Overview
Sponsor-declared trial summary
Parkinson's disease
To assess whether daily tadalafil improves motor symptoms in Parkinson-drug naïve patients with early-stage Parkinson’s disease over a two-week follow-up period
Key facts
- Sponsor
- Amsterdam UMC Stichting
- Participant type
- Patients
- Age range
- 18-64 years, 65+ years
- Gender
- Male and Female
- Therapeutic area
- Diseases [C] - Nervous System Diseases [C10]
- Trial duration
- 2 Mar 2026 → ongoing
- Decision date (initial)
- 2026-01-05
- Transition trial
- No
- Low-intervention
- No
- Rare-disease indication
- No
- Vulnerable population
- No
- Funding sources
- Research Institute Amsterdam Neuroscience, Amsterdam UMC, Amsterdam, the Netherlands
Trial design
CTIS Part I — objectives, methods, condition coding
Main objective
Scope: Therapy, Efficacy
To assess whether daily tadalafil improves motor symptoms in Parkinson-drug naïve patients with early-stage Parkinson’s disease over a two-week follow-up period
Secondary objectives 3
- Adverse effects during three-week follow-up
- Participant's treatment burden after two weeks follow-up
- Participant’s satisfaction after two weeks follow-up
Conditions and MedDRA coding
Parkinson's disease
Eligibility criteria
Principal inclusion / exclusion criteria as submitted by sponsor
Inclusion criteria 6
- Diagnosis of early-stage Parkinson’s disease, with no limitations in daily functioning that would necessitate symptomatic treatment
- No prior medication for Parkinson’s disease.
- Normal blood pressure (between >90/60 mm Hg and <120/80 mm Hg).
- Age older than 18 years.
- Informed consent and comply with the study protocol.
- Understand the Dutch language.
Exclusion criteria 15
- Currently taking PDE-inhibitors for erectile dysfunction.
- Immunocompromised.
- Mild cognitive impairment (MCI) or dementia.
- Pregnancy and breastfeeding.
- Legally incompetent adults.
- Clinically significant penile deformity.
- Concurrent nitrate, nitric oxide donors, guanylate cyclase, nicorandil, theophylline alpha-blocker, cytochrome P-450 3A4 (CYP3A4) inhibitor/inducer, or prostacyclin analog use.
- Suspicion of or a known history of renal (eGFR level < 80 ml/min) or hepatic insufficiency.
- Significant alcohol or drug abuse.
- (unstable) Cardiovascular and cerebrovascular disease.
- Unilateral blindness, hereditary retinal disorders, or increased risk of blindness.
- Unilateral deafness or history of severe hearing loss dependent upon hearing aid(s).
- Multisystem atrophy (MSA).
- Abnormal electrocardiogram (ECG).
- Orthostatic hypotension: a decrease in systolic blood pressure ≥ 20 mmHg, or a decrease in diastolic blood pressure ≥ 10 mmHg.
Endpoints
Primary and secondary outcome measures (English text)
Primary endpoints 1
- Change in motor symptoms using the MDS-UPDRS part III from baseline to two weeks after daily tadalafil administration.
Secondary endpoints 3
- All adverse events will be recorded during follow-up. The following specific side effects will be assessed (yes/no): 1) Headache, 2) Dyspepsia, 3) Back pain, 4) Muscle pain, 5) Flushing, 6) Nasal congestion, 7) Unwanted erections, and 8) Changes in libido. Blood pressure (mmHg) and heart rate (bpm) will be measured at baseline and after two weeks.
- Participant’s evaluation of the burden of the treatment after two weeks follow-up will be measured with a five-point Likert-type item.
- Participant’s satisfaction on the outcome of treatment after two weeks follow-up will be measured with a five-point Likert scale.
Investigational products
Investigational medicinal products (IMPs), comparators, placebo, auxiliary
Test 1
SCP102631331 · ATC
- Active substance
- Tadalafil
- Route of administration
- ORAL
- Max daily dose
- 20 mg milligram(s)
- Max total dose
- 210 mg milligram(s)
- Max treatment duration
- 14 Day(s)
- Authorisation status
- Authorised
- ATC code
- G04BE08 — TADALAFIL
- Marketing authorisation
- -
- Paediatric formulation
- No
- Orphan designation
- No
- Modified vs. Marketing Authorisation
- No
Sponsors and contacts
Sponsor organisations, regulatory contacts, third parties
Amsterdam UMC Stichting
- Sponsor organisation
- Amsterdam UMC Stichting
- Address
- De Boelelaan 1117
- City
- Amsterdam
- Postcode
- 1081 HV
- Country
- Netherlands
Scientific contact point
- Organisation
- Amsterdam UMC Stichting
- Contact name
- Prof. dr. R.M.A. de Bie
Public contact point
- Organisation
- Amsterdam UMC Stichting
- Contact name
- Prof. dr. R.M.A. de Bie
Locations
1 EU/EEA country · 1 investigational sites
By country
| Country | MS status | Planned subjects | Sites |
|---|---|---|---|
| Netherlands | Authorised, recruiting | 20 | 1 |
| Rest of world | — | 0 | — |
Investigational sites
Country notifications
Trial-start, recruitment-start, end and early-termination notifications submitted per Member State
| Country | Trial start | Trial end | Recruitment start | Recruitment end | Early termination |
|---|---|---|---|---|---|
| Netherlands | 2026-03-02 |
Results and documents
Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial
Documents 6 files
Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.
| Type | Title | Version |
|---|---|---|
| Protocol (for publication) | D1_ Protocol 2025-521819-39-00_redacted | 1.2 |
| Protocol (for publication) | D4_NL-NL_Patient facing document | 1 |
| Recruitment arrangements (for publication) | K1_ Recruitment arrangements | 1 |
| Subject information and informed consent form (for publication) | L1_NL-NL_SIS and ICF | 1.2 |
| Summary of Product Characteristics (SmPC) (for publication) | E2_ NL-NL_SmPC Tadalafil Teva | 1 |
| Synopsis of the protocol (for publication) | D1_ NL-NL_Protocol synopsis_2025-521819-39-00 | 1.1 |
Application history
1 submissions — initial application plus substantial / non-substantial modifications
| # | Type | Code | Submitted | Reference MS | Conclusion | Decision date |
|---|---|---|---|---|---|---|
| 1 | INITIAL | IN | 2025-09-23 | Netherlands | Acceptable 2025-12-19
|
2026-01-05 |