Rett SyndromePhase 1/2NCT06621043
Assessing the Safety and Efficacy of Full-Spectrum Medicinal Cannabis Plant Extract 0.08% THC (NTI164) in the Treatment of Rett Syndrome (RTT)
A Phase 1/2 study testing NTI164 in people with Rett Syndrome, run by Fenix Innovation Group at 1 site in Australia.
Trial summary
This 18-week open-label study examines the effectiveness of Full-Spectrum Medicinal Cannabis Plant Extract containing 0.08% THC (NTI164) in treating Rett syndrome (RTT) in children and young people. The study aims to determine the impact of NTI164 on RTT symptoms over a 16-week treatment period. Read more about this study
- Who is it for?
- Ages 5 to 20 years, women only
- Conditions the study is for
- Rett Syndrome
- What is being tested?
- NTI164
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 14 participants
- Where
- 1 siteAustralia
- Study dates
- 20 Sep 2023to 1 Dec 2025
- Phase
- Phase 1/2
- Are there results?
- None posted in the registry
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 5 to 20 years
- Women only
- No healthy volunteers
- Child, Adult
Who may be able to join
- Girls and women, aged 5-20 years
- Weight greater than or equal to 12kg
- Classical/typical RTT
- Documented disease-causing mutation in MECP2 gene
- At least 6 months post regression at screening (ie. no loss or degradation in ambulation, hand function, speech, nonverbal communicative or social skills within 6 months of screening) Rett Syndrome Clinical Severity Scale rating of 10-36
- CGI score of 4 or higher.
- Stable pattern of seizures, or has had no seizures, within 8 weeks of screening.
Who cannot join
- Current clinically significant cardiovascular, endocrine (such as hypo- or hyperthyroidism, type 1 diabetes, or uncontrolled type 2 diabetes), renal, hepatic, respiratory, or gastrointestinal disease (such as celiac disease or inflammatory bowel disease), or major surgery planned during the study.
- Known history or symptoms of long QT syndrome.
- QTcF interval \>450 ms, history of risk factor for torsades de pointes or clinically significant QT prolongation deemed to increase risk.
- Treatment with insulin, IGF-1, or growth hormone within 12 weeks of baseline.
- Currently receiving treatment with DAYBUETM (trofinetide).
- Currently using other unregistered drugs for the treatment of Rett syndrome such as Anavex.
- Currently using or has used recreational or medicinal cannabis, cannabinoid-based medications (including Sativex®, or Epidiolex®) within the 12 weeks prior to screening and is unwilling to abstain for the duration of the trial.
- Participant has any known or suspected hypersensitivity to cannabinoids or any of the excipients.
Trial locations and contacts
1 site in 1 country.
Australia1 site
The Childrens Hospital at Westmead
Sydney, New South Wales, 2145
About this study
This 18-week open-label study examines the effectiveness of Full-Spectrum Medicinal Cannabis Plant Extract containing 0.08% THC (NTI164) in treating Rett syndrome (RTT) in children and young people. The study aims to determine the impact of NTI164 on RTT symptoms over a 16-week treatment period.
Participants will start with a daily dose of 5 mg/kg of NTI164, which will be gradually increased over four weeks until they reach either the maximum tolerated dose or 20 mg/kg per day. They will then maintain this dose for eight weeks. Following this treatment phase, the dosage will be reduced by 5 mg/kg each week for four weeks until treatment concludes.
The effectiveness of the treatment will be assessed using tailored questionnaires that measure changes in the patients\' conditions. Additionally, full blood examinations will be conducted at multiple points throughout the study to monitor the effects of the treatment.
Read the detailed description
This study is an 18-week open-label trial designed to assess the effectiveness of Full-Spectrum Medicinal Cannabis Plant Extract containing 0.08% THC (NTI164) on the severity of symptoms in children and young people with Rett syndrome (RTT). The main objective is to determine how well NTI164 alleviates the symptoms of RTT over a 16-week treatment period.
The study involves multiple phases:
- Up-titration Phase (4 weeks): Treatment begins with an initial daily dose of 5 mg/kg of NTI164. Over the first four weeks, this dose is incrementally increased based on patient tolerance, aiming for a maximum daily dose of 20 mg/kg.
