Autism Spectrum DisorderPhase 2NCT07303907
A Phase 2A Trial of DT402 for Autism Spectrum Disorder
A Phase 2 study testing DT402 (R-enantiomer of 3,4-methylenedioxymethamphetamine (MDMA)) in people with Autism Spectrum Disorder and ASD, run by Definium Therapeutics US, Inc. at 1 site in United States.
Trial summary
A Phase 2A Trial of DT402 Open-Label Study in Adults with Autism Spectrum Disorder Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Autism Spectrum Disorder, ASD
- What is being tested?
- DT402 (R-enantiomer of 3,4-methylenedioxymethamphetamine (MDMA))
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 3 Dec 2025to Aug 2027
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Diagnosis of ASD per records as confirmed by standard semi-structured interview for Autism diagnosis (eg, Autism Diagnostic Observation Schedule-Second Edition)
- Male or Female aged 18 to 65
- Presents with clinically significant deficits in socialization and communication as determined by Social Responsiveness Scales (SRS-2) ≥66
Who cannot join
- Has uncorrected abnormalities in eye movement, alignment, or acuity or atypical eye features that could interfere with eye tracking
- First degree relative with or lifetime history of a psychotic disorder or bipolar disorder
- Current diagnosis of alcohol or substance use disorder (excluding nicotine and caffeine)
- Any clinically significant unstable illness
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Definium Therapeutics Clinical Trials Information Requests contact
United States1 site, 1 recruiting
- Recruiting
Spectrum Neuroscience and Treatment Institute
New York, New York, 10021
Casara Ferretti, 1-914-315-4236, cferretti@spectrumneuroscience.org
About this study
Official title: An Open-label Study Evaluating DT402 in Adults With Autism Spectrum Disorder
A Phase 2A Trial of DT402 Open-Label Study in Adults with Autism Spectrum Disorder
Read the detailed description
This study will enroll approximately twenty adults with Autism Spectrum Disorder (ASD) aged 18 to 65 years of age.
This is a multi-center, open-label study to evaluate the effects after a single administration of DT402 to adults with ASD.
- Conditions
- Autism Spectrum Disorder, ASD
- Being tested
- DT402 (R-enantiomer of 3,4-methylenedioxymethamphetamine (MDMA))
- Medical subject headings
- Autism Spectrum Disorder
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DT402 (R-enantiomer of 3,4-methylenedioxymethamphetamine (MDMA))Drug
Also called MM402, R-MDMA, MDMA
A psychoactive substance that mediates effects mainly through a release of the monoaminergic neurotransmitters, with the greatest effect on 5-HT, followed by NE and DA
| Study group | Role | What they receive |
|---|---|---|
| 200 mg DT402 | Experimental | A psychoactive substance that mediates effects mainly through a release of the monoaminergic neurotransmitters, with the greatest effect on 5-HT, followed by NE and DA Receives: Drug: DT402 (R-enantiomer of 3,4-methylenedioxymethamphetamine (MDMA)) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from Baseline in 11-point Numerical Rating Scale (NRS) scores
The NRS is an 11-point PRO scale used to measure the severity or intensity of effects from 0 (no effect) to 10 (high severity or intensity of effect). It consists of various items related to both positive and negative effects in the autism patient population.
Measured: Baseline, pre-dose and 2, 4, 6, 8, and 24 hours post-dose and day 15
Secondary outcomes (7)
Subjective 5-question Drug Effects Questionnaire (DEQ) scores
The Drug Effects Questionnaire is used in studies to assess the participant's acute subjective effects after ingesting substances. It consists of 5 PRO items. The analog scale of responses ranges from "not at all" to "extremely." The score is determined by the distance between the left anchor point and the participant's mark on the line. Each item is scored separately.
Measured: 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Plasma concentrations
Maximum Plasma Concentration [Cmax] of DT402 in the blood.
Measured: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Parameters (Cmax)
Maximum concentration (Cmax).
Measured: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Parameters (Tmax)
Time to maximum concentration (Tmax).
Measured: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Parameters (t1/2)
Time to maximum concentration half-life (t1/2).
Measured: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Parameters (AUC0-inf)
Area under the concentration curve from time 0 to infinity (AUC0-inf).
