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Safety, blood levels and effects of N,N-dimethyltryptamine [DMT (SPL026)] in healthy participants that have taken psychedelic substances before (Part A) and in healthy participants with little to no psychedelic experience (Part B)

An open-label, cross-over study of intramuscular (IM) and intravenous (IV) doses of SPL026 drug product (DMT fumarate [a serotonergic psychedelic]), in healthy, psychedelic-experienced subjects (Part A: IM and IV doses) and subjects with little to no psychedelic experience (Part B: IM dose only)

Status
Active, not recruiting
Phases
Phase 1
Study type
Interventional
Source
ISRCTN
Registry ID
ISRCTN63723571
Enrollment
30
Registered
2024-02-26
Start date
2023-01-03
Completion date
Unknown
Last updated
2024-04-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy volunteers Not Applicable

Interventions

SPL026 (dimethyltryptamine fumarate) by intramuscular injection and intravenous infusion. Single dose or two single doses, 2-3 weeks apart. Part A: crossover group study in psychedelic-experienced he

Sponsors

Cybin UK Ltd
Lead Sponsor

Eligibility

Sex/Gender
All

Inclusion criteria

Inclusion criteria: Part A only: 1. Healthy psychedelic-experienced female or male participants (psychedelic-experienced is defined as having at least two previous experiences, with breakthrough, of serotonergic psychedelic drugs, including but not limited to: DMT, ayahausca, LSD, LSA [morning glory seeds], DOI [2,5-Dimethoxy-4- iodoamphetamine], DOB [dimethoxybromoamphetamine], DOC [2,5- Dimethoxy-4-chloroamphetamine], 2CB [2-(4-bromo-2,5- dimethoxyphenyl)ethanamine], 2CE [1-(2,5-Dimethoxy-4-ethylphenyl)-2- aminoethane], mescaline, peyote, san pedro, ibogaine and psilocybin [including mushroom species containing psilocybin]) 2. No psychedelic drug use within 6 weeks prior to dosing Part B only: 3. Healthy female or male participants with little to no psychedelic experience (defined as having never taken serotonergic psychedelic drugs, or have only taken sub-breakthrough doses of serotonergic psychedelic drugs, in any form, <5 times, including but not limited to: DMT, ayahuasca, LSD, LSA, DOI, DOB, DOC, 2CB, 2CE, mescaline, peyote, san pedro, ibogaine and psilocybin [including mushroom species containing psilocybin]) 4. No psychedelic drug use within 6 months prior to dosing Parts A and B: 5. Aged 25-65 years 6. A body mass index (BMI; Quetelet index) in the range 18.0-33.9 kg/m2 7. Sufficient intelligence to understand the nature of the trial and any hazards of participating in it. Ability to communicate satisfactorily with the investigator and to participate in, and comply with the requirements of, the entire trial 8. Willingness to give written consent to participate after reading the information and consent form, and after having the opportunity to discuss the trial with the investigator or his delegate 9. Agree to follow the contraception requirements of the trial 10. Agree not to donate blood or blood products during the study and for up to 3 months after the (last) administration of the trial medication 11. Willing to refrain from psychedelic drug use (excluding the study drug) during the trial and until the follow-up call 12. Willingness to give written consent to have data entered into the Overvolunteering Prevention System (TOPS) 13. Willing to be contacted by email and video call, and have online access 14. Has veins deemed suitable for cannulation (IV infusion and/or blood sampling)

