A Phase 3 interventional study of amantadine HCl ER and Placebo in Parkinson's Disease and Levodopa Induced Dyskinesia (LID), sponsored by Adamas Pharmaceuticals, Inc.. Terminated at 56 sites in 5 countries. Open to participants aged 30 Years to 85 Years. Per ClinicalTrials.gov, last updated 2022-02-16.
Sponsored by Adamas Pharmaceuticals, Inc. (part of Supernus Pharmaceuticals, Inc.) · Phase 3, Interventional, and Treatment
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Among 12 studies testing amantadine in Parkinson Disease — none open to participants now, none under way, none of them phase 3. Amantadine · Parkinson Disease.
Among the 12 studies testing amantadine in Parkinson Disease, this one is the 3rd largest by enrollment, is one of 2 that started in 2014, is one of 3 in phase 3, and was the 9th registered.
4,576 studies on the registry are indexed under Parkinson Disease; 1,087 are open to participants now.
Browse Parkinson Disease studies →None of the 12 studies testing amantadine in Parkinson Disease is open now. The open studies under Parkinson Disease, anywhere →
Amantadine: first FDA approval 1968 (SYMMETREL). What it is approved for, and how studies give it, is on its page →
Of the 749 Parkinson Disease studies recruiting now, 311 (42%) set no upper age limit and 127 (17%) stop at 75 or younger; 64 take children under 18; 189 take healthy volunteers.
This study: 30 Years to 85 Years · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
12 studies; the count open now beside each. This study's row is marked.
First in 2007; this study’s year is marked. 2 started in 2014.
By drug class, each counting the studies that test any of its medicines:
This study's enrollment of 135 is above the median of 40 across 3,355 interventional studies indexed under Parkinson Disease.
Median enrollment 57 across the 12 interventional studies. Of the 11 that completed or were terminated, 6 (55%) have results posted.
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2 of 12 have an industry lead sponsor. The 8 most frequent:
This study is registered under Adamas Pharmaceuticals, Inc., one of the names counted as Supernus Pharmaceuticals, Inc.. Under that name alone:
Adamas Pharmaceuticals, Inc. is the lead sponsor of 10 studies on the registry; none are open to participants now.
13 studies in Parkinson Disease by Supernus Pharmaceuticals, Inc.: 1 open now, 2 under way, 1 of them phase 3. Of 11 finished, 11 (100%) have results posted.
Among the 13 studies in Parkinson Disease by Supernus Pharmaceuticals, Inc., this one is the 2nd largest by enrollment of the 11 interventional ones that give a count, is one of 5 that started in 2014, is one of 6 in phase 3, and was the 5th registered.
Supernus Pharmaceuticals, Inc.’s Parkinson Disease studies by the year they started, since 2011.
None of the studies under way reaches primary completion within a year.
Among the 12 studies testing amantadine in Parkinson Disease, from their registry updates:
Nothing recorded among them since 2026-09-25.
Among Supernus Pharmaceuticals, Inc.’s 13 in Parkinson Disease:
Nothing recorded among them since 2026-09-25.
This tab as a report to print or save as PDF → With an account.
The purpose of this multi-center, randomized, double-blind, parallel-group, 26 week study is to compare the efficacy and safety of two different dose levels of Amantadine Extended Release Tablets to placebo for the treatment of levodopa induced dyskinesia in patients with Parkinson's disease.
This study was terminated early due to slow enrollment with 135 of 162 planned subjects enrolled. Amantadine HCl ER has been used for many years as a treatment for Parkinson's disease. It has been reported in the literature to effectively treat the motor complications of levodopa, especially dyskinesia, but it must be given 2 to 4 times a day. The purpose of this multi-center, randomized, double-blind, parallel-group, 26 week study is to compare the efficacy and safety of two different dose levels of Amantadine Extended Release Tablets to placebo for the treatment of levodopa induced dyskinesia in patients with Parkinson's disease. The dose will be given once a day in the morning so that amantadine concentrations are maintained throughout the day for treating the levodopa induced dyskinesia, but will be lower during the night, potentially reducing the negative impact of amantadine on sleep.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
MMSE and MoCA
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
amantadine HCl ER, 240 mg tablets, once daily, 22 weeks
Drug: amantadine HCl ER
amantadine HCl ER, 320 mg tablets, once daily, 22 weeks
Drug: amantadine HCl ER
Placebo, tablets, once daily, 26 weeks.
