Randomized Placebo Controlled Trial Evaluating the Efficacy of Pimavanserin, a Selective Serotonin 5-HydroxyTryptamine-2A (5HT2A) Inverse Agonist, to Treat Impulse Control Disorders in Parkinson's Disease. (PIMPARK)

  • End date
    Jul 31, 2023
  • participants needed
  • sponsor
    University Hospital, Strasbourg, France
Updated on 25 March 2022
dopamine agonists
anticholinergic agents
impulse control disorder


There is no consensus on the treatment of Impulse Control Disorder (ICD) in Parkinson Disease (PD) though it is recommended to reduce the dosage of dopamine agonists (DA).

Reduction of DA frequently leads to a worsening of motor signs (parkinsonism or dyskinesias due to the concomitant increase of levodopa doses) and non-motor signs with the appearance of a DA withdrawal syndrome (DAWS).

Chronic stimulation of the sub-thalamic nuclei may reduce ICD but is restricted to a minority of patients and cases of new-onset ICD symptoms post stimulation have been reported. The benefit of amantadine in pathological gambling is controversial and the efficacy of clozapine has been reported in a few cases but with serious safety limitations. Very recently, naltrexone did not significantly improve ICD.

Thus, an efficacious and safe treatment of ICD in PD remains an unmet need for clinical practice.

Recently, it has been reported that pimavanserin, a selective serotonin 5-HT2A inverse agonist with a satisfactory safety profile without motor side effects, was efficient in improving psychosis, insomnia and day-time sleep in PD.

Pimavanserin, marketed under the tradename NUPLAZID® was approved in 2016 by the U.S. Food and Drug Administration (FDA) for the treatment of hallucinations and delusions associated with Parkinson's disease psychosis.

The link between serotonin and ICD has been well established, since the enhancement of 5HT2A receptors stimulation is associated to ICD, since serotonin modulates mesolimbic dopaminergic reward system transmission and given that serotonin neurotransmission is increased during chronic intake of dopamine agonist such as pramipexole which is well-known to induce ICD in PD patients. Thus, there is a large body of evidence suggesting that the decrease of the 5HT2A activity could be efficient in reducing ICD in PD. This further supports the concept of testing the efficacy of pimavanserin (a selective 5HT2A inverse agonist) for treating ICD in PD. Our aim is to conduct a study evaluating the efficacy and safety of pimavanserin on ICD in PD.

This clinical trial is conducted with the support of the French NS-Park/FCRIN (French Clinical Research Infrastructure Network) network.

Condition Parkinson Disease
Treatment cardiac monitoring, Blood analysis, Active drug: pimavanserin 17mg (2 strength tablets), Placebo: 2 tablets containing same excipients except active compound, Assessment of severity of ICD (impulse control disorders), Assessment of motor and non-motors symptoms of PD Evaluation of hyper- and hypodopaminergic behaviors, Assessment of quality of life, Assessment of depression, Assessment of cognition, Assessment of severity of Parkinson Disease
Clinical Study IdentifierNCT03947216
SponsorUniversity Hospital, Strasbourg, France
Last Modified on25 March 2022


Yes No Not Sure

Inclusion Criteria

Patient with PD according to the UKPDSBB criteria for at least 1 year before randomization
Patient, man or woman, aged from 35 to 75 years old
Patient with moderately severe ICD assessed by QUIP-RS (each item being rated 0-16) defined as
pathological gambling" sub-score from 6 to 12 (included)
a combined ICD total score (defined as the sum of the 4 ICD sub-scores (pathological gambling + buying + hypersexuality + eating)) superior or equal to 10 or
buying" sub-score from 8 to 12 (included)
at least one of the 4 ICD sub-scores in the following range
ICD onset after PD onset and after initiation of dopaminergic drugs
hypersexuality" sub-score from 8 to 12 (included)
Patient treated by dopaminergic drugs for at least 3 months before randomization
eating" sub-score from 7 to 12 (included) (Weintraub et al., 2012). The use of "lower" margins will guarantee that the patient experiences behavioral disturbances severe enough to justify pimavanserin treatment. On the other hand, the use of "upper" margins will guarantee that the patients included in the trial will not suffer from ICD severe enough to question ethically the use of placebo during the 8 weeks of the treatment. Eligibility of patients with QUIP-RS sub-scores above 12 will be assessed upon investigator's request by an adjudication committee composed by independent experts external to the study (cf IX.3 Adjudication Committee)
Patient with health insurance
Patient treated with a stable regimen of levodopa, dopamine agonists, COMT and MAOB inhibitors, amantadine, anticholinergic, antidepressant and benzodiazepine for at least 1 month before the randomization and be willing to remain on the same doses throughout the course of their participation in the trial (Papay et al., 2014)
Patient/ guardian / curator who sign the written informed consent
For women of childbearing potential, use of an effective contraception method _for at least 1 month prior to randomization until 8 weeks after the last dose of study drug administration. Women who do not have an effective contraception_ must : have had her last natural menstruation ≥24 months prior to the selection visit, or have been surgically sterilized prior to the selection visit, or have had a hysterectomy prior to the selection visit