- Treatment Phase (8 weeks): Once the maximum tolerated dose is established, participants continue to receive this dose for the following eight weeks. This phase focuses on maintaining a steady dosage to observe the therapeutic effects on RTT symptoms.
- Down-titration Phase (4 weeks): After completing the treatment phase, the dosage is systematically reduced by 5 mg/kg each week for four weeks until treatment cessation. This gradual reduction helps in assessing any withdrawal effects and the stability of symptom improvement post-treatment.
Throughout the study, the efficacy of NTI164 is evaluated using specifically designed questionnaires that track changes in the emotional, behavioral, and cognitive functions of the participants, providing insights into how the treatment impacts various aspects of RTT. Additionally, full blood examinations are conducted at key points during the study to monitor the physiological responses to the treatment and to ensure the safety and tolerability of NTI164. This comprehensive approach allows for a detailed assessment of both the immediate and longer-term effects of the medicinal cannabis extract on Rett syndrome symptoms.
- Conditions
- Rett Syndrome
- Being tested
- NTI164
- Keywords
- RTT
- Medical subject headings
- Rett Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NTI164Drug
Full-Spectrum Medicinal Cannabis Plant Extract containing 0.08% THC, administered orally starting with a dose of 5 mg/kg, titrated up to 20 mg/kg based on tolerance, followed by a maintenance phase at the maximum tolerated dose, and concluding with a gradual dose reduction.
| Study group | Role | What they receive |
|---|---|---|
| Active NTI164 Arm | Experimental | Participants in this arm receive Full-Spectrum Medicinal Cannabis Plant Extract containing 0.08% THC (NTI164), targeted at treating symptoms of Rett syndrome (RTT) in children and young people. The intervention starts with a daily initial dose of 5 mg/kg, which is increased gradually over a four-week up-titration phase to a maximum of 20 mg/kg per day, depending on individual tolerance. Participants then continue at their maximum tolerated dose for eight weeks during the treatment phase. The study concludes with a four-week down-titration phase, where the dosage is reduced by 5 mg/kg each week. The effectiveness of the treatment is monitored through specialized questionnaires and full blood examinations throughout the study duration. Receives: Drug: NTI164 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rett Syndrome: Symptom Index Score
The Rett Syndrome: Symptom Index Score (RTT: SIS) measures the severity of various symptoms in individuals with Rett syndrome. Individual scores are from 0 to 7 with lower scores reflecting improvement or milder symptoms.
Measured: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment
Secondary outcomes (7)
Clinical Global Impression - Improvement (CGI-I)
The CGI-I (Clinical Global Impressions - Improvement) scale rates patient improvement on a scale from 1 to 7. Lower scores indicate better improvement.
Measured: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment
Rett Syndrome Behaviour Questionnaire
The Rett Syndrome Behaviour Questionnaire (RSBQ) assesses behavioural symptoms in individuals with Rett syndrome. Individual items are scored from 0 to 2. Higher total scores indicate more severe behavioural issues, meaning lower scores reflect better behavioural functioning.
Measured: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
RTT-Clinician Domain Specific Concerns - Visual Analog Scale
The Rett Syndrome Clinician Domain Specific Concerns Visual Analog Scale (RTT-DSC-VAS) assesses clinician concerns across specific domains of Rett syndrome. Each domain is scored on a scale from 0 to 7, with higher scores reflecting greater impairment in specific areas, while lower scores suggest less concern.
Measured: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
Communication and Symbolic Behaviour Scales Developmental Profile™ Infant-Toddler Checklist
The Communication and Symbolic Behavior Scales Developmental Profile Infant-Toddler Social Composite (CSBS-DP-IT Social) assesses early social communication skills in young children. Individual items are scored on a scale from 0 to 2, with higher scores indicating stronger social communication abilities. A lower total score reflects more social communication difficulties, while a higher score suggests better social engagement and communication skills.
Measured: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
Impact of Childhood Neurological Disability Scale
The Impact of Childhood Neurological Disability Scale (ICND) assesses the impact of neurological disabilities on a child\'s daily life and functioning. Each item is scored from 0 to 3, where higher scores indicate greater disability impact. A lower total score reflects less impact or better functioning, while higher scores suggest more significant limitations due to the neurological condition.
