Parkinson DiseasePhase 1Allo-PDNCT06263010
Allopregnanolone as a Regenerative Treatment for Parkinson's Disease
A Phase 1 study testing Allopregnanolone in people with Parkinson Disease, run by Roberta Brinton at 1 site in United States.
Trial summary
The goal of this open-label, pilot clinical trial is to test allopregnanolone as a regenerative treatment in patients with Parkinson's disease (PD). The main questions this study aims to answer are: 1. Is a large-scale clinical trial testing how well it works in patients with PD feasible? 2. Read more about this study
- Who is it for?
- Ages 40 to 85 years
- Conditions the study is for
- Parkinson Disease
- What is being tested?
- Allopregnanolone
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 10 participants
- Where
- 1 siteUnited States
- Study dates
- 12 Jan 2024to 15 Jul 2025
- Phase
- Phase 1
- 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 40 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- History of Idiopathic sporadic Parkinson disease
- Hoehn \& Yahr stage 1-4
- Have been on stable doses of all anti-Parkinson's medications for 30 days prior to screening
- Provision of signed and dated informed consent form
Who cannot join
- Evidence of Parkinsonian syndrome.
- Any conditions that would contraindicate MRI studies.
- Undergone deep brain stimulation (DBS) surgery as treatment for PD.
- Iodine allergy, known serious hypersensitivity to ioflupane I-123, or other inability to undergo DaTscan.
- Clinically significant abnormal laboratory value and/or clinically significant unstable medical or psychiatric illness.
- History within the last 5 years of a primary or recurrent malignant disease, with the exception of resected cutaneous squamous cell carcinoma in situ, basal cell carcinoma, cervical carcinoma in situ, or prostate cancer in situ with a post-treatment prostatic-specific antigen within normal range.
Show all 10Show fewer
- Serious or unstable illnesses including cardiovascular, hepatic, renal, gastroenterologic, respiratory, endocrinologic, neurologic (other than PD), psychiatric, immunologic, or hematologic disease, and any other conditions that, in the investigator's opinion, could interfere with the safety and efficacy analyses in this study.
- History of chronic alcohol or substance abuse/dependence within the past 3 years.
- Current use of benzodiazepines, anticonvulsants, antipsychotics, or other drugs that might interact with the gamma-aminobutyric acid-A (GABA-A) receptor complex; use of calcium-channel blockers (e.g., amlodipine); use of dietary supplements containing Pregnenolone.
- Treatment with another investigational drug within 3 months of screening.
Trial locations and contacts
1 site in 1 country.
United States1 site
The University of Arizona Clinical & Translational Science Research Center
Tucson, Arizona, 85721
About this study
Official title: Allopregnanolone as a Regenerative Treatment for Parkinson's Disease: An Open-label, Pilot Clinical Trial
The goal of this open-label, pilot clinical trial is to test allopregnanolone as a regenerative treatment in patients with Parkinson's disease (PD). The main questions this study aims to answer are:
- Is a large-scale clinical trial testing how well it works in patients with PD feasible?
- Is allopregnanolone safe and well-tolerated in patients with PD.
- Can we see any signals of changes in imaging and clinical scales?
Participants will receive a weekly infusion in their vein of allopregnanolone for a total of 12 weeks. There is no placebo so everyone receives allopregnanolone and "Open-label" means the study is not blinded so both the participant and investigators know the assigned treatment.
Read the detailed description
This is an open-label, pilot clinical trial of allopregnanolone (Allo) as a regenerative treatment for Parkinson's disease. A total of 10 study participants will receive weekly infusions of Allo for 12 weeks. Participants will be male and female, age 40-80 years with a history of idiopathic, sporadic PD who have a Hoehn \& Yahr stage 1-4. Allo is a potent neuroregenerative agent that promotes proliferation of human neural stem cells and has the potential to function as a regenerative therapeutic to restore motor function in persons with PD. Results from several preclinical studies in rodent models of PD confirm improved motor function after Allo treatment.
Primary Objective: To assess the feasibility of a large-scale trial to determine the efficacy of weekly infusions of Allo in in patients with Idiopathic sporadic PD.
Secondary Objectives: To evaluate the safety and tolerability of weekly infusions of Allo in participants with idiopathic sporadic PD, and assess single-dose pharmacokinetics of allopregnanolone.
