The purpose of this study is to measure safety and efficacy of buntanetap/posiphen capsules compared with placebo capsules in participants with early PD.

Study details include:

• The study duration will be up to 7-8 months.
• The double-blind treatment duration will be up to 6 months.
• There will be 5 in-clinic visits and 7 phone calls

450 early Parkinson's Disease (PD) patients will be randomized to 10mg, 20 mg of buntanetap/posiphen or placebo. They will undergo a Screening Visit, and if they provide informed consent and are considered eligible per the inclusion and exclusion criteria, will proceed to participate in the treatment period. Randomized participants will visit the clinic for the first-time dosing in clinic with administration of 10 mg or 20mg of buntanetap/posiphen or placebo, followed by an at home dosing period of 6 months, with daily administration of 10 mg or 20mg of buntanetap/posiphen or Placebo. Participants will be required to visit clinics 1 month, 2 months, 3 months, and 6 months (end-of-trial), where they will undergo study procedures that include safety assessments (AE and concomitant medication monitoring, 12-lead ECGs, clinical laboratory testing, vital signs assessments, and physical examinations) and psychometric tests (MDS-United Parkinson's Disease Rating Scale (MDS-UPDRS), Clinical Global Impression of Severity (CGIS), Wechsler Adult Intelligence Scales (WAIS), Mini-Mental State Examination (MMSE)) and Participant Global Impression of Change (PGIC). At the end of blood sampling, the subjects will need to stay for a minimum of 1 hour of observation. After all end-of-study procedures are complete, the subject will be discharged to home. A 24-hour follow-up call will occur after all clinical visits to assess the participants current condition and if there are any additional adverse events to report.

Buntanetap/posiphen has shown to improve PD subjects' mobility. MDS-UPDRS sum of score of Part II + Part III and Total score of all four parts will be measured to assess its improvement on PD subjects daily living, mobility and complications. PGIC will also be measured to assess its effect.

Buntanetap/posiphen has shown to reduce inflammation and preserve axonal integrity and synaptic functions as well as neurotoxic proteins in previous Phase 2a studies. In this study we plan to measure plasma glial fibrillary acidic protein (GFAP), neurofilament light (NFL) and potentially TDP43.

Reports of adverse events (AEs) and serious adverse events (SAEs) during exposure to buntanetap/posiphen will be collected to evaluate if there are any significant clinical safety issues for the study population. Extensive clinical and laboratory safety data already exist for buntanetap/posiphen; therefore, these safety measures will be sufficient in the proposed study.

For clinical, functional, and cognitive assessment measures, The subjects will be administered the Hoehn & Yahr and the MMSE for determination of inclusion into the study. The MDS-UPDRS and PGIC will be administered for subjects' movement and daily function. The Coding subtest from the WAIS 4th edition will serve as a sensitive measure of Central Nervous System (CNS) dysfunction. MMSE will also be measured to assess subjects' cognitive change.

Inclusion Criteria:

1. Diagnosis of idiopathic Parkinson Disease according to MDS Clinical Diagnostic Criteria for Parkinson's Disease.

2. H&Y score =1, 2 or 3 during ON-state & OFF-state <2hrs per day.

3. Male or female aged 40 - 85 years.

4. MMSE score between the range of 22-30 during screening visit (ON-state) and subjects can live independently without a caregiver.

5. Female subjects of childbearing potential* must have a negative serum or urine pregnancy test at Screening, must be non-lactating and must agree to use a highly effective method of contraception (i.e., a method resulting in a failure rate of less than 1% per year when used consistently and correctly) during the trial and for 4 weeks after the last dose of trial treatment, such as:

   • Oral, intravaginal, or transdermal combined (estrogen plus progestogen) hormonal contraception associated with inhibition of ovulation
   • Oral, injectable, or implantable progestogen-only hormonal contraception associated with inhibition of ovulation
   • Intrauterine device (IUD)
   • Intrauterine hormone-releasing system (IUS)
   • Bilateral tubal occlusion
   • Vasectomized partner (a vasectomized partner is a highly effective contraception method provided that the partner is the sole male sexual partner of the participant, and the absence of sperm has been confirmed. If not, an additional highly effective method of contraception should be used)
   • Sexual abstinence (sexual abstinence is considered a highly effective method only if defined as refraining from heterosexual intercourse during the entire period of risk associated with the study treatment. The reliability of sexual abstinence needs to be evaluated in relation to the duration of the study and the preferred and usual lifestyle of the participant) *Non-childbearing potential includes surgically sterilized or postmenopausal with no menstrual bleeding for at least one year prior to study start.

