| E.1 Medical condition or disease under investigation | 
| E.1.1 | Medical condition(s) being investigated  | 
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| E.1.1.1 | Medical condition in easily understood language  | 
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| E.1.1.2 | Therapeutic area  | Diseases [C] - Nervous System Diseases [C10] | 
| MedDRA Classification | 
| E.1.3 | Condition being studied is a rare disease  |  No  | 
| E.2 Objective of the trial | 
| E.2.1 | Main objective of the trial  | 
To identify the biological mechanisms that mediate Exenatide-effect in the brain, and to measure true treatment-effect of Exenatide that is independent of the concurrent, symptomatic, dopaminergic treatment.  
 To evaluate the effect on motor-symptom progression.  (open-label extension part one). 
 To evaluate the rate and severity of AEs and the number of AEs related to long-term exposure to Exenatide(open-label extension part two).  | 
 
 
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| E.2.2 | Secondary objectives of the trial  | 
- To compare the effect of Exenatide to placebo on disease progression. - To compare the effect of Exenatide to placebo on motor-symptom progression.  - To compare the effect of Exenatide to placebo on the non-motor symptom progression. - To measure the safety of Exenatide in patients with PD.  - To evaluate pharmacokinetic properties of Exenatide.  - Frequency of adverse events (open-label extension part one). - To evaluate changes in motor, and non-motor symptoms activities of daily living and complications by dopaminergic treatment (open-label extension part one and two ). 
 
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| E.2.3 | Trial contains a sub-study  |  No  | 
| E.3 | Principal inclusion criteria  | 
•	Diagnosis of clinically probable Parkinson’s disease. •	Males or Females.  •	Hoehn and Yahr stage ≤ 2 in the ON medication state.  •	Patients are on levodopa treatment. •	No need for extended treatment adjustment, no significant motor fluctuations during the last year. •	All patients will be ≥25 and ≤80 years of age.  •	Ability to self-administer, or to arrange carer administration of the trial drug. •	Signed informed consent to participate in the trial. | 
 
 
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| E.4 | Principal exclusion criteria | 
•	Atypical or other causes of parkinsonism.  •	Prior intra-cerebral surgical intervention for Parkinson’s disease. Patients who have previously undergone Deep Brain Stimulation, intra-cerebral administration of growth factors, gene therapy or cell therapies will not be eligible.  •	Already actively participating in a trial of a device, drug or surgical treatment for Parkinson’s disease.  •	Previous exposure to Exenatide. •	Known abnormality on CT or MRI brain imaging considered likely to compromise compliance with trial protocol/FDG-PET acquisition. •	Patients with body mass index less than 18.5.  •	Patients with diabetes mellitus type 1. •	Patients with prediabetes, or T2DM. •	History of pancreatitis.  •	Severe gastrointestinal disease including gastroparesis. •	History of alcoholism. •	History of severe cardiac disease. •	History of pancreas cancer. •	History or suspicion of thyroid cancer.  •	Personal or family history of medullary thyroid cancer. •	Patients with Multiple Endocrine Neoplasia 2 (MEN2) syndrome. •	End-stage renal disease or creatinine clearance < 50 ml/min. •	Hyperlipidaemia.  •	Concurrent treatment with warfarin. •	Concurrent severe depression, defined as MADRS score more than 16. •	Concurrent dementia, defined as MMSE < 22.  •	Pregnancy and Breastfeeding. •	Known hypersensitivity or allergy or intolerance to GLP-1. •	Known hypersensitivity to Exenatide or any of its excipients. •	Potential participants who lack the capacity to give informed consent  •	Any medical, psychiatric or other condition which in the investigator’s opinion compromises the potential participant's ability to participate in the trial. 
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| E.5 End points | 
| E.5.1 | Primary end point(s) | 
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| E.5.1.1 | Timepoint(s) of evaluation of this end point | 
| Baseline, 9 and 21 months | 
 
