Multiple dose study of YTX-7739

Part A
1. Adult male or female subjects 18-55 years of age, inclusive.
Part B
2. Male or female subjects 40-75 years of age, inclusive, with a confirmed diagnosis of Parkinson’s disease (Hoehn and Yahr grade 1-3.

Part A + B
3. Healthy status as defined by absence of evidence of any significant active acute or chronic disease or illness following a detailed medical and surgical history, a complete physical examination including vital signs, 12-lead ECG, hematology, blood chemistry and urinalysis, as judged by the investigator;
4. Body mass index (BMI) between 18-32 kg/m2, inclusive, and with a minimum weight of 50kg and maximum weight of 120kg
5. If subject is a female, she agrees to report onset and duration of menses if it occurs anytime during participation in the study (screening to end of study)
6. Evidence of a personally signed and witnessed informed consent document indicating that the subject has been informed of all pertinent aspects of the study;

Part A:
1. Clinically significant findings as determined by medical history taking, physical examination, , fundoscopy, ECG, laboratory findings (including lipid or hormone profiles) and vital signs;
2. Hemodynamic status at screening: systolic blood pressure <100 or >160 mmHg, diastolic blood pressure <50 or >95 mmHg, heart rate <45 or >100 bpm;

Part B:
3. Clinically significant findings as determined by medical history taking, MRI, physical examination, fundoscopy, ECG and vital signs, other that Parkinson’s disease;
4. Any current, clinically significant, known medical condition other than Parkinson’s disease. Patients with a diagnosis of neurological diseases, other than Parkinson’s disease, including Alzheimer’s disease, Huntington’s disease, vascular dementia, progressive supranuclear gaze palsy, multiple system atrophy, drug-induced parkinsonism, essential tremor, primary dystonia, epilepsy, etc., that are considered clinically relevant by the investigator.
5. Dementia indicated by MMSE <18 at Screening;
6. Use of drugs known to prolong QT interval;
7. Hemodynamic status at screening: results that are considered clinically relevant by the investigator;
8. Any contra-indication to performing a MRI (including (an history of) a cardiac pacemaker, implanted cardiac defibrillator, neurostimulator, hydrocephalus pomp, drug pump, stents or clips in vessels, non-removable hearing aid, non-removable implants containing a magnet in the jaw, tissue expander in the breast, IUD, metal splinters of fragments in the body, non-removable medication patch, tattoo or permanent make-up applied less than 6 weeks ago, non-removable piercing, non-removable hair extensions containing metal);
9. An history of claustrophobia, tinnitus or hyperacusis;
10. An history of allergic reaction during previous MRI examination;
11. History of repeated head injury; history of epilepsy or seizure disorder other than febrile seizures as a child
12. Reside in a nursing home or assisted care facility
13. Concomitant disease or condition that could interfere with, or treatment of which might interfere with, the conduct of the study, or that would, in the opinion of the Investigator, pose an unacceptable risk to the participant in this study or interfere with the participant's ability to comply with study procedures or abide by study restrictions, or with the ability to interpret safety data
14. Prior lack of response to dopaminergic medication (for example, levodopa or a dopaminergic agonist)
15. Continuous use of any of the following within 30 days prior to baseline: antipsychotics (including clozapine and olanzapine), metoclopramide, alpha methyldopa, clozapine, olanzapine, flunarizine, amoxapine, amphetamine derivatives, reserpine, bupropion, buspirone, cocaine, mazindol, methamphetamine, methylphenidate, norephedrine, phentermine, phenylpropanolamine, and modafinil. Single use up to 7 days prior to the start of the study is allowed for metoclopramide.

Part A + B
16. Legal incapacity or inability to understand or comply with the requirements of the study;
17. Subjects with a QTcF of > 450 ms for males and > 470 ms for females at screening or a history of long QT syndrome;
18. Any current, clinically significant, known medical condition;
19. Pregnant, lactating or breast-feeding women
20. Have a urine drug screen detecting illicit drug(s) of abuse (morphine, benzodiazepines, cocaine, amphetamine, THC) or positive alcohol breath test at screening. For part B, a positive urine drug screen for prescribed medication is allowed at the discretion of the investigator;
21. Consume, on average, >8 units/day of (methyl)xanthines (e.g., coffee, tea, cola, chocolate) and not able to refrain from use during each stay at the CHDR clinic;
22. History or clinical evidence of alcoholism or drug abuse;
23. Smoking of >5 cigarettes/day or equivalent and not being able to refrain from smoking cigarettes for the duration of the study. For Parkinson’s disease patients, smoking up to 5 cigarettes/day is allowed during the study;
24. Being on a diet composed of relevantly altered amounts of fat, protein or carbohydrates that may affect triglyceride and fatty acid levels (such as high-fat, gluten-free, carbohydrate-free, protein rich diets);
25. Gastrointestinal disease (such as irritable bowel syndrome, inflammatory bowel disease, chronic gastritis, peptic ulcer disease, etc.) that could affect absorption of the study drug;
26. History of gastric surgery, including Roux-en-Y gastric bypass surgery, an antrectomy with vagotomy, or gastrectomy;

27. Use of prescription, illicit or herbal medication within 7 days or 5 half-lives of study initiation, except for contraception; For part B, use of concomitant medication for treatment of Parkinson’s disease and comorbidities is allowed.
28. Participation in a clinical trial with an investigational drug or device within 90 days of first dosing or more than 4 times in the previous year;
29. Loss of blood ≥ 500 ml within 3 months before screening;
30. Not willing to practice effective contraception during the study and not willing and able to continue contraception for at least 3 months after their last dose of study treatment;
31. Positive blood screen for human immunodeficiency virus (HIV antibody), hepatitis B virus surface antigen, or hepatitis C virus antibody at screening
32. History of spinal cord compression, any other current abnormalities in the lumbar region (skin infection, structural abnormalities in lower spine, etc.), or any other issue that, in the opinion of the investigator, would make CSF collection unsafe.
33. Contact lens wearer who does not agree to use glasses instead of lenses starting at least 7 days prior to study initiation and during the study.
34. History of eye dryness or diagnosis of dry eye.
35. History of cultivating plants or crops using rotenone or paraquat or MPTP containing pesticides during a period of over 10 years
36. Allergy to any component of YTX-7739