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Completed

NCT Number: NCT06643637

A Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of Multiple Doses of MLS101 in Healthy Participants

MLS101 is being developed as a low dose psilocybin, that can be administered to treat neurological and psychiatric conditions.

The purpose of this clinical trial is to assess how safe and tolerated MLS101 is; to see how MLS101 is distributed and cleared by the body (pharmacokinetics); and to assess the psychedelic effects of MLS101 in healthy, adult participants.

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Key information

Conditions

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

CMAX Clinical Research

Adelaide, South Australia, 5000, Australia

About this study

In recent years, high-dose psilocybin has gained attention for it potential therapeutic benefit in many psychiatric conditions, however existing clinical data for low psilocybin doses are limited.

Microdoses are generally considered to be those absent of profound sensory and cognitive effects that would interfere with normal everyday functioning, but only a small number of prospective studies have evaluated microdoses and/or low doses in a controlled manner.

As a foundational study of the therapeutic use of psilocybin microdoses, this study will assess the safety, tolerability, pharmacokinetics and sensorial effects using a prospective, controlled, multiple dose regimen in healthy volunteers.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Males or females aged 18 to 65 years old (inclusive) at the time of signing the informed consent form. Standard contraception measures are required for this clinical trial.
  • Healthy, in the opinion of the Investigator, based on prior (history of) or current (ongoing) medical and psychiatric screening assessments.
  • Participants with no clinically significant findings on physical examination, laboratory tests, and cardiac assessment.
  • Body mass index (BMI) within the range 18-32 kg/m2, inclusive.
  • Normal blood pressure.
  • Capable of giving signed informed consent which includes the requirements and restrictions as per the approved study protocol.

Exclusion criteria

  • Prior known exposure to psilocybin within the past 5 years.
  • Prior (history of) or current (ongoing) diagnosis, or first-degree relatives with clinically significant medical or psychiatric condition or disease.
  • History of or presence of cardiovascular disease.
  • Abnormal and clinically significant ECG.
  • History or presence of a neurodegenerative disorder such Alzheimer's disease or Parkinson's disease.
  • Use of medications that have CNS effects or affect performance.
  • Use of medications with serotonergic activity.
  • History or presence of hypersensitivity or idiosyncratic reaction to psilocybin or related compounds.
  • History of substance or alcohol abuse disorder in the last 1 year.
  • Participant who, for any reason, is deemed by the Investigator to be inappropriate for this study; or has any condition which would confound or interfere with the evaluation of the safety, tolerability, or PK of the investigational drug; or is unable to comply with the study protocol.

Treatment and study plan

Psilocybin

Drug

Capsule containing active ingredient, psilocybin

Other names: MLS101

Placebo

Drug

Capsule with no active ingredients

Primary outcomes

  1. Incidence, severity and seriousness of treatment-emergent adverse events (TEAEs)

    Time frame: Screening (Day -28) to end of study visit (Cohort 1: Day 15; Cohort 2: Day 23)

    Physical examinations, safety laboratory tests, ECGs

  2. Occurrence of clinically significant changes in physical examination, vital signs, ECGs, clinical laboratory tests, the Columbia-Suicide Severity Rating Scale (C-SSRS).

    Time frame: Screening (Day -28) to end of study visit (Cohort 1: Day 15; Cohort 2: Day 23)

    The Columbia Suicide Severity Rating Scale (C-SSRS) is a short questionnaire. If there is a positive result for suicidality on the C-SSRS after Screening (defined by a participant answering "yes" to questions 4 or 5 on the suicidal ideation portion of the C-SSRS), the participant will be evaluated by an Investigator or medically qualified Sub-investigator for continuation in the study. Participants with suicidal ideation or behaviour (a "yes" answer at any time during treatment to any one of the ten suicidal ideation and behaviour questions (Categories 1-10) on the C-SSRS) at any time during the study will be withdrawn from the study. If a participant becomes suicidal during the study, an Investigator or medically qualified Sub-investigator should provide the appropriate treatment to the participant.