Drug: Placebo
Subjects are given either 240 mg amantadine HCl ER tablet or 320 mg amantadine HCl ER tablet
Also known as: Osmolex ER Tablet
subjects are given an identical placebo tablet
Also known as: Placebo tablets
Unified Dyskinesia Rating Scale
The Unified Dyskinesia Rating Scale is a validated tool for assessment of dyskinesia (involuntary movements) in Parkinson's Disease patients. Rating consists of the change from baseline to Day 98 of the sum of the 26 questions comprising the questionnaire. Each question in the questionnaire is rated on a 5 point scale from 0-4 where 0 is a better outcome. Questions assess: over the past week total hours with dyskinesia and total hours without dyskinesia; problems with speech, chewing and swallowing, eating, dressing, hygiene, handwriting, hobbies, balance, socializing, emotions, spasm or cramps, pain without dystonia and pain from dystonia. The minimum (better) value is 0 and the maximum (worse) value is 130.
Time frame: Change from baseline to Day 98
Mobility State Self-Assessment - Subject Diary Cards
hange from baseline in the number of awake hours without troublesome dyskinesia (involuntary movements). Every half hour the subject will indicate in the diary if the medication has ("ON") or has not ("OFF") produced benefits in terms of mobility, slowness and rigidity. Valid diaries of the 3 consecutive days prior to each visit will be averaged with respect to the number of awake hours without troublesome dyskinesia. The change from baseline in the number of waking hours that subjects report being "ON" without troublesome dyskinesias will be analyzed at analysis visits Day 14 and Day 98 of treatment. Higher scores mean a better outcome and the maximum value is 24 hours.
Time frame: Day 14 and Day 98 of treatment
| Milestone | 240mg Amantadine HCl ER Tablets | 320mg Amantadine HCl ER Tablets | Placebo Tablets for Amantadine |
|---|---|---|---|
| Started | 45 | 46 | 44 |
| Completed | 27 | 27 | 25 |
| Not completed | 18 | 19 | 19 |
The Unified Dyskinesia Rating Scale is a validated tool for assessment of dyskinesia (involuntary movements) in Parkinson's Disease patients. Rating consists of the change from baseline to Day 98 of the sum of the 26 questions comprising the questionnaire. Each question in the questionnaire is rated on a 5 point scale from 0-4 where 0 is a better outcome. Questions assess: over the past week total hours with dyskinesia and total hours without dyskinesia; problems with speech, chewing and swallowing, eating, dressing, hygiene, handwriting, hobbies, balance, socializing, emotions, spasm or cramps, pain without dystonia and pain from dystonia. The minimum (better) value is 0 and the maximum (worse) value is 130.
| score on a scale | 240mg Amantadine HCl ER Tablets | 320mg Amantadine HCl ER Tablets | Placebo Tablets for Amantadine |
|---|---|---|---|
| Visit 2 (Baseline) | 41.3 ± 13.91 | 36.3 ± 12.40 | 40.7 ± 13.98 |
| Visit 7 (Day 98)/Stable Dose LOCF [1] | 41.3 ± 13.98 | 36.3 ± 12.40 | 40.7 ± 13.98 |
| Mean Change from Baseline (SD) | -15.2 ± 15.58 | -13.7 ± 10.95 | -9.0 ± 10.62 |
hange from baseline in the number of awake hours without troublesome dyskinesia (involuntary movements). Every half hour the subject will indicate in the diary if the medication has ("ON") or has not ("OFF") produced benefits in terms of mobility, slowness and rigidity. Valid diaries of the 3 consecutive days prior to each visit will be averaged with respect to the number of awake hours without troublesome dyskinesia. The change from baseline in the number of waking hours that subjects report being "ON" without troublesome dyskinesias will be analyzed at analysis visits Day 14 and Day 98 of treatment. Higher scores mean a better outcome and the maximum value is 24 hours.