6. Male subjects must be sterile or sexually inactive or agree not to father a child during the study and one month after the last dose of study medication and must agree to use a barrier method for contraception. Female partners of male subject must adopt a highly effective method of contraception with a failure rate of less than 1% per year when used consistently and correctly such as:

   • Oral, intravaginal, or transdermal combined (estrogen plus progestogen) hormonal contraception associated with inhibition of ovulation
   • Oral, injectable, or implantable progestogen-only hormonal contraception associated with inhibition of ovulation
   • Intrauterine device (IUD)
   • Intrauterine hormone-releasing system (IUS)
   • Bilateral tubal occlusion 6. Female participants will be given a urine pregnancy test at the screening visit for which they should test negative.

7. General cognition and functional performance sufficiently preserved that the subject can provide written informed consent.

8. No evidence of current suicidal ideation or previous suicide attempt in the past month as evaluated in the Columbia Suicide Severity Rating Scale.

9. Stability of permitted medications prior to screening for at least 4 weeks.

10. At screening subjects do not need to but may be on the following medication:

    • Standard of Care anti-parkinsonian medication
    • Anticonvulsant medications used for epilepsy or mood stabilization, neuropathic pain indications
    • Mood-stabilizing psychotropic agents, including, but not limited to, lithium.

11. Adequate visual and hearing ability (physical ability to perform all the study assessments).

12. Good general health with no disease expected to interfere with the study.

13. Subjects previously exposed to buntanetap can still be included in the study after a 28- day wash out period.

Exclusion Criteria:

1. Has a history of a psychiatric disorder such as schizophrenia, bipolar disorder or major depression according to the criteria of the most current version of the Diagnostic and Statistical Manual of Mental Disorders (DSM). Mild depression or history of depression that is stable on treatment with a selective serotonin reuptake inhibitor (SSRI) or selective norepinephrine reuptake inhibitor (SNRI) medication at a stable dose is acceptable.
2. History of a seizure disorder, if stable on medication is acceptable.
3. Has a history or current evidence of long QT syndrome, Fridericia's formula corrected QT (QTcF) interval ≥ 475ms, or torsades de pointes.
4. Has bradycardia (<50 bpm) or tachycardia (>100 bpm) on the ECG at screening.
5. Has uncontrolled Type-1 or Type-2 diabetes. A subject with HbA1c levels up to 7.5% can be enrolled if the investigator believes the subject's diabetes is under control.
6. Has clinically significant renal or hepatic impairment.
7. Has any clinically significant abnormal laboratory values. Subjects with liver function tests (aspartate aminotransferase [AST] or alanine aminotransferase [ALT]) greater than twice the upper limit of normal will be excluded.
8. Is at imminent risk of self-harm, based on clinical interview and responses on the C SSRS, or of harm to others in the opinion of the Investigators. Subjects must be excluded if they report suicidal ideation with intent, with or without a plan or method (e. g. positive response to Items 4 or 5 in assessment of suicidal ideation on the C SSRS) in the past 2 months, or suicidal behavior in the past 6 months.
9. Has cancer or has had a malignant tumor within the past year, except subjects who underwent potentially curative therapy with no evidence of recurrence. (Subjects with stable untreated prostate cancer or skin cancers are not excluded).
10. Alcohol / Substance use disorder, moderate to severe, in the last 5 years according to the most current version DSM.
11. Participation in another clinical trial with an investigational agent and have taken at least one dose of study medication, unless unblinded on placebo, within 60 days prior to the start of screening. The end of a previous investigational trial is the date the last dose of an investigational agent was taken, or five half-lives of the investigational drug, whichever is greater.
12. Subjects with learning disability or developmental delay.
13. Subjects whom the site PI deems to be otherwise ineligible.
14. Subjects with a known allergy to the investigational drug or any of its components.
15. Subject is currently pregnant, breast-feeding and/or lactating.
16. Subject is currently taking CYP3A4 inhibitors and/or inducers.