A Phase 2 study to assess the safety and efficacy of SUL-238 in patients with early, untreated Parkinson’s Disease

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Gen Ilac Ve Saglik Urunleri Sanayi Ve Ticaret A.S.

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Nervous System Diseases [C10]

Trial duration

5 Mar 2026 → ongoing

Decision date (initial)

2026-02-13

Transition trial

No

Low-intervention

No

Rare-disease indication

No

Vulnerable population

Yes

Funding sources

Gen Ilac Ve Saglik Urunleri Sanayi Ve Ticaret A.S.

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Dose response, Pharmacodynamic, Pharmacokinetic, Safety, Efficacy

To assess the effect of SUL-238 on mitochondria-related brain metabolites in Parkinson’s Disease Patients.

Secondary objectives 2

1. To assess the effect of SUL-238 treatment on systemic biomarkers of mitochondrial function and associated pathways in Parkinson’s Disease Patients.
2. To assess safety and tolerability of SUL-238 Parkinson’s Disease Patients.

Conditions and MedDRA coding

Parkinson’s Disease

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 10

1. Untreated Parkinson's Disease patients diagnosed in accordance with the UK PDS Brain Bank Criteria for the diagnosis of Parkinson's Disease. Patients must have bradykinesia and at least one of the following: a. muscular rigidity b. rest tremor (4–6 Hz) c. postural instability unrelated to primary visual, cerebellar, vestibular or proprioceptive dysfunction.
2. The duration of Parkinson's Disease since diagnosis is ≤ 1 year.
3. Patients with Modified Hoehn and Yahr stage ≤ 1.0.
4. Patients with Montreal Cognitive Assessment (MOCA) score of ≥22
5. Men and women aged ≥40 years at screening.
6. 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.
7. Able to complete all study related testing and evaluations.
8. 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.
9. 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). Male and female patients must refrain from sperm or oocyte donation in this period.
10. 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 criteria 16

1. Atypical parkinsonism, including that due to drugs, metabolic disorders, encephalitis, cerebrovascular disease, normal pressure hydrocephalus, or other neurodegenerative disease.
2. A history or presence of a clinically significant hepatic, renal, gastrointestinal, cardiovascular, endocrine, pulmonary, ophthalmologic, immunologic, hematologic, dermatologic, or neurologic (other than PD) abnormality.
3. 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.
4. 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): a. systolic blood pressure (SBP) < 90 or >140 mmHg, b. diastolic blood pressure (DBP) < 50 or > 95 mmHg, or c. heart rate < 45 or > 100 beats per minute.
5. 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.
6. Women of child-bearing potential, or men, who are unwilling or unable to use accepted methods of birth control for up to 6 months following study participation.
7. Contraindications for undergoing an MRI.
8. 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.
9. A positive Hepatitis B surface antigen, Hepatitis C antibody, or Human Immunodeficiency Virus (HIV) antibody test at screening.
10. 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.
11. 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).
12. 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.
13. 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.
14. 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.
15. 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.
16. A Columbia-Suicide Severity Rating Scale (C-SRRS) score of >3 at screening.

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. The (mean) change from baseline to Week 4 in each active dose group as compared to placebo in the concentration of mitochondria-related brain metabolites (ATP, phosphocreatine and inorganic phosphate), as measured by ³¹P-Magnetic Resonance Spectroscopic (MRS) imaging, in the following regions of interest (ROIs): • Putamen • Substantia Nigra • Motor Cortex

Secondary endpoints 2

1. Mean change from baseline to Week 4 in each active dose group as compared to placebo in the predefined mitochondria-related plasma targeted metabolomics and quantitative proteomics.
2. To assess safety and tolerability of SUL-238 Parkinson’s Disease Patients. a- Frequency, seriousness and intensity of adverse events (AEs). b- Changes in safety laboratory measurements, c- Clinically significant changes in vital signs d- Clinically significant changes in electrocardiogram (ECG) e- Clinically significant changes in physical and neurological examination.

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Placebo 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Gen Ilac Ve Saglik Urunleri Sanayi Ve Ticaret A.S.

Sponsor organisation

Gen Ilac Ve Saglik Urunleri Sanayi Ve Ticaret A.S.

Address

Mustafa Kemal Mahallesi 2119 Sokak No 3

City

Cankaya

Postcode

06520

Country

Turkey

Scientific contact point

Organisation

Gen Ilac Ve Saglik Urunleri Sanayi Ve Ticaret A.S.

Contact name

Nadir Ulu

Public contact point

Organisation

Gen Ilac Ve Saglik Urunleri Sanayi Ve Ticaret A.S.

Contact name

Nadir Ulu

Locations

1 EU/EEA country · 1 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 10 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

1 submissions — initial application plus substantial / non-substantial modifications