Measured: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Parameters (AUC0-24h)
Area under the concentration curve from time 0 to 24 hour (AUC0-24h).
Measured: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Dec 2025
- Study start3 Dec 2025
- Primary completionAug 2027 (estimated)
- Study completionAug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Autism Spectrum DisorderStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Definium Therapeutics US, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07303907
- Sponsor's protocol ID
- MM402-105
- Status last verified
- Mar 2026
- First submitted
- 22 Dec 2025
- Last updated
- 2 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-label Study Evaluating DT402 in Adults With Autism Spectrum Disorder
- ClinicalTrials.gov ID
- NCT07303907
- Acronym / sponsor ID
- MM402-105
- Conditions
- Autism Spectrum Disorder, ASD
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Definium Therapeutics US, Inc.Industry (pharma, biotech, devices)
- Study start
- 3 Dec 2025 (actual)
- Primary completion
- Aug 2027 (estimated)
- Study completion
- Aug 2027 (estimated)
- First posted
- 26 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A Phase 2A Trial of DT402 Open-Label Study in Adults with Autism Spectrum Disorder
Detailed description
This study will enroll approximately twenty adults with Autism Spectrum Disorder (ASD) aged 18 to 65 years of age.
This is a multi-center, open-label study to evaluate the effects after a single administration of DT402 to adults with ASD.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| 200 mg DT402 | Experimental | Drug: DT402 (R-enantiomer of 3,4-methylenedioxymethamphetamine (MDMA))A psychoactive substance that mediates effects mainly through a release of the monoaminergic neurotransmitters, with the greatest effect on 5-HT, followed by NE and DA |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Diagnosis of ASD per records as confirmed by standard semi-structured interview for Autism diagnosis (eg, Autism Diagnostic Observation Schedule-Second Edition)
- Male or Female aged 18 to 65
- Presents with clinically significant deficits in socialization and communication as determined by Social Responsiveness Scales (SRS-2) ≥66
Key exclusion criteria (4 listed)
- Has uncorrected abnormalities in eye movement, alignment, or acuity or atypical eye features that could interfere with eye tracking
- First degree relative with or lifetime history of a psychotic disorder or bipolar disorder
- Current diagnosis of alcohol or substance use disorder (excluding nicotine and caffeine)
- Any clinically significant unstable illness
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| DT402 (R-enantiomer of 3,4-methylenedioxymethamphetamine (MDMA))Also: MM402, R-MDMA, MDMAA psychoactive substance that mediates effects mainly through a release of the monoaminergic neurotransmitters, with the greatest effect on 5-HT, followed by NE and DA | Drug | 200 mg DT402 |
Primary outcome
Change from Baseline in 11-point Numerical Rating Scale (NRS) scores
Time frame: Baseline, pre-dose and 2, 4, 6, 8, and 24 hours post-dose and day 15
The NRS is an 11-point PRO scale used to measure the severity or intensity of effects from 0 (no effect) to 10 (high severity or intensity of effect). It consists of various items related to both positive and negative effects in the autism patient population.
7 secondary outcomes
Subjective 5-question Drug Effects Questionnaire (DEQ) scores
Time frame: 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Plasma concentrations
Time frame: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Parameters (Cmax)
Time frame: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Parameters (Tmax)
Time frame: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Parameters (t1/2)
Time frame: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Parameters (AUC0-inf)
Time frame: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Pharmacokinetic Parameters (AUC0-24h)
Time frame: pre-dose and 1, 2, 4, 6, 8, and 24 hours post-dose
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Sep 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Definium Therapeutics Clinical Trials Information Requests contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing DT402 (R-enantiomer of 3,4-methylenedioxymethamphetamine (MDMA)) in people with Autism Spectrum Disorder and ASD, run by Definium Therapeutics US, Inc. at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Definium Therapeutics Clinical Trials Information Requests (1-332-282-0479, clinicaltrials@definiumtx.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from Baseline in 11-point Numerical Rating Scale (NRS) scores (time frame: Baseline, pre-dose and 2, 4, 6, 8, and 24 hours post-dose and day 15). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Sep 2026.