Exclusion Criteria

Patient suffering from another parkinsonian syndrome (multiple system atrophy, progressive supranuclear palsy, Lewy body dementia, corticobasal degeneration)
Patient who have a known hypersensitivity to the study treatment, based on known allergies to drugs of the same class
Stroke, uncontrolled serious medical illness, myocardial infarction, congestive heart failure, cardiac function disorders, within 6 months before randomization
Patient with history of long QT syndrome
Patient treated with antipsychotic drugs during the last three months before randomization
Patient with long QTcB detected with ECG at inclusion visit (> 450 ms)
Patient treated with concomitant medication leading to torsade de pointes (TdP) without discontinuation ≥ 5 half-lives before randomization (please refer to medications list with known risks of TdP on appendix XVII.5.10 and check website <https://crediblemeds.org/index.php/tools/> for the most up-to-date information)
Patient with hydro-electrolytics troubles, particularly hypokaliemia or hypocalcemia not corrected, at inclusion visit or assessed no later than 8 days before randomization
Patient treated with a strong or moderate CYP3A4 inducer: carbamazepine, rifampicin, phenytoin, modafinil, efavirenz or a strong inhibitor of CYP3A4: azole antifungals, protease inhibitors, macrolids, without discontinuation ≥ 5 half-lives before randomization
Patient treated with medicinal plants interacting with CYP3A4 without discontinuation ≥ 5 half-lives before randomization (Echinacea (E.pupurea, E.angustifolia and E.pallida), Piperina, Artemisia, St. John's Wort and Ginkgo
Patient with Montreal Cognitive Assessment (MoCA) (Nasreddine et al., 2005) score < 20 (to exclude patients likely with dementia) at inclusion visit (Papay et al., 2014)
Patient suffering from severe depression or marked suicidal thoughts (score > 3 on the suicidal thoughts item of the MADRS) at inclusion visit (Papay et al., 2014)
History of DBS within the past year before randomization, or change in stimulation parameters less than one month prior to randomization
Hematologic or solid malignancy diagnosis within 5 years prior to randomization
[Note: Subjects with a history of localized skin cancer, basal cell or
squamous cell carcinoma, may be enrolled in the study as long as they are
cancer free prior to randomization. Subjects with other localized cancers
(without metastatic spread) who have previously completed their course of
treatment more than 5 years prior to randomization, are not currently
receiving treatment and have been in remission may be enrolled only if, in the
opinion of the Investigator, there is no expectation for recurrence or further
cancer treatment during the study period. Antihormonal therapy (e.g
tamoxifen) is allowed if the subject's cancer is in remission and the subject
is on stable maintenance therapy to reduce their risk of recurrence.]
Patient suffering from severe renal impairment define as CrCL<30 mL/min, Cockcroft-Gault at inclusion visit or assessed no later than 8 days before randomization
Clinically significant hepatic impairment
Current participation in another research involving human beings of category 1 or 2
Patient with language barriers precluding adequate understanding or co-operation or who, in the opinion of the investigator, should not participate in the trial
Treatment with an investigational treatment within 30 days prior to randomization
Woman pregnant, nursing or of childbearing potential age without effective contraception methods or intends to become pregnant
an effective contraception method is defined as implants, oral oestro-progestative contraceptives or progestative which inhibit ovulation contraceptives (e.g, desogestrel), or double barrier method (condom plus spermicide or diaphragm plus spermicide) or levonorgestrel intrauterine devices, or vasectomized partner (confirmed with two negative spermograms)
Clear my responses

How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact



Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider


Browse trials for

Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note