • Ability to receive IV medication (adequate venous access) and adhere to study regimen.
  • Medically stable as judged by Medical Officer/Lead Psychiatrist (screening medical exam, ECG, labs, urinalysis).
  • Agree to consume approximately the same amount of caffeine on session mornings as usual, or abstain if not habitual.
  • Agree to follow Medical Officer directions on non-prescription and prescription medications; refrain from nonprescription medications/supplements for 7 days before dosing except approved exceptions (eg paracetamol, NSAIDs, common vitamins, contraceptives).
  • Refrain from prescription medications for 14 days before dosing except hormonal contraceptives/HRT unless approved; no PRN meds on morning of dose.
  • Agree to have a support person for transport after dosing.
  • If required, successfully withdraw nominated medications prior to baseline.
  • Provide contact details for a medically qualified doctor and consent to contact.
  • Non- or ex-smokers and no nicotine products from 90 days prior to screening until study end.
  • Weight between 50 kg and 120 kg; BMI between 20 and 30 inclusive.
  • No psychedelic drug use in the 3 months prior to dosing and agree to refrain from non-study psychedelics during the study.
  • WOCBP must use two acceptable contraception methods from 30 days prior to screening until 30 days after dosing; men must avoid impregnation and sperm donation for 90 days after dosing.

Exclusion Criteria

  • Meets DSM-5 criteria for any psychiatric condition (including personality disorders) or other personal/situational factors judged incompatible with safe participation (eg lacking social support, unstable living situation, domestic violence, high autistic traits).
  • Recent (within 5 years) history of MDD, OCD, GAD, panic disorder, anorexia/bulimia, overeating disorder, PTSD, or SUD.
  • At screening, experiencing mild levels of depression or greater.
  • Recent history of suicide attempt (within 5 years) or suicidal ideation in past 6 months per C-SSRS.
  • History of psychosis or DSM-5 bipolar disorder, schizophrenia, or schizoaffective disorder.
  • Family history of psychosis (bipolar disorder, schizophrenia, schizoaffective disorder in first- or second-degree relatives).
  • History of alcohol abuse disorder within 1 year or regular alcohol abuse (AUDIT >8).
  • Meets DSM-5 criteria for substance use disorder (other than alcohol) within past 12 months or regular substance abuse (DAST-10 >3).
  • Currently taking or testing positive for drugs of abuse (eg amphetamines, benzodiazepines, cocaine, MDMA, opioids, synthetic cannabinoids).
  • Prior adverse effects from psilocybin/other psychedelics (eg severe headache or severe hypertension requiring treatment).
  • History of HPPD.
  • Serious medical condition that would interfere with safety (cardiovascular, metabolic, neurological, respiratory, oncological, haematological disorders, epilepsy/seizures).
  • Currently under treatment for epilepsy.
  • Cardiovascular conditions including uncontrolled hypertension (SBP >140 or DBP >90), angina, clinically significant ECG abnormality, recent TIA/stroke, peripheral/pulmonary vascular disease, significant QTc prolongation or conduction abnormalities.
  • Known conditions predisposing to hypercalcaemia, Cushing's, hypoglycaemia, SIADH, or carcinoid syndrome.
  • Serious abnormal haematology, electrolyte, renal or liver tests (eg AST/ALT ≥2x ULN or total bilirubin ≥1.5x ULN) unless medically cleared.
  • Insulin-dependent diabetes; oral hypoglycaemics excluded if history of hypoglycaemia.
  • Currently taking prohibited medications (eg certain antihypertensives, UGT1A9/1A10 inhibitors, aldehyde/alcohol dehydrogenase inhibitors) or antidepressants within 2 weeks (4 weeks for fluoxetine).
  • Serious infection requiring hospitalisation within last 28 days.
  • WOCBP who are pregnant, nursing, or trying to conceive.
  • Participation in another investigational study within 30 days or 5 half-lives, whichever is longer.
  • Any clinically significant lab or positive serology for HBsAg, HCV antibody, or HIV antibody.
  • Not suitable per investigator discretion.
  • Positive saliva drug test or blood alcohol >0 on dosing day.
  • Blood donation >500 mL within 30 days before screening.

Study Details

  • Status
    Not yet recruiting
  • Phase
    Phase I
  • Type
    interventional
  • Design
    Non-randomized
  • Target Enrollment4 participants
  • Timeline
    Start: 2025-09-01
    End: 2025-11-04
  • Topic
    Healthy Volunteers

Locations

Unknown facility — Australia

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