Measured: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
Rett Syndrome Caregiver Burden Inventory
The Rett Syndrome Caregiver Burden Inventory (RTT CBI) measures the burden experienced by caregivers of individuals with Rett syndrome. Individual items are scored from 0 to 4, with higher scores indicating a greater caregiver burden. Lower scores reflect less burden or stress, while higher scores suggest increased strain and challenges for caregivers.
Measured: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
The Overall Quality of Life Rating of the Impact of Childhood Neurological Disability Scale
The Overall Quality of Life Rating of the Impact of Childhood Neurological Disability Scale (ICND-QoL) is completed by the caregiver, who rates the child's overall quality of life on a scale from 0 to 6, with 0 indicating the worst possible quality of life and 6 indicating the best. Higher scores reflect a more positive perception of the child's quality of life, while lower scores suggest a greater negative impact of the neurological condition.
Measured: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Oct 2024
- Study start20 Sep 2023
- Primary completion1 Dec 2025
- Study completion1 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Rett SyndromeStudies 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 1/2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 14 participants (actual)
Sponsor and investigators
- Lead sponsor
- Fenix Innovation Group
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Neurotech International Limited
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06621043
- Sponsor's protocol ID
- NTIRTT1
- Status last verified
- Sep 2026
- First submitted
- 11 Sep 2024
- Last updated
- 9 Sep 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: IPD will not be shared as per commercial in confidence restrictions.
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessing the Safety and Efficacy of Full-Spectrum Medicinal Cannabis Plant Extract 0.08% THC (NTI164) in the Treatment of Rett Syndrome (RTT)
- ClinicalTrials.gov ID
- NCT06621043
- Acronym / sponsor ID
- NTIRTT1
- Conditions
- Rett Syndrome
- Keywords
- RTT
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 14 participants (actual)
- Lead sponsor
- Fenix Innovation GroupIndustry (pharma, biotech, devices)
- Collaborators
- Neurotech International Limited
- Study start
- 20 Sep 2023 (actual)
- Primary completion
- 1 Dec 2025 (actual)
- Study completion
- 1 Dec 2025 (actual)
- First posted
- 1 Oct 2024 (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.
This 18-week open-label study examines the effectiveness of Full-Spectrum Medicinal Cannabis Plant Extract containing 0.08% THC (NTI164) in treating Rett syndrome (RTT) in children and young people. The study aims to determine the impact of NTI164 on RTT symptoms over a 16-week treatment period.
Participants will start with a daily dose of 5 mg/kg of NTI164, which will be gradually increased over four weeks until they reach either the maximum tolerated dose or 20 mg/kg per day. They will then maintain this dose for eight weeks. Following this treatment phase, the dosage will be reduced by 5 mg/kg each week for four weeks until treatment concludes.
The effectiveness of the treatment will be assessed using tailored questionnaires that measure changes in the patients\' conditions. Additionally, full blood examinations will be conducted at multiple points throughout the study to monitor the effects of the treatment.
Detailed description
This study is an 18-week open-label trial designed to assess the effectiveness of Full-Spectrum Medicinal Cannabis Plant Extract containing 0.08% THC (NTI164) on the severity of symptoms in children and young people with Rett syndrome (RTT). The main objective is to determine how well NTI164 alleviates the symptoms of RTT over a 16-week treatment period.
The study involves multiple phases:
- Up-titration Phase (4 weeks): Treatment begins with an initial daily dose of 5 mg/kg of NTI164. Over the first four weeks, this dose is incrementally increased based on patient tolerance, aiming for a maximum daily dose of 20 mg/kg.
- Treatment Phase (8 weeks): Once the maximum tolerated dose is established, participants continue to receive this dose for the following eight weeks. This phase focuses on maintaining a steady dosage to observe the therapeutic effects on RTT symptoms.
- Down-titration Phase (4 weeks): After completing the treatment phase, the dosage is systematically reduced by 5 mg/kg each week for four weeks until treatment cessation. This gradual reduction helps in assessing any withdrawal effects and the stability of symptom improvement post-treatment.
