Safety and Tolerability of COMP360 in Post-traumatic Stress Disorder
Research type
Research Study
Full title
The Safety and Tolerability of COMP360 in Participants with Post-traumatic Stress Disorder
IRAS ID
301106
Contact name
James Rucker
Contact email
Sponsor organisation
COMPASS Pathfinder Limited
Eudract number
2021-002621-19
Duration of Study in the UK
1 years, 2 months, 17 days
Research summary
In this research study, an investigational medication (meaning that has not yet been approved for sale by government agencies in any country) called COMP360 is being tested for the treatment of Post-traumatic Stress Disorder (PTSD). Research suggests that psilocybin may help in treating PTSD. COMP360 is a synthetic form of psilocybin, a chemical compound found in some species of mushrooms.
The main purpose of this study is to investigate the safety and tolerability (whether side effects can be handled by a participant) of COMP360. The research study also aims to determine if COMP360 can help lessen the symptoms of PTSD.
Approximately 20 participants (males and females) who are currently suffering from PTSD after a traumatic event experienced in adulthood, aged 18 years and older, can take part in this research study. This study is being conducted in study clinics in the United Kingdom and the United States.
This is an open-label research study, meaning that all participants who are enrolled will receive COMP360.
There will be one treatment group. At the study clinic, the participant will receive a single-25 mg dose of study medication, consisting of 5 capsules containing 5 mg of COMP360.
The total participation in this study will be a minimum of 15 weeks and up to approximately 18 weeks. This includes the following:
• A screening period (to confirm that the participant is suitable for the study, meet with a trained therapist, and prepare for receiving the study medication) of a minimum of 3 weeks and up to 6 weeks.
• Dosing day (where the participant will receive the study medication, COMP360) following completion of the screening period and baseline visit.
• A safety follow-up period (to check the participant overall health) during which time the participant will attend the study clinic for regular visits over approximately 12 weeks.Lay summary of study results: CLINICAL STUDY REPORT LAYPERSON SUMMARY This is a short summary of the results of a clinical study and is written for a general audience. This summary was finalized on 03 Oct 2025 and does not include any information that may have become available after this date.
• The main purpose of this study was to examine the safety and tolerability of COMP360 for adults with post traumatic stress disorder (PTSD). This study also looked at whether COMP360 could help adults with PTSD.
• PTSD is a serious mental health condition. People with PTSD may experience intrusive memories, nightmares, or flashbacks, avoid any reminders of a traumatic event, and experience negative thoughts, mood, and feel tense or “on edge”.
• This was a fixed dose, open label study. The study doctor, study staff, and participants were all aware that all participants were assigned the same dose (25 mg taken as 5 × 5 mg capsules) of COMP360. Participants took COMP360 1 time by mouth and were monitored for 12 weeks.
• The study took place in 2 countries (United Kingdom and United States) and involved 22 participants with PTSD. Participants were between 18 and 64 years old, 36.4% were men, and 63.6% were women.
• The study results showed that the safety and tolerability of COMP360 in PTSD was consistent with the known safety profile from other COMP360 studies. The most common side effects were nausea (feeling sick), tension headache, headache, crying, and fatigue (lack of energy). There were improvements in PTSD symptoms and these effects lasted for 12 weeks.
• Overall, COMP360 was generally well tolerated with no serious side effects observed and able to improve PTSD symptoms in this study1. STUDY NAMES
• Study full scientific title: The Safety and Tolerability of COMP360 in Participants with Post-traumatic Stress Disorder • Study number: COMP 201 • Clinical studies have other unique numbers that are given when they are officially registered. These numbers may be used when the study is reported in publications (e.g. medical journals) and elsewhere (e.g. websites). The unique numbers for this study are:
o ClinicalTrials.gov Identifier: NCT05312151
o EudraCT Number: 2021 002621 19
2. WHO SPONSORED THIS STUDY?
The sponsor of this study was Compass Pathfinder Limited, a subsidiary of Compass Pathways plc.
