ApathyNCT05182151
Effect of Istradefylline Treatment on Behavioral Measures of Apathy in Parkinson's Disease.
An observational study of Apathy and Parkinson Disease, run by Medical University of South Carolina at 1 site in United States.
Trial summary
Apathy is defined as a lack of feeling, emotion, interest, or concern. Apathy also involves reduction or loss of motivation and goal-directed behavior. Clinically significant apathy, where meaningful activities are given up and quality of life is diminished, is common in people with Parkinson's disease (PD). Read more about this study
- Who is it for?
- Ages 18 to 99 years
- Conditions the study is for
- Apathy, Parkinson Disease
- What is being tested?
- Istradefylline 40 mg
- How many people
- 8 participants
- Where
- 1 siteUnited States
- Study dates
- 29 Jul 2022to 1 Dec 2023
- Phase
- Observational
- 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 18 to 99 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients treated with dopaminergic therapy for idiopathic Parkinson's disease who have clinically significant motor fluctuations or "off" time warranting adjuvant treatment with ISD.
Who may be able to join
- Diagnosis of PD consistent with United Kingdom Brain Bank Criteria or the Movement Disorder Society Research Criteria for the Diagnosis of Parkinson's Disease, with bradykinesia and sequence effect being present, and prominent motor asymmetry (if no rest tremor).
- Current treatment with levodopa.
- Stable on levodopa and other study-approved medications for PD motor symptoms for at least four weeks prior to screening.
- Clinically significant wearing-off / fluctuating symptomatology warranting treatment with ISD
- Presence of apathy at baseline (LARS > -22)
- Living with adult informant
Who cannot join
- Current or prior treatment with istradefylline. 2. History of Deep Brain Stimulation (DBS) surgery, ablative surgery (e.g., pallidotomy, thalamotomy, focused ultrasound, etc.), Duopa pump implantation, or other invasive intervention for Parkinson's disease symptoms. 3. Injury or concomitant health condition at screening that would preclude engagement in light physical activity. 10 4. Prior history of cerebrovascular accident (e.g., stroke or aneurysm) or seizure disorder (other than febrile seizures during childhood). 5. Dementia (MoCA<22) 6. Psychotic symptoms that would raise concern for safe use of ISD, as indicated by domains A (delusions) and B (hallucinations) of the Neuropsychiatric Inventory (NPI), and defined as a score of ≥4 on either the A (frequency × severity) or B (frequency × severity) scales of the NPI. 7. Depressive mood symptoms at baseline likely to interfere with response to treatment (BDI-II>19) 8. Active suicidal ideation within 1 year prior to Screening Visit as determined by a positive response to Question 4 or 5 on the C-SSRS. 9. Diagnosis or treatment for any central nervous system disorder other than Parkinson's disease that could be expected in the eyes of the investigator to impact ability to participate in study. 10. Contraindications / conditions that would preclude safe dosing of 40mg ISD 11. Change in medications for mood or anxiety within 6 weeks of enrollment or anticipation of change in medications for mood or anxiety during the 8-week study period. 12. Moderate or severe hepatic impairment. 13. Current treatment with strong CYP3A4 inhibitors 14. Current treatment with strong CYP3A4 inducers 15. Pregnant women are not able to participate due to unknown safety risks associated with ISD
Trial locations and contacts
1 site in 1 country.
United States1 site
MUSC Movement Disorders Program
Charleston, South Carolina, 29425
About this study
Apathy is defined as a lack of feeling, emotion, interest, or concern. Apathy also involves reduction or loss of motivation and goal-directed behavior. Clinically significant apathy, where meaningful activities are given up and quality of life is diminished, is common in people with Parkinson's disease (PD).
Many individuals with Parkinson's disease experiencing fluctuations in the severity of their movement problems and medication "off" time. "Off" time refers to periods of the day between doses of PD medication when your motor symptoms (e.g., tremor, stiffness, slowness, walking problems, etc.) are worse and interfere with your ability to complete tasks of daily living. The investigational drug, Istradefylline, is an FDA-approved medication to treat motor fluctuations and "off" time in PD.
The purpose of this study is to investigate whether people with Parkinson's disease (PD) who are treated with istradefylline (ISD) show improvements in motivation and apathy over a 12-week period. Specifically, we wish to see whether people with PD who are treated with ISD engage in more physical and recreational activities, such as hobbies and other interests.