Tertiary / Exploratory Objectives: To assess efficacy signals of weekly infusions of Allo in participants with idiopathic sporadic PD.
- Determine target engagement of Allo using dopamine transporter (DaT) imaging and magnetic resonance imaging (MRI).
- Evaluate effect of Allo on motor function tests.
- Evaluate the effect of Allo on cognitive function tests and clinical ratings.
- Compare response to Allo administration between APOE4 carriers and non-carriers.
- Conditions
- Parkinson Disease
- Being tested
- Allopregnanolone
- Keywords
- Parkinson, Allopregnanolone, Regenerative therapeutic
- Medical subject headings
- Parkinson Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AllopregnanoloneDrug
Allopregnanolone is a neurosteroid ( 3α,5α-tetrahydroprogesterone, 3α-hydroxy-5α-pregnan-20-one) and by-product of the metabolism of the hormone progesterone.
| Study group | Role | What they receive |
|---|---|---|
| Allo APOE4 carriers | Experimental | Group of 5 participants who are carriers of the APOE4 gene and will receive allopregnanolone 4mg administered weekly via a 30-min IV infusion for a duration of 12 weeks. Receives: Drug: Allopregnanolone |
| Allo APOE4 none-carriers | Active comparator | Group of 5 participants who are none-carriers of the APOE4 gene and will receive allopregnanolone 4mg administered weekly via a 30-min IV infusion for a duration of 12 weeks. Receives: Drug: Allopregnanolone |
What is being measured
The primary outcome is the main question the study is designed to answer.
Study completion
Proportion of participant progression to study completion.
Measured: Week 13
Secondary outcomes (6)
Adverse Events
Proportion of participants with adverse events to assess safety.
Measured: Weekly from Baseline to Week 16
Infusion Reactions
Proportion of participants with infusion reactions to assess tolerability.
Measured: Weekly from Week 1 to Week 16
Pharmacokinetics: Peak Plasma Concentration (Cmax)
The highest concentration in plasma of allopregnanolone after an IV dose.
Measured: Week 1
Pharmacokinetics: Time of peak concentration (tmax)
Time required to achieve peak plasma levels
Measured: Week 1
Pharmacokinetics: Half-life (t1/2)
The time required for plasma concentration of Allopregnanolone to decrease by 50%.
Measured: Week 1
Pharmacokinetics: Area under the plasma concentration versus time curve (AUC)
The concentration of phytoSERMs in blood plasma as a function of time. Gives insight into the extent of exposure to phytoSERM and its clearance rate from the body.
Measured: Week 1
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Feb 2024
- Study start12 Jan 2024
- Primary completion15 Jul 2025
- Study completion15 Jul 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Parkinson DiseaseStudies 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
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 10 participants (actual)
Sponsor and investigators
- Lead sponsor
- Roberta Brinton
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Roberta Brinton, University of Arizona
- Investigators
- Scott Sherman, MD, Principal investigator, University of ArizonaRoberta D Brinton, PhD, Study chair, University of ArizonaGerson D Hernandez, MD, MPH, Study director, University of Arizona
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06263010
- Sponsor's protocol ID
- CIBS-2023-01
- Acronym
- Allo-PD
- Status last verified
- Mar 2026
- First submitted
- 8 Feb 2024
- Last updated
- 13 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Allopregnanolone as a Regenerative Treatment for Parkinson's Disease: An Open-label, Pilot Clinical Trial
- ClinicalTrials.gov ID
- NCT06263010
- Acronym / sponsor ID
- Allo-PD / CIBS-2023-01
- Conditions
- Parkinson Disease
- Keywords
- Parkinson, Allopregnanolone, Regenerative therapeutic
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 10 participants (actual)
- Lead sponsor
- Roberta BrintonUniversity, hospital or other
- Study start
- 12 Jan 2024 (actual)
- Primary completion
- 15 Jul 2025 (actual)
- Study completion
- 15 Jul 2025 (actual)
- First posted
- 16 Feb 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.
The goal of this open-label, pilot clinical trial is to test allopregnanolone as a regenerative treatment in patients with Parkinson's disease (PD). The main questions this study aims to answer are:
- Is a large-scale clinical trial testing how well it works in patients with PD feasible?
- Is allopregnanolone safe and well-tolerated in patients with PD.
