Could a diabetes drug be the key to slowing Parkinson's?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Diagnosis of Parkinson's disease. 2. Hoehn and Yahr stage ≤2.5 in the ON medication state. 3. Between 25 and 80 years of age. 4. On dopaminergic treatment for at least 4 weeks before enrolment. 5. Ability to self-administer, or to arrange carer administration of trial medication. 6. Documented informed consent to participate. Exclusion Criteria: 1. Diagnosis or suspicion of other cause for Parkinsonism. 2. Patients unable to attend the clinic visits in the practically defined OFF medication state. 3. Body mass index \<18.5. 4. Known abnormality on CT or MRI brain imaging considered likely to compromise compliance with trial protocol. 5. Significant cognitive impairment defined by a score \<21 on the Montreal Cognitive Assessment. 6. Concurrent severe depression defined by a score ≥16 on the Patient Health Questionnaire (PHQ-9). 7. Prior intra-cerebral surgical intervention for Parkinson's disease. 8. Previous participation in one of the following Parkinson's disease trials (Biogen SPARK trial, Prothena Pasadena trial, Sanofi Genzyme MOVES-PD trial, UDCA-PD UP Study or any other trial still considered to involve a potentially PD modifying agent). 9. Participation in another clinical trial of a device, drug or surgical treatment within the last 30 days 10. Previous exposure to exenatide. 11. Impaired renal function with creatinine clearance \<50ml/min. 12. History of pancreatitis. 13. Type 1 or Type 2 diabetes mellitus. 14. Severe gastrointestinal disease (e.g. gastroparesis) 15. Hyperlipidaemia. 16. History or family history of medullary thyroid cancer (MTC). 17. Multiple endocrine neoplasia 2 (MEN2) syndrome. 18. Hypersensitivity to any of exenatide's excipients. 19. Females that are pregnant or breast feeding. 20. WOCBP who are unwilling or unable to use an acceptable method to avoid pregnancy for the entire trial period and up to 3 months after the last dose of trial medication. 21. Participants who lack the capacity to give informed consent 22. Any medical or psychiatric condition or previous conventional/experimental treatment which in the investigator's opinion compromises the potential participant's ability to participate.