Email: info@compasspathways.com
3. GENERAL INFORMATION ABOUT THIS STUDY
What is post-traumatic stress disorder?
Post traumatic stress disorder (PTSD) is a serious mental health condition. People with PTSD may experience intrusive memories, nightmares, or flashbacks, avoid any reminders of a traumatic event, and experience negative thoughts, mood, and feel tense or “on edge”. PTSD has a negative impact on quality of life. People with PTSD may have trouble in their relationships with other people and commonly also suffer from substance dependence and depression.What is COMP360?
COMP360 is the study medication and contains psilocybin, the active ingredient found in Psilocybe mushrooms, commonly known as “magic mushrooms”. Psilocybin can cause mystical experiences and altered states of consciousness, including changes in perception, mood, awareness, sense of time, as well as visual or auditory hallucinations.
Why was the study done (what did researchers want to find out)?
The main purpose of this study was to examine the safety and tolerability of COMP360 for adults with PTSD. This study also looked at whether COMP360 could help adults with PTSD.
The safety and tolerability of COMP360 were measured by looking at the number of participants that had side effects and what kind of side effects they had. Other safety measures included asking participants if they had any thoughts of harming themselves and how they felt during the study. Participants’ general health was also monitored during the study, including the electrical activity of the heart, pulse (the number of heart beats per minute), blood pressure (how much pressure it takes to move blood through the body), respiratory rate (the number of breaths per minute), body temperature, physical examinations, and any medicines taken during the study. Laboratory tests were done on blood and urine samples.
During the study, the researchers evaluated participants’ symptoms of PTSD, health-related quality of life, and impacts on participants’ work, family, and social functioning before and after COMP360 treatment.
When and where was this study done?
The study started in June 2022 and ended in February 2024. The study took place at 3 study sites and these sites were in the United Kingdom (1 site), and the United States (2 sites).Study Design
This was a fixed dose, open label study. The study doctor, study staff, and participants were all aware that all participants were assigned the same dose of the study medication and then monitored for 12 weeks.
There were 4 periods of the study:
• Screening Period: Happened about 2 to 6 weeks before participants received the study medication, to see if they could take part in the study. During this period, participants received treatment education (called preparation sessions) to ensure they were supported during treatment.
• Baseline: Happened 1 day before participants received the study medication. Assessments were done, and used as starting points for data comparison. Participants had another preparation session of treatment education.
• Treatment: Participants took 1 dose of the study medication (25 mg taken as 5 × 5 mg capsules) by mouth 1 time in a supportive environment with study staff.
• Follow up: Happened for 12 weeks after participants received the study medication to check on participants’ general health and collect data measuring changes in PTSD symptoms, health-related quality of life, and impact on participants’ work, family and social functioning. During this period, participants discussed their experiences after the treatment day (called integration sessions) to ensure adequate monitoring and support of participants.
4. WHAT WAS THE TREATMENT PLAN?
On the treatment day, all participants took 1 dose of the study medication (COMP360 25 mg taken as 5 × 5 mg capsules) by mouth 1 time in a supportive environment.
5. WHO TOOK PART IN THIS STUDY?
Studies have a list of requirements for people to see if they can take part.
Who was allowed to take part?
• Men and women who were at least 18 years old.
• People with a confirmed diagnosis of PTSD and able to identify a next of kin who was willing and able to be reached by the researchers in case of emergency.
• People who agreed to stop taking certain medications before the baseline visit.
Who was not allowed to take part?
• People with some severe mental health conditions that occurred in addition to PTSD were not able to take part.
• People with any other important medical condition which meant that taking part in the study may have put them at risk.
• People who had exposure in the past year to MDMA, psilocybin, or any other psychedelics (e.g. ayahuasca, LSD, or peyote).
Who took part?