Secondary outcomes

  1. Pharmacokinetics of MLS101: maximum observed serum concentration (Cmax)

    Time frame: Day 1 to Day 8 pre-dose, Day 1 to Day 9 post-dose (Cohort 1); Day 1 to Day 16 pre-dose, Day 1 to Day 17 post-dose (Cohort 2)

    Blood sample collections

  2. Pharmacokinetics of MLS101: area under the plasma concentration-time curve (AUC)

    Time frame: Day 1 to Day 8 pre-dose, Day 1 to Day 9 post-dose (Cohort 1); Day 1 to Day 16 pre-dose, Day 1 to Day 17 post-dose (Cohort 2)

    Blood sample collections

  3. Pharmacokinetics of MLS101: time corresponding to the occurrence of Cmax (Tmax)

    Time frame: Day 1 to Day 8 pre-dose, Day 1 to Day 9 post-dose (Cohort 1); Day 1 to Day 16 pre-dose, Day 1 to Day 17 post-dose (Cohort 2)

    Blood sample collections

  4. Pharmacokinetics of MLS101: apparent terminal elimination half-life (t½)

    Time frame: Day 1 to Day 8 pre-dose, Day 1 to Day 9 post-dose (Cohort 1); Day 1 to Day 16 pre-dose, Day 1 to Day 17 post-dose (Cohort 2)

    Blood sample collections

  5. Pharmacokinetics of MLS101: apparent total systemic clearance after oral administration (CL/F)

    Time frame: Day 1 to Day 8 pre-dose, Day 1 to Day 9 post-dose (Cohort 1); Day 1 to Day 16 pre-dose, Day 1 to Day 17 post-dose (Cohort 2)

    Blood sample collections

  6. Pharmacokinetics of MLS101: apparent volume of distribution during the terminal phase (Vz/F)

    Time frame: Day 1 to Day 8 pre-dose, Day 1 to Day 9 post-dose (Cohort 1); Day 1 to Day 16 pre-dose, Day 1 to Day 17 post-dose (Cohort 2)

    Blood sample collections

  7. Sensorial effects of MLS101

    Time frame: Day 1 to Day 8 pre- and post-dose (Cohort 1); Day 1 to Day 16 pre- and post-dose (Cohort 2)

    Using validated questionnaires, the nominal sensorial threshold dose of MLS101 will be identified. The nominal sensorial threshold dose is defined as the highest dose studied that is absent of clinically significant sensorial effects, and which would not interfere with the participant's ability to carry on with routine activities of daily living. Higher scores indicate presence of sensorial effects.

  8. Cognitive function: Digit Symbol Substitution Test (DSST)

    Time frame: Pre-dose (Day -1), Day 1, Day 4 and Day 8 (Cohort 1); Pre-dose (Day -1), Day 1, Day 4 and Day 16 (Cohort 2)

    The test taker's score is the number of correct symbol-to-number matches they complete within the allotted time.

  9. Cognitive Function: Stroop Color and Word Test (SCWT)

    Time frame: Pre-dose (Day -1), Day 1, Day 4 and Day 8 (Cohort 1); Pre-dose (Day -1), Day 1, Day 4 and Day 16 (Cohort 2)

    Participants read tables of words and colors as quickly as possible.

  10. Cognitive function: Trail Making Test A (TMT-A)

    Time frame: Pre-dose (Day -1), Day 1, Day 4 and Day 8 (Cohort 1); Pre-dose (Day -1), Day 1, Day 4 and Day 16 (Cohort 2)

    The participant draws lines to connect circled numbers in an ascending pattern (i.e., in numerical sequence 1-2-3, etc.) as rapidly as possible. The score is the time it takes the participant to complete the task in seconds.

Sponsors and collaborators

Lead sponsor

MycoMedica Life Sciences PBC

Industry

Registry information

Official study title

A Phase 1 Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of Multiple Doses of MLS101 (Psilocybin) in Healthy Participants

Important dates

Study start
2024
Primary completion
2025
Study completion
2025
First posted
Oct 16, 2024
Registry last updated
Jun 12, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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