Read the detailed description
Apathy is a clinical syndrome characterized by lack of motivation, interest, engagement, and emotional reactivity for goal-directed behaviors (Starkstein et al., 2008). A common and troublesome symptom in Parkinson's disease (PD), apathy is associated with diminished quality of life for both the patient and care partner (Van Reekum, Stuss, \& Ostrander, 2005; Barone et al., 2009). To the extent that apathy reduces engagement in physical and social activities, it may also result in more rapid disease progression and cognitive decline (e.g., Crotty \& Schwarzchild, 2020). Addressing apathy is therefore a crucial component of treating PD. A recent open-label study demonstrated significant reduction in self-reported apathy with Istradefylline (ISD) in PD (Nagayama et al, 2019). This unsurprising result likely reflects contributions from known benefits of ISD with respect to daytime somnolence and improved motor functioning (Matsuura et al., 2017; Suzuki et al. 2017), as well as enhanced functioning of dopamine-mediated reward pathways. However, patients with PD advanced enough to warrant treatment with ISD may also have diminished insight and awareness, and therefore not be particularly reliable reporters (e.g., Orfei et al., 2018). It is also unknown whether and to what extent this is correlated with actual changes in behavior and caregiver burden.
The objective of this study is to determine whether treatment with ISD increases engagement in physical and other meaningful activities in patients with Parkinson's disease.
- Conditions
- Apathy, Parkinson Disease
- Being tested
- Istradefylline 40 mg
- Keywords
- istradefylline
- Medical subject headings
- Lethargy, Parkinson Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Istradefylline 40 mgDrug
adenosine A2A receptor antagonist
| Study group | Role | What they receive |
|---|---|---|
| Patient | istradefylline 40mg daily over 12 week period Receives: Drug: Istradefylline 40 mg |
What is being measured
The primary outcome is the main question the study is designed to answer.
Physical Activity Scale for the Elderly (PASE)
telephone survey
Measured: 12 weeks
Secondary outcomes (7)
Engagement in Meaningful Activities Survey (EMAS)
telephone survey
Measured: 12 weeks
Lille Apathy Rating Scale (LARS)
apathy scale
Measured: 12 weeks
Apathy Evaluation Scale (AES)
patient and informant
Measured: 12 weeks
Beck Depression Inventory (BDI-2)
Depression scale
Measured: 12 weeks
Epworth Sleepiness Scale (ESS)
scale to assess sleepiness
Measured: 12 weeks
Global Impression of Change
patient and informant
Measured: 12 weeks
Unified Parkinson's Disease Rating Scale
motor symptom rating
Measured: 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jan 2022
- Study start29 Jul 2022
- Primary completion1 Dec 2023
- Study completion1 Dec 2023
Why it stopped: recruitment issues
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ApathyStudies of the same condition, open and under way.
- More trials run by Medical University of South CarolinaThe sponsor's other registered studies.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 8 participants (actual)
Sponsor and investigators
- Lead sponsor
- Medical University of South Carolina
- Sponsor type
- University, hospital or other
- Collaborators
- Kyowa Kirin, Inc.
- Responsible party
- Sponsor
- Investigators
- Lilia Lovera, MD, Study chair, Medical University of South Carolina
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05182151
- Sponsor's protocol ID
- Pro00108116
- Status last verified
- Jan 2026
- First submitted
- 20 Dec 2021
- Last updated
- 2 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: None shared outside investigator group
Study at a glance
From the registry record, last updated by the sponsor on 2 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Istradefylline Treatment on Behavioral Measures of Apathy in Parkinson's Disease.
- ClinicalTrials.gov ID
- NCT05182151
- Acronym / sponsor ID
- Pro00108116
- Conditions
- Apathy, Parkinson Disease
- Keywords
- istradefylline
- Study type
- Observational
- Recruitment status
- TerminatedReason stopped: recruitment issues
- Enrolment
- 8 participants (actual)
- Lead sponsor
- Medical University of South CarolinaUniversity, hospital or other
- Collaborators
- Kyowa Kirin, Inc.
- Study start
- 29 Jul 2022 (actual)
- Primary completion
- 1 Dec 2023 (actual)
- Study completion
- 1 Dec 2023 (actual)
- First posted
- 10 Jan 2022 (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.
Apathy is defined as a lack of feeling, emotion, interest, or concern. Apathy also involves reduction or loss of motivation and goal-directed behavior. Clinically significant apathy, where meaningful activities are given up and quality of life is diminished, is common in people with Parkinson's disease (PD).
Many individuals with Parkinson's disease experiencing fluctuations in the severity of their movement problems and medication "off" time. "Off" time refers to periods of the day between doses of PD medication when your motor symptoms (e.g., tremor, stiffness, slowness, walking problems, etc.) are worse and interfere with your ability to complete tasks of daily living. The investigational drug, Istradefylline, is an FDA-approved medication to treat motor fluctuations and "off" time in PD.
The purpose of this study is to investigate whether people with Parkinson's disease (PD) who are treated with istradefylline (ISD) show improvements in motivation and apathy over a 12-week period. Specifically, we wish to see whether people with PD who are treated with ISD engage in more physical and recreational activities, such as hobbies and other interests.
