Parkinson DiseasePhase 2/3NCT05116813
Open-label Safety Study of Dipraglurant (ADX48621) in Patients With Parkinson's Disease Receiving Levodopa-based Therapy
A Phase 2/3 study testing Dipraglurant in people with Parkinson Disease and Dyskinesia, Drug-Induced, run by Addex Pharma S.A. at 7 sites in United States.
Trial summary
This open-label study is designed to assess the long-term safety and tolerability of dipraglurant in PD patients for up to 52 weeks (at doses of 150-300 mg per day) for patients that have completed an Addex sponsored double-blind clinical trial of dipraglurant. Read more about this study
- Who is it for?
- Ages 30 to 85 years
- Conditions the study is for
- Parkinson Disease, Dyskinesia, Drug-Induced, Dyskinesias
- What is being tested?
- Dipraglurant
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 17 participants
- Where
- 7 sitesUnited States
- Study dates
- 25 Oct 2021to 15 Aug 2022
- Phase
- Phase 2/3
- 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 30 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Completed an Addex randomized controlled study of dipraglurant and, in the judgement of the Investigator, may benefit from open-label treatment
- Able to take study drug 3 times daily and no less than 3 hours apart
- Must be taking levodopa not less than 3 times daily throughout the study
- Must maintain stable regimen of antiparkinson's medications (including levodopa) and be willing to continue the same doses and regimens for the first 4 weeks of the study
Who cannot join
- Patient is judged by the Investigator to be inappropriate for the study (for reasons such as, but not limited to, significant noncompliance in the Addex randomized controlled study of dipraglurant)
- Use of amantadine or amantadine ER throughout the study
- Use of memantine throughout the study
- Any use of marijuana or other cannabis/cannabinoid products for the first 4 weeks of study participation
- Other protocol-defined inclusion and exclusion criteria may apply
Trial locations and contacts
7 sites in 1 country.
7 sites in 1 country
United States7 sites
Abington Neurologic Associates
Abington, Pennsylvania, 19001-3816
Augusta University
Augusta, Georgia, 30912
The Ohio State University Wexner Medical Center
Columbus, Ohio, 43210-1267
University of Kansas Medical Center
Kansas City, Kansas, 66160
Rutgers, the State University of New Jersey
New Brunswick, New Jersey, 08901
Icahn School of Medicine at Mount Sinai
New York, New York, 10029
University of Pennsylvania
Philadelphia, Pennsylvania, 19107
About this study
Official title: An Open-label Safety Study of Dipraglurant (ADX48621) in Patients With Parkinson's Disease Receiving Levodopa-based Therapy With or Without Concomitant Dopaminergic Medications
This open-label study is designed to assess the long-term safety and tolerability of dipraglurant in PD patients for up to 52 weeks (at doses of 150-300 mg per day) for patients that have completed an Addex sponsored double-blind clinical trial of dipraglurant.
- Conditions
- Parkinson Disease, Dyskinesia, Drug-Induced, Dyskinesias
- Being tested
- Dipraglurant
- Keywords
- Parkinson's disease, Dyskinesia, Levodopa-induced Dyskinesia
- Medical subject headings
- Parkinson Disease, Dyskinesia, Drug-Induced, Dyskinesias
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DipraglurantDrug
Also called ADX48621
Oral 50 mg and 100 mg tablet
| Study group | Role | What they receive |
|---|---|---|
| Dipraglurant TID | Experimental | Not described Receives: Drug: Dipraglurant |
What is being measured
The primary outcome is the main question the study is designed to answer.
Long-term safety and tolerability of dipraglurant as measured by incidence of adverse events
Testing the safety and tolerability of dipraglurant in patients with Parkinson's Disease Levodopa-induced dyskinesia based on the incidence of adverse events reported by patients and/or as identified by the Investigator based on clinical assessments conducted during the study.
Measured: Baseline (Day 1) to Week 52
Secondary outcomes (1)
Evaluate the continued utility of dipraglurant on dyskinesia as assessed by a change-from-baseline score on the Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS).
The MDS-UPDRS is a Parkinson's Disease (PD) rating scale scored from 0-272; it evaluates progression of disease in patients with PD. A higher score indicates more severe PD.