A total of 22 participants with PTSD were included in the study. All participants received the study medication 1 time at the treatment visit.
Participants were between 18 and 64 years old.
There were 8 (36.4%) men and 14 (63.6%) women who took part in the study.
The following table shows the number of participants in the study in different countries.Region / Country / Number of Participants Europe (non European Union) / United Kingdom / 13 North America / United States / 9
6. WHAT WERE THE SIDE EFFECTS?
Side effects are any undesired actions or effects of a drug or treatment that happen to a participant during the study. Other studies may give different results.
The safety results shown below are the results of this single study (COMP 201).
How many participants had side effects?
All 22 (100%) participants had at least one side effect after receiving the study medication during the study. Most side effects were reported on the day of receiving the study medication, and most participants recovered by the next day.
Were any side effects serious?
A side effect is considered serious if it meets 1 or more of the following:
• Leads to death or is life-threatening; • Causes the study participant to go to hospital or to stay longer in hospital; • Causes permanent damage; • Causes a health problem in the study participant’s baby; • Is considered as an important medical problem putting the study participant in danger.
No serious side effect was reported after participants received the study medication. Before participants received the study medication, there was 1 serious event of atrial fibrillation (electrical activity of the heart does not work properly) reported in 1 (4.5%) participant.
What were the most common side effects?
The most common side effects were nausea (feeling sick) in 8 (36.4%) participants, and tension headache, headache, crying, and fatigue (lack of energy) in 6 (27.3%) participants each.
What do these results tell us?
The study results showed that the safety profile of the study medication was consistent with known safety profile from other COMP360 studies with no serious side effects reported and was generally well tolerated with no participant withdrawals.
7. OTHER STUDY RESULTS
Participants showed improvements in PTSD symptoms, health-related quality of life, and their work, family and social functioning about 4 weeks after receiving the study medication, and these effects lasted for 12 weeks.
8. HOW HAS THIS STUDY HELPED PATIENTS AND RESEARCHERS?
This study has increased the knowledge of COMP360 in participants with PTSD. Researchers now know more about the safety profile and effects of COMP360. Overall, the study results encourage further investigation of COMP360 in people with PTSD.
9. ARE THERE PLANS FOR FURTHER STUDIES?
Yes, the sponsor is planning to conduct another study and is in the process of finalising a clinical study design for a late stage clinical study in PTSD.
10. WHERE CAN I FIND MORE INFORMATION ABOUT THIS STUDY?
Your doctor can help you to understand more about this study and the results. Speak to your doctor about treatment options available in your country. You should not make changes to your care based on the results of this or any single study.
You can find out more information, in English, about this study and its results on the following websites:
• https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3t%2Fwww.clinicaltrialsregister.eu%2FNBTI%2FBonAAQ%2FAQ%2F9448e29c-90dc-4d3d-a6a2-5c67cd930c29%2F2%2F2uYXQ93CGY&data=05%7C02%7Cbrent.rec%40hra.nhs.uk%7C8ebfe80b98714191363d08de057854bc%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638954211557587639%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=R83tItopgVlxMPrcpLPzBUVAO0iDkIigZ3gd7MKkzvQ%3D&reserved=0 (search for 2021 002621 19) • https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3t%2Fclinicaltrials.gov%2FNBTI%2FBonAAQ%2FAQ%2F9448e29c-90dc-4d3d-a6a2-5c67cd930c29%2F3%2FQq4HUooMfE&data=05%7C02%7Cbrent.rec%40hra.nhs.uk%7C8ebfe80b98714191363d08de057854bc%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638954211557622131%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=03rVh9Y263yQUJsPPsLN%2FRQS0bcu2Hh00HXVZSq%2FH08%3D&reserved=0 (search for NCT05312151)REC name
London - Brent Research Ethics Committee
REC reference
21/LO/0507
Date of REC Opinion
18 Oct 2021
REC opinion
Further Information Favourable Opinion