Throughout the study, the efficacy of NTI164 is evaluated using specifically designed questionnaires that track changes in the emotional, behavioral, and cognitive functions of the participants, providing insights into how the treatment impacts various aspects of RTT. Additionally, full blood examinations are conducted at key points during the study to monitor the physiological responses to the treatment and to ensure the safety and tolerability of NTI164. This comprehensive approach allows for a detailed assessment of both the immediate and longer-term effects of the medicinal cannabis extract on Rett syndrome symptoms.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Active NTI164 Arm | Experimental | Drug: NTI164Participants in this arm receive Full-Spectrum Medicinal Cannabis Plant Extract containing 0.08% THC (NTI164), targeted at treating symptoms of Rett syndrome (RTT) in children and young people. The intervention starts with a daily initial dose of 5 mg/kg, which is increased gradually over a four-week up-titration phase to a maximum of 20 mg/kg per day, depending on individual tolerance. Participants then continue at their maximum tolerated dose for eight weeks during the treatment phase. The study concludes with a four-week down-titration phase, where the dosage is reduced by 5 mg/kg each week. The effectiveness of the treatment is monitored through specialized questionnaires and full blood examinations throughout the study duration. |
Who may qualify
- Ages
- 5 to 20 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (7 listed)
- Girls and women, aged 5-20 years
- Weight greater than or equal to 12kg
- Classical/typical RTT
- Documented disease-causing mutation in MECP2 gene
- At least 6 months post regression at screening (ie. no loss or degradation in ambulation, hand function, speech, nonverbal communicative or social skills within 6 months of screening) Rett Syndrome Clinical Severity Scale rating of 10-36
Key exclusion criteria (8 listed)
- Current clinically significant cardiovascular, endocrine (such as hypo- or hyperthyroidism, type 1 diabetes, or uncontrolled type 2 diabetes), renal, hepatic, respiratory, or gastrointestinal disease (such as celiac disease or inflammatory bowel disease), or major surgery planned during the study.
- Known history or symptoms of long QT syndrome.
- QTcF interval \>450 ms, history of risk factor for torsades de pointes or clinically significant QT prolongation deemed to increase risk.
- Treatment with insulin, IGF-1, or growth hormone within 12 weeks of baseline.
- Currently receiving treatment with DAYBUETM (trofinetide).
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 |
|---|---|---|
| NTI164Full-Spectrum Medicinal Cannabis Plant Extract containing 0.08% THC, administered orally starting with a dose of 5 mg/kg, titrated up to 20 mg/kg based on tolerance, followed by a maintenance phase at the maximum tolerated dose, and concluding with a gradual dose reduction. | Drug | Active NTI164 Arm |
Primary outcome
Rett Syndrome: Symptom Index Score
Time frame: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment
The Rett Syndrome: Symptom Index Score (RTT: SIS) measures the severity of various symptoms in individuals with Rett syndrome. Individual scores are from 0 to 7 with lower scores reflecting improvement or milder symptoms.
7 secondary outcomes
Clinical Global Impression - Improvement (CGI-I)
Time frame: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment
Rett Syndrome Behaviour Questionnaire
Time frame: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
RTT-Clinician Domain Specific Concerns - Visual Analog Scale
Time frame: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
Communication and Symbolic Behaviour Scales Developmental Profile™ Infant-Toddler Checklist
Time frame: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
Impact of Childhood Neurological Disability Scale
Time frame: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
Rett Syndrome Caregiver Burden Inventory
Time frame: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
The Overall Quality of Life Rating of the Impact of Childhood Neurological Disability Scale
Time frame: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Sep 2026.
- Individual participant dataSharing planned: No. IPD will not be shared as per commercial in confidence restrictions.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing NTI164 in people with Rett Syndrome, run by Fenix Innovation Group at 1 site in Australia.
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 7 inclusion and 8 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: finished, as of the sponsor's last update on 9 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 Australia. 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 combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rett Syndrome: Symptom Index Score (time frame: Baseline (pre-dose), 4, 12, 16 weeks post-commencement of treatment). 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 9 Sep 2026; AzTrials last refreshed its copy on 8 Nov 2026.