Exclusion criteria

Exclusion criteria: 1. Current or previously diagnosed mental health disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) criteria 2. First degree relative with schizophrenia spectrum or other psychotic disorders, or bipolar and related disorders. 3. Disposition judged by the investigator (or delegate) to be incompatible with the establishment of rapport with therapy team and/or safe exposure to DMT. 4. Woman who is pregnant or lactating, or pre-menopausal woman who is sexually active and not using a reliable method of contraception (see section 11). 5. Clinically relevant abnormal history, physical findings, ECG, or laboratory values at the pre-trial screening assessment that could interfere with the objectives of the trial or the safety of the participant. 6. Presence of acute or chronic illness, condition or infection, or history of chronic illness or condition (including psychological and neurological [eg seizure] disorder) considered sufficient to invalidate the participant's participation in the trial or make it unnecessarily hazardous. 7. Impaired endocrine, thyroid, hepatic, respiratory or renal function, diabetes mellitus, coronary heart disease or any of the following cardiovascular conditions: arrhythmia, a clinically significant screening ECG abnormality or family history of long QT syndrome or sudden death, artificial heart valve, current or any history of hypertension, or any other significant current or history of cardiovascular condition, that may affect safety in the opinion of the investigator. 8. History of serious suicide attempts (ie those that require hospitalisation); as assessed by the BSS. 9. Presence or history of severe adverse reaction to any drug or a history of sensitivity to serotonergic psychedelic drugs. 10. Use of a prescription medicine (except oral contraceptives or any hormone therapy), certain herbal supplements (eg St John's Wort, to be reviewed by trial physician), or over-the-counter medicine, during the 28 days before the first dose of trial medication. Use of acetaminophen (paracetamol) and non-steroidal anti-inflammatory drugs (eg ibuprofen) is permitted up to 4 h before the first dose of trial medication. 11. Receipt of an investigational product (including prescription medicines) as part of another clinical trial within the 3 months before (first) admission to this study; in the follow-up period of another clinical trial at the time of screening for this study. 12. Presence or history of drug or alcohol abuse, or intake of more than 14 units of alcohol weekly. 13. Daily cannabis use or cannabis dependence as defined by ICD10. 14. Use of cannabis in the 24 h before each study visit. 15. Evidence of drug abuse on urine testing (with the exception of cannabis). 16. Unable to be nicotine-free (refrain from smoking or nicotine-containing products) for 24 h before and until the morning after dosing. 17. Blood pressure and pulse rate in the supine and standing position at the screening examination outside the ranges: blood pressure 80-150 mm Hg systolic; 30-100 mm Hg diastolic; pulse rate 40-100 beats/min. Borderline values (i.e. values that are within 5 mm Hg of the range for blood pressure or 5 beats/min of the range for pulse rate) will be repeated. Participants can be included if the repeat value is within range or still borderline but deemed not clinically significant by the investigator. 18. QTcF value at screening greater than 450 msec (men) or 470 msec (women) on 12-lead ECG

Design outcomes

Primary

MeasureTime frame
Safety and tolerability of single doses of SPL026 DP given by intramuscular (IM) injection in healthy participants, assessed using adverse events, laboratory values, and tolerability assessments. Data collected over at least 2 weeks.

Secondary

MeasureTime frame
1. Safety and tolerability of single doses of SPL026 Drug Product (DP) given by intravenous (IV) infusion in healthy participants, assessed using adverse events, laboratory values, and tolerability assessments. Data collected over at least 2 weeks. 2. Pharmacokinetics of IV infusion measured using frequent blood sampling from pre-dose to 2 hours post-dose 3. Pharmacokinetics of IM infusion measured using frequent blood sampling from pre-dose to 4 hours post-dose 4. Pharmacodynamics (PD) – Wellbeing assessed using the Warwick–Edinburgh Mental Well-being Scale (WEMWBS) on day -1 and day 15 of the second dosing session 5. PD – Anxiety assessed using the State-Trait Anxiety Inventory (STAI-T) on day -1 and day 15 of the second dosing session 6. PD – Post-treatment changes assessed using Post-Treatment Changes Scale (PTCS) at 15 days of the second dosing session 7. PD – Subjective experience assessed using the Mystical Experience Questionnaire (MEQ), Ego Dissolution Inventory (EDI), Emotional Breakthrough Inventory (EBI), Challenging Experience Questionnaire (CEQ) post-dose (before the first post-dose integration session) visual analogue scale (VAS) post-dose (after the first post-dose integration session) 8. PD – Arrhythmia measured using continuous 12-lead Holter ECG on Day -1, pre-dose, during-dosing, until at least 10 min after the 4 h (IM) and 2h (IV) post-dose PK blood sample

Countries

England, United Kingdom

Contacts

Public ContactAdeep Puri
hmr@hmrlondon.com+44 (0)20 8961 4130

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026