Measured: Baseline (Day 1) to Week 52
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Nov 2021
- Study start25 Oct 2021
- Primary completion17 Jun 2022
- Study completion15 Aug 2022
Why it stopped: Terminated prior to completing enrollment goals due to COVID-related difficulties in recruiting patients
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 2/3
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 17 participants (actual)
Sponsor and investigators
- Lead sponsor
- Addex Pharma S.A.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05116813
- Sponsor's protocol ID
- ADX48621-302
- Status last verified
- Aug 2025
- First submitted
- 1 Nov 2021
- Last updated
- 6 Aug 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-label Safety Study of Dipraglurant (ADX48621) in Patients With Parkinson's Disease Receiving Levodopa-based Therapy With or Without Concomitant Dopaminergic Medications
- ClinicalTrials.gov ID
- NCT05116813
- Acronym / sponsor ID
- ADX48621-302
- Conditions
- Parkinson Disease, Dyskinesia, Drug-Induced, Dyskinesias
- Keywords
- Parkinson's disease, Dyskinesia, Levodopa-induced Dyskinesia
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Terminated prior to completing enrollment goals due to COVID-related difficulties in recruiting patients
- Enrolment
- 17 participants (actual)
- Lead sponsor
- Addex Pharma S.A.Industry (pharma, biotech, devices)
- Study start
- 25 Oct 2021 (actual)
- Primary completion
- 17 Jun 2022 (actual)
- Study completion
- 15 Aug 2022 (actual)
- First posted
- 11 Nov 2021 (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 open-label study is designed to assess the long-term safety and tolerability of dipraglurant in PD patients for up to 52 weeks (at doses of 150-300 mg per day) for patients that have completed an Addex sponsored double-blind clinical trial of dipraglurant.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Dipraglurant TID | Experimental | Drug: Dipraglurant |
Who may qualify
- Ages
- 30 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Completed an Addex randomized controlled study of dipraglurant and, in the judgement of the Investigator, may benefit from open-label treatment
- Able to take study drug 3 times daily and no less than 3 hours apart
- Must be taking levodopa not less than 3 times daily throughout the study
- Must maintain stable regimen of antiparkinson's medications (including levodopa) and be willing to continue the same doses and regimens for the first 4 weeks of the study
Key exclusion criteria (5 listed)
- Patient is judged by the Investigator to be inappropriate for the study (for reasons such as, but not limited to, significant noncompliance in the Addex randomized controlled study of dipraglurant)
- Use of amantadine or amantadine ER throughout the study
- Use of memantine throughout the study
- Any use of marijuana or other cannabis/cannabinoid products for the first 4 weeks of study participation
- Other protocol-defined inclusion and exclusion criteria may apply
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 |
|---|---|---|
| DipraglurantAlso: ADX48621Oral 50 mg and 100 mg tablet | Drug | Dipraglurant TID |
Primary outcome
Long-term safety and tolerability of dipraglurant as measured by incidence of adverse events
Time frame: Baseline (Day 1) to Week 52
Testing the safety and tolerability of dipraglurant in patients with Parkinson's Disease Levodopa-induced dyskinesia based on the incidence of adverse events reported by patients and/or as identified by the Investigator based on clinical assessments conducted during the study.
1 secondary outcome
Evaluate the continued utility of dipraglurant on dyskinesia as assessed by a change-from-baseline score on the Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS).
Time frame: Baseline (Day 1) to Week 52
Results and safety
The study was stopped early (reason given: Terminated prior to completing enrollment goals due to COVID-related difficulties in recruiting patients). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Aug 2025.
- Individual participant dataSharing planned: No
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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.
7 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2/3 study testing Dipraglurant in people with Parkinson Disease and Dyskinesia, Drug-Induced, run by Addex Pharma S.A. at 7 sites 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 5 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: stopped early, as of the sponsor's last update on 6 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites 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 combined 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.
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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 was stopped early (reason given: Terminated prior to completing enrollment goals due to COVID-related difficulties in recruiting patients). Results are not available in the source record.
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?
Long-term safety and tolerability of dipraglurant as measured by incidence of adverse events (time frame: Baseline (Day 1) to Week 52). 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 6 Aug 2025.