 
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| E.5.2 | Secondary end point(s) | 
A. MDS-UPDRS part 3 in OFF-medication state and accelerometer-based parameters of physical activity, MDS-UPDRS part 3 in ON-medication state, MDS-UPDRS parts 1, 2 and 4,  biofluid-based parameters 
 B. LEDD 
 C. PDQ-39, NMSQuest, ESS, 
 D. MoCA 
 E. B-SIT 
 F. MADRS | 
 
 
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| E.5.2.1 | Timepoint(s) of evaluation of this end point | 
A. Baseline, 9, 18 and 21 months 
 B. Baseline, 3, 6, 9, 12, 15, 18 and 21 months 
 C. Baseline, 6, 12, 18 months 
 D. Baseline, 9 and 21 months 
 E. Baseline, 9 and 18 months 
 F. Screening, 6, 12 and 18 months | 
 
 
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| E.6 and E.7 Scope of the trial | 
| E.6 | Scope of the trial | 
| E.6.1 | Diagnosis |  No  | 
| E.6.2 | Prophylaxis |  No  | 
| E.6.3 | Therapy |  No  | 
| E.6.4 | Safety |  Yes  | 
| E.6.5 | Efficacy |  Yes  | 
| E.6.6 | Pharmacokinetic |  Yes  | 
| E.6.7 | Pharmacodynamic |  Yes  | 
| E.6.8 | Bioequivalence |  No  | 
| E.6.9 | Dose response |  No  | 
| E.6.10 | Pharmacogenetic |  No  | 
| E.6.11 | Pharmacogenomic |  No  | 
| E.6.12 | Pharmacoeconomic |  No  | 
| E.6.13 | Others |  No  | 
| E.7 | Trial type and phase | 
| E.7.1 | Human pharmacology (Phase I) |  No  | 
| E.7.1.1 | First administration to humans |  No  | 
| E.7.1.2 | Bioequivalence study |  No  | 
| E.7.1.3 | Other |  No  | 
| E.7.1.3.1 | Other trial type description |  | 
| E.7.2 | Therapeutic exploratory (Phase II) |  Yes  | 
| E.7.3 | Therapeutic confirmatory (Phase III) |  No  | 
| E.7.4 | Therapeutic use (Phase IV) |  No  | 
| E.8 Design of the trial | 
| E.8.1 | Controlled |  Yes  | 
| E.8.1.1 | Randomised |  Yes  | 
| E.8.1.2 | Open |  No  | 
| E.8.1.3 | Single blind |  No  | 
| E.8.1.4 | Double blind  |  Yes  | 
| E.8.1.5 | Parallel group |  Yes  | 
| E.8.1.6 | Cross over  |  No  | 
| E.8.1.7 | Other |  Yes  | 
| E.8.1.7.1 | Other trial design description | 
| A double-blind placebo-controlled trial followed by two open-label extensions, part one and part two | 
 
 
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| E.8.2 |  Comparator of controlled trial | 
| E.8.2.1 | Other medicinal product(s) |  No  | 
| E.8.2.2 | Placebo  |  Yes  | 
| E.8.2.3 | Other |  No  | 
| E.8.2.4 | Number of treatment arms in the trial | 2 | 
| E.8.3 | 
                                The trial involves single site in the Member State concerned
                             |  Yes  | 
| E.8.4 |  The trial involves multiple sites in the Member State concerned  |  No  | 
| E.8.5 | The trial involves multiple Member States |  No  | 
| E.8.6 Trial involving sites outside the EEA | 
| E.8.6.1 | Trial being conducted both within and outside the EEA |  No  | 
| E.8.6.2 | Trial being conducted completely outside of the EEA |  No  | 
| E.8.7 | Trial has a data monitoring committee |  Yes  | 
| E.8.8 | 
                        Definition of the end of the trial and justification where it is not the last
                        visit of the last subject undergoing the trial
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| E.8.9 Initial estimate of the duration of the trial | 
| E.8.9.1 | In the Member State concerned years | 6 | 
| E.8.9.1 | In the Member State concerned months | 6 | 
| E.8.9.1 | In the Member State concerned days |  |