RecruitingPhase 2NCT07322887

A Phase 2 Study to Assess the Effects of SUL-238 on High Energy Phosphates With ³¹P-MRS in Patients With Early, Untreated Parkinson's Disease

A Phase 2, Randomized, Double-blind, Placebo-Controlled, Single-Center Study to Assess the Effects of SUL-238 on High Energy Phosphates With Magnetic Resonance Spectroscopy (³¹P-MRS) in Patients With Early, Untreated Parkinson's Disease ("SHEPHERD" STUDY)

Sponsor

GEN İlaç ve Sağlık Ürünleri A.Ş.

Enrollment

45 participants

Start Date

Mar 2, 2026

Study Type

INTERVENTIONAL

Conditions

Parkinson's Disease (PD)

Summary

The main goal of the study is to investigate how well the new drug SUL-238 works in Parkinson's Disease (PD). This is done by means of an MRS scan. An MRS scan is similar to a regular MRI scan. It will also learn about the safety of new drug SUL-238. The main questions it aims to answer are: * Does new drug SUL-238 improve the mitochondrial function in patients with Parkinson's Disease (PD)? * What medical problems do participants have when taking new drug SUL-238? Researchers will compare new drug SUL-238 to a placebo (a look-alike substance that contains no drug) to see if SUL-238 works to improve mitochondrial function in patients with PD. Participants will: * Take new drug SUL-238 or a placebo every day for 28 days * Visit the clinic once every 2 weeks for checkups and tests during the treatment period and finally 28 days after the last dose of SUL-238 * Keep a diary of their symptoms and the number of times they use oral new drug SUL-238

Eligibility

Min Age: 40 Years

Inclusion Criteria13

Untreated Parkinson's Disease (PD) patients diagnosed in accordance with the UK PDS Brain Bank Criteria for the diagnosis of PD. Patients must have bradykinesia and at least one of the following:
muscular rigidity
rest tremor (4-6 Hz)
postural instability unrelated to primary visual, cerebellar, vestibular or proprioceptive dysfunction.
The duration of PD since diagnosis is ≤ 1 year.
Patients with Modified Hoehn and Yahr stage ≤ 1.0.
Patients with Montreal Cognitive Assessment (MOCA) score of ≥22.
Men and women aged ≥40 years at screening.
Able to understand the nature of the study and provide signed and dated written informed consent in accordance with local regulations before the conduct of any study related procedures.
Able to complete all study related testing and evaluations.
Patients must be, in the opinion of the Investigator, able to participate in all scheduled evaluations, likely to complete all required tests, and likely to be compliant.
Men and women of child-bearing potential with partners of child-bearing potential must agree to use highly effective contraception. For male patients, contraception should continue for 3 months after the last dose of investigational medicinal product (IMP, one spermatic cycle). For female patients, contraception should continue for 6 months after the last dose of IMP (one oocyte cycle).
Women of non-childbearing potential must be post-menopausal (the last menstrual period was at least 12 months ago, and follicle-stimulating hormone \[FSH\] at screening confirms post-menopausal status), or have no uterus, ovaries, or fallopian tubes (or have their fallopian tubes tied). All women must have a negative pregnancy test result before administration of test article. Women who are surgically sterile must provide documentation of the procedure by an operative report or by ultrasound.

Exclusion Criteria20

Atypical parkinsonism, including that due to drugs, metabolic disorders, encephalitis, cerebrovascular disease, normal pressure hydrocephalus, or other neurodegenerative disease.
Any history of intellectual disability or psychiatric disorders, including substance use disorders, according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria, except a history of mild depression/anxiety that has been resolved for at least the past 3 months.
A positive answer to questions 3 through 5 on the Columbia-Suicide Severity Rating Scale (C-SSRS) at screening.
A positive Hepatitis B surface antigen, Hepatitis C antibody, or Human Immunodeficiency Virus (HIV) antibody test at screening.
Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels greater than 1.5 times the upper limit of normal (ULN) at screening or between screening and first dose administration.
Received or used an investigational product (including placebo) or device within the following time period prior to day -1 in the current study: 90 days, 5 half-lives, or twice the duration of the biological effect of the investigational product (whichever is longer).
Use of non-prescription drugs, vitamins, herbal, and dietary supplements which has potential to influence the mitochondrial function (such as coenzyme Q10, carnitine, creatine, lipoic acid and vitamin E) within 30 days prior to day -1.
Use of drugs which are strong inhibitors of CYP3A4 or CYP3A4 substrates with narrow therapeutic index within 30 days prior to day -1.
History of clinically significant sensitivity to any of the study medications, or components thereof or a history of drug or other allergies that, in the opinion of the Investigator or Medical Monitor, contraindicates their participation.
Women with a positive pregnancy test, are lactating, or are planning to become pregnant during the study or within 6 months of the end of this study.
A history or presence of any disease, condition, or surgery likely to affect drug absorption, distribution, metabolism, or excretion. Patients with a history of cholecystectomy should be excluded.
A history or presence of a clinically significant hepatic, renal, gastrointestinal, cardiovascular, endocrine, pulmonary, ophthalmologic, immunologic, hematologic, dermatologic, or neurologic (other than PD) abnormality.
At screening, any clinically significant abnormalities in rhythm, conduction, or morphology of the resting ECG and any abnormalities in the 12-lead ECG that, in the judgement of the Investigator or Medical Monitor, may interfere with the interpretation of QTc interval changes, including abnormal ST-T-wave morphology or left ventricular hypertrophy.
A clinically significant vital signs abnormality at screening or day -1. This includes, but is not limited to, the following, in the sitting position (3 measurements, each 5 minutes apart):
systolic blood pressure (SBP) \< 90 or \>140 mmHg,
diastolic blood pressure (DBP) \< 50 or \> 95 mmHg, or
heart rate \< 45 or \> 100 beats per minute.
In the opinion of the Investigator or Medical Monitor, the patient is unlikely to comply with the protocol or is unsuitable for any reason, e.g., known issues with ability to swallow tablets.
Women of child-bearing potential (WOCBP), or men, who are unwilling or unable to use accepted methods of birth control for up to 6 months following study participation.
\. Contraindications for undergoing an MRI.