- Can we see any signals of changes in imaging and clinical scales?
Participants will receive a weekly infusion in their vein of allopregnanolone for a total of 12 weeks. There is no placebo so everyone receives allopregnanolone and "Open-label" means the study is not blinded so both the participant and investigators know the assigned treatment.
Detailed description
This is an open-label, pilot clinical trial of allopregnanolone (Allo) as a regenerative treatment for Parkinson's disease. A total of 10 study participants will receive weekly infusions of Allo for 12 weeks. Participants will be male and female, age 40-80 years with a history of idiopathic, sporadic PD who have a Hoehn \& Yahr stage 1-4. Allo is a potent neuroregenerative agent that promotes proliferation of human neural stem cells and has the potential to function as a regenerative therapeutic to restore motor function in persons with PD. Results from several preclinical studies in rodent models of PD confirm improved motor function after Allo treatment.
Primary Objective: To assess the feasibility of a large-scale trial to determine the efficacy of weekly infusions of Allo in in patients with Idiopathic sporadic PD.
Secondary Objectives: To evaluate the safety and tolerability of weekly infusions of Allo in participants with idiopathic sporadic PD, and assess single-dose pharmacokinetics of allopregnanolone.
Tertiary / Exploratory Objectives: To assess efficacy signals of weekly infusions of Allo in participants with idiopathic sporadic PD.
- Determine target engagement of Allo using dopamine transporter (DaT) imaging and magnetic resonance imaging (MRI).
- Evaluate effect of Allo on motor function tests.
- Evaluate the effect of Allo on cognitive function tests and clinical ratings.
- Compare response to Allo administration between APOE4 carriers and non-carriers.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Allo APOE4 carriers | Experimental | Drug: AllopregnanoloneGroup of 5 participants who are carriers of the APOE4 gene and will receive allopregnanolone 4mg administered weekly via a 30-min IV infusion for a duration of 12 weeks. |
| Allo APOE4 none-carriers | Active comparator | Drug: AllopregnanoloneGroup of 5 participants who are none-carriers of the APOE4 gene and will receive allopregnanolone 4mg administered weekly via a 30-min IV infusion for a duration of 12 weeks. |
Who may qualify
- Ages
- 40 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- History of Idiopathic sporadic Parkinson disease
- Hoehn \& Yahr stage 1-4
- Have been on stable doses of all anti-Parkinson's medications for 30 days prior to screening
- Provision of signed and dated informed consent form
Key exclusion criteria (10 listed)
- Evidence of Parkinsonian syndrome.
- Any conditions that would contraindicate MRI studies.
- Undergone deep brain stimulation (DBS) surgery as treatment for PD.
- Iodine allergy, known serious hypersensitivity to ioflupane I-123, or other inability to undergo DaTscan.
- Clinically significant abnormal laboratory value and/or clinically significant unstable medical or psychiatric 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 |
|---|---|---|
| AllopregnanoloneAllopregnanolone is a neurosteroid ( 3α,5α-tetrahydroprogesterone, 3α-hydroxy-5α-pregnan-20-one) and by-product of the metabolism of the hormone progesterone. | Drug | Allo APOE4 carriers, Allo APOE4 none-carriers |
Primary outcome
Study completion
Time frame: Week 13
Proportion of participant progression to study completion.
6 secondary outcomes
Adverse Events
Time frame: Weekly from Baseline to Week 16
Infusion Reactions
Time frame: Weekly from Week 1 to Week 16
Pharmacokinetics: Peak Plasma Concentration (Cmax)
Time frame: Week 1
Pharmacokinetics: Time of peak concentration (tmax)
Time frame: Week 1
Pharmacokinetics: Half-life (t1/2)
Time frame: Week 1
Pharmacokinetics: Area under the plasma concentration versus time curve (AUC)
Time frame: Week 1
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 13 Mar 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. This study is not recruiting at the moment.
Scott Sherman, MD principal investigator
University of Arizona
Roberta D Brinton, PhD study chair
University of Arizona
Gerson D Hernandez, MD, MPH study director
University of Arizona
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Allopregnanolone in people with Parkinson Disease, run by Roberta Brinton 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 4 inclusion and 10 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 13 Mar 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 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.
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?
Study completion (time frame: Week 13). 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 13 Mar 2026; AzTrials last refreshed its copy on 8 Nov 2026.