Condition category
Nervous System Diseases
Date applied
30/08/2005
Date assigned
26/09/2005
Last edited
23/05/2016
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information

Type

Scientific

Primary contact

Dr David Burn

ORCID ID

Contact details

Regional Neurosciences Centre
Newcastle General Hospital
Westgate Road
Newcastle
NE46BE
United Kingdom
+44 (0)1912563425
d.j.burn@ncl.ac.uk

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

A1481189

Study information

Scientific title

A randomized double blind placebo controlled study to evaluate the modulation of cognitive functions in Parkinson's subjects by sildenafil

Acronym

SCOPE

Study hypothesis

That 48 weeks of sildenafil therapy will stabilize or slow down the progression of cognitive impairment in Parkinson's disease subjects with mild cognitive impairment when compared with untreated Parkinson's disease controls. The study will also assess the effects of sildenafil upon motor state and olfaction in Parkinson's disease since these parameters may also be improved by sildenafil.

Ethics approval

Not provided at time of registration

Study design

Randomised controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Not specified

Trial type

Treatment

Patient information sheet

Condition

Parkinson's disease (PD)

Intervention

Sildenafil dosing in the treatment group will start at 50 mg once daily for 4 weeks. Dosing is then increased to 100 mg daily for a further 44 weeks. The control group will receive matching placebo teatment for 48 weeks.

Intervention type

Drug

Phase

Not Specified

Drug names

Sildenafil

Primary outcome measures

1. To test if 48 weeks of sildenafil therapy will result in improved cognitive functions in Parkinson's disease subjects as measured by the paired association learning (PAL) test
2. To test if 48 weeks of sildenafil therapy will result in improved olfaction in Parkinson's disease subjects as measured by the UPSIT test

Secondary outcome measures

To test if 48 weeks of sildenafil therapy will result in improved motor and cognitive function in Parkinson's disease subjects as measured by the Unified Parkinson's Disease Rating Scale (UPDRS), Dyskinesia Rating Scale, Spatial Working Memory Test and Reaction Time Test.

Overall trial start date

14/12/2004

Overall trial end date

30/09/2006

Reason abandoned

Eligibility

Participant inclusion criteria

1. Male or female subjects (excluding women of child bearing potential) between the ages of 50 and 80 years, inclusive
2. Diagnosis of Parkinson's disease according to UK Parkinson's Disease Society Brain Bank Criteria
3. Diagnosis of Parkinson's disease >12 months
4. Mild cognitive impairment insufficient to fulfill Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for dementia, with MMSE score 18-27
5. University of Pennsylvania Smell Identification Test (UPSIT) test score of <30
6. Subjects must be willing and able to provide written informed consent

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

100 subjects, 50 randomised to both sildenafil and placebo group

Participant exclusion criteria

1. Subjects with evidence of severe or unstable concomitant medical illness
2. Known hypersensitivity to, or current use of sildenafil, or other PDE5 inhibitors
3. Clinically significant orthostatic hypotension (defined as disabling postural light-headedness or syncopal episodes associated with a fall in systolic blood pressure on standing of over 30 mmHg)
4. Patient taking anti-psychotic or cholinesterase inhibitor medication
5. Patient taking dopamine agonists
6. Major depressive disorder
7. Anosmia secondary to head injury/non-PD related cause
8. Exclusion of patients with Multiple Systems Atrophy
9. Exclusion of patients with colour-blindness
10. Subjects who were prescribed and/or are taking nitrates or nitric oxide donors in any form (oral, sub-lingual, tansdermal, inhalation,aerosols), alpha blockers and/or class IA or III anti-arrhythmic medication
11. Use of medication known or suspected to be potent or moderate inhibitors of cytochrome P4503A4 (excluding ketoconazole, itraconazole, cimetidine, ritonavir)
12. Subjects with congenital QT prolongation
13. Electrocardiogram (ECG) evidence of severe life-threatening rhythm or ischaemic disturbances including acute myocardial infarction (within last year), left bundle branch block, or ventricular tachycardia
14. QTcF prolongation >500 msecs
15. Sustained hypertension >170 mmHg systolic or >110 mmHg diastolic; sustained hypotension <90 mmHg systolic or <50 mmHg diastolic
16. History of regular alcohol abuse within 6 months of screening
17. Treatment with investigational drug within 30 days or 5 half-lives (whichever is longer) preceding the first dose of study medication

Recruitment start date

14/12/2004

Recruitment end date

30/09/2006

Locations

Countries of recruitment

United Kingdom

Trial participating centre

Regional Neurosciences Centre
Newcastle
NE46BE
United Kingdom

Sponsor information

Organisation

Pfizer Inc. (USA)

Sponsor details

Groton Laboratories
Clinical Sciences Dept.
445 Eastern Point Road
Groton
CT06340
United States of America

Sponsor type

Industry

Website

Funders

Funder type

Industry

Funder name

Study is fully funded by Pfizer Inc. (USA)

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes

23/05/2016: No publications found, verifying study status with principal investigator