| Hours | 240mg Amantadine HCl ER Tablets | 320mg Amantadine HCl ER Tablets | Placebo Tablets for Amantadine |
|---|---|---|---|
| Visit 2 (Baseline) | 10.4 ± 3.76 | 9.8 ± 3.48 | 9.1 ± 3.48 |
| Visit 7 (Day 98)/Stable Dose LOCF [1] | 12.7 ± 3.91 | 13.3 ± 3.83 | 11.1 ± 4.03 |
| Mean Change in Hours from Baseline (SD) | 2.3 ± 3.25 | 3.6 ± 3.93 | 1.6 ± 3.56 |
Collected over 26 weeks. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| 240mg Amantadine HCl ER Tablets | 0/45 (0%) | 1/45 (2.2%) | 36/45 (80%) |
| 320mg Amantadine HCl ER Tablets | 0/46 (0%) | 4/46 (8.7%) | 38/46 (82.6%) |
| Placebo Tablets for Amantadine | 0/44 (0%) | 6/44 (13.6%) | 29/44 (65.9%) |
| Event | 240mg Amantadine HCl ER Tablets | 320mg Amantadine HCl ER Tablets | Placebo Tablets for Amantadine |
|---|---|---|---|
| transient ischaemic attackNervous system disorders | 0/45 | 0/46 | 1/44 |
| lumbar spinal stenosisMusculoskeletal and connective tissue disorders | 0/45 | 0/46 | 1/44 |
| intervertebral disc protrusionMusculoskeletal and connective tissue disorders | 0/45 | 0/46 | 1/44 |
| brain abscessInfections and infestations | 0/45 | 0/46 | 1/44 |
| contipation diabetes mellitus inadequate controlMetabolism and nutrition disorders | 0/45 | 0/46 | 1/44 |
| thoracic vertebral fractureInjury, poisoning and procedural complications | 0/45 | 0/46 | 1/44 |
| hypertensionVascular disorders | 1/45 | 0/46 | 0/44 |
| osteoarthritisMusculoskeletal and connective tissue disorders | 0/45 | 1/46 | 0/44 |
| constipation hemorrhoidsGastrointestinal disorders | 0/45 | 1/46 | 0/44 |
| vestibular neuronitisInfections and infestations | 0/45 | 1/46 | 0/44 |
| Event | 240mg Amantadine HCl ER Tablets | 320mg Amantadine HCl ER Tablets | Placebo Tablets for Amantadine |
|---|---|---|---|
| NauseaGastrointestinal disorders | 6/45 | 6/46 | 1/44 |
| FallInjury, poisoning and procedural complications | 5/45 | 4/46 | 5/44 |
| DyskinesiaNervous system disorders | 5/45 | 3/46 | 3/44 |
| Dry mouthGastrointestinal disorders | 4/45 | 5/46 | 0/44 |
| Urinary tract infectionInfections and infestations | 3/45 | 5/46 | 3/44 |
| FatigueGeneral disorders | 0/45 | 3/46 | 4/44 |
| SomnolenceNervous system disorders | 3/45 | 0/46 | 4/44 |
| Oedema peripheralGeneral disorders | 0/45 | 4/46 | 1/44 |
| ArthralgiaMusculoskeletal and connective tissue disorders | 3/45 | 1/46 | 0/44 |
| DizzinessNervous system disorders | 3/45 | 2/46 | 0/44 |
| Age, Categorical(Participants) | 240mg Amantadine HCl ER Tablets | 320mg Amantadine HCl ER Tablets | Placebo Tablets for Amantadine | Total |
|---|---|---|---|---|
| <=18 years | 0 | 0 | 0 | 0 |
| Between 18 and 65 years | 45 | 46 | 44 | 135 |
| >=65 years | 0 | 0 | 0 | 0 |
| Age, Continuous(years) | 240mg Amantadine HCl ER Tablets | 320mg Amantadine HCl ER Tablets | Placebo Tablets for Amantadine | Total |
|---|---|---|---|---|
| Mean | 63.9 ± 8.88 | 63.0 ± 8.98 | 63.5 ± 10.36 | 63.5 ± 9.36 |
| Sex: Female, Male(Participants) | 240mg Amantadine HCl ER Tablets | 320mg Amantadine HCl ER Tablets | Placebo Tablets for Amantadine | Total |
|---|---|---|---|---|
| Female | 16 | 21 | 18 | 55 |
| Male | 29 | 25 | 26 | 80 |
| Region of Enrollment(participants) | 240mg Amantadine HCl ER Tablets | 320mg Amantadine HCl ER Tablets | Placebo Tablets for Amantadine | Total |
|---|---|---|---|---|
| Canada | 3 | 1 | 2 | 6 |
| United States | 15 | 23 | 23 | 61 |
| France | 10 | 7 | 8 | 25 |
| Germany | 7 | 6 | 6 | 19 |
| Spain | 10 | 9 | 5 | 24 |
Ran from Jul 2014 to primary completion in May 2016, 21 months.
Results were first posted in Apr 2019, 2 years 10 months after primary completion.
How these figures are worked out, and which studies are left out of them.
This study is terminated, as verified in Feb 2022. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Amantadine
Adamas Pharmaceuticals, Inc. →