Detailed description
Apathy is a clinical syndrome characterized by lack of motivation, interest, engagement, and emotional reactivity for goal-directed behaviors (Starkstein et al., 2008). A common and troublesome symptom in Parkinson's disease (PD), apathy is associated with diminished quality of life for both the patient and care partner (Van Reekum, Stuss, \& Ostrander, 2005; Barone et al., 2009). To the extent that apathy reduces engagement in physical and social activities, it may also result in more rapid disease progression and cognitive decline (e.g., Crotty \& Schwarzchild, 2020). Addressing apathy is therefore a crucial component of treating PD. A recent open-label study demonstrated significant reduction in self-reported apathy with Istradefylline (ISD) in PD (Nagayama et al, 2019). This unsurprising result likely reflects contributions from known benefits of ISD with respect to daytime somnolence and improved motor functioning (Matsuura et al., 2017; Suzuki et al. 2017), as well as enhanced functioning of dopamine-mediated reward pathways. However, patients with PD advanced enough to warrant treatment with ISD may also have diminished insight and awareness, and therefore not be particularly reliable reporters (e.g., Orfei et al., 2018). It is also unknown whether and to what extent this is correlated with actual changes in behavior and caregiver burden.
The objective of this study is to determine whether treatment with ISD increases engagement in physical and other meaningful activities in patients with Parkinson's disease.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Patient | – | Drug: Istradefylline 40 mgistradefylline 40mg daily over 12 week period |
Who may qualify
- Ages
- 18 to 99 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients treated with dopaminergic therapy for idiopathic Parkinson's disease who have clinically significant motor fluctuations or "off" time warranting adjuvant treatment with ISD.
Key inclusion criteria (6 listed)
- Diagnosis of PD consistent with United Kingdom Brain Bank Criteria or the Movement Disorder Society Research Criteria for the Diagnosis of Parkinson's Disease, with bradykinesia and sequence effect being present, and prominent motor asymmetry (if no rest tremor).
- Current treatment with levodopa.
- Stable on levodopa and other study-approved medications for PD motor symptoms for at least four weeks prior to screening.
- Clinically significant wearing-off / fluctuating symptomatology warranting treatment with ISD
- Presence of apathy at baseline (LARS > -22)
Key exclusion criteria (1 listed)
- Current or prior treatment with istradefylline. 2. History of Deep Brain Stimulation (DBS) surgery, ablative surgery (e.g., pallidotomy, thalamotomy, focused ultrasound, etc.), Duopa pump implantation, or other invasive intervention for Parkinson's disease symptoms. 3. Injury or concomitant health condition at screening that would preclude engagement in light physical activity. 10 4. Prior history of cerebrovascular accident (e.g., stroke or aneurysm) or seizure disorder (other than febrile seizures during childhood). 5. Dementia (MoCA<22) 6. Psychotic symptoms that would raise concern for safe use of ISD, as indicated by domains A (delusions) and B (hallucinations) of the Neuropsychiatric Inventory (NPI), and defined as a score of ≥4 on either the A (frequency × severity) or B (frequency × severity) scales of the NPI. 7. Depressive mood symptoms at baseline likely to interfere with response to treatment (BDI-II>19) 8. Active suicidal ideation within 1 year prior to Screening Visit as determined by a positive response to Question 4 or 5 on the C-SSRS. 9. Diagnosis or treatment for any central nervous system disorder other than Parkinson's disease that could be expected in the eyes of the investigator to impact ability to participate in study. 10. Contraindications / conditions that would preclude safe dosing of 40mg ISD 11. Change in medications for mood or anxiety within 6 weeks of enrollment or anticipation of change in medications for mood or anxiety during the 8-week study period. 12. Moderate or severe hepatic impairment. 13. Current treatment with strong CYP3A4 inhibitors 14. Current treatment with strong CYP3A4 inducers 15. Pregnant women are not able to participate due to unknown safety risks associated with ISD
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 |
|---|---|---|
| Istradefylline 40 mgadenosine A2A receptor antagonist | Drug | Patient |
Primary outcome
Physical Activity Scale for the Elderly (PASE)
Time frame: 12 weeks
telephone survey
7 secondary outcomes
Engagement in Meaningful Activities Survey (EMAS)
Time frame: 12 weeks
Lille Apathy Rating Scale (LARS)
Time frame: 12 weeks
Apathy Evaluation Scale (AES)
Time frame: 12 weeks
Beck Depression Inventory (BDI-2)
Time frame: 12 weeks
Epworth Sleepiness Scale (ESS)
Time frame: 12 weeks
Global Impression of Change
Time frame: 12 weeks
Unified Parkinson's Disease Rating Scale
Time frame: 12 weeks
Results and safety
The study was stopped early (reason given: recruitment issues). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Feb 2026.
- Individual participant dataSharing planned: No. None shared outside investigator group
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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.
Lilia Lovera, MD study chair
Medical University of South Carolina
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Apathy and Parkinson Disease, run by Medical University of South Carolina 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 6 inclusion and 1 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 2 Feb 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.
Are results available for this study?
The study was stopped early (reason given: recruitment issues). 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?
Physical Activity Scale for the Elderly (PASE) (time frame: 12 weeks). 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 2 Feb 2026.